岩溶流域典型农业区水体氢氧同位素的空间异质性及形成机制

分别于平水期和枯水期采集了花溪河流域典型农业区地表水和地下水样品。利用氢氧同位素示踪技术,结合土地利用类型对研究区不同水体的补给来源、季节变化及主要影响过程进行了分析,并对不同水体氢氧同位素值进行了空间插值分析,同时对其形成机制进行了分析,阐明了不同土地利用类型影响下的主要水文过程。结果表明:(1)研究区不同水体的主要补给来源为当地大气降水,月亮湖水库受蒸发作用影响明显,地表水和地下水的δD和δ~(18)O整体上呈现平水期高于枯水期的特征。(2)地下水的δD和δ~(18)O在枯水期与平水期均呈现明显的空间分异性特征,西部水田/水库集中区富集,东部旱地集中区贫化,土地利用对研究区环境水文过程影响明显。该研究结果有助于了解不同土地利用方式下地表水对地下水的影响,为流域管理提供科学依据。

Spatial Heterogeneity of Hydrogen and Oxygen Isotopes in Typical Agricultural Areas of Karst Basin and Its Formation Mechanism

Samples of surface water and groundwater were collected from typical agricultural areas in the Huaxi River Basin during the normal and dry seasons.Combined hydrogen and oxygen isotope tracer technique with land use type,the supplying sources of in different water,seasonal changes and its influence factors are analyzed.Based on spatial interpolation,the main hydrological processes under the influence of different land use types are expounded.The results show that:①different waters in the research area are mainly supplied by local atmospheric precipitation,the Moon Lake Reservoir is remarkably affected by evaporation,andδD andδ18O values of surface water and groundwater in the normal season are generally higher than those in the dry season.②TheδD andδ18O of groundwater show obvious spatial differentiation characteristics during the dry and normal seasons.The paddy field and water reservoir in the west area are flourished inδD andδ18O,but the dry land concentrated area in the east are depleted inδD andδ18O,thus the land use has a significant impact on environmental hydrological processes in this research area.The results of this study are helpful to catching on the impact of surface water on groundwater under different land uses and provide a scientific basis for watershed management.