Monitoring Rock Desert Formation Caused by Ice–Snow Melting in the Qinghai-Tibet Plateau Using an Optimized Remote Sensing Technique: A Case Study of Yushu Prefecture

Abstract

The rapid and effective identification of the spatial distribution of rock deserts in ice–snow melting areas can provide useful information for the prevention of natural disasters. In this study, Landsat TM/OLI were used to track the evolution of snow lines in the snow melting areas of Yushu Tibetan Autonomous Prefecture of the Qinghai-Tibet Plateau (hereinafter referred to as Yushu Prefecture) during the last 30 years. A total of seven extraction schemes were used to classify the rock desert in the ice–snow melting area by remote sensing. Our results show that: (1) The accuracy of the multi-index factor compound analysis and object-oriented classification compound method was the highest. This method can provide a rapid and efficient reference scheme for rock desert extraction in the plateau ice–snow melting area. (2) The combinations of two single methods with higher accuracy can further improve the total accuracy. If a single method with lower accuracy is involved in the multi-method fusion, the accuracy of the method with lower accuracy can be improved. (3) In the past 30 years, there has been a large amount of ice–snow melting in Yushu Prefecture. The ice–snow melting area accounts for 53.78% (1451.04 km2) of the ice–snow area, and the bare rock and bare stone in the rock desert account for 63.77% of the total area of the ice–snow melting area. Bare sand and bare soil area account for 30.27% of the total area of ice and snow melting area.

Geographically and Ontologically Oriented Scoping of a Dry Valley and Its Spatial Characteristics Analysis: The Case of the Three Parallel Rivers Region

“…In the binary classification task, the verification samples were divided into true positive (TP), true negative (TN), false positive (FP), and false negative (FN) categories. This study used a confusion matrix to measure the accuracy of the results according to overall accuracy (OA), producer accuracy (PA), user accuracy (UA), and kappa coefficient (Kappa) [47,48] (Equations ( 4)-( 7)).…”

Monitoring rock desert formation caused by two different origins (ice-snow melting and drying) in the Qinghai-Tibet Plateau of China by considering topographic and meteorological elements

“…The concrete manifestations include soil coarsening, nutrient and water content tending to decrease, and vegetation coverage and productivity obviously decreasing. Based on the particle size of surface weathered material particles, we can divide the rock desert into bare rock, bare stone, bare gravel, bare sand, and bare soil (Zhao et al, 2019;Jia et al, 2022). According to the different driving forces, we divided the rock desert into the ice-snow melting and dry areas.…”

“…Taking climate zoning as the main indicator, combined with external forces as well as current land use and surface characteristics of degraded land, the Qinghai-Tibet Plateau desert can be divided into arid desert and freeze-thaw desert (Wang and Sun, 1996;Li et al, 2005). And freeze-thaw desert includes rock desert in ice-snow melting areas (Jia et al, 2022).…”