Geopolitical and logistical factors in the evolution of North

Traditionally in socialist economies, maritime transport has been considered costly and useless, its role being often limited to coastal shipping within the socialist block [START_REF] Vigarié | La Mer et la Géostratégie des Nations[END_REF]. Nevertheless, North Korea possesses and operates eight international trading ports located along two maritime façades, which directly connect its major cities with international trade. North Korean ports are the potential gateways for a Eurasian land bridge [START_REF] Choi | North Korea in the World Economy[END_REF][START_REF] Rozman | Northeast Asia's Stunted Regionalism: Bilateral Distrust in the Shadow of Globalization[END_REF]. Internally, coastal shipping may remedy the growing logistical difficulties caused by a prolonged economic crisis. Maritime transport remains the principal vector of inter-Korean economic exchange with 90% of commercial relationships ensured by sea (Kim, 2001;[START_REF] Olsen | Maritime Cooperation for the Koreas[END_REF]. Studying North Korea's shipping flows thus presents numerous challenges for academic research in both conceptual and empirical terms. How does a major and deepening economic and geopolitical crisis impact the pattern and evolution of shipping flows? What are the respective roles of internal and external factors? (see Chapters 6, 10, and 20 on Portugal, USA, and China for other analyses of external linkages of national port systems, and Chapters 8 and 19 on the link between shipping flows and socialist economies).

The fact that even an ostensibly closed country like North Korea is fully part of a global system for recording vessel movement means that such questions do not go unanswered.

The majority of North Korean vessels are insured in London by Lloyd's Register [START_REF] Smith | North Korean shipping: a potential for WMD proliferation? East-West Center[END_REF]; thus, vessel movement at North Korean ports has been surveyed for decades, although it is only recently that such information has served economic and geographic analyses and offset the lacks and deficiencies of data on North Korea as a whole [START_REF] Noland | Avoiding the Apocalypse. The Future of the Two Koreas[END_REF][START_REF] Nanto | The North Korean economy: background and policy analysis[END_REF]) by looking at the changing distribution and concentration of maritime flows internally and with the rest of the world [START_REF] Ducruet | Political and economic factors in the evolution of North Korea's maritime connections[END_REF]. This chapter proposes to update and extend previous analyses by expanding the time period, from the early twentieth century to the year 2015, for which shipping data has recently become available. Vessel calls at North Korean ports were measured across different units and time periods, either through a simple count based on the Shipping Index or on their tonnage weight and spatial distribution using digital information from Lloyd's List Intelligence. We systematically confront traffic trends with general (and often limited) knowledge of transport and trade characteristics gathered from field observation and official, second-hand information sources. This will help us to better understand the origin and ultimate development of maritime transport in the North Korean economy, through the successive phases of Korean unity, Japanese colonization, war and partition, Cold War growth and Soviet support, isolation, decline, and Chinese influence.

The second section of the chapter provides a historical background on ports, transport, and economic development in the light of contemporary political changes. It also presents new results on traffic evolution at North Korean ports from various angles, such as fleet nationality and performance. The third section investigates the importance of maritime transport in the North Korean economy. Lastly, we analyse the changing distribution of overseas linkages, with a specific focus on shipping flows between the Koreas and with China.

The North Korean port system

There is evidence that ports in North Korea have been operating since the Three Kingdoms and Goryeo era (37BC-1392AD). In particular during the Balhae Kingdom (698-934), shipping routes existed between Seoanpyeong (Amnok River) and the Shandong Peninsula in China; between Yeomju (current Russia) and Namgyeong with Japan. Under the Goyeo period, Seogyeong (currently Pyongyang) was well connected with China. Later on, the Korean fleet became the most important on the Yellow Sea, frequently trading with Arab merchants along the Yaeseong River near the then capital city, Gaeseong. Before the Manchu invasions, sea transport was promoted by the government, which even planned to build a national fleet around 1402, before letting private interests do so after 1529, due to the related cost and labor issues. In that period, ports in North Korea remain less connected to main trade routes, except from Wonsan, which connects the East coast with southern Siberia. The Choseon era is mainly characterized by the decline of maritime trade, due to Manchu invasions, China's confucianist preference for landward development and growing Japanese pressure on the construction and modernization of North Korean ports before the 1910 invasion and colonial rule. Investments particularly concentrated at Nampo, Haeju, Yongampo-Sinuiju, Wonsan (with the British) but also Incheon and Busan in the South, while the Japanese created the rail link Seoul-Wonsan in 1904, buying the rights from the British but also from the French (Seoul-Sinuiju). After the Japanese and Manchu invasions, several ports kept a domectic role only, such as Hwangju (south of Pyongyang), Wonsan, Yongampo (Amnok River), and Cheongjin. While shipping activity in North Korea (and Korea as a whole) does not appear in Lloyd's Shipping Index before 1905, it provides us with a long-term view over the last century (Figure 21.1).

[Figure 21.1] Under Japanese rule , the northern part of the Korean Peninsula became the prime focus of Japan's strategy to conquer Manchuria, with investments in railways, mining (purchasing rights from the US or UK), ports, and factories. During the Korean War (1950)(1951)(1952)(1953), many port sites were heavily damaged if not entirely destroyed. While North Korea managed to overcome such a disaster and become East Asia's second most industrialized nation in the 1960s after Japan, its dynamism faltered in the 1970s and started to collapse in the 1980s. The 1961 seven-year Development Plan with its strong focus on maritime transport and foreign trade had somewhat limited effects (Ahn, 2003) due to the reliance, during the Cold War, on Soviet and Chinese support [START_REF] Cotton | China and Tumen river cooperation: Jilin's coastal development strategy[END_REF]. Ports received little investment apart from the creation of Rajin port in 1974 and some oil berths and storage facilities. A move towards openness started in 1984, with the opening of the Rajin-Seonbong (Raseon) free-trade zone in 1991 [START_REF] Jo | Rajin-Seonbong, new gateway of Northeast Asia[END_REF]. However, the collapse of the Soviet Union (1989Union ( -1993) ) and the Socialist Block immediately resulted in the loss of North Korea's main trading partners and the lack of capital to purchase hydrocarbons on international markets, resulting in traffic decline. Subsequently, factories ceased to operate, mines were flooded, transport became paralyzed, and agricultural productivity declined without sufficient fertilizers and mechanization, aggravated by natural disasters (1994)(1995) and the three-year vacancy at the head of the State after the death of President Kim Il-Seong (1994). US-North-Korean tensions rose over Pyongyang's nuclear program, leading to an internal policy more and more centred on the Army as a reaction against the Wassenaar Agreement (1996), restraining exports and controlling the importation of technological goods. Limited foreign trade and the deterioration of infrastructure and capital stock [START_REF] Yoon | Understanding North Korea's economic crisis[END_REF] persisted until the agricultural reforms of 1998, the June 2000 inter-Korean summit, and the July 2002 reforms, which conferred certain autonomy to businesses, and led to improved labor welfare, and commercial distribution (e.g. Pyeonghwa Automobiles), and the development of factories, farms and private businesses. One important factor had also been to become able to purchase oil, giving a small boost to the economy. Despite the failure of the Special Administrative Region (SAR) of Sinuiju in 2002, a number of economic development projects grew rapidly, such as the International Tourism Zone of Mount Geumgang (1999), and the Gaeseong Industrial Complex (2004) financed by South Korea. Such initiatives, in addition to the development by the army of hydro power plants, housing, and highways, helped compensate for the decline of the industrial sector (Ahn, 2003), However, despite its numerous advantages over China in terms of labour force and natural resources [START_REF] Roussin | A brief journey in DPRK. A geo-economic approach[END_REF], North Korea's appeal for the international business community continuously decreased [START_REF] Lee | Trade and Investment in North Korea[END_REF]. The devastation in the manufacturing and transport sector was such that only 20% of factories remained operational, with energy production meeting only 30-50% of the country's needs, and companies spending about 40% of their manufacturing costs on logistics (Foster-Carter, 2001). The priority given to railways and heavy industries, combined with poor technical standards and cumbersome customs regulations, resulted in prolonged shipping time [START_REF] Ahn | Restoration of the Seoul-Sinuiju line: review and outlook[END_REF], a lack of modern cargo-handling facilities (Kim, 2001), exorbitant port-entry fees and 45% of containers returning empty (Foster-Carter, 2001).

