多源多分辨率DEMs对宁金康桑峰地区冰川模拟的影响研究

研究宁金康桑峰地区第四纪冰川面积、体积、冰厚及平衡线高度特征参数的变化，将加深对该区气候响应的认识。数字高程模型（DEM）描述地面的起伏形态特征，为冰川模拟的基础数据，对冰川模拟影响较大。已有研究通过DEM空间分辨率来探究对流域、坡度等的影响，然而目前尚缺乏对古冰川重建影响的研究。文章分别选择4种DEMs（ALOS PALSAR RTC HIGH RES 12 m DEM（简称ALOS 12 m DEM）、ASTER 30 m GDEM、SRTM 30 m DEM、SRTM 90 m DEM）采用改进的冰川流线模型来模拟宁金康桑峰地区卡若拉西沟冰川、枪勇冰川、西坡冰川和岗布沟冰川自末次冰盛期以来的冰川厚度及规模，基于变异系数法比较计算不同DEM模拟冰川参数的稳定性，分析不同DEM模拟的冰川冰储量变化对区域水资源的影响。结果显示：1）冰川的塑性流变使其对细微的高程变化可能并不敏感。冰川模拟和实测数据的对比表明，ALOS 12 m DEM的高精度地形数据和SRTM 90 m DEM的低分辨率高程数据对冰川的模拟都差于SRTM 30 m DEM数据，说明30 m分辨率的DEM可能与冰川塑性流变的尺度较一致，能够更好地模拟冰川的变化。同时SRTM 30 m DEM比ASTER 30 m GDEM具有更好的数据质量和高程精度，更加适合本地区的冰川模拟。2）从现代冰川到末次冰盛期冰川，随着冰川面积增大，不同DEM模拟的冰川面积、体积、冰厚和平衡线高度变化总体趋于稳定，DEM的影响减小。3）不同DEM模拟的冰川变化影响对区域水资源的评估。从小冰期到末次冰盛期，不同DEM模拟的冰川水当量的差异在15%以内。

Influences of multi-source and multi-resolution DEMs on glacier simulation in Mt. Noijin Kangsang

Glaciers are sensitive to climate change especially on the transition zones of different climate systems. Located on the transition zone between South Asian monsoon and westerlies, glaciers around Mt. Noijin Kangsang(28.9°N, 90.1°E; 7191 m a.s.l.) on the northern slope of the Himalayas have created series of glacial landforms with distinct morphology, providing evidence to reconstruct palaeo glaciers, as well as their corresponding climate and environmental conditions. We reconstructed palaeo glaciers of Karola West Valley, Qiangyong Valley, West Glacier, and Gangbu Valley in this are during the Little Ice Age(LIA), Neoglacial(NEO), Early Holocene(EH), and the Last Glacial Maximum(LGM). The glacier reconstructions were based on an improved glacial flowline model and four types of Digital Elevation Models(DEMs), including ALOS PALSAR RTC HIGH RES 12 m DEM(ALOS 12 m DEM), ASTER 30 m GDEM, SRTM 30 m DEM, and SRTM 90 m DEM. Glacier area, volume, and thickness were estimated and the Equilibrium Line Altitude(ELA) was derived using the Accumulation Area Ratio(AAR) method for each glacial stage and each DEM type. We then analyzed the impacts of different DEMs on estimated glacier area, volume, thickness, and ELA, as well as the impact of glacier change on regional water resources.