水沙物理模型CASC2D-SED的DEM尺度效应发生机制  

Mechanism of DEM Scale Effect Based on Runoff and Sediment Model CASC2D-SED

作　　者：张传才 秦奋[2,3] 张喜旺[2,3] 王航[2,3] 肖培青[4] ZHANG Chuancai;QIN Fen;ZHANG Xiwang;WANG Hang;XIAO Peiqing(College of Surveying and Mapping,Anhui University of Science and Technology,Huainan 232001,China;College of Environment and Planning,Henan University,Kaifeng 475004,China;Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions,Ministry of Education,Kaifeng 475004,China;Yellow River Institute of Hydraulic Research,Key Laboratory of Soil and Water Loss Process and Control on the Loess Plateau of Ministry of Water Resources,Zhengzhou 450003,China)

机构地区：[1]安徽理工大学测绘学院,安徽淮南232001 [2]河南大学环境与规划学院,河南开封475004 [3]黄河中下游数字地理技术教育部重点实验室,河南开封475004 [4]黄河水利科学研究院水利部黄土高原水土流失过程与控制重点实验室,河南郑州450003

出　　处：《水文》2018年第2期15-24,共10页Journal of China Hydrology

基　　金：国家科技支撑计划项目(2013BAC05B01);安徽省对外科技合作计划项目(1503062020);淮南矿业集团2017科研计划项目(HNKYLTJS(2017)-83)

摘　　要：DEM分辨率对分布式水沙过程模拟具有重要影响,然而,产生影响的内部机制尚不明确。改进水沙物理模型CASC2D-SED的结构,将坡度由DEM在模型内部直接提取改为由模块单独计算,并将坡度设计为模型的独立输入参数,通过单独改变坡度参数来研究坡度对水沙模拟DEM尺度效应的影响。基于改进的CASC2D-SED模型,以内蒙古准格尔旗沙圪堵镇附近的一个小流域为研究对象,以无人机航测的1m分辨率DEM数据、野外实测与室内实验获得的土壤特性数据、土地利用数据和降雨数据为基础,采用3种水沙模拟方案进行多象元尺度的水沙过程模拟,进而探索水沙过程模拟的DEM尺度效应及发生机制。研究表明:⑴在4~20m GRID分辨率区间模拟的径流量位于323.18m3和411.43m3之间,波动不大;⑵2~20m GRID分辨率区间内,模拟的侵蚀流量在3.43m3和65.61m3间变化,波动很大;(3)坡度和径流路径是水文过程模拟DEM尺度效应的两个对立影响因子,是水文过程模拟DEM尺度效应不明显的主要原因;⑷DEM尺度效应对侵蚀输沙具有重要影响,地形坡度是侵蚀输沙DEM尺度效应的主要控制因子;⑸地形坡度随DEM分辨率降低而发生的空间上的波动变化是侵蚀输沙量随DEM分辨率降低而波动变化的原因。DEM resolution has important effects on process simulation of runoff and sediment.However,the internal mechanism of them are unclear.Through calculating the slope separately by the module instead of the gradient extraction directly by the DEM in internal model and slope design as independent input parameters for the model,the runoff and sediment CASC2D-SED was im-proved.We researched the slope contribution to DEM scale effect of runoff and sediment modeling by changing the parameters of slope alone.The small watershed,near Shagedu Town of Jungar Banner in Inner Mongolia,as the research object,we simulated the process of runoff and sediment using three kinds of schemes in different grid cell size taking UAV one resolution DEM data,soil characteristics data obtained by field survey and experiment,land use data,rainfall data,runoff and sediment data as basic input parameter based on the improved CASC2D-SED model.The results show that(1)the simulated runoff lies between 323.18m3 and 411.43m3,and fluctuation is not big within the range of 4 to 20m grid resolution;(2)the simulated erosion flow changes between 3.43m3 and 65.61m3 within the range of 2 to 20m grid resolution,and fluctuation is big;(3)the slope and runoff path are two op-posing factors on DEM scale effect of hydrological process simulation and it is the main cause of DEM scale effect on hydrological process simulation without obvious changes;(4)DEM scale effect has important effects on erosion sediment,and terrain slope is the main control factor on DEM scale effect of erosion sediment;(5)the spatial variation of terrain slope changing result from DEM resolution is the main reason of the change of eroded sediment discharge in volatility.

关 键 词：分布式 水文 土壤侵蚀 DEM 泥沙 

分 类 号：P339[天文地球—水文科学]