Glacier change over the past four decades in the middle Chinese Tien Shan

摘要

Terminus fluctuation and area change in mountain glaciers in the middle Chinese Tien Shan over the past four decades are examined, based on Landsat multispectral scanner (MSS), Enhanced Thematic Mapper Plus (ETM+), Système Probatoire pour l'Observation de la Terre (SPOT) high-resolution visible (HRV) imagery, topographical maps and China Glacier Inventory data using Geographical Information System (GIS) and remote-sensing techniques. This study shows that the glaciers in the study area have undergone continuous recession between 1963 and 2000. Over the past 37 years the total glacier area decreased from 55 × 106 m2 to 48 × 106 m2 (a 13% decrease). The glaciers at low elevations decreased more rapidly than those at high elevations. Seven of the ten large valley glaciers in the study area retreated by at least 150 ± 49 m during this period. The average rate of recession for these glaciers was 4-8 m a?1. The recession rate between 1986 and 2000 was larger than between 1963 and 1986. The glacier changes in the study area were similar to those in the ürümqi river basin in the northern Chinese Tien Shan. It is apparent that temperature rise over the past four decades has had a profound impact on these glaciers.