２１世纪制约中国国民经济、人口、资源、环境协调发展的重要因素之一是水资源问题。我国北方水荒严重，黄河中游（甘肃、宁夏、内蒙、陕西、山西）与黄河下游（山东、河南、河北）工农业争水的矛盾日益突出，工业化和城镇化对淡水的需求愈来愈大，黄河流域７５万ｋｍ２的土? One of the important factors restricting the coordinated development of China’s national economy, population, resources and environment in the 21st century is the issue of water resources. The water shortage in north China is very serious. The conflicts between industry and agriculture in the middle reaches of the Yellow River (Gansu, Ningxia, Inner Mongolia, Shaanxi and Shanxi) and the lower reaches of the Yellow River (Shandong, Henan and Hebei) have become increasingly prominent. The demand for fresh water from industrialization and urbanization is getting larger and larger, 750,000 km2 of soil in the Yellow River?