摘要
自2006年11月到2007年12月对重庆丰都雪玉洞地下河水和滴水进行了近1年的观测,结果表明其主要水化学指标均表现出明显的季节变化趋势。地下河水Ca2+、Mg2+、HCO3-浓度和电导率在雨季升高而旱季降低,pH值在雨季降低而旱季升高。在地下河径流路径上,由于溶蚀效应与沉积效应的相互制约以及受采样点水动力条件和水气CO2交换程度的影响,水化学指标的空间变化较为复杂。位于洞穴顶部的滴水由于受顶板覆盖层厚度的影响,洞穴上层滴水点Ca2+、Mg2+年平均浓度分别为95.1mg/L、7.87mg/L,而下层滴水点分别为110.1mg/L、9.68mg/L,表现出上层高、下层低的空间变化特征。由于[Mg2+]/[Ca2+]值具有雨季低而旱季高的变化特征,所以可用之来指示洞穴所在地区降雨条件的变化。
In Xueyu cave, we have monitored underground stream water and drip water for nearly one year and revealed the space-time variation of the cave＇s hydrological system. Four underground stream water sites and two drip water sites are chosen to collect water samples every month and the dominant hydro-chemical indicators, including Ca^2＋ , Mg^2＋, HCO3^- and pH, are analyzed. The results indicate that the main hydro- chemical indicators give obvious seasonal variation. Ca^2＋, Mg^2＋, HCO3^- and electrical conductivity of the underground stream water rise in rainy season and fall in dry season. Inversely, pH falls in rainy season and increases in dry season. The main hydro-chemical indicators of the underground stream water show complex spatial variation along the flow path because of the mutual constraints of dissolution and deposition, and the impact of the hydrodynamic conditions and the extent of air convection. The thickness of the cave roof results in spatial hydro-chemical variations in drip water. [Mg^2＋]/[Ca^2＋] value also shows seasonal variation, and is used to indicate changes in precipitation.
出处
《中国岩溶》
CAS
CSCD
2009年第1期49-54,共6页
Carsologica Sinica
基金
国家自然科学基金项目(40672165)
重庆市科技攻关项目(CSTC2007BC7001)
重庆市科技攻关专项(CSTC2005AB7006)
教育部博士点基金项目(20050635001)
关键词
地下河水
洞穴滴水
水文地球化学特征
时空变化
重庆丰都雪玉洞
underground stream water
cave drip-water
hydro-geochemical characteristics
space-time vari-ation
Xueyu cave, Chongqing
