基于水文要素过程的流域地下水与地表水交换径流成分定量分析

Identification of runoff components in groundwater and surface water interaction based on hydrograph analysis

流域地表水-地下水相互作用中包括枯水季节深层地下水向河流稳定补给的基流,降雨入渗后形成的快速与慢速壤中流和洪水时期河道水位抬升引起的地表水补给地下水。目前对于地下水-地表水交换量的组成并没有清晰的定义,已有的水文实验和模拟方法不能准确辨析地下水-地表水交换组分。利用水文要素过程线,提出了综合新安江水文模型、改进马斯京根-康格(Muskingum-Cunge, MC)法和基流分割方法的技术框架,研究地下水-地表水交换量的组成情况,并以婺源江小流域出口断面为例进行了方法应用。研究结果表明:婺源江小流域的地下水-地表水交换量占出口断面总径流的43.54%~54.66%。饱和带中的浅层地下水占出口流量的8.41%~10.57%;降雨下渗进入浅层土壤补给河道的水流占6.81%~20.59%;深层地下水的稳定补给量占河道总径流的23.34%~26.54%。本研究提出了可以精细化辨析地下水-地表水交换分量的技术框架,结果可为类似流域水资源保护与管理提供理论依据。

The interaction between surface water and groundwater in the basin includes the stable recharge of deep groundwater to the river in dry season,the formation of fast and slow soil flow after rainfall infiltration,and the vertical exchange from surface water to groundwater caused by the rise of river water level during flood period.However,there is no clear definition of the composition of groundwater-surface water exchange capacity,and the existing hydrological conceptual models cannot indentify different components of groundwater-surface water exchange.Therefore,based on the hydrograph of hydrological elements,a new technical framework combined with three different classical hydrological methods,namely Xin’anjiang model,improved Muskingum-Cunge(MC)method and base-flow separation method,was proposed to study the composition of groundwater-surface water exchange,and the Wuyuan River Baisn was taken as an example.The results show that the groundwater-surface water exchange capacity of Wuyuan River Basin accounts for 43.54%-54.66%of the total runoff of the outlet section.Among them,the shallow groundwater in the saturation zone accounts for 8.41%-10.57%;the water that infiltrates into the shallow soil through rainfall and rapidly replenishes the river accounts for 6.81%-20.59%;and the stable recharge from deep groundwater accounts for 23.34%-26.54%of the total runoff.The proposed technical framework can clearly identify the components of groundwater-surface water interaction,and it can provide a basis for water resources protection and management in similar basins.