Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Debris-covered glaciers are widely distributed in Western China. Their ablation areas are covered byvarying degrees of rock debris, and consequently, their melting statuses differ greatly when compared to debrisfreeglaciers. There is currently a need for melting simulations to better understand debris- covered glaciers. Inthis paper, driven by field meteorological data, an energy balance model for debris- covered glaciers has beenused to simulate the energy and ablation in debris-covered areas of Qingbingtan Glacier No. 72 in Mt. Tomor,Tianshan. Based on the heat conduction process and the energy balance equation, the model calculates the debrissurface temperature and the internal temperature of the debris, then estimates the subdebris melt using the internaldebris temperature. The results showed that the modeled ablation was 0.39 m w.e. in the summer of 2008, and thesimulation accuracy (R2 = 0.92, RMSE = ± 0.03 m w.e.) was higher when compared with the field data. Thesimulated debris temperatures at the surface and a depth of 10 cm inside the debris were also found to fit wellwith the measured data (R2 = 0.91 and 0.60, respectively). During energy exchange in the debris area, netshortwave radiation was the only energy income item, and sensible heat flux was the largest energy expenditureitem (49.7%), followed by the heat conduction flux (ablation heat consumption) (25.8%), net longwave radiation(19.8%), and latent heat flux (4.6%), while precipitation heat was <1%. Cloud cover had a significant impact onthe meteorological and energy characteristics of the debris area. Under overcast conditions, the incomingshortwave radiation in the debris area decreased from 854 W·m- 2 on sunny days to 587 W·m− 2, while thedownward longwave radiation and relative humidity increased, and the average ablation decreased by 12%, whencompared with sunny days. In addition, the sensitivity analysis of the key parameters for debris shows that thesimulated ablation is most sensitive to the changes in thermal conductivity, and the changes in albedo and surfaceroughness cannot be ignored.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The arid region of Northwest China is one of the driest regions in the world and is characterized with severe water scarcity.Water shortage is the most critical natural factor limiting the high-quality economic and social development and ecological security in the arid region of Northwest China. Based on the long-term monitoring data from the field stations of Chinese Academy of Sciences, observation data of meteorological stations, water resources bulletin and the remote sensing data, this study systematically analyzes the basic characteristics of water resources and ecological environment in the arid region of Northwest China, assesses the changing trends of hydrological elements, water resources, and ecological environment. Besides, this study analyzes the changes of water resources carrying capacity in terms of water use structure and water resources utilization efficiency, and puts forward some suggestions on sustainable water resources utilization and ecological and environmental protection. The results show that the temperature in the arid region of Northwest China has increased at a rate of 0.32℃/decade and precipitation has increased at a rate of 9.32 mm/decade. The glaciers are shrinking at accelerating rate and the runoff supplied by glacier/snow meltwater has increased. The amount of water resources has increased by about 11 billion m3 since the mid-1990s. In the past decade, water use efficiency has been improved, water-saving irrigation area has been expanded, and agricultural water production efficiency has been improved due to water conservation and utilization measures. Water environment capacity has been increased, water carrying capacity has been enhanced, surface water area has been expanded, and the ecosystem condition has improved. However, water resources problems are still prominent in the arid region of Northwest China, the intensity of extreme climate and hydrological events has increased, and the ecological environment is still fragile. In the future, it is necessary to further explore the water resources potential of this region, improve the water resources management, and enhance ecological protection and restoration efforts for better adaptation to the possible risks of climate change, so as to provide scientific and technological support for promoting the construction of the “Green Silk Road” and realizing high-quality regional economic and social development.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-19 Cooperative journals: 《中国科学院院刊》
