摘要:
黄土高原是我国水资源短缺以及土地利用变化水文影响敏感区域.为正确认识土地利用变化对水资源的影响,并为今后该地区土地利用规划、管理提供依据,该研究以黄土高原吕二沟流域为例,分析了1982和1989年两期土地利用变化的水文动态响应.经剔除不同时期降水因素对径流的影响后,研究结果表明:土地利用变化对年径流有显著影响,后期土地利用较前期土地利用径流系数下降57%,林地面积较多、植被条件较好的后期土地利用总体年产流减少27.09%~100%,且随着降雨的增多,土地利用与植被变化对径流的影响效应增强;土地利用变化对径流产量的影响表现为季节性,在同一降水条件下两期土地利用的产流量仅在生长季具有明显差异.虽然不同土地利用时期枯水季节径流系数具有不同表现,但作者认为此时的径流系数并不代表实际的降雨产流能力,推断这种分布可能与降水的丰、枯情况有关;经洪水频率分析,认为若前后两期土地利用具有相同频率的降水,则一定频率范围内的洪峰流量将可能对土地利用与植被变化产生明显响应.
Abstract:
Predicting hydrological effects of land use change is a currently focus in the field of hydrology. Land use change impacts the water resources available to watershed by changing the runoff process. As we all know, the Loess Plateau is limited in water resources, and sensitive to hydrological environment. In order to understand the effects of the change in land use on water resources and provide planners and managers with theoretical bases, this study compared the runoff production during two periods of 1982-1988 and 1989-2000 in the Lüergou watershed in the Loess Plateau. The results showed that land use change had effects on annual runoff production, which decreased by 27% to 100% during land use period with more forest land or good land cover, and runoff coefficient decreased by 57%. The effects of land use on runoff production had been found to be seasonal, i.e. the significant differences between the good land cover and the poor one only could be found in growth season. Although the runoff coefficients of the previous and the later land use periods had demonstrated different trends in low water season, it should be noted that it did not represent the runoff production capacity for low water season. The authors deduced that this difference was to some extent relevant to the amount of precipitation. Flood peak discharge frequencies had indicated that peak discharge would response to the land use and vegetation change obviously, provided the same frequencies of rainfall intensity of the earlier and later periods existed.
百度学术
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