喜马拉雅山脉典型地区冰川变化的遥感监测方法

青藏高原 冰川 遥感 纳木那尼峰 珠穆朗玛峰
叶庆华 2007-01 项目
【英文摘要】This project studies glacier changes using multi-source and multi-temporal remote sensing data and GIS technologies in the Mt. Naimona'Nyi area and Mt. Qomolangma region of the Himalayas on the Tibetan Plateau in China. On one hand, several comprehensive methods on glacier delineation from satellite images were tried; results were integrated by sequential time series using the algebraic operations in the Arc/Info Grid module to verify the methods and the results. The spatial-temporal integrated GRID data sets were generated to identify areas of real glacier changes and "noises" in the last three decades. Measurement accuracy of the glacier area from multi-source data was improved in the study. DEM generation and evaluation from images of stereos pairs from ALOS/PRISM was also carried out. The research has made a progress in methods for glacier detection and mapping, which provides a methodological and technical support for monitoring glacier change on Tibetan Plateau. On the other hand, it shows that glaciers retreat extensively and faster in the Himalayas on the Tibetan Plateau, both retreat and advance glaciers existed in the past 30 years, with retreat dominating and accelerating, while the nearby lakes has increased both by area and by quantities at the same time. Glacier coverage change is different both by glacier sizes and by different spatial features, e.g. different elevations, slopes and aspect. Smaller glaciers are more sensitive to climate change than larger ones. For smaller glaciers that were smaller than 1 km2, glacier coverage increased obviously in Mt. Naimona'Nyi area in 2003-2007, with an accelerated changing rate that includes both advance and retreat. Similarly, in Mapam Yumco basin, locates northern to the Mt. Naimona'Nyi area, both enlargement and reduction of lakes were accelerated in 1974-2003. Speeding change of glaciers and lakes might be an indicator of an accelerated water cycle process over the Tibetan Plateau forced by warming climate. It would serve for the future research on change of glaciers, hydrology and water resources in the warming climate on the Tibetan Plateau.
【中文摘要】本项目综合利用多源、多时相遥感数据和GIS技术,在喜马拉雅山脉纳木那尼峰和珠峰北坡地区,一方面,研究冰川的多种遥感识别及其综合提取方法,以时间先后为序集成各期数据,检验方法的有效性,建立了三十多年来的冰川变化图谱,进行图谱分析与图谱重建,有效检测并屏蔽多源数据之间的"变化噪声",改进了基于多源遥感数据进行冰川变化测算的不确定性评价方法,并基于ALOS/PRISM光学立体像对,合成DEM数据,为青藏高原冰川变化的大范围、长期遥感监测提供方法支持。另一方面,通过研究三十多年来不同规模冰川及其附近湖泊的时空变化,进一步证实了青藏高原山地冰川有进有退,但以广泛退缩为主,且在加速退缩,而附近湖泊的面积和数量都在迅速增加。冰川变化在不同海拔、坡向、坡度等地形特征的空间差异显著。小冰川变化敏感,在纳木那尼峰地区,面积小于1 km2的小冰川在2003~2007年,退缩和前进变化都已在加快。在纳木那尼峰北部玛旁雍错高海拔内陆流域,湖面的扩涨与缩小近年来也在加速。冰川与湖泊的加速变化很可能是青藏高原水循环过程加速的表征之一,这为人们进一步研究全球变暖对青藏高原冰川、水文、水资源的影响提供参考依据。