摘要
The precise glacier boundary is a fundamental requirement for glacier inventory,the assessment of climate change and water management in remote mountain areas.However,some glaciers in mountain areas are covered by debris.The high spatial resolution images bring opportunities in mapping debris-covered glaciers.To discuss the capability of Chinese GaoFen-1 satellite lacking the short wave infrared band and thermal infrared band in mapping glaciers,this study distinguished supraglacial terrain from surrounding debris by combining GaoFen-1(GF-1)wide-field-view(WFV)images,the ratio of the thermal infrared imagery and morphometric parameters(DEM and slope)with 30 m resolution.The overall accuracy of 90.94%indicated that this method was effective for mapping supraglacial terrain in mountain areas.Comparing this result with the combination of GF-1 WFV and low-resolution morphometric parameters shows that a high-quality DEM and the thermal infrared band enhanced the accuracy of glacier mapping especially debris-covered ice in steep terrain.The user's and producer's accuracies of glacier area were also improved from 89.67%and 85.95%to 92.83%and 90.34%,respectively.GF data is recommended for mapping heavily debris-covered glaciers and will be combined with SAR data for future studies.
The precise glacier boundary is a fundamental requirement for glacier inventory, the assessment of climate change and water management in remote mountain areas. However, some glaciers in mountain areas are covered by debris. The high spatial resolution images bring opportunities in mapping debris-covered glaciers. To discuss the capability of Chinese GaoFen-1 satellite lacking the short wave infrared band and thermal infrared band in mapping glaciers, this study distinguished supraglacial terrain from surrounding debris by combining GaoFen-1(GF-1) wide-field-view(WFV) images, the ratio of the thermal infrared imagery and morphometric parameters(DEM and slope) with 30 m resolution. The overall accuracy of 90.94% indicated that this method was effective for mapping supraglacial terrain in mountain areas. Comparing this result with the combination of GF-1 WFV and low-resolution morphometric parameters shows that a high-quality DEM and the thermal infrared band enhanced the accuracy of glacier mapping especially debris-covered ice in steep terrain. The user’s and producer’s accuracies of glacier area were also improved from 89.67% and 85.95% to 92.83% and 90.34%, respectively. GF data is recommended for mapping heavily debris-covered glaciers and will be combined with SAR data for future studies.
基金
Science&Technology Basic Resources Investigation Program of China(Grant Nos.2017FY100502,2017FY100503)
the National Natural Science Foundation of China(Grant Nos.41471291,41801273)
