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1 我国水资源及利用现状 1.1 水资源贫乏 人所共知干旱缺水是我国北方地区农业可持续发展的主要限制因素。由于人类活动的负效应及气候变迁,全球性干旱已成定势,我国水资源更为贫乏,而且日趋严重,受旱面积从50年代的1.7亿亩(15亩=1公顷)发展到90年代的4亿亩(15亩=1公顷)。近年来发展更快,是世界上少数缺水国家之一,我国水资源人均占有量2400立方米,只为世界人均占有量的1/4,我国北方旱区水资源更为严重
1 Current situation of water resources and utilization in our country 1.1 The well-known shortage of water resources Arid and water shortage is the main limiting factor of agricultural sustainable development in northern China. Due to the negative effects of human activities and climate change, the global drought has become a reality. Our country’s water resources are much poorer and more serious. The area affected by drought has grown from 170 million mu (15 mu = 1 hectare) in the 1950s to 90 years 4 million mu (15 mu = 1 hectare). In recent years, the development is even faster. It is one of the few water-scarce countries in the world. The per-capita share of water resources in China is 2,400 cubic meters, only 1/4 of the world’s average. Water resources in northern China’s arid regions are even more serious