Certain containers even disappear or are changed into hangars or lodging boxes. Port modernization mainly occurred thanks to Chinese and Russian support, such as in Nampo and Rajin [START_REF] Jo | Maritime trade and port evolution in a socialist developing country: Nampo, gateway of North Korea[END_REF], leading to greater accessibility and a boost to transit trade, but for the external interests of Russia and China.

Traffic dynamics of North Korean ports

Domestic versus foreign fleet traffic

As referred to by [START_REF] Smith | North Korean shipping: a potential for WMD proliferation? East-West Center[END_REF] based on Lloyd's Register 2008 data, the vast majority of North Korean vessels are general cargo ships (53%) and fishing vessels (24%), followed by some oil tankers and bulk carriers. The same report also underlined its ageing and limited capacity, the fragmentation of ownership, and the majority of vessels being flagged at home. It was possible to verify a number of traffic dynamics based on daily vessel movement data.

Based on Figure 21.2, one can observe significant traffic fluctuations over the period, with a noticeable decline from the 1980s to the 2000s until a recent but timid recovery. Following regular traffic growth until 1987, the economy started to falter before the Soviet Union collapsed. Certain exceptions can be observed, such as the effects of the Rajin-Seonbong free-trade zone (1991)(1992), humanitarian aid, economic reforms, the KEDO project, and inter-Korean cooperation (1999)(2000)(2001)(2002), the inter-Korean maritime agreement (2004)(2005), and growing trade with China (2014China ( -2015)).

[Figure 21.2] Disaggregating traffic figures according to vessel flags, -North Korean or foreign -allows us to further understand the technical evolution of the domestic fleet as well as North Korea's level of reliance upon other fleets (Figure 21.3). As such, foreign traffic concentrated more than 70% of the total traffic on average, but with different phases: 85% in 1977-1984; 70% in 1985-1992; 57% between 1993-2002 (under 50% in 1996-1998) In terms of fleet age, North Korean vessels have always been older than foreign vessels except in the period 1977-1984. From 1985 onwards, domestic and foreign fleets followed a similar trend, but from 1997 North Korean vessels aged more rapidly and foreign vessels stabilized. The average age of foreign ships was 15 years, compared with 18 for the North Korean fleet, while the average age per ship for fleets from developing countries was around 14 years (see UNCTAD, 2000). Due to the crisis in the North Korean shipbuilding sector since the mid-1980s most of the currently operated vessels were constructed before 1984. Again, the impact of the mid-1990s crisis is clearly visible, North Korea being forced to push the fleet to its limits to palliate deficiencies in the wider transport system. As a result, Japanese authorities banned North Korean ships from their ports on the grounds of technical and hygiene issues (Lloyd's Register, 2004). Thus, while North Korean vessels were aged 14 years on average between 1977 and 1996, this had increased to 23 between 1997 and 2015, compared with 13 and 17 years for foreign vessels for the respective periods.

Shipping and trade

Traditionally in North Korea, inland transportation has dominated the modal split, as a longterm effect of Japanese occupation and of the priority given to railways as in Russia. The modal split in North Korea is as follows: railways (70%), roads (17%), sea (10%) and air (3%) [START_REF] Roussin | A brief journey in DPRK. A geo-economic approach[END_REF]. However, railways were particularly affected by the economic crisis [START_REF] Oh | Strategies for developing transport infrastructure in North Korea[END_REF]; the high electrification rate became a constraint in a context of energy scarcity, while only 7% of roads were paved [START_REF] Bang | Research notes: towards an integrated logistics system in Northeast Asia[END_REF]. The road network, costlier to maintain and less well adapted to the transport of raw materials (80% of transported products according to [START_REF] Tsuji | The Transport Infrastructure of the DPRK[END_REF], remains strictly controlled by the government through inspection tolls between main cities and provinces. Train and truck accidents were frequently reported [START_REF] Cotton | China and Tumen river cooperation: Jilin's coastal development strategy[END_REF], aggravated by the rarity of signals, gas stations, and the poor condition of tracks and roads. The deepening crisis reinforced the influence of elevation and climate [START_REF] Roussin | A brief journey in DPRK. A geo-economic approach[END_REF], harming smooth domestic transport connectivity and concentrating traffic within Pyongan province, while 80% of North Korea's exports passed through Sinuiju at the Chinese border [START_REF] Tsuji | The Transport Infrastructure of the DPRK[END_REF]. Eastern regions, by contrast, declined rapidly [START_REF] Pons | Fragile dégel en Corée du Nord[END_REF].

The respective evolution of North Korea's international trade and maritime traffic, however, exhibit a widening gap (Figure 21.5), mainly due to increased cross-border trade with China, which occurred inland. According to the Korea International Trade Association (KITA), nearly 91% of North Korea's products were exported to China in 2013, compared with 51% in 2003, while Chinese investments in North Korea expanded from US$ 1.12 million to US$ 86.2 million between 2003 and 2013. Some experts reported a steady increase of trade between North Korea and Dandong between 2000 and 2008 [START_REF] Lee | Analysis of Chinese companies' border trade with North Korea[END_REF], as Dandong's exports to North Korea tripled and its imports from North Korea increased tenfold. Overall, border trade with China represented about one-third (32%) on average of North Korea's total trade with China, and 9% on average of North Korea's total foreign trade in 1997-2005 (Kim, 2001).

In 2011, coal was being shipped from North to South China through the port of Rajin, while in the late 2000s the Chinese government announced the restart of the Changchun-Jilin-Tumen project as a pilot economic zone and obtained a 50-year concession for operating a port terminal in Rajin in 2010, the two other terminals being operated by Russia and North Korea, respectively. Cross-border trade thus experienced steady growth, especially with Shandong, Hebei and Jiangsu provinces, which altogether reached 50% of the total [START_REF] Kim | Open North Korea: Economic Benefits to China from the Distance Effect in Trade[END_REF]. In 2012, just over 87 percent of both North Korea's exports and imports were with China, which is indicative of its growing dependency. Nearly 90 percent of trade between China and North Korea was with the six provinces, of which 42.7% with Liaoning and 32.3% for Shandong, Hebei, and Jiangsu. The Jilin province witnessed a Gross Regional Domestic Product (GRDP) growth rate of 13.4% in 2012, more than China's own GDP growth rate [START_REF] Kim | Open North Korea: Economic Benefits to China from the Distance Effect in Trade[END_REF].

[Figure 21.5] Another approach has been to estimate the importance of maritime transport in total foreign trade (Figure 21.6). We estimated the value of maritime flows by converting deadweight tons (dwt) into dollars based on US$250 per ton [START_REF] Ducruet | Coastal cities, port activities and logistics constraints in a socialist developing country: The case of North Korea[END_REF], which was the average dwt-dollar ratio for Japanese and South Korean trade with North Korea in the 2000s. Results were compared with a weighted figure based on the estimation of value differentials among traffic types. As a result, the two ratios give a very different importance to maritime trade, with average shares of 19.2% for unweighted traffic and 11.1% for weighted traffic during the period. In fact, unweighted figures overestimate the importance of maritime transport mainly due to the high volume and low value of bulks. The observed evolutions show that North Korean trade was much less dependent on maritime flows in the recent period (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014), with 4.3% on average compared with 16.3% for 1985-2001. 1991 registered an exceptional peak that can only be explained by the Rajin-Seonbong initiative, which mainly used the port during the construction and starting phases of the economic zone project [START_REF] Jo | Rajin-Seonbong, new gateway of Northeast Asia[END_REF]. Another factor was the dramatic decline of shipping with Japan since 2002 (e.g. the Wonsan-Niigata ferry link). Lastly, maritime transport was mainly being used to carry lower-valued (but highly strategic) goods, such as oil or humanitarian aid, so that even in times of shipping growth in the recent period, the net value of shipping could not be reflected on account of its overall shrinking volume.

