CAJ | 학술논문

重庆地区分布有380条岩溶地下河,是重庆市重要的水资源。为掌握岩溶地下河水稳定同位素地球化学特征及其环境意义,研究了重庆市不同地区51条地下河水体的稳定同位素地球化学特征。研究表明,重庆市岩溶地下河旱、雨季δ18O、δD值均沿大气降水线分布,表明地下河水均起源于大气降水。受雨季降水云团运动规律(环流效应)和区域地形的影响,地下河水δ18O、δD 值雨季表现出渝东北地区(渝西地区,渝东地区)<渝东南地区的明显区域分布规律(“<”表示偏负于),旱季由于地下河水在含水层中运动较慢,δ18O、δD值的区域性规律不明显,且由于具有较雨季长的滞留时间,导致其d-excess值明显小于雨季。利用岩溶地下水δ18O值和区域高程建立了二者之间的二元回归模型,揭示了重庆岩溶地下河水旱季δ18O值随高度的变化率为-0.34‰/100 m,雨季为-0.31‰/100 m,这对于区域水循环研究具有重要意义。
중경지구분포유380조암용지하하,시중경시중요적수자원。위장악암용지하하수은정동위소지구화학특정급기배경의의,연구료중경시불동지구51조지하하수체적은정동위소지구화학특정。연구표명,중경시암용지하하한、우계δ18O、δD치균연대기강수선분포,표명지하하수균기원우대기강수。수우계강수운단운동규률(배류효응)화구역지형적영향,지하하수δ18O、δD 치우계표현출투동북지구(투서지구,투동지구)<투동남지구적명현구역분포규률(“<”표시편부우),한계유우지하하수재함수층중운동교만,δ18O、δD치적구역성규률불명현,차유우구유교우계장적체류시간,도치기d-excess치명현소우우계。이용암용지하수δ18O치화구역고정건립료이자지간적이원회귀모형,게시료중경암용지하하수한계δ18O치수고도적변화솔위-0.34‰/100 m,우계위-0.31‰/100 m,저대우구역수순배연구구유중요의의。
Karst groundwater constitutes the important water resources and life support systems in the karst areas, and its geochemical research is an indispensable method for karst aquifer protection. There are approximately 380 subterranean karst streams (SS) which are the important part of the groundwater resources in Chongqing City. The isotope geochemistry of 51 subterranean karst streams in Chongqing shows that all the SS waters originate from modern precipitation because theirδ18O andδD values are distributed along the line of GMWL or LMWL, which shows that the evaporation of groundwater does not occur or is not strong. Under the control of movement of rain cloud cluster from south to north (atmospheric circulation effect) and the regional relief, the regional distribution of δ18O and δD for SS in Chongiqng in rain season is in order of northeastern Chongqing < western Chongqing, central area of Chongqing < southeastern Chongqing (the symbol “<” means “more minus”). In dry season, the regional distribution of δ18O and δD for SS is not clear due to the slower movement velocity in karst aquifer. Because of the slower movement velocity and longer staying time in karst aquifer in dry season, the d-excess value of SS in dry season is obvious smaller than that in wet season. Considering the relationship between the altitude and the mean value of δ18O for SS within 100 m altitude, the authors established the second order polynomial of karst groundwater between δ18O and altitude. According to the equations, the δ18O-elevation gradient of karst groundwater in Chongqing is -0.34 ‰/100 m in dry season and -0.31‰/100 m in wet season. These results are very useful to the study of the groundwater cycle in karst aquifers. The achievements obtained by the authors are applicable to the reasonable protection and exploitation of subterranean karst streams.