Changes in sediment connectivity following glacial debuttressing in an Alpine valley system

Dataset containing historical data concerning the evolution of Little Ice Age lateral moraine in the Otemma Valley (VS, Switzerland) during the debuttressing phase since mid-1960s. Our aim was to study how the morphological and hydrological sediment connectivity of the lateral moraine responded to the progressive glacier retreat. The dataset is composed by two type of data: 1. DEMs generated using SfM photogrammetry starting from aerial imagery. These data were used to detect both morphological changes and hydrological sediment connectivity evolution during the debuttressing phase. We conclude that gullying, activated by the glacier thinning which act as hydrological base level, in the main geomorphological process determining the hydrological sediment connectivity between the lateral moraine and the proglacial plain. 2. Historical climatic data (MAAT, glacier length and accumulated snow hight during winters) since 1960 to understand how these parameters impacted the behavior of the Glacier d'Otemma over time. As the glacier d'Otemma, unlike other Alpine glacier, showed a continuous retreat since the end of the Little Ice Age we found that the morphology of the valley (very long distance between the accumulation and the ablation zone due to the low slope of the bottom) played a most important role compared to the climatic parameters.本数据集收录了1960年代中期以来，瑞士奥泰马山谷（瓦莱州，VS）小冰期侧碛在冰川去压阶段的演化历史数据。本研究旨在探究该侧碛的形态与水文泥沙连通性如何随冰川渐进式退缩发生响应。本数据集包含两类数据：1. 基于航空影像通过运动恢复结构（SfM, Structure from Motion）摄影测量法生成的数字高程模型（DEM, Digital Elevation Model），此类数据被用于监测冰川去压阶段内侧碛的形态变化与水文泥沙连通性演化过程。研究结果表明，以冰川变薄作为水文基准面而激活的沟蚀作用，是决定侧碛与冰前平原间水文泥沙连通性的主要地貌过程。2. 1960年以来的历史气候数据（年均气温MAAT, Mean Annual Air Temperature、冰川长度与冬季积雪厚度），用于分析上述参数随时间对奥泰马冰川动态的影响。相较于其他阿尔卑斯冰川，奥泰马冰川自小冰期结束以来便持续退缩，本研究发现，相较于气候参数，山谷地形（因谷底坡度平缓导致积累区与消融区间距极长）对冰川动态的影响更为显著。