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1.
Groundwater in China’s permafrost region is vital for humans and cold-climate ecosystems. Permafrost responses to global warming have significantly changed the spatio-temporal patterns and distribution of properties associated with the groundwater system. The main areas of current and past studies on permafrost hydrogeology in China include four aspects: groundwater distribution and dynamics in permafrost regions, interplay between groundwater and permafrost, the impact of permafrost degradation on groundwater, and the regional effect of groundwater changes on the environment in permafrost regions. Over the last 10 years, the development and use of coupled heat-transport and groundwater models have focused on the hydrogeology of permafrost, and on groundwater development and distribution in permafrost regions. Progress in groundwater-related research on issues surrounding permafrost regions of China are comprehensively summarized and discussed in this review paper, which should provide a theoretical basis for further study of the groundwater system and its effects on the ecological environment under climate change. 相似文献
2.
青藏高原的高海拔多年冻土的分布格局及其动态变化、季节冻结融化作用与地下水的补给、径流和排泄关系密切,对各种尺度的水文地质环境具有控制或重要影响。作为一个隔水层或弱透水层,冻土层在地下水形成、演化、运移和水动力过程方面具有抑制作用,从而对地下水的分布、动态和水循环产生重要影响。而且,冻土可通过其中的水分迁移、冰分凝和地下冰结构重组等方式,形成和改变地下冰储量及地下水动静储量,调节水文地质循环。气候变暖显著和人类活动日益增加,冻土退化显著,已经普遍影响到了高原冻土生态水文地质环境,并引发了一系列水文（地质）、生态和环境问题,亟待系统、长期和细致的观测、试验和模型研究。 相似文献
3.
中国冻土地下水研究现状与进展综述 总被引：6，自引：5，他引：1
冻土地下水系统不仅在寒区水文循环中扮演着重要的角色,同时也在寒区水文过程和地表过程及其科学研究中起到了集蓄、融冻和泄流等至关重要的作用。近几十年随着全球气候变暖及人类活动（寒区工程量）的增加,冻土退化趋势显著,这一过程改变了寒区的水文地质条件,导致地下水动态特征发生显著变化,从而引起一系列的生态环境变化。近些年,诸多学者通过构建水热耦合模型来研究冻土地下水的运动机理、分布状况和季节动态,促进了寒区地下水理论知识的发展,推动了寒区水文地质知识体系的进步。本文主要针对目前我国多年冻土区地下水的研究现状进行了分析、整理、归纳,为进一步研究气候变化下地下水系统的发展与演变,以及对生态环境的影响提供参考依据。 相似文献
4.
Gao Shuhui Jin Huijun Wu Qingbai Bense Victor F. Luo Dongliang Wang Qingfeng Yang Yuzhong Chang Wenwen 《Hydrogeology Journal》2023,31(3):789-811
Warming climate and thawing permafrost have profound impacts on groundwater flow regimes in cold regions because of the shrinkage or disappearance of the confining unit formed by the permafrost layers and improving hydraulic connections. Numerical simulations of coupled groundwater flow and heat transfer are often used to characterize the changing permafrost hydrogeology. In this study, a number of scenarios for different hydraulic gradients and lake-water depths have been used to simulate the concordant permafrost evolution and groundwater movement using a two-dimensional cylindrical coordinate model at time scales of decades to centuries in response to a warming climate. The model is applied to a representative headwater catchment in the south-central headwater area of the Yellow River on the northeastern Qinghai-Tibet Plateau, China. The results show that the presence and movement of groundwater and the deeper subpermafrost aquifer can substantially accelerate permafrost degradation, and the disappearance of residual permafrost at depth can result in the sudden establishment of deep groundwater flow paths. All hydrological impacts will become evident after the stabilization of the hydrothermal and flow fields at 100–200 years. The stable discharge rate of groundwater flow varies from 8.0 to 12.4 m3 s−1, and the stable velocity of groundwater flow varies from 1.6 × 10−7 to 4.4 × 10−7 m s−1 under different scenarios within the model domain. The modeling results also demonstrate that flow velocity and discharge rate in local groundwater flow systems can be enhanced by an increased hydraulic conductivity, leading to an accelerated degradation of isolated permafrost bodies.
相似文献5.
