不同土地利用变化情景下的洪汝河流域水文响应

目的]研究洪汝河流域土地利用变化对水文过程的影响,为当地水资源的合理规划和利用提供依据和参考。方法]本研究以土壤水体评价模型(soil and water assessment tool,SWAT)为基础,通过设计多种土地利用情景模式模拟洪汝河流域水文情景,首先利用数字高程模型(digital elevation model,DEM),土地利用数据、土壤数据以及日气象数据建立模型;其次选用2006—2008年的水文观测数据进行模型率定,并进行敏感性和不确定性分析;最后,设置4种土地利用情景模式进行水文模拟。结果]退耕还林情景下径流减少4.23%;而在耕地增加,城镇用地增加和以城镇用地、林地草地增加为主的复杂土地利用变化这3种情景下,径流分别增加3.01%,4.91%和1.50%。结论]退耕还林增加了可涵养水源的森林,使得径流减少,而增加耕地开垦或城市建设用地则会增加地表径流。

Hydrological Responses to Various Scenarios of Land Use Change in Hongru River Watershed

Objective] The objective of this study is to analyze the impacts of land use change on the hydrological process in the Hongru river basin in order to provide the basis and reference for the rational planning and utilization of local water resources. Methods] Various scenarios of land use change were designed to simulate the hydrological process in Hongru river watershed based on SWAT(soil and water assessment tool) model. DEM(digital elevation model), land use data, soil data, daily meteorological data were used as the input to establish the SWAT model. Observation data from 2006 to 2008 were used to calibrate and analyze the sensitivity and uncertainty of the established model. Four land use scenarios(S₁: conversion of degraded farmland into forest; S₂: increase farmland; S₃: increase urban land; S₄: increase urban land, forest, and grassland) were set up for hydrological modeling. Results] The runoff was expected to decrease by 4.23 % in S₁, while it was expected to increase by 3.01% in S₂, 4.91% in S₃ and 1.50 % in S₄. Conclusion] Returning cultivated land to forest and grassland can reduce the runoff, while reclamation or urbanization will increase the runoff.