Abstract： China has 48 571 glaciers with a total area of 5.18×104 km2, which accounts for 11%–14.5% of the total area of mountain glaciers in the world. These glaciers constitute a vital source of water for more than 100 million people and for wildlife ecosystems in this vast arid and semi-arid land in northwestern China. Urumqi Glacier No. 1, the best monitored glacier in China, is located at the headwaters of the Urumqi River in eastern Tianshan and is within the core area of central Asia. To implement the long term monitoring of Urumqi Glacier No. 1, the Tianshan Glaciological Station (TGS) was established by Chinese Academy of Sciences (CAS) in 1959. Since then, Urumqi Glacier No. 1 has been the subject of extensive studies. Internationally, it has been one of the ten referential glaciers in the World Glacier Monitoring Service (WGMS), and considered to be of great importance because of its special geographical position. The Urumqi Glacier No. 1 complements similar long-term monitoring programs covering more maritime-type glaciers and glaciers in transitional climates in polar, temperate, and tropical regions. Over the past 60 years, the TGS has served as a research and training base for domestic and overseas scientists and graduate students. It plays a central role in central Asian climatological, hydrological and glaciological research. As such, it is well known and highly regarded by the international scientific community. As a permanent year-round glacier station among glaciers in central Asia, it is the benchmark to which other relevant studies can make reference.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2021-01-25 Cooperative journals: 《干旱区研究》
Abstract：基于天山乌鲁木齐河源1号冰川区1980—2016年的水文和气象资料，对冰川区径流在月、日和时尺度的变化特征及其原因进行了分析。结果表明：（1）1980—2016年该区消融期（5—9月）径流总体呈上升趋势，倾向率为3.44×104 m3·a-1，其中6—8月上升趋势较为显著；37 a来8月对径流增多贡献率最大，其次为6月和7月，5月和9月最低；消融期径流在1993年显著增加，5—8月径流均在20世纪90年代发生突变。（2）日径流量自1980s、1990s至2000s显著增加，而2010—2016年径流量有所减少；日径流峰值出现时间在1980s—1990s有明显提前趋势，但在2010—2016年，日径流峰值出现日期趋于稳定。（3）2011—2016年7月和8月昼夜流量变化较为显著；日流量曲线呈现“峰-谷”的日变化特征，且7月和8月峰值出现时间小于6月和9月。（4）1980—2016年，该流域消融期气温和降水均呈上升趋势；相关分析表明6—8月径流与气温均呈显著正相关。总体上冰川区年内径流与气温、降水在月、日尺度上表现出较好的同步性，表明其变化主要受控于同期的气温与降水量状况。
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：冰川物质平衡作为表征气候变化的重要指标，通常被用来评估冰川对径流及海平面上升的贡献。本文采用世界冰川监测服务处（World Glacier Monitoring Service, WGMS）最新公布的物质平衡、平衡线高度及积累区面积比率资料，以北极地区具有长时间观测序列的23条冰川为研究对象，分析了北极山地冰川物质平衡状况及物质平衡与平衡线高度和积累区比率的关系。分析表明：（1）1960—2017年北极冰川厚度平均减薄14.8 m，俄罗斯北极减薄最小，为4.3 m，阿拉斯加地区减薄最严重，为27.7 m；（2）23条冰川中，仅Engabreen冰川平均物质平衡为正值，Kongsvegen冰川保持微弱的负平衡，其他21条冰川的物质平衡均处于较强的负平衡状态，北极冰川整体物质损失严重；（3）过去60 a，北极冰川物质平衡整体呈负平衡，20世纪90年代后期开始，冰川开始加速消融，损失速率从-128.2 mm·a-1上升至-594 mm·a-1；（4）物质平衡与平衡线高度呈负相关，与积累区比率呈正相关，相关性显著；（5）北极气温升高是冰川物质消融的主要原因，90年代之后气温大幅度升高造成同期冰川物质大量流失，降水量对物质平衡影响较小
Subjects: Geosciences >> Geography submitted time 2019-01-11 Cooperative journals: 《干旱区地理》
Abstract：科学监测祁连山积雪面积及变化特征对该区域气候研究、雪水资源开发利用、环境灾害预报及生态环境保护等具有重要意义。基于2001—2017年MOD10A2积雪产品和气象数据，分析祁连山积雪面积动态变化特征及与气温降水关系。结果显示：（1）2001—2017年祁连山积雪面积年际波动趋势较大，呈减小趋势，多年平均积雪面积约为5x104 km2，占祁连山总面积的25.9%；年内变化成 “M”型，即在一个积雪年中有两个波峰和波谷，波峰出现在11月和1月，波谷出现在7月；季节变化波动趋势较大，夏冬季积雪面积减小趋势大于春季，秋季呈现略微增加趋势。（2）祁连山区积雪面积主要分布在3 000~4 000 m及4 000~5 000 m，积雪覆盖率随着海拔上升呈现逐渐增大的趋势；祁连山区不同坡向积雪覆盖面积差异较大，积雪覆盖率差异较小；积雪频率高值区呈典型的条带状分布，与祁连山地形相一致，呈西北-东南分布，积雪频率高值区的分布西部大于东部。（3）初步分析认为祁连山积雪面积变化对气温要素更敏感。
Subjects: Geosciences >> Geography submitted time 2019-01-11 Cooperative journals: 《干旱区地理》
Abstract：为认识全球变暖背景下中国西部大陆性冰川与海洋性冰川物质平衡变化及其对气候响应，本研究以天山乌鲁木齐河源1号冰川和藏东南帕隆94号冰川为例，结合大西沟与察隅站气象资料，对1980 — 2015年两条冰川的物质平衡变化特征及差异进行了分析。结果表明：36 a来乌源1号冰川与帕隆94号冰川物质平衡总体上均呈下降趋势，累积物质平衡达-17102与-8159 mm w.e.，相当于冰川厚度减薄19与9.01 m，且分别于1996、2004年左右发生突变。同期两条冰川所处区域年均温呈显著上升趋势，而降水量却表现出不同的变化态势；二者年内气温分配相仿，但降水分配差异较大。初步分析认为气温上升是导致乌源1号冰川与帕隆94号冰川物质亏损的主要原因，冰川区气温和降水变化幅度的差异和地性因子（坡度、冰川面积）的不同使得乌源1号冰川对气候变化响应的敏感性高于帕隆94号冰川，由于目前海洋性冰川物质平衡监测时段相对较短，为深入研究中国西部冰川物质平衡变化及过程仍需加强对冰川的持续观测。
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