Permafrost thaw in a nested groundwater-flow system 总被引：3，自引：2，他引：1
Groundwater flow in cold regions containing permafrost accelerates climate-warming-driven thaw and changes thaw patterns. Simulation analyses of groundwater flow and heat transport with freeze/thaw in typical cold-regions terrain with nested flow indicate that early thaw rate is particularly enhanced by flow, the time when adverse environmental impacts of climate-warming-induced permafrost loss may be severest. For the slowest climate-warming rate predicted by the Intergovernmental Panel on Climate Change (IPCC), once significant groundwater flow begins, thick permafrost layers can vanish in several hundred years, but survive over 1,000 years where flow is minimal. Large-scale thaw depends mostly on the balance of heat advection and conduction in the supra-permafrost zone. Surface-water bodies underlain by open taliks allow slow sub-permafrost flow, with lesser influence on regional thaw. Advection dominance over conduction depends on permeability and topography. Groundwater flow around permafrost and flow through permafrost impact thaw differently; the latter enhances early thaw rate. Air-temperature seasonality also increases early thaw. Hydrogeologic heterogeneity and topography strongly affect thaw rates/patterns. Permafrost controls the groundwater/surface-water-geomorphology system; hence, prediction and mitigation of impacts of thaw on ecology, chemical exports and infrastructure require improved hydrogeology/permafrost characterization and understanding. 相似文献
6.
东北多年冻土退化及环境效应研究现状与展望 总被引：6，自引：3，他引：3
东北多年冻土属中高纬度多年冻土,对气候变化非常敏感。数据模型模拟表明,21世纪东北多年冻土区气温会持续上升,显著的变暖将导致多年冻土退化。东北多年冻土呈现自南向北的区域性退化趋势,多年冻土区南部表现为南界的北移、融区的扩大和多年冻土的消失,而北部表现为多年冻土下限的上移、活动层厚度增大及地温升高等。多年冻土的退化会导致寒区生态环境的恶化,如兴安落叶松占绝对优势的天然林带锐减,林带北移,沼泽湿地萎缩等。随着多年冻土的迅速退缩和变薄,原多年冻土中蕴藏的碳将释放出来,对气候变化产生积极的正反馈,加速变暖,并影响全球碳循环。多年冻土退化导致其热状态失稳而造成寒区基础设施损坏,并且影响冻土微生物、碳循环、寒区生态和水文等,而它们是区域气候变化的重要因子,也将成为未来多年冻土研究的重点。而这些研究都需要长期的基础数据作支撑,因此需要进一步完善冻土参数监测网络,用模型厘清气候变化与多年冻土退化及其环境效应之间的关系。 相似文献
7.
东北北部多年冻土的退化现状及原因分析 总被引：9，自引：4，他引：5
在全球范围内,我国东北冻土区是受气候变暖和人为活动影响最显著的地区之一.近几十年来,区内冻土退化显著,大兴安岭多年冻土退化主要表现为多年冻土上限下降,温度升高,厚度减薄,融区扩大;多年冻土岛消失及多年冻土南界北移等几个方面.多年冻土退化的主要自然原因归结于气候变暖,特别是冬季变暖,降水和积雪时段和厚度等气候变化因素.以城镇化、重大工程建设为代表的人类活动,已对该区冻土和环境产生深刻影响,导致了多年冻土的快速、显著和大规模退化,但其影响机制的合理解释还需深入研究. 相似文献
8.
9.
Impacts of climate, lake size, and supra- and sub-permafrost groundwater flow on lake-talik evolution, Yukon Flats, Alaska (USA) 总被引：3，自引：2，他引：1
In cold regions, hydrologic systems possess seasonal and perennial ice-free zones (taliks) within areas of permafrost that control and are enhanced by groundwater flow. Simulation of talik development that follows lake formation in watersheds modeled after those in the Yukon Flats of interior Alaska (USA) provides insight on the coupled interaction between groundwater flow and ice distribution. The SUTRA groundwater simulator with freeze–thaw physics is used to examine the effect of climate, lake size, and lake–groundwater relations on talik formation. Considering a range of these factors, simulated times for a through-going sub-lake talik to form through 90 m of permafrost range from ～200 to >?1,000 years (vertical thaw rates <?0.1–0.5 m?yr?1). Seasonal temperature cycles along lake margins impact supra-permafrost flow and late-stage cryologic processes. Warmer climate accelerates complete permafrost thaw and enhances seasonal flow within the supra-permafrost layer. Prior to open talik formation, sub-lake permafrost thaw is dominated by heat conduction. When hydraulic conditions induce upward or downward flow between the lake and sub-permafrost aquifer, thaw rates are greatly increased. The complexity of ground-ice and water-flow interplay, together with anticipated warming in the arctic, underscores the utility of coupled groundwater-energy transport models in evaluating hydrologic systems impacted by permafrost. 相似文献
10.
