随着城市的发展,水的需求量越来越大,用水状况日趋紧张,大部分城市都在考虑开发新的水源,由于城市附近水源频于枯竭,不能继续开采,而新的水源又往往距城市较远,故长距离输水已成为发展方向,因长距离输水投资较大,大部分城市都采用混 With the development of cities, the demand for water is getting larger and larger, and water use conditions are getting tighter. Most cities are considering the development of new water sources. Due to the frequent depletion of water near cities, they can not continue to be mined. However, The city is far, so long-distance water has become the development direction, due to large investment in long-distance water, most cities are mixed