那陵格勒河山谷段数字流域特征提取与流域调蓄能力初探

Extraction of the Digital Watershed Features on the Nalinggele River Valley and Simple Discussion on Capacity of Watershed Flood Regulation

流域特征的精确提取对深入研究流域水文过程和水资源管理至关重要。利用DEM数据进行数字流域特征分析，尤其在难以进入、地形复杂的无资料山区，可高效精准地提取、统计和研究地貌和水系特征。基于ArcGIS实验平台，利用DEM数据，从流域产汇流形成以及洪水调蓄角度对那陵格勒河山谷段进行流域特征提取。结论如下：1）流域地貌特征表明产汇流面较大，地面侵蚀过程较强，重力侵蚀过程较弱。2）流域水系为狭长形弯曲河道，主河道比降小。实际沟谷网络密度为1．71～2．32km／km^2。3）流域地貌特征使子流域的沟谷集水面广量大且速度快，易形成大的径流汇入主河道；但流域水系特征可降低主河道汇流速度，延长；12流时间，有利调蓄，洪峰不易集中。

Hydrological process is determined by the watershed features. The accuracy of watershed feature plays a significant role in research about the hydrological process and water resources management. Accuracy and efficiency of the extraction, statistics and analysis of features of geomorphology and drainage through using DEM data analyzing digital watershed features, especially for hard to get into the complex terrain of mountainous area without any data. Hence,in this study, we use DEM data based on ArcGIS experiment platform, to extract digital watershed features on the Nalinggele River valley, from the perspective of flow accumulation＇ s formation and flood regulation. We got the concluteons that ： （ 1 ） the geomorphology features make larger of the water contributing surface area, serious of erosion process, and weak of gravity erosion process. （2） Channel features belong to a long and narrow basin shape, and the channel is tortuous. The channel gradients of main channels are smaller. Actual gully network densities are within 1.71 -2.32 km/km^2. （3）The geomorphology features make larger of the water contributing surface area and the amount of flow accumulation, rapid of flow formation, and the flow go into the main channel easi- ly. However, the features of main channels are benefit to reduce the main channel flow velocity, prolong conflux time, adjust the flood peak. And flood peak is diffcuh to focus.