Multi-factor analysis of water area changes in Han-Jiang river basin

Hanjiang River basin is very rich in water resource which contains a total of more than 500 billion cubic meters of surface water. However, after years of development of cities along the river, the planning of seven hydropower stations and the construction and operation of the middle-lower reaches of eight hydropower stations will be a tremendous impact to the resources in Hanjiang River basin. The district's water area data is extracted by multitemporal remote sensing data from TM/ETM of LANDSAT. The correlation method is used to analysis the effect of temperature, precipitation, evaporation, water consumption and hydropower cascade development project to the water area changes of Hanjiang River basin. The results show that the water area of Hanjiang River basin has decreased from 3084.10 km² 1990 to 2422.12 km² 2010 and the hydropower cascade development project is a tremendous impact on the basin surface area change. The impact of cascade hydropower development will pay close attention in watershed management in Hanjiang River basin.