不同土地利用方式下漓江流域降水-径流特征变化分析研究

An Analysis of the Change of Rainfall-Runoff Characteristics in the Lijiang River Basin under Different Types of Landuse

为揭示变化环境下土地利用类型对流域降水-径流特征的影响,选用集总式水文模型MODHYDROLOG模拟漓江流域2008-2016年的日径流量,在不同时段人类活动和气候变化情景下,分析土地利用类型与模型时变参数的相关性,揭示流域降水-径流特征的变化情况,探索流域特征受人类活动影响的动态定量感知。结果表明,MODHYDROLOG模型能较好地模拟漓江流域的日径流过程,NSE和R2均超过0.7,Dv在0.2%以内。大部分土地利用类型变化与地下水相关参数dlev、k1、k3等密切相关,个别与植被相关参数呈现不同程度的相关性,而渗透和洼地相关参数并未体现出显著性。分析土地利用方式对产汇流的影响,表现为耕地和林地会抑制地下水基准面抬升,增加地下水深层渗漏量,同时促进基流交换作用从而有利于含水层对河道的补给,水域和城乡的作用机制则相反。草地减小了壤中流的比例,增加地下水的补给量。本研究结果可为变化环境下流域的水文模拟及预报预测提供参考依据。

In order to reveal the impact of landuse on rainfall-runoff characteristics of the basin under changing environments,a lumped hy‐drological model MODHYDROLOG is selected to simulate the daily runoff in the Lijiang River Basin from 2008 to 2016.Under the scenarios of human activities and climate change in different periods,the correlation between landuse and time-varying parameters of the model is ana‐lyzed to reveal the changes of rainfall-runoff characteristics of the basin,and the dynamic quantitative perception of watershed characteris‐tics affected by human activities is explored.The results show that the MODHYDROLOG model can simulate perfectly the daily runoff pro‐cess of Lijiang River Basin,with NSE and R2 both exceeding 0.7 and Dv within 0.2%.Most landuse changes are closely related to groundwa‐ter-related parameters,such as dlev,k1 and k3,and some are related to vegetation-related parameters in different degrees,while the infil‐tration and depression-related parameters does not show significance.The analysis of the impact of landuse on runoff generation shows that cultivated land and forest inhibited the rise of groundwater base level has increased deep groundwater leakage and promoted the exchange of base flow,which is conducted to the recharge of aquifer to river channel,while the mechanism of water areas and urban and rural areas is op‐posite.Grassland has reduced the proportion of interflow and increased the recharge of groundwater.The results of this research can provide a reference for the hydrological simulation and prediction of watershed under changing environments.