基于分项调查法和SWAT模型的水资源评价方法

Approach for water resources assessment based on runoff component investigation method and SWAT model

现状下垫面条件下长系列天然径流资料是水资源评价的基础,但下垫面变化以及人类活动常常改变了水文循环过程,给水资源评价带来系统性偏差与较大的不确定性。以浠水流域为实例,提出将分项调查法和SWAT模型相结合的水资源评价方法,即根据水文站与水库位置关系建立不同水量平衡方程进行径流还原,利用与现状下垫面条件相近年份的还原后的径流数据进行参数率定与验证,并将构建的模型应用于长系列天然径流过程模拟计算。结果表明:仅采用分项调查法还原后的水文站降水-径流关系的一致性存在明显偏差;而通过构建基于现状下垫面条件下的SWAT模型,各水文站径流模拟值的降水-径流相关性优于还原值,且不同时期降水-径流关系一致性得到显著改善,表明该方法能够有效修正下垫面变化对径流的影响,有助于进一步开展水资源规划、水旱灾害风险评估等工作。

Long series of natural runoff data under current underlying surface conditions are the basis of water resources assessment.However,changes of the underlying surface and human activities often affect the hydrological cycle process,bringing systematic deviation and great uncertainty to water resources assessment.Taking the Xishui River Basin as an example,a water resources assessment model is proposed combining the runoff component investigation method and the SWAT model.Different water balance equations are established for runoff reconstruction according to the relationship between the locations of the hydrological station and the reservoir,and the parameters of the model is calibrated and verified using the runoff data which is reconstructed by the years with similar underlying surface conditions.Then the model is applied to the simulation of a long-series natural runoff process.The results show that there are obvious deviations in the consistency of the rainfall-runoff series of the hydrological stations reconstructed only by the runoff component investigation method.However,by constructing the SWAT model based on the current underlying surface conditions,the correlation between rainfall and runoff of the simulated runoff values of each hydrological station is better than the reconstructed values,and the consistency of the rainfall-runoff relationship in different periods is significantly improved,which indicates that this approach can effectively correct the impact of underlying surface changes on runoff,and is helpful for the further study of water resources planning and risk assessment of flood and drought disasters.