Abstract:

The shortage of water has become one of the main factors limiting the social economic development in North China.And the reduce of water in mountain areas has been the key problems to be solved.The purpose of this paper is to analyze the landuse/cover change and its hydrological dynamic response of Hongmenchuan watershed,which is the typical watershed in rocky mountain area of North China.The landscape pattern analysis method and statistical methods were used in this paper.The major results are as follows.(1) Watershed landscape showed obvious fragmentation in the past 16 years from 1990 to 2005,during which the change of the areas of forest was not so obvious,farmland and construction land increased rapidly by 431%and 444%,water area dropped sharply by 208%.(2) The land use/cover change could regulate the runoff significantly.As the optimization of land use structure and the increase of the forest vegetation cover and farmland from 1998 to 2005,the average runoff coefficient of years was dropped by 77% compared to the years from 1990 to 1998,while the runoff coefficient dropped by 64%,31% and 85% in high flow year,average flow year and low flow year.Moreover,under the premise of removing the precipitation factors,the average runoff coefficient of months was decreased by 16% to 100%.(3) The effects of land use on runoff production had been found to be seasonal,as a particularly significant influence in the plant growing period