T-M水量平衡模型在流域产流计算中的应用

目的]旨在通过研究流域各月度产水量,对水资源管理和农业灌溉用水调度进行指导。方法]以锦阳川流域为研究对象,运用遥感(remote sensing,RS)和地理信息系统(geographic information system,GIS)提取和处理空间土地利用、土壤及数字高程模型数据,结合降雨、气温及不同植物的根深数据,采用Thornthwaite and Mather(T—M)模型计算了水分亏缺与剩余,土壤水分补给与利用的周期及月度产流量。结果]研究区2011年平水年全年总径流量为281.0mm,在1,3—4,6和10月,存在水分亏缺及土壤水分利用,面积加权的水分亏缺值为5.8mm;2月,11—12月降水对土壤水分进行补给;5和7—9月,存在水分剩余,面积加权的剩余值为286.2mm。丰水年(25%)、平水年(50%)和枯水年(75%)多年平均产水量分别为8.3×107,4.8×107及2.2×107 m3。结论]研究区在丰水年(25%)的2,7—11月,平水年(50%)的2—3,7—9月和枯水年(75%)的12—2,7—9月存在水分剩余。

Application of Thornthwaite and Mather Water Balance Model in Runoff Yield Calculation at Watershed Scale

Objective] This paper aims to study the monthly water production to guide water resource management and agriculture irrigation scheduling.Methods] Per capita water possession is only 290 m³ in Jinan City, which is less than one seventh of the nation's level. So Jinan City is in extreme lack of water resources. By taking Jinyangchuan watershed in southern area of Jinan City as the case research area, this paper estimated the water yield under the assistance of image interpretation of remote sensing(RS) and spatial analysis of geographic information system(GIS). First of all, image preprocessing of TM remote sensing data of 2009 was done under ERDAS IMAGINE 9.1 platform, including image synthesis, mosaic, enhancement and correcting. Seven kinds of land use types were identified through supervised classification, the land use map of study area was produced. Second, the soil map of Jinan was vectorized in ARCGIS 9.3 to get the soil texture map in the study area. Third, this study adopted Thornthwaite and Mather (T-M) water balance model to calculate the water balance, obtained the runoff from various land use-soil texture types and cycle of water deficit, moisture surplus, soil moisture recharge and soil moisture utilization in Jinyangchuan watershed. Finally, the runoff path and sub-watershed were generated with Digital Elevation Model (DEM) in EMS-I.WMS.v8.0 (Watershed Modeling System). Then the sub-watershed map was intersected with land use-soil texture map, runoff yield of every sub-watershed in different hydrological years was calculated using weather data from 1960 to 2 011 and subsequently spatially expressed.Results] The total annual runoff was 281.0 mm, water yield was 51 million m³ in Jinyangchuan watershed in 2011. In January, March, April, June and October, there was water deficit. In February, November and December the soil water was supplied by precipitation; In May, July to September, there was water surplus. The annual average water yield was separately 83 million m³, 48 million m³ and 22 million m³ in wet year, normal flow year and low flow year.Conclusion] There is water surplus in February, July to November of wet year (25%), in February, March, July to November of flat water year (50%), in January, February, July to September, December of dry year (75%).