SWAT模型的原理、结构及应用研究

The Theory of SWAT Model and its Application in Heihe Basin

SWAT(SoilandWaterAssessmentTool)是一个具有很强物理机制的长时段的流域分布式水文模型。它能够利用GIS和RS提供的空间数据信息,模拟复杂大流域中多种不同的水文物理过程,包括水、沙、化学物质和杀虫剂的输移与转化过程。本文着重探讨SWAT模型的水文学原理和模型的基本结构与独特的分布式运行控制方式,并将其成功应用于西北寒区(黑河莺落峡以上流域)的分布式日径流过程的模拟。

SWAT (Soil and Water Assessment Tool) model is a river basin, or watershed, scale model developed to predict the impact of land management practices on water, sediment, and agricultural chemical yields in large, complex watersheds with varying soils, land use, and management conditions over long periods of timeThe model is physically based and enables users to study longterm impactsThis paper mainly introduces and discusses the issues of the hydrological theory, the structure and functions of SWAT modelSWAT separates the hydrology of a watershed into two major divisionsThe first division is the land phase of the hydrologic cycle which controls the loadings to the main channel in each subbasinThe second division is the water or routing phase of the hydrologic cycle which can be defined as the movement of water, sediments, etcthrough the channel network of the watershed to the outletSWAT uses a command structure for routing runoff and chemicals through a watershedUsing a routing command language, the model can simulate a basin subdivided into grid cells or subbasinIn case study, SWAT model was used to simulate the hydrology of Heihe (Yingluo Valley) Basin in the cold Northwest ChinaFirst, Based on DEM, Heihe (Yingluo Valley) Basin was subdivided into four subbasinsBy building user soil type database and modifying land use coding, the model made a good runoff simulation result on a daily time step,and the model NSE (NashSutcliffe error judge standard) is up to 083So, SWAT model can be applied to water resource management in Northwest China