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Water management in Greater Damascus, a metropolitan area with more than 4 million inhabitants, is characterized by numerous challenges, including groundwater overexploitation, increasing water demand, intermittent supply, and pollution. These challenges could be exacerbated by the impact of climate change, since projections indicate that a decrease in rainfall is likely. The quality of residential water supply mirrors social divisions within the metropolitan area, with the poorest neighborhoods receiving the worst service. Irrigation in the rural parts of Greater Damascus, in particular in the Ghouta, still accounts for about 70% of water use in the metropolitan area, with the remainder being used for residential, commercial and industrial use. The government has responded to the above challenges by banning the drilling of new agricultural wells, promoting water-saving irrigation techniques, rehabilitating the distribution network to reduce leakage, investing heavily in wastewater treatment for reuse, and experimenting with groundwater recharge. However, none of these measures has been successfully completed so far. Reallocation of water from irrigation to urban uses has also been suggested, but it has never been seriously considered by the government for political reasons, including strong traditional links of the ruling Baath Party to the Peasant's Union. Instead of forcefully promoting local solutions, the government continues to contemplate the large-scale transfer of water from Lake Assad on the Euphrates River through a costly mega-project. Decision-making concerning water remains highly centralized. Ultimately the President of Syria takes all key decisions. Below him responsibility for the water sector is fragmented between different Ministries. One of them is the ''Ministry of Housing and Construction'', which supervises the ''Damascus Water Supply and Sewerage Authority'', the public utility for Greater Damascus. The Ministry of Irrigation also plays an important role in the sector. == Water resources == Greater Damascus is located within the Barada basin, a closed basin that covers 8,630 km², and the neighboring Awaj basin. The Barada basin stretches over a distance of 81 km from the Anti-Lebanon mountains in the Northeast of Damascus at an altitude of more than 2,000 m with precipitation of up to 1,800 mm per year to the Ghouta oasis to the West of Damascus at an altitude of 600 m with less than 100 mm of rainfall. The smaller 70 km-long Awaj river runs South of the Barada river. Total primary water resources in the two basins, surface and groundwater, have been estimated at 452 million cubic per year. These water resources are augmented by reused wastewater and return flows from irrigation, estimated at between 500 and more than 800 million cubic metres per year, adding up to a total of 900 and almost 1300 million cubic metres per year.〔Elie Elhadj:(The Household Water Crisis in Syria’s Greater Damascus Region ), SOAS Water Research Group, Occasional Paper 47, School of Oriental and African Studies and King's College London, University of London, May 2004〕 Precipitation is highly seasonal and occurs primarily during winter. The main sources of water supply for Damascus are the Fijeh and Barada springs. The Fijeh springs are a group of three large karstic springs - The Fijeh main spring, the Fijeh side spring and the Harouch spring - in the Barada gorge. The three springs used to contribute half the flow of the Barada River. The Barada spring is located North of the Fijeh springs close to the Lebanese border. The entire flow of all these springs is captured today, including through wells positioned around the springs. This is why it appears during the summer that the Barada spring has dried up, while its flow is actually being captured and transferred along the river to supply various towns in the Barada gorge as well as Damascus itself with drinking water. Water from the Barada and Fijeh springs is transferred to a mixing station near Dummar where it is being chlorinated and distributed to the city. The city’s water supply is complemented by well fields in the plains around the city. The flow of the springs is highly seasonal, lagging several months behind the precipitation because of snow melt and the karstic characteristics of the rocks from which they emerge. The flow of the Figeh springs is less than 4 m3/second during the low-flow period from July to December. However, it reaches a maximum of more than 12m3/second (average 1962-1991) in April.〔 The remaining winter flow of the Barada river is not used for drinking water supply in Damascus. However, it plays an important recreational role for the numerous restaurants along its upper course. It also aliments the Ghouta oasis. When it leaves the Barada gorge and enters the plain of Damascus the Barada river splits into five branches. The two Northern branches flow along the foot of the Qasium mountain towards the East. The central branches, including the Barada proper, flow through the city center alongside the old city into the heart of the Ghouta. The southernmost branch takes a turn to the West before entering the city, and flows into what is called the Western Ghouta. Historically, much of the summer base flow of these rivers derived from the Fijeh and Barada springs. However, since the springs have been captured the river carries fresh water only during the winter and spring. Downstream of Damascus, it also carries more or less diluted wastewater that is being indirectly reused for irrigation in the Ghouta. Some winter flows also end up in the intermittent Lake Al-Utaybah, the lowest point of the closed Barada basin where the water infiltrates or evaporates. Greater Damascus had about 4.2 million inhabitants in 2007 or about 25% of the population of Syria. This includes 1.7 million in Damascus governorate itself and 2.5 million in the surrounding governorate of Damascus Rif. Most of the population of Greater Damascus lives within the Barada and Awaj basins. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Water management in Greater Damascus」の詳細全文を読む スポンサード リンク
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