我国杰出的寒区水文学家叶柏生研究员不幸因公殉职. 选取了叶柏生研究员若干代表性研究成果, 包括与他人的合作研究成果, 重点从冰川水文、 冻土水文和区域水文变化三方面总结了其对寒区水文学发展所做的创新与贡献. 文章列出了每项研究成果的核心内容, 并给予了简要评述. 所选成果中, 冰川水文方面研究涉及冰川对河川径流的调节作用、 冰川径流对气候变化的响应机理等; 冻土水文研究着重介绍了多年冻土变化对流域径流过程及其变化影响方面的系统性成果; 区域水文变化研究方面, 选取了降水观测误差修正、 气候变化对区域径流的影响等方面的创新成果. 这些研究成果极大地提高了我国在世界寒区水文学研究的地位, 对认识寒区水文过程及气候变化对水资源的影响具有重要科学意义. 相似文献
11.
Response of the groundwater system in the Guanzhong Basin (central China) to climate change and human activities 总被引：1，自引：0，他引：1
Wenke Wang Zaiyong Zhang Lei Duan Zhoufeng Wang Yaqian Zhao Qian Zhang Meiling Dai Huizhong Liu Xiaoyan Zheng Yibo Sun 《Hydrogeology Journal》2018,26(5):1429-1441
The Guanzhong Basin in central China features a booming economy and has suffered severe drought, resulting in serious groundwater depletion in the last 30 years. As a major water resource, groundwater plays a significant role in water supply. The combined impact of climate change and intensive human activities has caused a substantial decline in groundwater recharge and groundwater levels, as well as degradation of groundwater quality and associated changes in the ecosystems. Based on observational data, an integrated approach was used to assess the impact of climate change and human activities on the groundwater system and the base flow of the river basin. Methods included: river runoff records and a multivariate statistical analysis of data including historical groundwater levels and climate; hydro-chemical investigation and trend analysis of the historical hydro-chemical data; wavelet analysis of climate data; and the base flow index. The analyses indicate a clear warming trend and a decreasing trend in rainfall since the 1960s, in addition to increased human activities since the 1970s. The reduction of groundwater recharge in the past 30 years has led to a continuous depletion of groundwater levels, complex changes of the hydro-chemical environment, localized salinization, and a strong decline of the base flow to the river. It is expected that the results will contribute to a more comprehensive management plan for groundwater and the related eco-environment in the face of growing pressures from intensive human activities superimposed on climate change in this region. 相似文献
12.
Thermokarst lake is the most visible morphologic landscape developing during the process of permafrost degradation, and it is still an international hot topic in permafrost research. The climate warming, and the consequent degradation of the permafrost on the Qinghai-Tibet Plateau aggravate thermokarst lake development. The permafrost is normally considered as an aquiclude, and the permafrost degradation, especially when the permafrost is completely thawed by a thermokarst lake, might influence regional ground water. Therefore, a research program focusing on environmental and hydrological effects of thermokarst lakes in permafrost regions of the Qinghai-Tibet Plateau was started and supported by the National Natural Science Foundation of China. The work proposed by the application includes: To analysis the spatial and temporal distribution rule of thermokarst lakes in the Qinghai-Tibet Engineering Corridor (QTEC) under the climate change and engineering activities, and to evaluate the ecological environment effects through remote sensing and field investigation; to reveal the main factors influencing a typical thermokarst lake and its hydrothermal condition, and to elucidate the conversion relationship between the thermokarst lake and the groundwater with hydrological and isotope tracer tests; to make an analysis of the influences of different lake stage and size on regional permafrost, hydrological conditions and ecological environment through numerical simulation and statistical modelling, considering the relationships between the thermokarst lake and the ground water level. The research results will help to accurately assess regional permafrost ecological environment evolution and trend prediction, and to reasonably understand the impact factors of the permafrost hydrological evolution and its response mechanism to the ecological environment in the river source regions of the Qinghai-Tibet Plateau. In this paper, the research status analysis, the main research contents, research objectives and prospects were introduced so as to provide some references for related researchers and engineers. 相似文献
13.
