thumb|250px|West Lake in Hangzhou, at night Inland drainage involving upland basins in the north and northeast accounts for 40 percent of the country's total drainage area. Many rivers and streams flow into lakes or diminish in the desert. Some are used for irrigation.
thumb|250px|West Lake in Hangzhou, at night Inland drainage involving upland basins in the north a?nd northeast accounts for 40 percent of the country's total drainage area. Many rivers and streams flow into lakes or diminish in the desert. Some are used for irrigation.