河南平原第四系地下水氢氧同位素特征与补给分析

河南平原第四系地下水氢氧同位素分布特征,总体上由北向南呈渐高趋势,浅、深层地下水系统水的δ18O值变化规律基本一致。平原北部系统水的δ18O值最低,并随着距离黄河越来越近而变得愈来愈小,呈现出"∨"型变化的特征。平原南部系统水的δ18O值最高,并随着距离淮河越来越近而变得愈来愈大,呈现出"∧"的变化特征。平原中部系统水的δ18O值介于该二者之间,且变化较平缓。浅层系统水主要为大气降水补给。深层系统水受开采作用,使得浅层水的越流补给已成为主要的补给来源。此外,平原北部浅层系统水,黄河侧渗补给亦是沿岸地下水的重要补给来源;而平原南部浅层系统水在接受降水补给的同时,还受到淮河的排泄。

Features of hydrogen and oxygen isotopes of Quaternary groundwater in Henan plain and the recharge analysis

The distribution of the hydrogen and oxygen isotopes in Quaternary groundwater is generally an increasing trend from the north to the south in Henan plain.The variation law of the δ18 O value in the shallow groundwater and in the deep groundwater is approximately consistent.The δ18 O value in the northern plain is the lowest one which is reducing with getting closer to Yellow river,showing the ∨-shape varying feature.The δ18 O value in the southern plain is the highest one which is increasing with getting closer to Huai river,showing ∧-shape varying feature.The δ18 O value of the system water which has a smooth variation in the middle of the plain is between the two values mentioned above.The primary recharge of the shallow groundwater is the precipitation,and the leakage recharges from the shallow groundwater becomes the main supply of the deep groundwater because of the groundwater exploitation.In addition,the lateral seepage of Yellow river is an important supply for the coastwise groundwater in the north part of the plain,and the shallow groundwater could receive both the recharge of the precipitation and the water from Huai river.