Abstract: Extraction and analysis of hydrological characteristics not only provide important parameters for the hydrological processes simulation,but also offer beneficial support to health monitoring and evaluation of aquatic ecosystem.Based on DEM with 30 m resolution of Lijiang river basin,river network is extracted;the watershed is determined;the sub catchments are divided;and the river length,river density,and fractal dimension are calculated,etc.According to the average rainfall and runoff data of many years,the runoff coefficient of drainage basin is calculated.The results indicate that:1)By using the catchment threshold value and drainage density curve,the network density of0.53 km·km^-2 is ultimately determined to extract the network.2)With the main drainage line characteristics,and health monitoring and evaluation scale,the river is at last divided into 15 sub-watershed.3)The spatial distribution trend of rainfall and runoff depth isbasically the same,with slight difference between rainfall and runoff coefficient.The runoff coefficient of each sub-watershed ranges from 0.637 to 0.800.Differences in runoff coefficient is mainly affected by vegetation cover,stratum lithology and human activities.

Key words: Lijiang river basin, hydrological characteristic, spatial analysis