Ecological Water Demand by the Slope System in the East Liaohe River Basin
东辽河流域坡面系统生态需水研究

Based on GIS and RS with the source information of hydrological data of 46 hydrological monitoring stations during the 52 years and the digital imageries of Landsat TM in 1986, 1996 and 2000, the landscape patterns, precipitation and runoff in the East Liaohe River Basin were analyzed. With the result of the above analysis, the spatial and temporal changes of the ecological water demand (EWD) in the slope systems of the East Liaohe River Basin were derived. Landscapes in the East Liaohe River Basin have great dominance and the standard form, however, the distribution of the landscape in that basin is disperse and strongly disturbed by human activities. The hydrological regime has distinct spatial variations. The annual average EWD of the slope system in the East Liaohe River Basin over years is 504.72 mm (between 324.08 mm and 618.89 mm), and that in the growing period (between May and September) is 88.29% of that of the whole year with the lower reaches of the basin facing crisis of the EWD. The ultimate satisfaction of the EWD of the slope system is 90%. The areas lacking of the EWD in the whole year and in the growing period are 60.47% and 74.01% of the whole basin, respectively. The trend of area lacking of the EWD is particularly serious with respect of the quantity and area lacking of the EWD.