鱼卡河中下游鱼卡—马海盆地地下水循环模式研究

发布时间：2018-09-13 05:57

【摘要】：我国西北内陆地区由于气候干旱，水资源相对贫乏导致供需矛盾十分突出。西北内陆干旱盆地的水资源主要形成于山区而消耗于山间盆地，补给源为降水和冰雪融水。由于水资源主要产自高山区，经历漫长径流最终转化为平原区盆地地下水，这决定了干旱盆地地下水循环的复杂性，如地下水的起源和成因、地表水与地下水的转化关系、地下水补给量的时空变化、地下水的可更新能力等问题是当前干旱区水资源评价过程中的难点。因此，开展干旱区典型流域的地下水循环模式研究，，有助于科学认识区域水资源的形成机制，从而制定合理的区域水资源开发利用方案。本文依托于中国地调局项目“柴达木盆地循环经济试验区重点地区水文地质调查”专题《鱼卡河流域地下水与地表水转化关系及地下水可更新能力研究》，以鱼卡河流域中下游鱼卡-马海盆地为主要研究区，对研究区地下水来源、地表水-地下水的转化关系、地下水循环模式等方面展开展了系统的研究，从而为鱼卡河流域及周边地区制定合理的地下水开采利用方案提供依据。为研究鱼卡河流域地表水与地下水转化关系，本次研究中分别通过河水和周边地区水体TDS含量、δ18O值指示鱼卡河河水与地下水之间的沿程转化关系：在鱼卡河上游山区，主要表现为地下水转化为河水；中游鱼卡盆地，河水入渗补给地下水，而后地下水又溢出补给河水；在绿梁山峡谷段，地表水-地下水水力联系不密切，仅在局部地段地下水溢出。在下游马海盆地山前戈壁带，河水入渗补给地下水；在鱼卡河尾段马海河，地下水溢出补给河水。论文在分析鱼卡河流域天然水体的水化学和环境同位素时空分布变化特征的基础上，初步阐明了鱼卡河流域地下水的补给来源和区域水循环基本特征。研究表明，鱼卡河流域地下水补给源于高山区的鱼卡河及其支流嗷唠河，在地表水的径流和沿程的地表水-地下水转化的共同作用下，鱼卡河中下游鱼卡-马海盆地均得到相对稳定且丰富的水补给。鱼卡盆地地下水、马海盆地戈壁带潜水及细土带大部分承压水都基本保持了上游鱼卡河河水的水化学特点。在马海盆地细土平原带，则距离河流越远，潜水TDS含量受蒸发和溶滤增加越高，承压水TDS含量则在溶滤作用下缓慢升高，同时地下水14C活度、3H浓度逐渐降低，显示其年龄逐渐变老，更新交替逐渐变缓，地下水δ18O、δ2H值逐渐低于河水，显示古大气降水补给的特征。马海盆地是鱼卡河流域水资源的最终排泄区，在其细土平原带，地下水埋深变浅，以蒸发和泉的形式排泄。综合分析马海盆地北缘泉群的水化学、氢氧稳定同位素、温度、地下水年龄和断层的分布特征，推断了泉群的成因：马海盆地北缘各泉主要源于鱼卡河及其支流嗷唠河在马海盆地入渗补给，河水入渗补给形成地下水后向西径流过程中经NE向断层导水至NW向阻水断层处出露成泉，泉水年龄在1837~5228年之间，更新交替较慢。
[Abstract]:The contradiction between supply and demand is very prominent in the northwest inland area of China because of the drought climate and the relative shortage of water resources. The complexity of groundwater cycle, such as the origin and origin of groundwater, the transformation relationship between surface water and groundwater, the spatio-temporal variation of groundwater recharge, and the renewable capacity of groundwater, is determined by groundwater in arid basins. The study of the environmental model is helpful to understand the formation mechanism of regional water resources scientifically and to formulate a reasonable scheme for the development and utilization of regional water resources.
Based on the project of "Hydrogeology Survey of Key Regions in the Experimental Zone of Circular Economy in Qaidam Basin" of China Geological Survey Bureau, the relationship between groundwater and surface water transformation and renewable capacity of groundwater in Yuka River Basin are studied in this paper. The relationship between water and groundwater, groundwater circulation model and other aspects have been studied systematically, so as to provide a basis for formulating reasonable groundwater exploitation and utilization schemes in Yuka River Basin and its surrounding areas.
In order to study the relationship between surface water and groundwater transformation in Yuka River Basin, the TDS content and the delta 18O value of the river water and the surrounding area were used to indicate the relationship between the surface water and groundwater in Yuka River Basin. Groundwater, and then groundwater overflow recharge River water; in the Luliangshan Gorge, surface water-groundwater hydraulic connection is not close, only in local areas of groundwater overflow.
Based on the analysis of the temporal and spatial variations of Hydrochemistry and environmental isotopes in the natural waters of the Yuka River Basin, the source of groundwater recharge and the basic characteristics of regional water cycle in the Yuka River Basin are preliminarily clarified. Under the combined action of runoff and surface water-groundwater transformation, the Yuka-Mahai basin in the middle and lower reaches of the Yuka River is relatively stable and abundant in water recharge. In the fine soil plain zone, the farther away from the river, the higher the TDS content of phreatic water increased by evaporation and leaching, and the TDS content of confined water increased slowly under leaching. At the same time, the activity of 14C and the concentration of 3H of groundwater decreased gradually, indicating that the groundwater was getting older gradually, and the regeneration was slowing down gradually, and the values of delta 18O and delta 2H of groundwater were gradually lower than those of river water. The characteristics of recharge. The Mahai Basin is the final discharge area of water resources in the Yuka River Basin. In its fine soil plain zone, the groundwater is buried shallowly and discharged in the form of evaporation and springs.
Based on the analysis of hydrochemistry, stable isotopes of hydrogen and oxygen, temperature, age of groundwater and distribution characteristics of faults in the northern margin of the Mahai Basin, the genesis of the spring group is deduced as follows: the springs in the northern margin of the Mahai Basin mainly originate from the infiltration and recharge of the Yuka River and its tributary, the Suohe River, in the Mahai Basin, which flows westward after the formation of groundwater. From NE-trending fault to NW-trending water-resisting fault, springs emerge and become springs. The age of springs ranges from 1837 to 5228, and the replacement is slow.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P641.2

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