冰湖的界定与分类体系——面向冰湖编目和冰湖灾害研究（英文）

Glacial lakes are not only the important refresh water resources in alpine region, but also act as a trigger of many glacial hazards such as glacial lake outburst flood(GLOF) and debris flow. Therefore, glacial lakes play an important role on the cryosphere, climate change and alpine hazards. In this paper, the issues of glacial lake were systematically discussed, then from the view of glacial lake inventory and glacial lake hazards study, the glacial lake was defined as natural water mainly supplied by modern glacial meltwater or formed in glacier moraine's depression. Furthermore, a complete classification system of glacial lake was proposed based on its formation mechanism, topographic feature and geographical position. Glacial lakes were classified as 6 classes and 8 subclasses, i.e., glacial erosion lake(including cirque lake, glacial valley lake and other glacial erosion lake), moraine-dammed lake(including end moraine-dammed lake, lateral moraine-dammed lake and moraine thaw lake), ice-blocked lake(including advancing glacier-blocked lake and other glacier-blocked lake), supraglacial lake, subglacial lake and other glacial lake. Meanwhile, some corresponding features exhibiting on remote sensing image and quantitative indices for identifying different glacial lake types were proposed in order to build a universal and operational classification system of glacial lake.     

近50年来祁连山冰川变化——基于中国第一、二次冰川编目数据（英文）

Glaciers are the most important fresh-water resources in arid and semi-arid regions of western China. According to the Second Chinese Glacier Inventory(SCGI), primarily compiled from Landsat TM/ETM+ images, the Qilian Mountains had 2684 glaciers covering an area of 1597.81±70.30 km~2 and an ice volume of ~84.48 km~3 from 2005 to 2010. While most glaciers are small(85.66% are 1.0 km~2), some larger ones(12.74% in the range 1.0–5.0 km~2) cover 42.44% of the total glacier area. The Laohugou Glacier No.12(20.42 km~2) located on the north slope of the Daxue Range is the only glacier 20 km~2 in the Qilian Mountains. Median glacier elevation was 4972.7 m and gradually increased from east to west. Glaciers in the Qilian Mountains are distributed in Gansu and Qinghai provinces, which have 1492 glaciers(760.96 km~2) and 1192 glaciers(836.85 km~2), respectively. The Shule River basin contains the most glaciers in both area and volume. However, the Heihe River, the second largest inland river in China, has the minimum average glacier area. A comparison of glaciers from the SCGI and revised glacier inventory based on topographic maps and aerial photos taken from 1956 to 1983 indicate that all glaciers have receded, which is consistent with other mountain and plateau areas in western China. In the past half-century, the area and volume of glaciers decreased by 420.81 km~2(–20.88%) and 21.63 km~3(–20.26%), respectively. Glaciers with areas 1.0 km~2 decreased the most in number and area recession. Due to glacier shrinkage, glaciers below 4000 m completely disappeared. Glacier changes in the Qilian Mountains presented a clear longitudinal zonality, i.e., the glaciers rapidly shrank in the east but slowly in the central-west. The primary cause of glacier recession was warming temperatures, which was slightly mitigated with increased precipitation.     

高亚洲冰川的近期退缩及其对西北水资源的影响

近几十年来, 高亚洲冰川在气候变暖的影响下随着冰川物质平衡的持续亏损而不断退缩. 过去10 a是20世纪高亚洲冰川退缩最强烈的时期. 高亚洲冰川退缩的空间特征是: 青藏高原内陆地区退缩幅度最小; 从青藏高原内陆向边缘地区退缩幅度逐渐增大; 在最边缘的藏东南和喀喇昆仑, 冰川退缩幅度最大. 高亚洲冰川退缩对中国西北干旱地区水资源产生重大影响. 利用冰川变化的长度、面积、体积间的比例关系估算的结果和用经验公式估算的结果都说明, 从20世纪90年代开始的冰川退缩导致冰储量减小, 致使西北地区冰川径流量增加5.5%以上. 在冰川融水补给量大的塔里木河, 冰川径流增加量更大.     

青藏高原及周边冰川区表碛影响研究进展北大核心CSCD

青藏高原及周边冰川区表碛分布十分广泛,其通过地-气-能-水交换、反照率变化等影响冰川消融及空间特征,导致表碛覆盖型冰川物质平衡响应机制、水文效应及其致灾过程不同于无表碛覆盖型冰川。本文在系统梳理青藏高原及周边冰川区表碛空间分布特征的基础上,综合分析了表碛对冰川区消融、物质平衡和水文过程的影响及其对气候的响应过程,并系统分析了表碛影响观测与模拟的研究进展。目前不同尺度冰川物质平衡和径流模型对表碛影响的考虑依然不足,导致应用现有模型开展表碛分布及动态变化和评估气候变化条件下表碛影响面临诸多挑战。展望未来,深入认识气候-冰川-表碛系统相互作用与反馈机制,发展考虑多物理过程的冰川-表碛系统协同演化的动态模型,预估气候变化驱动下的冰川区表碛动态影响及趋势,进而服务于区域社会经济发展和“绿色丝绸之路”建设。     

