Hydrochemical and hydrological processes in the different landscape zones of alpine cold region in China

Investigation of water sources and flow pathways is crucial to understand and evaluate the characteristics of surface water and groundwater systems. This article aims to identify the hydrochemical and hydrological processes in different landscape zones based on hydrochemical analyses of various samples, including samples from glacier, snow, frozen soil meltwater, surface water, groundwater, and precipitation, in the alpine cold region of China. Hydrochemical tracers indicated that chemical compositions are characterized by the Ca-HCO₃ type in the glacier-snow zone; the Mg-Ca-SO₄ type in the alpine cold desert zone; the Ca-HCO₃-SO₄ type in the marsh meadow zone; the Ca-Mg-HCO₃ type in the alpine shrub zone; and the Ca-Na-SO₄ type in the mountain grassland zone. An end-member mixing model was used for hydrograph separation. The results showed that the Mafengou River in the wet season was recharged by groundwater in the alpine cold desert and alpine shrub zones (67%), surface runoff in the glacier-snow zone (11%), surface runoff in the alpine cold desert zone (8%), thawed water from frozen soil in the marsh meadow and mountain grassland zones (9%), and direct precipitation on the river channel (5%). This study suggests that precipitation from the whole catchment yielded little direct surface runoff; precipitation was mostly transformed into groundwater or interflow and was then concentrated into the river channel. This study provides a scientific basis for evaluation and management of water resources in the basin.     

近期新疆哈密代表性冰川变化及对水资源影响

新疆哈密是资源性缺水地区,冰川是该区主要的供给水源。为了对该区冰川和水文水资源的现状和未来变化做出合理评价和预估,以榆树沟6号冰川和庙尔沟冰帽为代表,结合野外实测资料以及近年来在冰川变化领域所取得的相关研究成果,综合分析了在气候变暖背景下新疆哈密地区冰川近年来的变化过程及对水资源的影响。结果表明,1972-2011年,榆树沟6号冰川厚度平均减薄20 m,减薄速率约为0.51 m/a,冰川末端退缩254 m,年均退缩约6.5 m。由于强烈消融,冰川表面径流发育明显,且在末端有冰碛湖形成。相比之下,庙尔沟冰帽消融速率相对较小,对气候变暖的敏感度较低,这与冰帽类型和所处海拔较高有直接关系。综合分析发现,流域有无冰川覆盖及覆盖的比率大小,直接造成哈密地区不同流域近期河川径流变化的差异。     

中国冰冻圈水文未来变化及其对干旱区水安全的影响

受气候变暖持续影响, 中国冰冻圈水文过程正在发生着显著变化。在梳理已有过去冰冻圈融水变化基础上, 重点分析了冰冻圈融水径流未来变化特点, 尤其是对冰川融水拐点及温升2 ℃阈值情况下, 到2050年和21世纪末, 冰川融水的可能变化进行了辨析, 进而研判了冰冻圈水文变化对流域、 重点是干旱区内陆河流域水安全的影响。研究表明, 中国未来大部分流域冰川融水径流总体呈现减少趋势, 并呈现冰川径流持续减少、 在不久的将来出现峰值和持续增加三种情况; 单条冰川融水可能会出现拐点, 而且拐点是否出现和出现的时间与升温速率和冰川面积大小有关; 在流域尺度上, 冰川覆盖率较大、 大型冰川面积占比较高的流域, 到2050年融水径流持续稳定增加; 冰川规模较小的流域, 冰川径流峰值早已出现; 介于上述两种情况之间的大多数流域, 冰川融水峰值在2020 - 2030年相继出现或变化呈现不显著增加或减少, 相对稳定; RCP情景温升2 ℃阈值下, 到21世纪末, 西北干旱区冰川融水量减少34% ~ 74%。冰冻圈水文变化导致水源涵养能力下降、 径流补给量减少、 对水资源的调节作用减弱、 流域径流变化幅度增加、 发生旱涝的风险增加、 春汛提前进而影响用水制度。     

The origin of groundwater in Zhangye Basin,northwestern China,using isotopic signature

