Environmental Characteristics of High Ice-Content Permafrost on the Qinghai–Tibetan Plateau

Abstract

Permafrost areas are sensitive to climate change and have a significant impact on energy and water cycles. Ground ice is a crucial component on the Qinghai–Tibetan Plateau (QTP). Understanding the environmental characteristics of ground ice is vital for accurately modeling its distribution and evolution. In this study, we analyzed 15 environmental characteristics of high ice-content permafrost sites. These attributes were extracted from 400 high ice-content permafrost datasets including 300 drilling boreholes and 100 thaw slumps collected throughout the entire plateau using large-scale remote sensing data and their products. The results are as follows: The mean annual air temperature in areas where high ice-content permafrost exists ranges from −5 to −3.5 °C, with an average warming rate of 0.08 °C/a. Additionally, there was an average increase in precipitation of about 25 mm/10a and an increase in soil moisture of about 4%/10a. Geomorphology strongly influences the occurrence of high ice content permafrost, with 85% of high ice-content permafrost development at altitudes between 4400 and 5100 m. Approximately 86% of high ice-content permafrost were developed in lowland or relatively flat areas, preferably in gently sloping and shady slope regions. Soils exhibit less variability in clay particles and more variability in silt and sand. Key indicators in the high ice content permafrost region include warming rate, active layer thickness, elevation, bulk density, soil thickness, clay content, precipitation, soil moisture, and NDVI. High ice-content permafrost is the result of a combination of environmental factors and is expected to undergo significant changes in the future. This study provides a foundation for comprehending the environmental changes in the high ice-content permafrost areas and modeling the distribution of ground ice. It underscores the urgent need to address the significant environmental changes faced by high ice-content permafrost regions.

Impact of Ecological Restoration on the Physicochemical Properties and Bacterial Communities in Alpine Mining Area Soils

“…The warm season spans from May to September, with an average temperature of 5.5 • C, peaking at 19.7 • C, and showing a daily temperature fluctuation of 25.1 • C. Rainfall mainly occurs during the warm season, contributing to an average annual precipitation of 375.2 mm, with over 80% being heavy rainfall. The area is predominantly covered by alpine meadow-type flora, including Elymus nutans, Poa crymophila, Elymus sibiricus, and Festuca sinensis [20]. These natural grasses are crucial pastureland for local herders, supporting their livelihoods.…”

Spatiotemporal Distribution Characteristics and Influencing Factors of Freeze–Thaw Erosion in the Qinghai–Tibet Plateau

“…The QTP is a typical FT erosion area in China due to its high latitude, high altitude, and low temperature [22]. Indeed, the QTP includes the largest and most extensive permafrost area in the world's low and middle latitudes [23], accounting for about 49.3% and 5% of the permafrost area in China and worldwide, respectively [24]. In this context, 11 factors were selected in this study to assess the intensity and spatial distribution characteristics of FT erosion in the QTP using ArcGIS 10.7 software, including not only the seven basic influencing factors of FT erosion, namely the annual temperature difference (ATD), annual mean precipitation (AMP), slope degree, slope aspect, elevation, vegetation coverage (NDVI), and soil-sand content, but also four additional factors, including maximum freezing depths (MFD), active layer thicknesses (ALT), thaw slumps, and rock glaciers.…”