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日本东京都是典型的现代化大都市。面积1121平方公里,总人口1091万。年平均降水量1550毫米,由于河短、坡陡、水急,降水很难拦蓄。因此,历史上就是个水资源比较短缺的城市。1955年日平均供水不足200万立方米。从六十年代起,由于工业和城市的高速发展,用水量急剧增加,每年以日平均30万立方米的速度递增,供需矛盾尖锐。为了满足城市发展的需要,他们一方面大力开辟新水源,增建供水设施,发展自来水事业;同时,从1973年起大抓
Tokyo, Japan is a typical modern metropolis. Area of 1121 square kilometers, the total population of 10.91 million. The average annual rainfall of 1550 mm, due to the river is short, steep slope, water emergency, precipitation is difficult to intercept. Therefore, historically it is a city with relatively short water resources. In 1955, the average daily water supply was less than 2 million cubic meters. Since the 1960s, due to the rapid development of industry and cities, the water consumption has increased dramatically, with an annual average of 300,000 cubic meters per day. The contradiction between supply and demand is acute. In order to meet the needs of urban development, on the one hand, they have energetically opened up new water sources, built water supply facilities and developed water utilities; and at the same time, they have made great efforts since 1973