[Figure 21.6]

Overseas maritime connectivity

General trends

North Korea's foreign trade used to be dominated by the Soviet Union, whose share surpassed 50% in 1960, dropped to 25% in 1977, and reverted to 50% around 1986, while China's share gradually declined from 32% to 11% in the same period [START_REF] Choi | Foreign trade of North Korea: 1946-1988[END_REF]. Available statistics for trade with its main economic partners provided complementary results for the 1989-2014 period (Figure 21.7). Soviet Russia still occupied about 60% of total foreign trade in 1989-1990, and nearly disappeared in subsequent years (1% in 2014), superseded by Japan and China. The "rest of the world", namely countries outside Northeast Asia, accounted for around 30% of total trade on average from the early 1990s to the early 2000s, but went through a drastic drop since then, reaching only 11% in 2014. This evolution confirms the shrinking of North Korea's long-distance economic ties, and greater concentration on its proximity, a key factor being the lack of oil to feed the economy. Japan officially ceased all trade with North Korea from 2009, after oscillating around 20% in the first half of the period. Conversely, South Korea's share rose rapidly since the 2000s due to the thaw in inter-Korean ties. In general, North Korean imports and exports were based on humanitarian shipments, non-commercial exports (i.e. cooperation projects), material aid, but also commercial exports (e.g. machinery and transport equipment, textile and chemicals, electric and electronic products (80% to 90%), while its exports to South Korea increased regularly after 2002 -mainly textiles, metals, agricultural and fish products. However, an escalation of tensions from both sides caused the reduction of South Korea's share to the advantage of China, mainly based on inland border trade, as discussed above.

[Figure 21.7] A similar but fuller picture is provided by vessel movement data. A major factor has been the drastic decline of Japan's share, from about 80% to negligible amounts in recent years (despite its official trade interruption with North Korea). A similar decline occurred for Hong Kong, despite a slight recovery to roughly 15% in 2011-2012. As for trade values, major changes concern South Korea and China. The latter had even become dominant in the last two years under study, culminating in around 73-78% of total traffic, reflecting its role as North Korea's dominant trading partner. While the respective shares of China and South Korea had been relatively even in the early period, China's share was superior to South Korea's share between 1986 and 1998, namely before North Korea's reforms. From 1999-2000 South Korea became North Korea's largest maritime partner for eight consecutive years (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010), reaching peaks of 74%, 80%, and 81% in 2008-2010. This is somewhat counterintuitive, given the worsening of North-South political relationships from 2007 onwards and reinforced tensions around the Northern Limit Line [START_REF] Gelézeau | An island as interface: critical position of paengnyŏn-do in the Korean border region[END_REF]. Growing trade with China and uneven North-South relationships caused a rapid decline of South Korea's share, which fell to 20-30% in 2011-2013, and to only 9% and 6% in 2014 and 2015, respectively, i.e. the same share as in the late 1970s. Lastly, an interesting element is the share of domestic shipping, which fell from an average of 12% in the period 1985-1995 to 9% in 1996-2007 and only slightly more than 1% in the rest of the period. This indicates that domestic (or coastal) shipping was not used to palliate the deficiencies of the land-based transport system and logistics. Because coastal shipping is more likely to occur between East coast ports, its decline might also relate to the deliquescence of such cities, which are mostly connected by long-distance shipping bringing external aid. growth since 1996, echoing earlier works that described this process as North Korea's growing "hub dependence" on South Korea [START_REF] Ducruet | Hub dependence in constrained economies: The case of North Korea[END_REF].

Inter-Korean maritime flows

Mapping shipping flows across the Korean peninsula provides a clear picture of such an evolution (Figure 21.8). In the early phase of the period under study, inter-Korean flows shifted from almost non-existent to a concentration along the East coast between Wonsan and Ulsan principally (followed by Busan), all of which specialized in liquid bulks (oil and chemicals). Growing traffic became visible at Heungnam and Cheongjin to connect Busan, while Nampo and Incheon were also increasingly connected. We also see that East and West coasts were mainly connected through Busan and Incheon. That was followed by a multiplication of North-South linkages, with a marked increase in the number of connected ports.

Traffic had concentrated mainly along the West coast, with a shift from the Nampo-Busan line to the Nampo-Incheon line, followed in 2004-2006 by Haeju and Pyeongtaek, to absorb the growing traffic near the two country's capital cities. Shipping a container between Incheon and Nampo once cost as much as US$ 1,000 for 24h and a distance of only 100 kilometers, as much as the cost to reach Europe [START_REF] Ahn | Slow boat to North Korea[END_REF]. Later, operated by South Korean companies such as Hansung Shipping (90% of inter-Korean maritime flows), which exported South Korean textiles and imported North Korean raw materials for Samsung, LG, and Daewoo [START_REF] Kim | Inter-Korean Relations: Problems and Prospects[END_REF]. Kook Yang Shipping was also involved on the Incheon-Nampo line to support further container traffic and weekly ferry shuttles, which would reduce the cost to US$ 750 (Korea Times, 2001;[START_REF] Ahn | Restoration of the Seoul-Sinuiju line: review and outlook[END_REF]. In the more recent period, the Nampo-Incheon line maintained its importance, notwithstanding a drastic decline of all traffic (2010-2012).

On the East coast, Cheongjin and Heungnam remained the central nodes, connected primarily with Ulsan and Busan, while Wonsan began to lose ground gradually. In the last phase, the Incheon-Nampo linkage had nearly disappeared, replaced by new lines between secondary ports, such as Rajin, Daesan, Pyeongtaek, Boryoung, Donghae, and Pyongyang.

Overall, North-South maritime dynamics were quite irregular, not only in traffic volumes, but also in terms of spatial distribution, with important shifts from one coast to the other, and between large and small ports. Recent figures corroborate certain press releases about plans to use Rajin as an inter-Korean hub, echoing earlier plans for Heungnam (Joongang Daily, 2006).

[Figure 21.8]

North Korea -China maritime flows

The overwhelming importance of China in North Korea's recent foreign trade is worth analysing on a longer-term basis, notably for a comparison with inter-Korean shipping dynamics. Although most of the border trade of any value between China and North Korea occurs by land, on average 85% of its tonnage was transported by sea in the recent decade (Table 21.1). While the number of vessel crossings quadrupled between 2001 and 2013 and tonnage nearly doubled, it is only from 2009 that China has surpassed South Korea in this area.

[Table 21.1] Maritime linkages have experienced very distinct patterns over time since the early 1980s (Figure 21.9). One recurrent configuration is North Korea's reliance on the Hong Kong hub, a good indicator of long-distance shipping connecting regions such as the Black Sea and Europe. However, this link had become secondary in the late 1990s and has nearly disappeared since the 2000s, in line with South Korea's emerging role as North Korea's main transit hub. One exception is 2010-2012, when Hong Kong remained the only major link, just before South Korea lost its prominence in this network. Another stable feature has been the overarching importance of Nampo for shipping to and from China, mainly due to its geographic proximity (Yellow Sea) and gateway function for Pyongyang. Mainland Chinese connections have shifted hugely over time and space. Dalian is one of the major Chinese hubs, especially in the early period, mainly for containers. Other hubs have emerged, such as Rizhao and Dandong, to receive iron ore and coal from North Korea. The fact that bulk products are the main flow largely explains why Shanghai and Shenzhen, China's main container ports, are underrepresented in the figure .   In the late period, a major driving force for reinforced shipping flows is the rapid increase of North Korea's coal exports to China [START_REF] Vitelli | North Korea gains in China coal exports as Vietnam bows out[END_REF], thereby becoming the latter's primary supplier after Australia and Indonesia. Although it was recently reported that the Russian port of Zarubino was preferred to Rajin for developing further Chinese (but also Russian and Mongolian) transit trade with the Pacific (Asia Cargo News, 2014), Rajin appears as a very central hub in the latest period, developing strong links with the coal-dependent region of Southern China [START_REF] Wang | Transport corridors and regional balance in China: The case of coal trade and logistics[END_REF]. One favourable factor is Rajin's wide and standard railway gauge, offering easy and cheap access of Russian coal to the port, making it more attractive than Zarubino [START_REF] Hong | International cooperation and the logistics market in Northeast Asia: problems and prospects for North Korea[END_REF]. The Russian railway company RDZ even sold part of Rajin port's concession rights on the third pier to a South Korean consortium (POSCO, Hyundai Merchant Marine, and Korea Railway) for shipping coal to Pohang, Gandjin andGwangyang (2013-2015), but nuclear tests in early 2016 interrupted the process.

