基于GIS的小流域特征信息提取

Extraction of Small Watershed Feature Information Based on GIS

以重庆市巴南区安澜镇为研究区域,采用大比例尺地形图建立数字高程模型,基于ArcGIS水文分析模块,经过洼地填充、水流方向计算、汇流累积量计算、河网提取、河网分级、小流域划分等对研究区流域特征进行综合分析。研究结果表明：当集水栅格阈值为15 000（集水面积阈值1.5 km2）时提取的河网与实际河网最接近,并将研究区划为41个小流域。在划分的41个小流域中：小流域的面积主要分布在1~5 km2;小流域平均海拔在257.07~749.95 m;小流域平均坡度在13.36°~26.64°;小流域起伏度在80~307.54 m;汇流累积量在16 568~1 109 434。

The article conducted integrative analysis on drainage basin features at Anlan town, Banan district, Chongqing through building digital elevation model with large scale topographical map, based on ArcGIS hydrological analysis module, via depressions, flow direction calculation, flow accumula- tion calculation, drainage network extraction and classification, small watershed division and other techniques, As it is shown in research, when the threshold value of collecting grid equals 15 000 （ collecting grid area threshold value is 1.5 km2 ） , the extracted drainage network is the closest to the real one. The article divided the study area into 41 smaller watershed, among which the area of the watershed is mainly distributed between 1 and 5 km2, and the average altitude is between 257.07 and 749.95 m, and the average gradient is between 13.36° and 26.64°, and the waviness is between 80- 307.54m and the flow accumulation is between 16 568 and 1 109 434.