基于径流模拟的汉江上游区水资源对气候变化响应的研究  

Responses of Water Resources to Climatic Changes in the Upper Stream of the Hanjiang River Basin Based on Rainfall-Runoff Simulations

作　　者：朱利[1] 张万昌[1] 

机构地区：[1]南京大学国际地球系统研究所,南京210093

出　　处：《资源科学》2005年第2期16-22,共7页Resources Science

基　　金：国家重点基础研究发展规划项目(编号:2001CB309404);海外青年学者合作研究基金(编号:40128001);教育部科学技术重点项目(2001)。

摘　　要：本文简要介绍了基于水文过程的、具有较强物理机制的流域分布式水文模型SWAT。然后由遥感和地理信息系统手段得到流域的土壤类型与植被覆盖及雨量气象站点分布图,通过改进的SWAT气象模拟器模拟出缺乏实测的日气象资料,再结合实测的降雨资料作为SWAT模型的输入,对两河口流域1981年～1985年进行年月径流模拟,并利用汉江上游地区两河口流域1981年～1985年5年间的年、月径流量实测资料,以月径流模拟的N S模型效率系数为主要指标,对SWAT模型中3个最敏感参数ESCO、AWC和CN2进行敏感性分析,进而率定出使得月模拟效果最佳的参数值或参数变化值。参数率定后月径流模拟N S模型效率系数达0 913,对数误差为0 339,峰值误差为-0 083。在5年准确月径流模拟基础上,以全球变化背景可能出现的25种不同气候变化模式为假设条件,研究了该流域径流及实际蒸发的响应,分析指出汉江流域降水的变化对水资源的影响要大于气温的变化对水资源的影响,降水增加或气温降低都会导致径流增加,而降水增加或气温增加都会导致实际蒸发的增加。SWAT(Soil and Water Assessment Tool), a distributed hydrologic model integrated with geographic information system (GIS) and remote sensing (RS) technique to simulate the hydrological processes and stream flows, was improved and applied to LIANGHEKOU catchment located in the upper stream of the HANJIANG River Basin, middle Western China. Based on 60m resolutions DEM of the catchments, SWAT-GIS divided the watershed into 13 simulation sub-watersheds. With correspondence to different topography, soil types, land use/cover classifications in the catchments of (2 816) km^2, SWAT-GIS sub-divided those sub-catchments into 77 Hydrological Response Units (HRU), each of which was thought unique in hydrological characteristics. A classification method was used to obtain the land use/cover classification from 500m resolution MODIS imagine. Soil type imagines was digitalized from a (1∶250 000) soil maps provided by the local government. The measured daily rainfall data, together with other climate data that were absent but generated from an improved SWAT climate generator, were input to SWAT model and DEM, and soil type and land use/cover imagine data to simulate the monthly stream flow for 5 years (1981～1985) were also input. The three most sensitive factors, including ESCO, AWC and CN2, were calibrated through sensitivity analysis under the simulation efficiency optimization principles. After ascertaining the parameters, satisfactory simulation results were obtained with the accuracy of 0.913 for Nash- Sutcliffe coefficient over the 5 years continuous monthly simulations on discharges, which suggested an excellent modeling performance of SWAT2000 in the study basin. On the basis of this study, the hydrological responses of the catchment to possible climate changes were studied under 25 climate-change scenarios according to the most possible climate change predictions in the study region. Preliminary results indicated that runoff from the basin would increase with the increase of precipitation or decrease with the incre

关 键 词：气候变化 月径流 降水 气温 SWAT模型 气象资料 气象站 流域径流 土壤类型 效率系数 

分 类 号：TV12[水利工程—水文学及水资源]