基于稳定同位素的海河源区地下水与地表水相互关系分析

对海河流域源区的丰、枯水期降水、地下水、河水进行取样测试,分析了海河源区不同水体氢氧稳定同位素组成及水化学的时空分布特征,同时运用同位素二元混合模型对典型采样点地表水地下水间的相互作用进行了定量分析。结果表明：① 丰水期地下水及地表水δD和δ¹⁸O及总溶解性固体(TDS）表现出显著的空间差异性,而枯水期只有地下水的同位素组成及水化学特性表现出空间差异。②研究区的地下水水化学类型以Ca-HCO₃·SO₄、Ca-HCO₃型为主,丰水期河水与地下水化学类型较为相似,枯水期地下水化学类型与同时期的河水及大气降水的水化学类型存在显著的差异,说明枯水期地表水与地下水之间的转化关系不明显。Gibbs分析结果表明,控制海河源区水体化学性质的主要影响为岩石风化作用。③枯水期地下水受其他水体影响较弱,而丰水期河水及大气降水对地下水具有显著的补给作用,3个源流区中西源的地表河水对地下水影响最显著。

Relationship Between Groundwater and Surface Water Based on Environmental Isotope and Hydrochemistry in Upperstream of the Haihe River Basin

The surface water and groundwater are very important for the farmland irrigation, industrial production and living water. Normally, there is transformation relationship between the surface water and groundwater. The mechanism of transformation relationship between surface water and shallow groundwater is a key factor role for the regional water cycle and the formation and management of water recourse. The Haihe River is an important river of the northern China. The water crisis caused by over exploitation for the groundwater has become the most important limiting factor for the development of the regional economy. This research based on the δ¹⁸O, δD and chemical data of different water samples of two sampling events were collected from the southern upstream of the Haihe River Basin (headstream of the Zhanghe River). We analyzed the hydrochemical and isotopic characteristic of groundwater and surface water during the two seasons by using the methods of study statistics, spatial interpolation analysis, Gibbs and Piper third-line graphs. Based on the two element mixed isotope hydrology separate model, we quantitative analysis the transformation relationship between groundwater and surface water for some sampling sites. The results shown that: 1) δ¹⁸O, δD and TDS of groundwater and surface river water samples of the headstream of Zhanghe River during wet season have significant variation. However, in the dry season, only the δ¹⁸O, δD and TDS of groundwater show the significant variation. 2) Whether wet season or dry season, the mainly water type are the Ca-HCO₃·SO₄ and the Ca-HCO₃ for the shallow groundwater in the headstream of the Zhanghe River of upstream of the Haihe River Basin. The river water chemical type has significant season variation. The water type of river water were Ca-HCO₃ changed to Na-Cl type during wet season, in wet season, due to the stronger evaporation, the river water chemical type were Ca.Na-Cl type. In wet season, the water type of river water and groundwater are similar and further indicate the conversion between the surface water and groundwater. There is obviously different between the water chemical type for precipitation, river water and groundwater during the dry season of headstream of the Zhanghe River. The results of Gibbs analysis shown, the groundwater and river water were controlled by the interaction between rock and water. 3) In dry season, the groundwater and river water have not significant interaction, however, the groundwater and river water shown strong transformation during wet season. About 10.95%-82.90% groundwater discharge from river water and the mean about 48.72%. Western headstream of the Haihe River shown larger interaction between groundwater and river water. The knowledge of these can promote effective management of water resources, and add new trace element data to the world water geochemistry.