Zhangye Basin, in arid northwestern China, has recently been repeatedly flooded by rising groundwater. Isotope signatures of sampled waters gained insight into the recharge source of the groundwater. The summer Heihe River water and most of the spring water in Zhangye and Yongchang basins plotted above the global meteoric water line (GMWL) on the δ¹⁸O-δD plot. The spring water had R/Ra ratio >1, low TDS and high tritium, which indicates origin from Qilian Mountain glacier meltwater. The groundwater of Qilian Mountains was transported to the Hexi Corridor (in which Zhangye Basin is located) through underground fault zones. Additionally, some of the groundwater in the alluvial plain, and all spring water surrounding Zhangye Basin, plotted below the GMWL on the δ¹⁸O-δD plot along an evaporation line, and had R/Ra ratio?<?1 and high TDS. It is proposed that the Tibetan rivers or lakes source the Hexi Corridor groundwater through either the NE-trending or NW-trending buried fault zones. The isotopic signatures presented as part of this study rule out the conventional viewpoint that groundwater of the Zhangye Basin was recharged by local precipitation and infiltration of Heihe River water on the alluvial plain.     

Implication of drainage basin parameters of Chhoti Gandak River,Ganga Plain,India

The drainage basin parameters of the groundwater-fed Chhoti Gandak River originating in the terai area of the Ganga Plain were analyzed using topographical sheets, satellite data, and field documentation with emphasis to its implication for flood mitigation and recharging of groundwater. The analyses indicate dominance of first order streams, gentle slope gradient, low surface run-off, low sediment production, high infiltration rate, and low value of basin relief. The low water storage capacity, spreading of water and concentration of peak discharge in the distal part of the river basin explain that whenever precipitation is high in the catchment area there is flood in the distal part of the basin. The bifurcation ratio value (4.34) of this basin describes that the drainage is carved naturally by slope and local relief and not influenced by geological structures like lineaments and faults.     

塔里木河流域水文特性分析

塔里木河是我国最大的内陆河,历史上是九大水系144条河流的总称.由于气候变化和人类活动影响生态环境急剧恶化,目前形成了"四源一干"的格局.根据水文气象监测资料,从50 a来流域内的降水、蒸发、径流、洪水、泥沙、水质等方面对塔里木河流域生态环境恶化的成因进行分析.     

Relationship Between Surface Water and Groundwater in the Liujiang Basin—Hydrochemical Constrains

The interaction between surface water and groundwater is not only an important part of the water cycle, but also the foundation of the study on regional water resources quantity. The field hydrogeological investigation and sampling in the Liujiang basin were conducted in the dry season, in April, 2015. The isotopic ratios of hydrogen and oxygen and ion compositions as well as the hydrogeochemical characteristics indicated that the groundwater in the basin was mainly HCO₃-Ca and HCO₃-Ca·Mg type low salinity water. The groundwater of each region had a unified connection, experiencing the same or similar hydrochemical formation, and the surface water had the same hydrochemical type and source of hydrochemical composition as groundwater. The hydrogen and oxygen isotopic compositions of surface water and groundwater were close to each other, which were mainly from the atmospheric precipitation. In the runoff process, the river water was affected by the evaporation concentration so that the heavy isotopes were slightly enriched. Under the influence of topographical, geological and hydrogeological conditions, the interaction between groundwater and surface water in the basin had obvious segmentation and mutual transformation. The river was recharged by both sides of groundwater in upstream region of Dashi River and Donggong River basin while river water supplied groundwater on both sides of it in downstream region of Dashi River.     

黑河流域水资源转化特征及其变化规律

黑河流域水资源主要以冰雪水资源、 地表水资源与地下水资源的形式存在.上游祁连山区分布有现代冰川428条, 发育大小河流共计29条, 多年平均出山径流量37.83×10⁸m³·a^-1; 中下游走廊平原由松散沉积的第四系盆地组成, 接受出山河水及引灌河水的入渗补给, 是地表水资源的重复表现形式, 地下水补给量为25.637×10⁸m³·a^-1.受构造-地貌条件的制约, 自南部山区至北部盆地, 地下水与河水之间经过5个不同地带有规律的、 大数量的、 重复的转化过程, 形成完整统一的"山区地下水-出山地表水-中游盆地地下水-中游盆地地表水(泉水)-下游盆地地下水"水资源循环转化系统.     

