复杂下垫面海洋性冰川消融过程及其空间异质性

High sensitivity of monsoonal temperate glaciers to climate changes makes them unique mountain geophysical features as the index of monsoon dynamics, and thus in crucial relationship with the local changing hydrological, ecological and natural hazards regimes. However, number of extensively monitored temperate glacier in China as well as around world is very limited, especially yet few larger temperate glaciers in China been currently well studied. The proposed project aims to conduct detailed glacier wide metrological and surface ablation monitoring and modeling on two typical larger temperate glaciers in Mt. Gongga, Southeastern Tibet Plateau. We will use coordinated field observations, combined with multiple remote sensing methods and distributed physical based glacier ablation model to analysis current and historical glacier mass dynamics and their responses to the changing climate. By integrating with multiple processes existing on temperate glaciers, including difference ice ablation process related to debris-cover, ice cliff, ice crevasses and typical glacial drainage systems (channel, stream, pond/lake, liquid precipitation et al.), the constructed models are expected to discriminate several major control factors that affect ice ablation on larger temperate glaciers. This study is supposed to improve our understandings of monsoonal temperate glaciers mass balance processes, dynamics and their temporal-spatial heterogeneity due to local glacio-geomorphology and climate variations.

海洋性冰川对气候变化响应敏感，而较大型海洋性冰川由于其相对高的融水产流总量和相对强的地貌改造作用，对区域/流域水资源变化、生态演化以及灾害发育过程影响更为显著。目前，国内外针对海洋性冰川尤其是较大型海洋性山地冰川物质平衡的综合集成观测与模拟研究总体相对缺乏。由于较大型海洋性冰川其冰面下垫面结构复杂，基于花杆消融观测进行空间插值的传统冰川学方法无法对冰川物质平衡进行准确估算，需全面考虑复杂冰面状况（如表碛覆盖、冰崖/冰裂隙、冰面湖/河及其他冰川排水系统等）对冰川消融进而对物质平衡过程的影响。拟申请项目将选取我国西南地区海洋性冰川集中分布的贡嘎山地区，针对其典型冰川开展系统、全方位、多要素野外定位与遥感监测和模型模拟对比研究，深入剖析具有复杂下垫面的海洋性冰川消融过程及其空间异质性。

本项目以贡嘎山地区的典型海洋性冰川为重点研究区，针对区内典型冰川（海螺沟冰川、贡巴冰川等）开展了系统、全方位、多要素野外定位与遥感监测和模型模拟对比研究，开展了表碛覆盖型复杂下垫面海洋型冰川的冰面温度、表碛覆盖多年变化、冰裂隙分布与变化、冰缘边坡失稳等系统研究，深入剖析了具有复杂下垫面的海洋性冰川消融过程及其空间异质性。项目执行期间针对贡嘎山海螺沟冰川开展了大量的野外调查，开展了典型冰川消融区多期重复无人机航拍测量、表碛厚度实测、冰崖与冰裂隙调查等，结合遥感Landsat热红外波段的冰面温度反演、UAV高分辨率影像冰裂隙分布绘制等，系统揭示了贡嘎山地区表碛覆盖型冰川冰面温度变化及其与冰川表碛覆盖、冰川变化间的关系。项目积累了贡嘎山典型表碛覆盖型冰川的基础观测数据，包括海螺沟冰川消融、冰川运动、冰川消融区高分辨率重复航拍影像以及对应的数字高程模型、冰川融水径流水文数据以及冰川区气象数据等。同时，发布或发表的典型冰川表碛厚度反演、冰裂隙分布、冰面湖冰崖分布等数据，可为未来深入开展复杂下垫面表碛覆盖型冰川动态提供基础数据，也可为表碛覆盖冰川的动态模拟、水文响应和冰川相关灾害等的相关研究提供支撑。