[Figure 21.9]

Conclusion

Overall, this research has shed new light on the maritime dynamics of one of the most unknown countries in the world. In turn, the analysis of maritime traffic evolution over 39 years reveals interesting features that help to document and understand the economic and political issues at stake in North Korea. Accessing such untapped and first-hand statistics has been the only way to palliate the inadequate, approximate and outdated nature of other data on transport, logistics, and shipping in North Korea. This analysis of data provided many clues about the long-term and short-term maritime dynamics affecting North Korean ports and their linkages with the outside world. On a daily, monthly or yearly basis, North Korea's maritime activity had been growing until the 1980s and has been on the decline since then, except for certain peaks largely attributable to humanitarian aid, at least for the early 2000s. This decline was at variance with growing foreign trade, leading to a high dependency on land-based freight flows (road, rail) with China. A rapid shrinkage of North Korea's forelands occurred in parallel with an ageing, considerably smaller and increasingly immobile North Korean fleet. Foreign vessels remained dominant to ensure the future of North Korean shipping and raising questions regarding the isolated reputation of a country which could not rely on its own ships. Drastic traffic shifts occurred within Northeast Asia, from Japan to South Korea and then China, reflecting wider trade patterns, i.e. from who are North Korea's oil and food needs fulfilled. This research can be considered as an introduction to the potential offered by shipping data for the investigation of North Korea's changing economic and trading dynamics and linkages. This has enormous implications in terms of security and cargo tracking for organisations concerned with under-embargo trade. Further research will consider carrying out a survey of ship operators visiting North Korean ports, based on the identity of ship operators. For academic research, this chapter may well contribute to a better understanding of how a major crisis affects shipping network design and spatial distribution.

  Korea's shipping flowsCésar DUCRUET, Sung-Woo LEE, Stanislas ROUSSIN Pre-final version of the chapter published in Ducruet C. (Ed.) (2017) Advances in Shipping Data Analysis and Modeling. Tracking and Mapping Maritime Flows in the Age of Big Data, Routledge Studies in Transport Analysis, pp. 357-379.

  ; and 80% in 2003-2015. Yet in absolute terms, foreign traffic has registered a constant decline since the mid-1980s. By comparison, traffic under the North Korean flag remained somewhat stable between 1984 and 2002. This may be explained by the use of naval ships for commercial purposes in emergencies. Trains that were responsible for most landward communications got paralyzed by the lack of electricity, most of the railway network being electrified.In terms of average vessel size, foreign traffic largely dominated, except in1984, 1997, and 2004-2009, while both foreign and domestic vessels have regularly reduced over time, due to falling demand, accessibility issues and a deterioration in cargo-handling equipment. In addition, larger ships that are costlier to repair and operate tend to disappear over time, as North Korea lacks sufficient capital or shipbuilding facilities to maintain and modernize its fleet. The exception of 1999-2002 for foreign vessels relates to humanitarian support. Vessel sizes also reflect wider issues, such as the missile crisis with Japan (1998) and the levy of sanctions by Washington in 1999. The sudden decline in 2002 marks an end to oil shipments from the United States, Japan, and the European Union due to Pyongyang's suspected uranium enrichment program. The upward turn in 2005 could reflect the impact of the inter-Korean agreement that liberalized the movement of vessels between North and South. From 2008-2009, the average vessel size for both fleets grew once again despite low cargo volumes.[Figure21.3] The analysis of turnaround times (Figure21.4) by fleet, excluding a few exceptional stays lasting more than one year, is based on the average time difference between arrival date and sailing date for each call at North Korean ports. Without exception, North Korean ships stayed longer in ports than foreign ships, partly due to the "home effect". Maritime transport by sea often constituted a secondary option compared with overland (crossborder). Despite inspection and bureaucratic procedures affecting foreign ships, the latter witnessed a growing turnaround time gap compared with the domestic fleet from the 1990s onwards. The reduction and disappearance of former trade routes deprived North Korean ships of their activity, which was aggravated by the lack of fuel supplies. Thus, the majority remained anchored at their home terminals, until the situation improved from 2000 onwards, although important delays at North Korean ports were regularly reported in the press, most cargoes being handled by hand. The peak of 2005 marks North Korea's very unstable attitude in relation to humanitarian organizations and nuclear talks with other nations. Nevertheless, a decrease in turnaround times for foreign ships also suggests greater flexibility in the management of North Korean ports through less cumbersome regulations.[Figure 21.4]

  Official statistics provided by the Ministry of Unification in South Korea (2015) do not detail the modal split of inter-Korean trade and exchanges. Older statistics had underlined that inter-Korean maritime trade reached 15.7 million tons in 2006, a 240% growth rate compared with 2005, while the amount of vessels crossing the Korean border doubled between 2004 and 2005, following the 2004 inter-Korean maritime agreement, but this number has greatly reduced since then. Thus, the precise geographic distribution of inter-Korean maritime flows remains unknown. Absolute tonnage between North and South has been somewhat irregular: almost non-existent until the mid-1980s, moderate between 1989 and 1998, relatively strong between 1999 and 2010 (with a peak in 2005), and returning to low values since 2011. South Korea's share eventually reached 68% in 2008, after regular

Figure 21 . 1 :

 211 Figure 21.1: Infrastructures (2005) and vessel calls (1905-2008) at Korean ports Source: own elaboration based on the Lloyd's Shipping Index and various sources

Figure 21 . 6 :

 216 Figure 21.6: North Korea's overseas linkages in total foreign trade (top) and maritime traffic (bottom) Source: own elaboration based on Bank of Korea, KOTRA, and LLI data

Acknowledgements

The authors would like to thank Dr. Sungjun Park, Korea Maritime Institute, for his useful comments, and Dr. Chengjin Wang, Chinese Academy of Sciences, for sharing Chinese crossborder data. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. [313847] "World Seastems".


had dramatically decreased from about 20% in the 1950s to less than 5% in the 2000s, but had witnessed an increasing trend in the early 2010s [START_REF] Ng | The changing tides of port geography (1950-2012)[END_REF]. However, a number of scholars promoted historical approaches to port studies from an individual case perspective (Castillo Hidalgo, 2014;[START_REF] Olukoju | The Liverpool of West Africa. The Dynamics and Impact of Maritime Trade in Lagos, 1900-1950[END_REF][START_REF] Peterec | Dakar and West African Economic Development[END_REF]. A key issue is to explore the degree of stability of port hierarchies and maritime networks over time, namely from the colonial age up to the first stage of global container shipping. It could be argued that colonial dynamics and path-creation processes reinforced permanent effects on seaborne flows for the African ports, as underlined in early spatial models of port system evolution based on the cases of Ghana and Nigeria [START_REF] Taaffe | Transport expansion in underdevelopped countries: A comparative analysis[END_REF], although such models focused more on coastal and inland dynamics than on seaborne flows. Thus, the main port functions and regional economic specialization promoted the emergence and consolidation of self-reinforcement effects [START_REF] Martin | The place of path dependence in an evolutionary perspective on the economic landscape[END_REF] on African ports, which were tied to inland transport infrastructures created to support economic extraction processes. Hence, the dynamics of seaborne trade remained almost unchanged from the late nineteenth century up to the last third of the twentieth century (UNCTAD, various issues). This chapter deals with an analysis of the evolution of ports and port systems in Northwest Africa from 1880 to 1972. The chronological period studied runs from the first international shipping revolution (steamship navigation) to the first global wave of containerization [START_REF] Guerrero | The waves of containerization: shifts in global maritime transportation[END_REF]. We shall demonstrate how regional seaborne flows over time and how port hierarchies changed or remained unchanged in a historical perspective. It is important to note the role played by the African ports in the overall process of port reform that began in the second half of the nineteenth century [START_REF] Kaukianen | The advantages of water carriage: Scale economies and shipping, c.1870-2000[END_REF].The nature and evolution of regional economic structures -mainly south of the Sahara-delayed the modernization of ports and it was a decisive obstacle to economic development in terms of decreasing transaction and transport costs. In this chapter, we will expose the main arguments that explain how this technical gap was motivated by the weakness of local capitals and the colonial policies developed by the imperial nations.