Response of glacier area variation to climate change in the Kaidu-Kongque river basin,Southern Tianshan Mountains during the last 20 years

Glaciers are crucial water resources for arid inland rivers in Northwest China. In recent decades, glaciers are largely experiencing shrinkage under the climate-warming scenario, thereby exerting tremendous influences on regional water resources. The primary role of understudying watershed scale glacier changes under changing climatic conditions is to ensure sustainable utilization of regional water resources, to prevent and mitigate glacier-related disasters. This study maps the current (2020) distribution of glacier boundaries across the Kaidu-Kongque river basin, south slope of Tianshan Mountains, and monitors the spatial evolution of glaciers over five time periods from 2000–2020 through thresholded band ratios approach, using 25 Landsat images at 30 m resolution. In addition, this study attempts to understand the role of climate characteristics for variable response of glacier area. The results show that the total area of glaciers was 398.21 km² in 2020. The glaciers retreated by about 1.17 km²/a (0.26%/a) from 2000 to 2020. The glaciers were reducing at a significantly rapid rate between 2000 and 2005, a slow rate from 2005 to 2015, and an accelerated rate during 2015–2020. The meteorological data shows slight increasing trends of mean annual temperature (0.02°C/a) and annual precipitation (2.07 mm/a). The correlation analysis demonstrates that the role of temperature presents more significant correlation with glacier recession than precipitation. There is a temporal hysteresis in the response of glacier change to climate change. Increasing trend of temperature in summer proves to be the driving force behind the Kaidu-Kongque basin glacier recession during the recent 20 years.© 2021 China Geology Editorial Office.     

1961—2006年叶尔羌河上游流域冰川融水变化及其对径流的影响

叶尔羌河是塔里木河的主源之一,发源于喀喇昆仑山北坡,冰川融水是其主要补给.以叶尔羌河流域库鲁克栏杆水文站以上流域国家气象台站的月降水与月气温资料、90 m分辨率的数字高程模型(DEM)以及1970年代的冰川分布矢量数据为基础,利用冰川度日因子融水径流模型重建了叶尔羌河上游流域平均冰川物质平衡、冰川融水径流序列,分析了叶尔羌河上游流域冰川融水径流变化的特征、趋势及其对河流径流的影响.结果表明:1961—2006年流域冰川平均年物质平衡为-163.1 mm,累积物质平衡为-7.5 m,平衡线平均海拔为5 395.7 m.1991年之后流域冰川物质平衡呈显著负平衡,平均年物质平衡为-301.2 mm,1991—2006年与1961—1990年相比平衡线平均高度上升了64.2 m.1961—2006年流域年平均冰川融水径流深为807.7 mm,冰川融水对河流径流的补给比重为51.3%;2000年之后冰川融水对河流径流的补给比重增大到63.3%,与多年平均值相比冰川融水对河流径流的贡献在2000年后明显增大.     

Unraveling the mechanisms underlying lake expansion from 2001 to 2020 and its impact on the ecological environment in a typical alpine basin on the Tibetan Plateau

Yanhu Lake basin (YHB) is a typical alpine lake on the northeastern Tibetan Plateau (TP). Its continuous expansion in recent years poses serious threats to downstream major projects. As a result, studies of the mechanisms underlying lake expansion are urgently needed. The elasticity method within the Budyko framework was used to calculate the water balance in the Yanhu Lake basin (YHB) and the neighboring Tuotuo River basin (TRB). Results show intensification of hydrological cycles and positive trends in the lake area, river runoff, precipitation, and potential evapotranspiration. Lake expansion was significant between 2001 and 2020 and accelerated between 2015 and 2020. Precipitation increase was the key factor underlying the hydrological changes, followed by glacier meltwater and groundwater. The overflow of Yanhu Lake was inevitable because it was connected to three other lakes and the water balance of all four lakes was positive. The high salinity lake water diverted downstream will greatly impact the water quality of the source area of the Yangtze River and the stability of the permafrost base of the traffic corridor.©2023 China Geology Editorial Office.     

1990年以来天山乌鲁木齐河上游水资源研究进展

乌鲁木齐河是我国西北地区典型的降水、冰川和地下水综合补给的内陆河,对其水资源的研究不仅是西北寒区旱区水环境和水资源研究的热点,而且对区域生态环境改善和经济可持续发展具有重要意义。乌鲁木齐河水文水资源的研究内容十分广泛,并取得了很多高水平的学术成果。从高山区气候变化与冰冻圈的相互影响,山区降水变化与径流的相互影响,出山口径流对气候变化的响应以及洪灾、致灾因子分析,流域内同位素、树轮气候和水环境研究等四个方面总结了相关研究。结果表明：（1）乌鲁木齐河上游气候趋于暖湿。气温的升高很大程度上受冬季气温大幅度升高影响,气温对高山区冰川积雪的影响要大于降水;冬季负积温也加快了冻土的消融;气温和降水的变化导致乌鲁木齐河上游河段冰川后退加速,积雪融化、雪线上升,冻土活动层增厚。（2）乌鲁木齐河流域降水量和降水变化速率具有明显的垂直特征,在中高山地区降水量和降水变率较大;山区降水还具有年代际特征,20世纪90年代以来,山区降水量呈现增加趋势并促进了山区径流量的增加。（3）降水量和冰川融雪量的增加,很大程度上加大了乌鲁木齐河流域山区的径流量,使得出山口区域洪水灾害的发生频率增加。（4）同位素分析的运用对探索径流形成和转化的机理具有重要意义。树轮研究为乌鲁木齐河流域气候变化序列的重建提供了技术手段。今后,乌鲁木齐河水资源承载力、水循环过程和水污染问题,是区域实现生态环境建设和可持续发展的重要研究内容。     

