新疆水循环变化机理与水资源调蓄

发布时间：2018-12-18 18:39

【摘要】：干旱区水资源紧缺,研究气候变化与人类活动双重营力作用下水循环变化机理,制定合理有效的调蓄对策,是应对全球变化的重要任务。新疆作为全球极端干旱区之一,近期水循环发生了显著变化。作为中国最西端及中亚地区的水资源发源地,天山发挥了中亚水塔的作用,其周边干旱区广泛分布,人类生存与生态系统受水资源变化影响十分强烈。近十年来,笔者在天山山区及其周边的塔里木盆地、准噶尔盆地等地开展了大气-地表-地下的多尺度水循环研究。本文从降水形成条件、地表水变化、地下水对地表水变化的响应等不同视角对水循环进行系统分析,探讨在气候变化与人类活动影响下水循环发生变化的机理及其水资源效应。在此基础上,提出干旱区水资源的调蓄途径。研究表明,青藏高原和天山隆升在新疆产生雨影效应,新疆大气降水的水气来源以西风带水气为主,本地再循环水气在降水构成中仅占8%,区域造雨能力低下。双重因素长期作用导致新疆地区干旱化。天山山区与盆地相比,更有利于形成降水,加上冰雪储备丰厚,因此在区域水循环中占主导地位。在气候变化的影响下,气温升高、降水增加、冰川融化加速、主要河流出山径流平均增加约10%,对于气候变化敏感的一些冰川河,增加可达40%以上,造成洪水灾害。下游荒漠中的绿洲,基本上没有降水,水循环由地表水主导,河道断流导致地下水位下降,引发生态退化。塔里木河调水,在流域尺度上证明了这一点。天山山前地带的绿洲农业,是区域用水最多的环节,因而,也是调蓄水资源的有利位置。利用山前戈壁带有利的地质结构和快速循环的地下水,地下水库工程符合干旱区水循环基本规律,相对于平原水库具有明显优势。天山南北符合条件的储水构造很多,可调蓄水量可观。这一地表水地下水联合调蓄的模式,将成为干旱区应对环境变化带来的水资源问题的重要途径。
[Abstract]:Water resources are scarce in arid areas. It is an important task to study the mechanism of water cycle change under the dual effects of climate change and human activities and to formulate reasonable and effective regulation and storage countermeasures. As one of the extreme arid regions of the world, the water cycle in Xinjiang has changed significantly recently. As the source of water resources in the westernmost part of China and Central Asia, Tianshan plays a role as a water tower in Central Asia. The surrounding arid areas are widely distributed, and the human survival and ecosystem are strongly affected by the changes of water resources. In the past ten years, the authors have carried out a multi-scale study on the atmospheric, surface and underground water cycle in the Tarim Basin and Junggar Basin in the Tianshan Mountain area and its surrounding areas. In this paper, the formation conditions of precipitation, the change of surface water and the response of groundwater to the change of surface water are analyzed systematically, and the mechanism and effect of water resources on the influence of climate change and human activities on the water cycle are discussed. On this basis, the way of water resources regulation and storage in arid area is put forward. The results show that the uplift of Qinghai-Xizang Plateau and Tianshan Mountains produce rain shadow effect in Xinjiang. The water vapor in the west of the wind belt is the main source of the precipitation in Xinjiang, and the local recycled water gas accounts for only 8% of the precipitation composition, and the regional rain-making capacity is low. Double factors lead to drought in Xinjiang for a long time. Compared with the basin, Tianshan mountain area is more favorable to the formation of precipitation and rich ice and snow reserves, so it plays a dominant role in the regional water cycle. Under the influence of climate change, the temperature increases, the precipitation increases, the glacier melts speed up, the average runoff of main rivers increases about 10 percent, and some glaciers that are sensitive to climate change can increase by more than 40%, resulting in flood disaster. There is no precipitation in the oasis in the downstream desert, the water cycle is dominated by the surface water, and the river cut off leads to the decrease of the groundwater level and the ecological degradation. The Tarim River diversion proves this on a watershed scale. The oasis agriculture in the front of Tianshan Mountain is the most important link of regional water use, therefore, it is also a favorable position for regulating and storing water resources. With the favorable geological structure and rapid circulation of groundwater in the Gobi zone in front of the mountains, the underground reservoir engineering accords with the basic law of water circulation in arid area, and has obvious advantages over the plain reservoir. The north and south of Tianshan have a lot of water storage structures and considerable water storage. This model of combined regulation of surface water and groundwater will be an important way to deal with the problem of water resources caused by environmental change in arid areas.
【作者单位】：中国科学院地质与地球物理研究所页岩气与地质工程重点实验室;
【基金】：国家自然科学基金项目(批准号:40672171) 中国科学院知识创新工程重要方向性项目(批准号:KZCX2-YW-127) 国际原子能机构(IAEA)“亚太地区的地下水补给与动力学”项目(批准号:RAS7022)共同资助
【分类号】：P339;TV213

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