Glacier elevation change during two periods in the Lenglongling mountains derived from bistatic SAR interferometry

Abstract

Bistatic SAR interferometry is a feasible technique of deriving glacier height changes. Early studies on glacier change in the Qilian Mountains showed that the glacier area declined, terminus retreated, and flow velocity slowed down. In this study, five pairs of X-band bistatic TerraSAR-X/TamDEM-X images from 2014 to 2019 and an iterative D-InSAR method respect to SRTM DEM of 2000 were employed, which improved the reliability and accuracy of glacier height changing observations. From 2000 to 2014, the height of glaciers in the Lenglonglin Mountains decreased by (–0.64 ± 0.06) m year−1. Glaciers in the Gangshika peak and its surrounding region thinned at the rate of (–0.68 ± 0.09) m year−1 from 2014 to 2019. The values observed using remote sensing was in accordance with RTK–GPS measured values. Stable precipitation and increasing temperature since 1990 could be responsible for the quick glacier mass loss.