新疆山地冰川变化及影响研究进展

揭示新疆山地冰川变化及其影响,对新疆山地-绿洲-荒漠系统的健康和稳定发展意义重大。系统梳理新疆冰川物理变化、化学过程、生物资源、气候响应与生态效应等研究成果。结果表明:①新疆山地冰川总体上呈加速消融之势,且受地形、气候影响,冰川变化的区域性差异明显;②气溶胶解释了乌鲁木齐河源1号冰川表层物质的组成与来源,同位素定量了各流域径流中冰川融水的比例;③冰川变化对极端微生物生存条件、空间分布的影响研究较为成熟,但其与生物资源间的综合反馈机理尚不明晰;④冰川消融对水资源的影响随冰川融水拐点的到来而加剧,造成的生态服务缩减和冰雪产业损失日益凸显。制定统一的冰川提取标准、扩宽研究视角、全面系统观测冰川、提高模拟预测精度、加强灾害预警与制定对策是未来新疆山地冰川研究的关注点。     

新疆山地冰川变化及影响研究进展

揭示新疆山地冰川变化及其影响,对新疆山地-绿洲-荒漠系统的健康和稳定发展意义重大。系统梳理新疆冰川物理变化、化学过程、生物资源、气候响应与生态效应等研究成果。结果表明：①新疆山地冰川总体上呈加速消融之势,且受地形、气候影响,冰川变化的区域性差异明显;②气溶胶解释了乌鲁木齐河源1号冰川表层物质的组成与来源,同位素定量了各流域径流中冰川融水的比例;③冰川变化对极端微生物生存条件、空间分布的影响研究较为成熟,但其与生物资源间的综合反馈机理尚不明晰;④冰川消融对水资源的影响随冰川融水拐点的到来而加剧,造成的生态服务缩减和冰雪产业损失日益凸显。制定统一的冰川提取标准、扩宽研究视角、全面系统观测冰川、提高模拟预测精度、加强灾害预警与制定对策是未来新疆山地冰川研究的关注点。     

黑河流域地下水循环演化规律研究

大量野外调查研究表明，气候变化和人类活动对黑河流域地下水循环和更新演变具有重要影响；平原区浅层地下水主要是现代水补给，35％来自祁连山区基岩裂隙水通过地表径流转化补给，其他是降水和冰雪融水在山前戈壁带入渗补给，具有较强的更新能力；深层承压水主要形成于地质历史时期区域性补给，与现代水循环有联系；中游区人类活动是造成下游区地下水补给能力减弱、地下水水位持续下降和生态环境退化的重要因素。因此强化中游区人类活动的科学调控，是实现黑河流域地下水可持续利用和下游区生态环境有效保护的关键。     

Glacier change and glacier runoff variation in the Tuotuo River basin,the source region of Yangtze River in western China

Glaciers in the Tuotuo River basin, western China, have been monitored in recent decades by applying topographical maps and high-resolution satellite images. Results indicate that most of glaciers in the Tuotuo River basin have retreated in the period from 1968/1971 to 2001/2002, and their shrinkage area is 3.2% of the total area in the late 1960s. To assess the influence of glacier runoff on river runoff, a modified degree–day model including potential clear-sky direct solar radiation has been applied to the glaciated regions of the river basin over the period 1961–2004. It was found that glacier runoff has increased in the last 44 years, especially in the 1990s when a two-thirds increase in river runoff was derived from the increase in glacier runoff caused by loss of ice mass in the entire Tuotuo River basin.     