In this study, we have used the United Nations' geographical delimitation of territories to define the explored area of northwest Africa (for other analyses of transnational port systems, see Chapters 5, 8, 9, 11, 19, 23, and 24 on Taiwan Strait, Black Sea, Arctic, Mediterranean, USSR, and Indian subcontinent areas). Thus, we have collected data from all countries (former colonies) and territories (i.e. Spanish possessions) running from Tunisia to Angola. The first issue to bear in mind is the existence of historical port hierarchies where a central seaport concentrated most of the cargo handled and on the other hand, the number of vessels calling the country. As will be demonstrated later, these central ports were complemented by secondary ports. Most of them functionedsimilarly to Hoyle's description (1967, p. 65) of the East African ports: "The smaller ports, where the tonnages of oil products imported are much smaller and where exports outweigh imports by a wide margin. This pattern reflects the fact that the primary function of both these ports is the export of a single primary product from the immediate hinterland, an area which does not constitute in either case a very important market for imported goods".

Under this scheme, from the 1970s cargo handled at regional ports (both central and secondary) featured a massive predominance in cash-crop exports (peanuts, palm-oil, vegetables, wheat, wax, rubber, coffee, cocoa, timber), mining commodities (phosphates, iron ores, copper) and oil products (crude oil and derivates). By contrast, imports were usually less important in volume but not in value: industrial manufactures, machinery, clothes, building materials, staples, etc. In the case of imported goods, a number of great seaports absorbed most of them and we provide compelling evidence on the lack of port development south of the Sahara during the first half of the twentieth century that contributed to economic stagnation in these regions. Otherwise, great seaports concentrated seaborne trade and promoted urban growth through the consolidation of a primate city, which hampered regional integration [START_REF] Seck | Dakar, Métropole Ouest-Africaine[END_REF] see also the mercantile model of [START_REF] Vance | The Merchant's World. The Geography of Wholesaling[END_REF].

In this chapter, we have collected data from Lloyd's List to rebuild shipping patterns across Northwest Africa between 1900 and 1970. This chronology is representative for the whole covered period and it permits a comparison between different primary sources. In particular, the Shipping Index provides a snapshot of global and regional maritime activity based on the last inter-port movement of every registered vessel. We then compiled port throughput data from a number of archival sources in France, United Kingdom, Senegal, Spain, Portugal andother African countries between 1913 and1972. Further efforts are being made to palliate the lack of information for all the region's ports and countries1. Using multiple shipping data sources also represents a challenge in terms of potential gaps and overlaps which may be caused by different measurement units and methods.

The waves of port modernization in Northwest Africa

The first consideration of note is the clear difference between the African Mediterranean ports and the Atlantic ports south of the Sahara. If we compare both regions, in terms of volume of cargoes, maritime connectivity and historical development, the Maghreb ports were well integrated into the Mediterranean maritime network during the late nineteenth century. Nevertheless, most colonial seaports in the West African colonies were poorly equipped in terms of modern infrastructures: berth posts, jetties, warehouses, bunkering facilities, intermodal connections, etc. If we observe the charts (see Tables 23.1 and23.2) denoting port activity before 1950, we could argue that these point to an evident lack of port development. Comparing these charts with port throughput figures confirms the deficiency of port development in these regions. Yet, a number of large seaports constitute interesting exceptions, at least for the first half of the century, such as Dakar, Lagos, Accra, and Matadi. These ports retained important commercial functions and they operated as regional gateways for their hinterlands. They basically contributed to the cash-crop revolution in the late nineteenth century [START_REF] Austin | Explaining and evaluating the cash-crop revolution in the "Peasant" colonies of tropical Africa, ca.1890-ca.1930: Beyond "Vent for Surplus[END_REF] which triggered the expansion of external trade and the construction of inland transport infrastructures, mainly colonial railways [START_REF] Chaves | Reinventing the wheel: the economic benefits of wheeled transportation in early colonial British West Africa[END_REF]. Hence, key to the understanding of the evolution of regional seaborne flows is the evolution of regional exports that marked the configuration of trade.

The colonial economic extroverted system promoted this trend and how transport infrastructures were to evolve in a linear way (Mohammed-Chérif and Ducruet, 2016).

[Table 23.1] Table 23.1 summarizes the main driving factors that affected port evolution in general terms.

We have included a number of elements that helped to explain how endogenous and exogenous events transformed the port systems in our study area. The first stage is marked by the consolidation of colonial rule and the expansion of international steam navigation. During this period, port infrastructures were scarcely developed in most countries. On the eve of the Great War, ports and railways began to expand (i.e. Dakar, Conakry, Accra) and the main direct consequence was the rise of external trade and the consolidation of colonial economic and political institutions.

The second period is characterized by interwar instability. Improvements in shipping (transition from coal to fuel) required further changes in port infrastructures, which were hampered by international crises. The most important issue was the emergence of Casablanca as the world's main phosphate export port in the early 1920s. As we showed below, Casablanca represented an interesting example of mega-concentration in terms of volume and value of seaborne trade in Africa. On the other hand, before World War II, most regional ports expanded (i.e.: Lomé, Douala, Cotonou, Matadi) as a consequence of the growth of export sectors.

From 1946 to 1960 an important phase of port expansion (throughput, connectivity) takes place throughout the African continent. Several major events such as the first Suez crisis, the independence processes, and a conjuncture of regional instability characterized this transitional stage. In the case of the Suez crises (1956)(1957)(1958)(1959)(1960)(1961)(1962)(1963)(1964)(1965)(1966)(1967)(1968)(1969)(1970)(1971)(1972)(1973)(1974)(1975), the deviation of the new generation super-tankers from the Persian Gulf routes to the Atlantic stopover ports such as Cape Town, Dakar, and Las Palmas challenged the efficiency of port infrastructures and the organizational capacity of other port communities. Further consequences of the Egyptian crises permanently affected regional bunkering ports which retained a part of these traffics in a context of enlarged vessels and the entrepreneurial policies of scale economies (Kaukianen 2012, pp. 67-68). The institutional flexibility of port institutions, the state of infrastructures and the quality of port services were key factors which help to explain the retention of these stopover traffic at these ports.

On the other hand, the French FIDES plan launched after 1947, which massively invested in infrastructure modernization in French West Africa (FWA), resulted in the improvement of "There is considerable evidence that this "escalating" structure of freight rates is due to the arbitrary pricing policies of liner shipping cartels that charge what the traffic will bear.

Nonetheless, their effect is to create a bias against further commodity processing in developing countries (…) The deterioration of ports and related infrastructures also plays a key role" (UNCTAD, 1990, p.52) Nevertheless, during this last period, new commercial ports like Abidjan emerged and other specialized ports such as Bonny, Escravos (both in Nigeria) Ghazaouet, Arzew, Port Gentil, Cabinda, Kenitra or Bedjaia notably expanded. These ports were devoted to crude oil and refinery activities and their throughput increased at the same pace as that of global demand up to the 1973 crisis. The massive exportation of crude oil during the early 1970s from emergent ports in the Gulf of Guinea represents a new phase of regional evolution.

