湍口小流域水文下垫面要素调查与分析

Investigation and Analysis of Hydrological Underlying Surface in Tuankou Basin

为探讨分布式水文模型(如新安江模型等)在极小流域的适用性,针对闭合的湍口小流域,利用ArcGIS软件将实测的等高线图生成DEM,即可推求湍口流域地形坡度坡向值;利用手持GPS定位方法,获得了流域内植被种类及其覆盖率;采用探地雷达探测到了土壤厚度,通过室内试验确定了土壤种类、容重及含水量;最后对湍口小流域进行格网划分,将每个网格内实测值在ArcGIS中表示出来,就可获得湍口流域内水文下垫面各要素值(如田间持水量、凋萎含水量、饱和持水量参数、产流参数张力水蓄水容量WM、自由水蓄水容量SM、蓄水容量曲线指数等),进而简化新安江模型参数及降低参数率定的难度,以确保水文预报的准确性并提高预见期。

To discuss the applicability of distributed hydrological model（e.g.Xinanjiang model et al.）in small basin,DEM of a small closed basin,Tuankou basin,was generated by using ArcGIS software with the measured contour map,which could be used to get terrain gradient and slope direction information of the study area.Vegetation types and their coverage were obtained by field survey with a handheld GPS.Soil depth was detected by using ground penetrating radar（GPR）,and other soil characteristics,such as soil depth,soil type,bulk density and water content,were determined by indoor test.The basin was discretized into grids by ArcGIS in which all the measured information was included.Thus,hydrological underlying surface elements（field capacity,wilting,saturated water capacity parameter,storage capacity of tesion water W M,storage capacity of free water SM,the index of water storage capacity curve）can be obtained.Based on the above results,Xin＇anjiang model parameters can be simplified and calibrated easily,and the accuracy of hydrological forecast can be ensured and forecast lead time can be increased.