Seawater intrusion has been an important topic in hydrogeology in China in recent decades. The rapid growth of the population and economy in the coastal regions has been consuming a tremendous amount of groundwater resources and has increased the extent of seawater intrusion. The spatial discrepancy of water resource distribution has caused the studies of seawater intrusion into China to mainly be concentrated on the area around the Bohai Sea in the northern part of China. The total area of seawater-intruded land due to excessive groundwater utilization in the area was estimated to be approximately 2,457 km2 in 2003. Great efforts have been made to mitigate the extent of seawater intrusion and to secure more freshwater resources, including building monitoring networks, subsurface barrier and groundwater reservoirs, and artificial infiltration facilities. Management projects over the years were evaluated to satisfy the objectives and to provide valuable experiences for future research and planning. It is expected that the coastal groundwater conditions of the northern region will improve through the development of a national water resource plan, such as the ongoing south-to-north water diversion project. 相似文献
14.
多年冻土区斜坡稳定性研究综述 总被引：1，自引：0，他引：1
全球变暖、极端天气频发,引发的地质灾害对自然生态环境和人类生产生活造成了很大的影响。尤其对气候变化较为敏感的高温（年平均地温>-1 °C）和高含冰量多年冻土区,气候变暖以及人类活动导致的冻融地质灾害日益频繁。冻土退化条件下,土体结构和物理力学性质发生改变,黏聚力和抗剪强度降低,造成多年冻土区斜坡发生滑坡、崩塌、泥流等灾害。斜坡失稳加剧了多年冻土区脆弱生态环境的恶化,同时对建（构）筑物安全运营产生威胁。与非冻土区相比,多年冻土区斜坡稳定性研究主要针对高含冰量斜坡段,斜坡失稳模式主要以热融滑塌和活动层滑脱为主。热融滑塌由斜坡段地下冰暴露融化引起,而活动层滑脱产生的原因是冻土融化导致土体孔隙水压力过大,形成的超孔隙水压力降低了土体强度,造成斜坡失稳。此外,多年冻土区斜坡失稳模式还包括融冻泥流、崩塌以及蠕变滑坡等。通过综述近期多年冻土区斜坡稳定性研究进展,概括了多年冻土区斜坡失稳的模式、特征、影响因素、失稳机理、分析方法及防治措施等,并对未来多年冻土区斜坡失稳的研究重点提出建议。 相似文献
15.
长江源区高寒生态与气候变化对河流径流过程的影响分析 总被引：24，自引：5，他引：19
近40 a来长江源区气候变化剧烈,是青藏高原增温最为显著的地区之一,高寒生态系统与冻土环境不断退化.采用多因素逐次甄别方法与半经验理论方法相结合,基于多年冻土的不同植被覆盖降水-径流观测场观测试验结果,分析了长江源区气候-植被-冻土耦合系统中各要素变化对河川径流的不同影响.结果表明:近40 a来长江源区河川径流呈持续递减趋势,年均径流量减少了15.2%,频率>20%的径流量均显著减少,而>550 m3·s-1的稀遇洪水流量发生频率增加;气候变化与高寒草甸覆盖变化对源区径流变化的影响较大,分别占5.8%和5.5%;气候与植被覆盖变化对径流的显著影响是与冻土耦合作用的结果,但冻土环境与冰川变化对径流的贡献尚不能准确评价.高寒沼泽湿地和高寒草甸生态系统对于源区河川径流的形成与稳定起到关键作用,这两类生态系统的显著退化是驱动河川径流过程中变差增大、降水-径流系数减少以及洪水频率增加的主要原因.保护源区高寒草甸与独特的高寒湿地生态,对于维护源区水涵养功能和流域水安全意义重大. 相似文献
16.
东北北部冻土退化与寒区生态环境变化 总被引：12，自引：8，他引：4
我国东北地区位于中高纬度欧亚大陆东缘,大、小兴安岭多年冻土区是欧亚大陆高纬冻土区向南最突出的部位,属于高纬山地冻土.东北多年冻土区是我国,乃至全球范围内,受气候变暖和人为活动影响最显著的冻土区之一.过去40 a来该区冻土显著退化,主要表现在:1)冻土南界及不连续多年冻土各分区边界北移而导致总面积减小、空间分布破碎化;2)活动层加深,融区扩大,局地冻土岛消失;3)冻土温度升高、厚度减薄、热稳定性降低等.由于各种因素的共同影响,寒区生态环境也发生了一系列变化.这具体表现为以兴安落叶松占绝对优势的天然林带锐减,整个北方森林带北移,沼泽湿地面积减小等,寒区生态系统和环境已出现恶性循环.关注、研究、整治和管护寒区环境对区域社会、经济和生态可持续发展不可或缺. 相似文献
17.