梅里雪山1991年和2019年雪崩事件重建及影响因素分析北大核心CSCD

梅里雪山雪崩多发,但缺乏系统监测和研究。1991年1月3日梅里雪山发生了造成中日联合登山队17名队员遇难的巨大雪崩事件。2019年安装在明永冰川末端附近的物候相机拍摄到临近梅里雪山明永冰川的一次雪崩事件。两次事件类型不同,这对我们进行雪崩预测预警有良好的指示作用。本研究以RAMMS(Rapid Mass Movement System)模型为手段,利用经验值和经验公式确定影响模拟结果的主要模型参数和积雪可能断裂深度,在优化分析的基础上,对两次雪崩事件进行重建,定量分析雪崩堆积量、堆积范围等。结果显示:1991年雪崩共持续了192s,雪崩体从海拔5730m处断裂,沿坡面崩塌而下最终堆积在海拔约5000m的冰川粒雪盆地区,形成面积为0.6km^(2),体积约67×10^(4)m^(3)的堆积体。2019年雪崩共持续了158s,雪崩流最大高度35.91m,最大速度79.34m·s,堆积量76.2×10^(4)m^(3),雪崩堆积范围与野外观测到的一致。两次雪崩事件发生地位于雪崩极高危险区和高危险区,在一定程度上验证了风险评估的准确性。研究结果可为梅里雪山地区未来潜在雪崩灾害的风险评估提供依据,为雪崩预测预警提供良好的参考。     

Review on snowmelt runoff simulation in mountain regions,Northwest China北大核心CSCD

Snowmelt runoff is a valuable water resource in Northwest China. In the past few decades, progress has been achieved in snowmelt runoff simulation in mountainous areas, including observation and simulation of snow melt process, improvement and development of distributed snow melt runoff model, and ability for application of snow melt runoff model with temporal and spatial distribution driving data. The development of interpolation algorithm, remote sensing and data assimilation technology provides data support for the widespread application of distributed snowmelt runoff model in northwest mountainous regions of China. Climate warming and economic and social development will further aggravate the contradiction between supply and demand of water resources in the arid regions of Northwest China, which requires higher precision and detail spatial and temporal resolution of snowmelt runoff simulation. Based on the progress and challenges on snowmelt runoff simulation in mountainous regions of Northwest China, following studies need more attention：the mechanism of snow accumulation and ablation, snow cover spatial and temporal distribution monitoring and high precision of snow distribution data acquisition, quantitative climate change impact on river basin snowmelt runoff. © 2022 The authors.     

青藏高原冰川底部滑动估算方法研究:进展、问题与展望

冰川底部滑动是冰川运动重要的组成部分,是冰川动力过程的底部边界条件.底部滑动速度的估算,对于研究青藏高原及周边地区冰川运动规律、冰川内部应力分布和冰川异常变化机制等具有重要意义.系统总结了冰川底部滑动速度的影响因素及其估算模型的发展现状,其模型从单纯考虑底部剪切应力与冰床特性的关系逐渐扩展到考虑底部有效压力和冰下水文过程等综合影响,剖析了现有模型的结构和功能.进而分析了现有模型存在的主要问题和挑战,为进一步完善模型提供参考.未来冰川底部滑动研究需基于遥感大数据、新技术等进一步强化观测,着重耦合冰下水文过程的影响,进而促进气候变化—冰川物质平衡—冰川动力学响应过程的集成研究.     

天山南坡科契卡尔巴西冰川消融期雪面能量平衡研究

根据2005年6～9月的野外观测资料,计算了天山南坡科契卡尔巴西冰川积雪表面的能量平衡各分量,其中感热和潜热采用空气动力学-梯度方法计算得到,净辐射由观测获得.结果表明,消融期净辐射是雪面最主要的能量来源,占能量收入的81.4%,平均值为63.3 W·m^-2;其次为感热供热,占18.6%,为14.4 W·m^-2.吸收的热量主要通过融化和蒸发两种方式消耗,融化和蒸发耗热分别为54.0 W·m^-2和23.0 W·m^-2,占能量总支出的69.5%和29.7%,剩下的0.8%由感热消耗.在积雪表面的能量组成中,感热值在6月和9月较大而8月较小;对于潜热来说,6月潜热交换绝对值最大,蒸发最强烈,这与6月风速大且天气晴好有关.另一方面,净辐射值较大的6月和9月融化热较多,说明此时段冰川消融较为强烈.     

中国西部冰川度日因子的空间变化特征

在冰川与积雪消融研究中,度日模型应用较为广泛,该模型是基于冰雪消融与气温,尤其是正积温之间的线性关系建立的。度日因子是该模型的重要参数,反映了单位正积温产生的冰雪消融量,其空间变化特征对于不同模型模拟冰雪消融过程的精度有较大影响。 本文根据中国西部不同地区数十条冰川的短期考察和观测资料,分析了西部冰川度日因子的空间变化特征,结果表明：由于青藏高原及其周围地区独特的气候和热量条件,西部冰川度日因子具有明显的区域特征。在同一冰川上,度日因子的空间变化较为明显。从冰川类型来看,与极大陆型及亚大陆型冰川相比,海洋型冰川的度日因子较大。总体看来,西部冰川的度日因子由西北向东南逐渐增大,这与中国西部冰川的气候环境变化趋势是一致的,即在干冷的气候条件下,度日因子较小;而在暖湿的气候条件下度日因子较大。     

青藏高原土壤水热过程模拟研究(Ⅰ):土壤湿度

模拟青藏高原土壤水分和热量迁移过程的连续变化对于全球变化研究具有非常重要的意义,其准确模拟是提高陆面过程模拟精度的重要条件.利用大尺度水文模型中对冻土中水分和能量平衡过程的描述,对沱沱河站点超过一年时间的土壤湿度进行了步长为1h,总时间为399d的连续模拟.与Game Tibet项目中同一时刻的土壤湿度观测资料比较的结果表明,Fuchs方程对于描述冻土中的最大未冻水含量是有效的,利用能量平衡计算获得的土壤各层的湿度与观测值相比较,其连续变化基本合理.结果表明,用该模型对高原水热过程进行长期模拟是可行的.