Water resources in small basins with different land use

In recent years, water scarcity and irrational utilization have beacome the pivotal issues for sustainable development of river basins.The aim of optimal water resources allocation is to reallocate the limited water resources scientifically among different water use sectors based on a fair, effective and sustainable principle in a given region through measure such as restraining water demand reasonably, increasing water supply effectively, and protecting the ecological environment positively.Land use and cover is considered in a historical as well as current perspective to determine the types of activities that have occurred in the watershed and their potential as sources of pollution. It is important to consider the natural and cultural resources of the watershed as well as the human activities.Land use changes are altering the hydrologic system and have potentially large impacts on water resources. Rapid socio-economic development drives land use changes, which include changes of land use classes (conversion of cropland to urban area due the urbanization, as well as changes within classes such as a change of crops or crop rotations). In regions where water availability is limited, land use changes could result in an increase of water scarcity and thus contribute to a deterioration of living conditions.