Furthermore, the analysis of port indicators reveals the configuration of port hierarchies which experienced self-reinforcement effects due to the centrality and predominance of great imperial seaports, at least for general cargo. Dobusch and Kapeller (2013, pp. 298-300) have proposed a number of elements that help to explain how major ports retained their key functions over time. Mainly, based on their approach we argue that the learning and expectation effects (memory effects, habits, routines, historical trends, etc.) in imperial seaports such as Dakar, Algiers, Casablanca or Lagos encouraged port activity, their regional centrality and the economic clustering processes that occurred during the colonial period and this trend strongly remained during the postcolonial Age. Moreover, the institutional choice made by the colonial powers promoted the consolidation of port hierarchies but lockin processes too. A relevant example could be found in Senegal (and subsequently the FWA) and French Morocco. In both cases, colonial institutions promoted the creation of an imperial seaport to provide support for colonization and then the effective exploitation of human and natural resources from the hinterland. The establishment of the first port of Dakar during the 1860s promoted its regional importance [START_REF] Ba | Analyse de la dynamique spatiale du port de Dakar de 1900 à 2009: enjeux multi-scalaires et aménagements[END_REF]. The port articulated the inland transport network from the whole FWA, and as a consequence, seaports in Guinea, Benin (formerly Dahomey), and the Ivory Coast were not developed. The lion's share of investments occurred in Dakar during the first decades of colonial occupation and then, in the aftermath of World War II massive investments were made in other infrastructures like in Abidjan. The case of Casablanca is the most impressive as we shall see.

From the establishment of the French Protectorate in Morocco in 1912, the port of Casablanca began to increase its influence. After the Great War, the phosphate revolution in Morocco changed the maritime façade of the country and the concentration process began.

By 1929, the port of Casablanca handled nearly 80 percent of Moroccan external trade in volume and value [START_REF] Bosa | The port of Casablanca in the first stage of the protectorate[END_REF]. Such a concentration of port activity was mainly a consequence of political conjunctures, in addition to other factors such as natural conditions or the financial capability of each government. In the next section, we will provide an analysis of port traffics and the configuration of historical hierarchies.

The historical evolution of port traffic in Northwest Africa

Port hierarchies

Based on a historical database of port throughput volumes by maritime façade between 1913 and 1972, we analyze cargo distribution as well as port specialization. Although the completion of this database is still underway, especially to include better coverage of the former British colonies, this analysis reports on four selected years (1913, 1938, 1955, and 1972), each of them corresponding to a relatively stable conjuncture from the eve of the Great War to the first decade of political independence in most countries included in the study. Then, referring to Castillo and Valdaliso (forthcoming) we propose a taxonomy of ports based on their throughput volume and evolution:  Leading ports: ranking among the top five in the early periods analyzed and remaining on top throughout.  Declining ports: initially high-ranking but lost ground and became secondary.  Emergent ports: did not exist in the early years but climbed to relevant positions.  Secondary ports: played an ancillary role during the entire period under analysis.

Table 23.2 presents the top 20 ports ranked by throughput for the selected years.The first column (1913) with the notable absence of Lagos, Freetown and Accra, represented an overall economic expansion on the eve of the Great War. Bearing in mind that figures collected from archival sources could be not entirely accurate (lack of figures for a number of ports), there is little doubt that the predominance of Algiers is confirmed. Located in North Africa, the top five operated as commercial gateways, coaling stations (mainly Oran) or phosphate export centers (e.g. Sfax). The main Canary Island ports -Las Palmas and Santa Cruz de Tenerife -enjoyed important positions thanks to their logistical functions as coal suppliers (Suárez 2004). It must be noted that Saint Vincent (Mindelo) had lost importance as stopover port and by 1913 the port began to compete with the recently inaugurated commercial port of Dakar (1910). This was triggered by the replacement of Mindelo as a port of call for the Italian shipping lines to Brazil and Argentina and the rerouting of this traffic to the port of Dakar, where Italian coaling companies were also established. A number of smaller ports deserve attention as well, such as Matadi and Douala (the main port of the former German colony of Cameroon), specialized in palm oil, palm kernels, and timber.

External trade value at Ghanaian ports for instance grew impressively before the Great War from £4,434,535 in 1907 to £9,908,613 in 1913. Complementary figures on port calls confirm such a trend for Ghana during the same period, while the gross tonnage of vessels calling at Gold Coast ports increased from 560,578 tons (1896) to 1,526,048 tons (1913), representing an average growth of 62.3 percent (Colonial Reports of the Gold Coast, Colonial Office, various issues). Olukoju (2014, p.125) found compelling evidence of a sustained growth of throughput in the wharves (Iddo, Ijora, Apapa) of Lagos during the period 1919-29, but overall figures must be tested through the analysis of the Blue Books of the Colonies or similar sources.

[Table 23.2] Figures for 1938 represent interesting changes in port hierarchy. The emergence of Oran, Annaba (Bône), Casablanca and Dakar and the stagnation of Algiers are some of the main developments. Phosphate exports expanded in Algeria and Morocco, while the fall of the Canary Island ports is directly attributable to the outbreak of the Spanish Civil war and the deviation of vessels to Dakar for bunkering activities. Previously regional secondary ports (but leading ports for the colony), such as Matadi, exhibited rapid growth (i.e. over half a million tons). By 1955, port hierarchies remained relatively stable and Casablanca reached the first rank. The mid-1950s were characterized by an overall growth of port throughput (Table 23.3). An example of this is the impressive growth of Conakry that began in 1953 with massive iron-ore and bauxite exports (80-85 percent of the country's entire exports during that decade). Other key aspects include the aforementioned emergence of Abidjan, partly to exploit the economic resources of the Gulf of Guinea (Rougerie 1950, p. 753) The last column introduces interesting shifts within the port hierarchy. This was the most complete year with 67 ports. New ports had emerged to occupy some of the top ten positions and other formerly leading ports had dropped. The key factor was the introduction and expansion of oil activities at these ports. The Nigerian port of Bonny climbed to the top thanks to the discovery of oil deposits in the Niger´s Delta. The next four places were occupied by oil-related ports, with the emergence of Arzew (Algeria) and La Skhira (Tunisia).

Only Casablanca retained its position. A number of bulk export ports such as Bedjaia (oil refinery), Monrovia and Buchanan (iron ores and timber), and Cabinda (crude oil) reached the top 10 for the first time. Abidjan superseded Dakar due to its faster growth in comparative terms. The drop of historical ports in relative terms (they remained to hold onto the general cargo trade) is important. Moreover, the main ports of the wealthiest former colonies of the Gold Coast and Nigeria remained below three million tons (relative higher value of exported cargoes, e.g., cocoa), but greatly expanded during the 1980s due to the expansion of oil market in the region, as Nigerian figures stated. [Table 23.3]

We have summarized some key figures on the evolution of port activity for the same test years in Table 17.3. This confirms the clear difference between North and West African ports in aggregated terms. By 1913, North Africa as a whole surpassed West Africa tenfold, even including Lagos, which was excluded due to lack of data. In 1938, differences were narrower due to the important growth, consolidation, and first phase of port sub-Saharan port reform, as seen with West Africa's 149.84% growth rate compared with 68.59% for North Africa. In 1955, the throughput ratio between North and West Africa declined to 3:1, as only Dakar reached a level comparable to that of North Africa's largest ports. In 1972, there was impressive growth in both regions, although it radically more accelerated in West Africa (1,103.49 percent) than North Africa (240.70 percent). This growth was directly tied to the expansion of oil activities, as explained. Individual case studies of port evolution in a number of West African ports need to be explored from a holistic perspective in order to analyze how internal evolution and the emergence of new ports modified the regional maritime networks.

