Acta Geographica Sinica ›› 2020, Vol. 75 ›› Issue (3): 470-484.doi: 10.11821/dlxb202003003

• Climate Change • Previous Articles     Next Articles

Monitoring of snowline altitude at the end of melting season in High Mountain Asia based on MODIS snow cover products

WANG Xiaoru1,2, TANG Zhiguang1(), WANG Jian3, WANG Xin2,3, WEI Junfeng2   

  1. 1. National-local Joint Engineering Laboratory of Geo-spatial Information Technology, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China
    2. Department of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China
    3. Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
  • Received:2019-01-23 Revised:2019-12-14 Online:2020-03-25 Published:2020-05-25
  • Contact: TANG Zhiguang E-mail:tangzhg11@hnust.edu.cn
  • Supported by:
    National Nature Science Foundation of China(41871058);National Nature Science Foundation of China(41501070);National Nature Science Foundation of China(41701061);National Nature Science Foundation of China(41771075);Natural Science Foundation of Hunan Province(2018JJ3154)

Abstract:

The remote sensing extraction method of large-scale snowline altitude at the end of melting season is developed based on MODIS snow cover products. The spatial and temporal variation characteristics of snowline altitude at the end of melting season of the High Mountain Asia during 2001-2016 are detailedly estimated on a grid-by-grid (30 km) basis. In this method, the cloud removal of the daily MODIS snow cover products was firstly carried out based on the developed cubic spline interpolation cloud-removel method, and snow covered days (SCD) of the 16 years are extracted using the cloud-removed MODIS snow cover products. In addition, the MODIS SCD threshold for estimating perennial snow cover is calibrated using the observed data of glacier annual mass balance and Landsat data at the end of melting season. Finally, the altitude value of the snowline at the end of melting season is determined by combining the perennial snow cover area and the terrain area-elevation curve. The results are as follows: (1) There is strong spatial heterogeneity of the snowline altitude at the end of melting season in the High Mountain Asia, and the snowline altitude at the end of melting season generally decreases with the increase of latitude. Under the influence of mass elevation effect, snowline altitude at the end of melting season gradually decreases from the high altitude area to the surrounding low mountainous area. (2) Generally, the snowline altitude at the end of the melting season from 2001 to 2016 in High Mountain Asia shows an obvious increasing trend. In the 744 monitoring grids (30 km), the snowline altitude at the end of melting season in 24.2% of the grids shows a significant increasing trend, while only 0.9% with a significant decrease. The snowline altitude at the end of melting season shows an increasing trend almost in the whole the High Mountain Asia, except for the regions of Hindukush and West Himalayas. The Tianshan Mountains, central and eastern Himalayas and Nyainqentanglha mountains show a significant increasing trend, and the eastern Himalayas experiences the most significant increase of 8.52 m yr -1. (3) The summer temperature is the main factor affecting the change of snowline altitude at the end of melting season in the High Mountain Asia, with a significant positive correlation (R=0.64, p<0.01).

Key words: snowline altitude, MODIS, snow cover products, High Mountain Asia, remote monitoring