Cryospheric changes and their impacts are receiving wide attention from international scientific and social communities. Here, we summarize the present hotspots of international cryospheric sciences and hence conclude four major aspects of it. They are respectively ① mechanism of cryospheric changes, ② interaction of cryospheric and other spheres of climate/earth system, ③ impacts of cryospheric changes, and ④ adaptation methods and strategy to these changes. Among the four areas, mechanism study is the basis for cryospherc sciences, interaction between different spheres is the currently developing aspect of the field, impacts of cryospheric changes are increasingly studied and yet still have large gaps, while adaptation study is still an iniative nowadays. For the above four aspects, there are key issues for each of them. For instance, dynamic responses and spatial/temporal differences are the key challenges in the mechanism studies. Rational and precise description on physical/chemical/geochemical processes of cryosphere is one of critical issues on improving the climate models. Scoping the spatial/temporal scales, as well as defining the influence degree is the key gaps in studying the cryospheric impacts. Methods and related index system for vulnerability assessment is the key issue in the study of the adaptation strategy of cryospheric impacts. Cryospheric sciences are developing towards, in the near future, the coupling of cryoshperic components into climate system in global scale, detecting the impacts of cryospheric changes using multiple and integrated methodology, and innovated approaches in adaptation.

冰冻圈变化及其影响日益显著并受到广泛关注。系统梳理了目前国际冰冻圈科学研究的主要关注热点, 认为冰冻圈的变化机理、冰冻圈与气候相互作用、冰冻圈变化的影响与适应等构成了国际冰冻圈科学研究的4大科学问题。冰冻圈变化机理是冰冻圈科学研究的基础领域, 冰冻圈与气候相互作用是当前着力加强的重点, 冰冻圈变化的影响日益受到关注, 但研究基础还较薄弱, 冰冻圈变化影响的适应机制是尚处在萌芽状态的研究领域。围绕上述重大科学问题, 紧抓冰冻圈变化过程中的动力响应与时空差异性问题, 气候模式中冰冻圈过程的精细化描述问题, 准确认识影响的时空尺度与程度问题和脆弱性评价方法和指标体系等科学问题, 是寻求科学突破的关键。以全球的视野审视冰冻圈的变化过程, 从有机耦合的角度探讨气候模式中的冰冻圈过程, 以多因素、多过程综合与集成的手段辨析冰冻圈变化的影响, 从方法创新上寻求科学评估冰冻圈变化脆弱性及适应性的突破途径, 是未来研究的重点。

Alpine cold desert broadly distributed in the high-altitude of mountain area, account for about 20%-30% of area in Tibet Plateau and Tian Mountain regions. It is an important hydrological functional area, owing to precipitation highly, infiltration rapidly and the high runoff coefficient. It is also the ecological fragile region, due to the high altitude, low air temperature, steep terrain and the sparse vegetation. Moreover, the sparse vegetation and the cold-adapted microorganism in the alpine cold desert is the important signal to climatic change. However, the relevant research on alpine cold desert is rare. Furthermore, human activity impact on alpine cold desert little than lower altitude area, therefore, it is suitable for us to monitor the climatic change effect in the high mountain region. In this paper, the authors summarize the importance of alpine cold desert for cryospheric hydrology, ecology and climate in China and its relevant research progress, and suggest that the alpine cold desert should be a special research area in cryospheric sciences.