Following on from this taxonomy, we could argue that historical port hierarchies marked the broader economic and institutional evolution of the analyzed regions. Yet, two distinct periods can be distinguished. Before 1955, historical port hierarchies remained unchanged and were tied to the colonization process and the continuation of long term trajectories (i.e., Algiers, Tunis-Goulette, Bône and Dakar). In the second half of the twentieth century, new ports with new functions emerged and throughput expanded following the global trends of seaborne trade. New specialized ports (oil ports) tied to export activities emerged and altered the regional port hierarchy, but former leading ports retained their influence as political and economic centers. Despite their relative decline, these port-cities retained their influence and urban hierarchy in terms of population, industrial clusters (e.g. Dakar) or regional redistribution of general cargoes.

Secondary ports managed to grow despite the persistent predominance of great imperial ports, notably due to their articulation of coastal shipping networks at various scales and their specific functions as micro-local hubs exporting commodities. The Moroccan port system provides an interesting example where the dominance of Casablanca was challenged by emerging ports. [Figure 23.1] The progress of shipping activities supported by the institutional environment in Casablanca contrasted with the stagnation of the "international" port of Tangiers. This port had been one of the most active port-cities on the Moroccan coast since the seventeenth century but since the signature of the Treaty of Fes (1912), it was transformed in a sort of no man´s land where international interests were represented. The self-reinforcement effects of Casablanca promoted by institutional decisions and commercial expectation dynamics strengthened its predominant position. Such an artificial lock-in process causing the stagnation of Tangiers as a regional hub for northern Morocco could have been verified based on French diplomatic archives. By 1946, the French consular agent in Tangiers officially stood against further investment in the local port to avoid competition with Casablanca, as the international administration of the port of Tangiers was seen as a threat to the imperial private interests around general cargo redistribution in Morocco2. A closer look at inter-port shipping patterns is provided in the next section to complement our understanding of port system evolution, port hierarchies and specialization in Northwest Africa.

As seen in

Shipping patterns and connectivity

Vessel movement data extracted from Lloyd's List archives were first compared with previous section figures based on tonnage in order to test their comparability. Results are relatively significant, based on a Pearson correlation coefficient (between the number of vessel calls and port throughput volume) of 0.63, 0.75, 0.83, and 0.15 for the years 1910/1913, 1935/1938, 1951/1955, and 1970/1972. The sudden decline in statistical significance in 1970/1972 is directly attributable to the emergence of new bulk ports as mentioned above, with a gap between low connectivity and high volume. Less significant results were obtained when replacing vessel calls by degree centrality (i.e., the number of flows of each port with other ports). The main objective of using Lloyd's shipping data in addition to throughput data is to provide a relational perspective by mapping the evolution of Northwest Africa's maritime network between 1910 and 1970 (Figure 23.2). If the main results in terms of port hierarchies subtsnatially confirm the above discussions, they also provide new evidence on the roles and functions of regional ports internally and externally.

For instance, if the St. Vincent and Canary ports often appear as major nodes based on vessel movements, they remain poorly connected to the region as a whole through secondary linkages. One exception is the year 1930, with Dakar/Las Palmas as the region's largest flow. Yet, if their intra-regional connectivity is limited, such nodes are important to ensure connectivity between North and West Africa, which would otherwise have nearly inexistent, or very minor linkages. This division between North and West was already made evident in Table 17.3 in terms of throughput growth dynamics. In fact, the region's major linkages remain internal to either North or West Africa.

Another interesting affirmation is the parallel stability and shift among the major nodes of the network over time. For instance, Algiers in North Africa had been the leading node before the 1930s and was surpassed from then onwards by Casablanca (but also Oran in 1930 and1940). As for other larger nodes, size is reflected in local connectivity, as such ports also carry out a hub function towards their immediate neighbors. However, there are sometimes huge gaps also between size (number of vessel calls) and local connectivity, as seen in the case of St. Vincent and the Canaries. For instance, if Casablanca clearly became North Africa's largest node, it did not increase an equivalent hub function for the Maghreb.

This means that such large ports are mainly extraverted, their activity being mainly linked to external regions such as Western Europe and North America for instance.

A very distinct pattern emerged over time in West Africa, where Dakar had become the main pivotal hub for the whole sub-region, starting with a few minor linkages in 1900-1910 and gradually becoming connected to most of its neighbors in subsequent years, in a multilayered fashion (i.e. trunk lines and small linkages). We also observe that despite the predominance of Dakar, West Africa is quite polycentric, but with important shifts among the other hubs, such as Sapele (1920,1960), Abo (1940Abo ( , 1950)), Douala (continuous), Takoradi (up to 1960), Freetown (1940and 1960), Abidjan and Pointe-Noire (since the 1950s mainly), and Lagos (1970). In comparison, the limited intra-regional maritime connectivity of the Maghreb is rather specific compared with West Africa [START_REF] Mohamed-Chérif | Regional integration and maritime connectivity across the Maghreb seaport system[END_REF]. Some factors, such as the relatively "institutional" homogeneity among the northern territories under French colonial rule, could explain this specificity. On the other hand, institutional policies developed in the rest of territories promoted the direct linkages with overseas forelands [START_REF] Debrie | The West African port system: Global insertion and regional particularities[END_REF]. This trend aggravated during the decolonization processes where countries competed against each other in the international markets.

[Figure 23.2]

Conclusion

This chapter has proposed a first approach to the evolution of port networks in Northwest Africa in a historical perspective. We have shown how the resilience of great imperial ports promoted the concentration processes, which were tied to the evolution of extroverted economic structures. We found compelling evidence of a delayed port modernization process in West Africa that affected the evolution of port indicators (both throughput and connectivity). In terms of port hierarchies in the long run, we have observed how they were almost unchanged until the decade of 1950. In a context of political independences, new ports with new functions emerged but the key feature is that these ports were specialized in the export of cash-crops, mining-ores or crude oil and oil products. These ports were built to enlarge the capacity of their respective countries in terms of external trade, but in general terms the structure did not change, except with the emergence of oil ports such as Bonny or Arzew. A process of divergence between North and West Africa can be observed on the basis of both tonnage and vessel movement data, defined by increasing gaps in terms of traffic growth and intra-regional shipping connectivity. Except for this divergence, the overall evolution remained relatively similar during the first decades of political independences (at least on a country-level analysis), while port hierarchies tended to persist over time.

Individual studies by countries must be developed in order to detect the permanent selfreinforcement effects which could help to obtain valid explanations. The unbalanced structure of trade with high value imports hampered the economic performance of these countries. In the beginning of the 1970s, the first wave of containerization reached Africa but this market did not expand as a result of technical, political and financial obstacles.

Therefore, further studies must be made regarding the fully-long-term evolution of African maritime façades in order to observe the adaptation of African ports to global shifts in shipping and in particular the containerized general cargo revolution. Further research can also complement the current databases and expand the analysis by providing additional metrics in terms of centrality indicators and foreland traffic distribution.

  Dakar's port infrastructures and the construction of Abidjan port. Both ports absorbed almost 60 percent of global investments in port infrastructures for the whole federation between 1947 and 1957. The last period analyzed (1960-72) coincides with the onset of the second global shipping revolution whereby African ports faced important obstacles in terms of financial capacity. The first containerized cargo in Africa was handled in 1972, reinforcing established port hierarchies and shipping patterns based on bulks and non-containerized cargoes. The global dynamics of progressive decline of seaborne freights analyzed by Ekberg, Lange and Merok (2012) did not reach most African countries due to trade tax restrictions, the state of regional infrastructures, the structure of seaborne trade and the entrepreneurial policies developed by the global shipping liners. These conditioning elements and mainly the latter aggravated during the 1980 decade. By 1990 UNCTAD states:

  . The opening of the Vridi Canal in early 1951 and other works boosted throughput from 215,256 tons in 1938 to 692,673 tons in 1951. Abidjan thus superseded the old wharfs of Grand Bassam and Port Bouët which had been the main commercial ports of the colony until the late 1930s (Direction du Port d´Abidjan, 1955). Another important event that marked the further evolution of the regional port system was the modification of Dakar´s hinterland. In 1934, the Ivorian railway reached Bobodioulasso (Burkina, former Upper Volta); by 1956 it extended to Ouagadougou and to Niger in 1958. Thus, Abidjan became a vital gateway for land-locked territories during the second half of the 1950s, causing important changes to historical trade patterns in the context of the balkanization of the FWA. Meanwhile, Santa Cruz de Tenerife's throughput expansion related to the growth of world oil markets due to the existence of a refinery close to the port that was inaugurated in November 1930.