帕米尔中部North Kyzkurgan冰川跃动变化遥感监测

跃动冰川作为一种特殊类型的冰川,蕴含着巨大的灾害风险,对其开展监测研究具有重要意义。本研究基于1973年以来的Landsat影像、ASTER立体像对和ITS_LIVE数据产品,监测分析了帕米尔中部North Kyzkurgan冰川在跃动前、跃动中、跃动后的面积、高程、流速变化,揭示了该冰川完整的跃动发生过程。结果表明：North Kyzkurgan冰川是一条典型的跃动冰川,在1973—2011年处于恢复阶;2011—2016年处于跃动阶;2016年之后重新进入恢复阶。North Kyzkurgan冰川所在地区气候寒冷,降雪量丰富,同时该冰川积累区面积比率超过0.8,冰川作用正差近1 000 m,因此冰川补给物质充足。在积蓄区物质积累、不断增厚的情况下,冰川底部达到压力熔点,融水不断增多,在融水的润滑和顶托作用下,最终导致冰川发生跃动。因此,North Kyzkurgan冰川跃动的发生主要与热力学因素有关。     

Snowmelt runoff and groundwater discharge in Himalayan rivers: a case study of the Satluj River,NW India

The Himalayas are one of the largest cryospheric systems outside the Polar Regions, and include more than 12,000 glaciers spread over an area of about 33,000 km². The Himalayan glaciers and snow packs retreating at an accelerating rate, thereby creating an alarming situation for the huge population that resides in northwestern India and southeastern Pakistan, as they depend on surface water resources in the region and rivers emanating from the Himalayas. This work attempts to quantify the contribution of different sources such as glacial/ice/snow melt and groundwater discharge to the Satluj River using the stable isotopes based hydrograph separation method at Ropar (foot hill) and Yusufpur in plain of Punjab, India. A mass balance model of three-component mixing has been engaged using the values of δ¹⁸O and electrical conductivity of the river water, and its discharge fraction, to estimate the time-varying relative proportion of each component from July 2013 to January 2014. The proportion of glacier melt was found to peak up to ~?64% at Ropar and ~?15% at Yusufpur during the wet summer months. The fraction of groundwater discharge was found to vary between 10–20% at Ropar and 25–35% at Yusufpur (Punjab plain) over time. The observed trend of d-excess (deuterium excess) values of river water also suggests that the glaciers and snow packs at higher altitudes contain a significant fraction of snow derived from vapor originating in the Mediterranean region, driven by the mid-latitude westerlies known as western disturbances.     

新疆阿克苏河流域洪水演变趋势研究

全球气候变暖将加剧水循环,增大洪水风险。阿克苏河流域位于天山南坡,是北半球中纬度典型的高山流域。本流域不仅有暴雨洪水、冰川和积雪融水造成的洪水,而且还有冰川溃决突发洪水。以阿克苏河的两条支流库玛拉克河和托什干河为研究对象,利用块最大值抽样方法（block maximum）和超定量阈值（peak over threshold,POT）抽样方法提取出1958—2011年的洪水事件,其中基于POT方法在两条支流分别提取106次和112次洪水事件,主要集中在6月、7月和8月份。研究表明：阿克苏河的两条支流库玛拉克河和托什干河的年最大洪水强度分别以8.48 m³?s^-1和3.40 m³?s^-1的速率增加;在洪水发生时间上,以冰川融水补给为主的库玛拉克河,洪水发生时间有提前的趋势,而以降雨和融雪水补给为主的托什干河,洪水发生时间变得更加分散,表现为春季最大洪水提前、秋季最大洪水推后。     

喜马拉雅山北坡典型冰川流域水文过程比较研究北大核心CSCD

2005年为喜马拉雅山中段的暖干年,夏季气温为历年最高。本文利用2005年珠穆朗玛峰绒布冰川下游水文观测资料及附近定日气象站资料、羊卓雍湖卡鲁雄曲冰川流域水文资料及附近浪卡子站气象资料,分析了两个流域的融水过程,建立冰雪消融数值模型,并进行了对比研究。结果表明:统计相关得到两流域气温和降水高度相关性(r>0.8),说明在区域尺度上两个地区的气候过程相似。绒布冰川消融强度比卡鲁雄曲冰川约大2倍,冰川退缩速率二者也差2.5倍,说明用冰川消融气温估计的水量损失基本反映两地冰川变化的事实。本文提出的冰雪融水模型,可以用于两个冰川区之间广大无资料冰川流域融水及冰川变化的估计,以及恢复珠穆朗玛和喜马拉雅山脉其他地区的长期水文过程及水资源变化的计算。