 高山寒漠带在青藏高原和天山地区的面积比率约为20％～30％，在高海拔山区面积分布广阔，是山区流域降水的高值区，下渗迅速，产流系数高，是山区流域的主要产流区。由于其海拔高、气温低、地形陡峭、植被稀疏，是重要的水文功能区和极端寒区生态脆弱区，附生在其中的稀疏植被和低温微生物是高山生命带的重要组成部分，对气候变化也有指示意义，但国内相关研究很少。人类活动对高山寒漠生境植被的影响比低海拔区要小，因而为我们提供了一个可以进行气候变化效应比较监测的机会。提出高山寒漠带在我国冰冻圈水文、生态和气候等方面的重要性，并对相关进展进行初步总结，建议将高山寒漠带作为一个特殊的生态、气候和水文功能区，专门进行研究。
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Taking the mountain watershed at the upper stream of the Heihe River in the Hexi Corridor area in northwest China as an example, some problems with relation to hydrological and ecological researches are discussed from the aspects of mountain hydrological cycle, hydrology and ecosystems, runoff generation and prediction. The spatial and temporal distribution of precipitation and its composition of solid and liquid form are mainly influenced by elevation and topography in the mountains, while evapotranspiration is mainly influenced by various land cover and heterogeneity of underlying surfaces under different elevation and topographic conditions.
The basic characteristics of hydrological cycle and water balance of an inland river basin rest with the fact that the runoff does not run out off from the basin, and the normal annual precipitation and evapotranspiration are equal, forming the local hydrological cycle system: water vapor transportation→precipitation→runoff→evapotranspiration→water vapor transporation. The investigation of this local hydrological cycle redounds to the understanding of the interrelationship of hydrological and ecological processes between the areas at the upper, middle and lower streams of an inland river.
As yet the researches are very inadequate on mountain hydrological and ecological processes and their interactions. In the mountain glaciers, snow and permafrost zone, the researches should be put on the hydrological conditions to maintain the alpine meadow growing. In the mountain vegetation zone, the ecosystems of mountain forest and grass land should be studied on for their functions in the mountain hydrological cycle and for their role in maintaining and protecting the mountain ecosystems and environment. In this way, we can understand as a whole the interactions between hydrological processes and ecosystems and their environmental significance.
The hydrological processes of an inland river basin are very complex, multidisciplinary and comprehensive. The measurements and researches should be strengthened on the various hydrological processes to understand the mechanism of the mountain runoff generation. In this aspect, ground measurements and remote sensing monitoring are mutual compensatory. Based on this, the physical distributed hydrological models should be developed to reflect the complex mountain hydrological processes. In order to bring the measured data into play fully in the simulation, the mountain hydrological data assimilation system should be developed to form the hydrological modeling system. Furthermore, the researches on and developing of the coupled regional atmospheric and hydrologic models should be carried out in the mountain watershed scale. In this way, the incessant improvements of the response simulation and modeling prediction of mountain runoff change will be achieved under the climate change and human activities.

Alpine glaciers are the natural solid reservoirs that releases amount of meltwater to supply streams every year. Glacier meltwater, adjuSting the yearly variation of stream runoff and making it trend to wards stableness, becomes the relible water resources to streams in mountain area. In accordance with the statistics,s there are glacier meltwater, obout 564 × 10⁸m³, to supply the streams in western mountain of China every year, which accounts for 2% of the total stream runoff all over the country and equals to the average annual runoff of the Huanghe (Yellow) River. It is also an important component of stream water resources in the north-west region.

Alpine glaciers are the natural solid reservoirs that releases amount of meltwater to supply streams every year. Glacier meltwater, adjuSting the yearly variation of stream runoff and making it trend to wards stableness, becomes the relible water resources to streams in mountain area. In accordance with the statistics,s there are glacier meltwater, obout 564 × 10⁸m³, to supply the streams in western mountain of China every year, which accounts for 2% of the total stream runoff all over the country and equals to the average annual runoff of the Huanghe (Yellow) River. It is also an important component of stream water resources in the north-west region.

Alpine desert is the mainly runoff yield regions and headwater regions for most large river and inland river basins in China. However, due to lack of observation data and theoretical basis, there are few researches focusing on the hydrological process of alpine desert at home and abroad. In this paper, water cycle observation and experiment were done to analyze the hydrological characteristics in the alpine desert zone of Hulugou watershed in non-freezing period. Observations show that: (1) during the experimental period (2009.6.7-9.30), precipitation was 541.4 mm at the experimental site, pan evaporation was 256.9 mm, Micro-Lysimeter evaporation was 122.8 mm, mean evaporation was 1.1 mm·d^-1; (2) based on the experimental observation, condensation water was relatively abundant in the alpine desert zone. Although condensation water do not directly involve in the hydrological cycle of mountain runoff generation and confluence process, it consumed energy, offset part of solar radiation, indirectly involved in the runoff generation and confluence process; (3) runoff depth of the small watershed was 461.2 mm. Using elevation precipitation gradient, it was obtained that the average precipitation of the alpine desert watershed was 639.1 mm, with a runoff coefficient of 0.72.

高山寒漠带是我国内陆河山区和我国多数大江、大河源头的主产流区之一. 由于缺乏系统观测数据及相关研究的支撑，当前国内外研究较为匮乏，高山寒漠带水文循环过程机理尚不清楚. 通过在黑河上游葫芦沟流域高山寒漠带试验点布设水文循环观测试验，分析了典型高山寒漠带非冻结期水文特征. 结果表明：高山寒漠试验点观测期(2009年6月7日-9月30日)的降水量为541.4 mm；蒸发皿的蒸发量为256.9 mm，桶式微型蒸渗仪(Micro-Lysimeter)的蒸发量为122.8 mm，平均蒸发量为1.1 mm·d^-1. 根据观测，高山寒漠带凝结水量也比较丰富，凝结水虽然没有直接参与高寒山区水文循环的产汇流过程，但它消耗了能量，抵消了部分太阳辐射，间接地参与了产汇流过程. 高山寒漠带小流域在观测期的平均径流深为461.2 mm. 根据降水梯度获取的流域平均降水量为639.1 mm，径流系数为0.72.