  Figures for 1972 are in line with the global expansion of bulk trade (liquid and solid), which at the global scale increased from 540 million tons in 1960 to 1,654 million tons in 1972. The same goes for dry bulk commodities, which passed from 233 million tons to 505 million tons in the same period (UNCTAD, various issues). Major port reforms across the African continent began in the second half of the 1970s and funds were granted by international institutions (World Bank, International Monetary Fund, European Development Bank) or global investors from the Western, Soviet, and Arab countries.

  Figure 23.1, the market shares of Moroccan ports between 1911 and 1972, despite missing data from 1955 to 1966, reveals an important trend of cargo concentration in Casablanca. Indeed, Casablanca itself concentrated about eighty per cent of Moroccan seaborne trade by 1930 and more than seventy per cent by 1972, despite the emergence of phosphate exports and fishing activities in the port of Saffi during the 1950s. Casablanca´s hinterland permitted the evacuation of cash-crop productions (wheat, vegetables and livestock) from the rich agricultural regions of Tadla and Chaouia (Suárez and Maziane, 2014, p.78). Until the inauguration of the container terminal of Tangiers-Med in the late 1990s, most of Moroccan external trade concentrated in Casablanca. Such a concentration is typical of most national port systems in Africa, backed by the institutional choice made by the French governors during the Protectorate. In particular, the Marèchal Liautey administration decided to create an imperial port capable of confronting the British coaling station of Gibraltar.

Figure 23 . 1 :

 231 Figure 23.1: Port hierarchy and shipping routes in Northwest Africa, 1900-1970 Source: own elaboration based on Lloyd's Shipping Index

Table 17 .1. Historical driving factors of port evolution in Northwest Africa, 1880-1972

 17 Series of GDP obtained from Maddison Project. Made by the authors Note: NA (North Africa); WA (West Africa). Figures for Nigeria, Gold Coast and Sierra Leone for early periods before 1972 are not yet completed. The same goes for Conakry by 1972. So, this rank must be considered as provisional and relatively representative. Sample of ports for: 1913 n=32; 1938 n=37; 1955 n= 29; 1972 n=51. African Ports Historical Database (forthcoming). Author´s elaboration.

	Period	World	African port	Inland	Regional	Regional
		Shipping	development	Transport	Economic Factors	Institutional
		Industry		Infrastructures		Factors
	1880-1913 Last transition	Scarcely	Scarcely	Expansion of cash-crop	Scramble of
		from sail to	developed.	developed.	productions and mining	Africa.
		steam. British	Wharfs and	Railway	sectors. Growth of external	Colonial
		merchant fleet	low-developed	systems (sea-	sectors (trade) and GDP per	occupation.
		hegemony.	infrastructures	producer	capita.	Border´s
		Increased	(WA). Higher	regions). Poor		configuration.
		tonnages.	port	road systems.
		Maritime	performance in	Non-
		industry	Northern	competitive
		changes.	Africa.	waterways.
	1914-1945 Oil-Tankers.	Expansion of	Railway growth	Cash-crop prices crisis. Urban	Development
		Introduction of	port	(until 1930s).	growth and regional	of colonial
		liquid fuels.	infrastructures.	Road transport	metropolization of imperial	institutional
		Increased drafts.	Improved	concurrence	port-cities. Drop of GDP per	model.
			facilities	(wagons) (late	capita.	Definitive
			(export cash-	1930s).		occupation
			crops and			and control of
			ores). Slow			the inner-lands
			mechanization.			(WA).
						Introduction of
						modern port
						management
						models.
	1946-1960 Post-war	New port	Decline of	Post-war inflation. Stagnation of	Socio-
		shipping boom.	functions. Port	railways.	cash-crop productions. Transfer	economic
		Increased	expansion	Increased	of transport-economic	instability and
		tonnages and	(WA) (Suez	importance of	infrastructures. Relative weak	decline of
		drafts. Scale	crisis).	road transports.	growth of GDP per capita.	colonial rule.
		economies and		Expansion of		North-African
		Super-Tankers		the paved roads.		revolutions.
		(late 1950s).				New
		Beginnings of				management
		containerization.				models in port
						infrastructures.
	1960-1972 First wave of	Relative	Financial	Massive public investments	New pro-
		containerization.	stagnation of	troubles and	and nationalization of	socialist
		Expansion of	old colonial	weak	productive sectors.	States.
		bulk trade	ports.	investments on	Increased international	Nationalism

Source:

Note: Source:

Table 17 .3 Throughput analysis in North and West Africa (1913, 1938, 1955 and 1972)

 17 Sources: African Ports Historical Database (forthcoming). Author´s elaboration.

				North Africa
	1913		1938		1955		1972
	Ports		Ports		Ports		Ports analyzed
	analyzed (n)	20	analyzed (n)	19	analyzed (n)	16	(n)	24
	Total	12.35	Total	20.83	Total	34.52	Total	84.45
	Throughput	8.490	Throughput	5.989	Throughput	9.994	Throughput	9.463
			Growth rate		Growth rate		Growth rate	144.5
	Growth rate	n/a	(1913-38)	68.59	(1938-55)	65.72	(1938-55)	9
	Throughput	617.9	Throughput	1.096.	Throughput	2.158.		3.519.
	avg.	25	avg.	631	avg.	125	Throughput avg.	144
	Throughput	263.6	Throughput	411.0	Throughput	1.910.	Throughput	2.936.
	median.	04	median.	00	median.	500	median.	570
	Ports >		Ports >		Ports >
	1.000.000		2.000.000		3.000.000		Ports >
	tons	5	tons	4	tons	4	10.000.000 tons	3
			Ports >		Ports >
	Ports >		1.000.000		2.000.000		Ports >
	500.000 tons	7	tons	6	tons	8	4.000.000 tons	7
				West Africa
	1913		1938		1955		1972
	Ports		Ports		Ports		Ports analyzed
	analyzed (n)	12	analyzed (n)	18	analyzed (n)	13	(n)	27
	Total	1.970.	Total	4.922.	Total	10.67		64.49
	Throughput	138	Throughput	200	Throughput	6.585	Throughput	8.507
			Growth rate	149.8	Growth rate	116.9	Growth rate	504.1
	Growth rate	n/a	(1913-38)	4	(1938-55)	0	(1938-55)	1
	Throughput	164.1	Throughput	273.4	Throughput	821.2		2.388.
	avg.	78	avg.	56	avg.	76	Throughput avg.	834
	Throughput	81.05	Throughput	130.8	Throughput	456.0	Throughput	1.966.
	median.	0	median.	50	median.	00	median. (top.20)	268
	Ports >		Ports >		Ports >
	1.000.000		2.000.000		3.000.000		Ports >
	tons	0	tons	1	tons	1	10.000.000 tons	1

A complete free access online database for African ports from 1880 up to

is being completed.We expect that it will be available in its provisional first version by November

CADN. Tanger, 675POE, Carton 24. Protectorat de la RF au Maroc. Direction des Travaux Publics. Note pour le Secrétaire Générale du Protectorat, 2 September 1946.

Acknowledgements

This chapter benefited from the R&D project HAR2015-64044-R and ULPGC-2014-01. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. [313847] "World Seastems".