利用海拉尔河流域内气象站点1974—2006年冻土冻结深度资料和水文站点1974—2008年的径流资料,通过建立冻结深度和径流的关系,研究了区域近30年来冻土变化对径流变化的影响。结果表明:近30年来,海拉尔、坝后和红花尔基水文站1~3月份径流量有13%~20%的增长,牙克石水文站径流量增长不显著。退水曲线由陡峭趋于平滑,冬季2月份径流量与秋季11月份径流量比值呈增大趋势,同期流域冻土的最大冻结深度减小了50 cm左右。这表明海拉尔河流域冬季退水过程有减缓趋势且冻土的退化是导致退水变慢的主要原因。冻土退化的这一水文效应主要是由于:① 随着冻土年内隔水效应减弱,流域内有更多的地表水入渗变成地下水,造成流域地下水储水量加大,导致冬季径流增加; ② 随着春夏季冻土平均厚度的减薄,流域地下水库库容增加,地下水枯季径流补给能力增强,导致流域退水时间延迟;③ 冻土对气候变暖的响应是一个缓慢的过程,因此冻土退化对径流过程的影响也是一个渐变过程。 相似文献
18.
不同下垫面对多年冻土浅层热状况的影响分析 总被引：1，自引：1，他引：0
近年来在气候变化和人类活动影响下, 青藏高原地表状况发生了大规模的改变, 并引发了多年冻土的退化, 给寒区环境与工程产生一系列不良影响. 而多年冻土作为地气系统相互作用的产物, 其变化主要取决于地气系统能量交换的方向. 应用青藏高原实地观测资料, 对不同地表状况下多年冻土浅层热状况进行了分析. 结果表明: 下垫面的改变对多年冻土区能量平衡状况产生明显影响. 在天然状态下地表能量收支基本保持平衡, 冻土变化也比较缓慢;而在下垫面改变特别是天然地表遭破坏后, 原有的能量平衡发生改变, 从而引起多年冻土的变化. 覆盖度较高的植被暖季能够阻止部分热量进入土层, 降低地表温度;而在冷季则能减少土层热量散发, 有助于保持地表温度. 植被的存在有利于保持多年冻土的稳定. 黑色薄膜覆盖能够增加地表吸收的太阳辐射, 并减少地表蒸发耗热, 造成地表吸热量大于放热量. 透明薄膜的"温室效应"可以有效地防止地表长波辐射的散发, 减少表层土壤热量的消耗, 从而引起地表温度的显著升高. 相似文献
19.
青藏高原作为“亚洲水塔”对气候变化极为敏感,研究气候变化下青藏高原多年冻土退化对蒸散发的影响有助于理解多年冻土地区水文过程对气候变化的响应情况。基于Budyko-Fu假设,构建了考虑多年冻土活动层厚度变化的水热耦合模型,建立了符合青藏高原多年冻土区的模型参数化方案,通过设置情景假设探讨了多年冻土退化对蒸散发的影响。模拟结果表明:1982—2018年青藏高原多年冻土区平均年蒸散发为275.6 mm,空间分布由东南向西北递减;研究区年蒸散发整体上以3.57 mm/a的速率上升。多年冻土活动层加深会引起蒸散发的增大,忽略冻土退化因素将导致约2.2%的蒸散发低估。冻土退化对蒸散发的影响呈现显著的空间异质性,土壤有效含水量和植被覆盖度越低的地区,蒸散发对冻土退化的响应越敏感。 相似文献
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Ronald C. Flemal 《Quaternary Research》1976,6(1):37-53
Pingos are large frost mounds which develop in permafrost as the result of the segregation of massive ground-ice lenses. At least two genetic varieties of pingos, open- and closed-systems, form under differing conditions of climate, topography, and groundwater occurrence. Active pingos are known to occur in many high latitude regions. Pingo scars are the degeneration products of pingos. Ideally they are ramparted, circular depressions, although they may be expressed in a variety of divergent forms due to differing conditions of topography, substrate materials, degree of thermokarst overprint, and erosional/depositional histories. Pingo scars occur in many modern permafrost regions. Presumed pingo scars have also been identified in many regions beyond the present permafrost limit and therefore may have utility in reconstructing former permafrost environments. 相似文献