Research progress on hydrological effects of permafrost degradation in the Northern Hemisphere

• Published in: Geoderma
• Main Authors: Wenwen Li, Denghua Yan, Baisha Weng, Lin Zhu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2023
• Subjects: Climate warming; Hydrological effect; Permafrost degradation; Cryosphere; Cold regions; Soil water content; Science; Q; permafrost
• Online Access: https://doi.org/10.1016/j.geoderma.2023.116629; https://doaj.org/article/a0fe1cd8829c49faa3023c88c0f317ae

Permafrost degradation alters the flow rate, direction, and storage capacity of soil moisture, affecting ecohydrological effects and climate systems, and posing a potential threat to natural and human systems. The most widely distributed permafrost regions are coastal, high-latitudes and high-altitudes (mainly by the Qinghai-Tibet Plateau). Past studies have demonstrated that permafrost degradation in these regions lacks sorting out regional driving factors, assessing cascading effects on the hydrological environment and monitoring methods. To address this, we reviewed the historical research situation and major topics of permafrost degradation from 1990 to 2022. We analyzed the spatio-temporal dynamics and driving mechanism of permafrost degradation. Then, we comprehensively discussed the effects of permafrost degradation on the soil physical structure and hydraulic properties, soil microorganisms and local vegetation, soil evapotranspiration and stream runoff, and integrated ecohydrological effects. Permafrost field site data were then collected from existing findings and methods for direct or indirect monitoring of permafrost changes at different scales. These results revealed that the research on the hydrological effects of permafrost change was mainly centered on the soil. In addition, regional environmental factors driving permafrost degradation were inconsistent mainly in coastal regions influenced by sea level, high-latitude regions influenced by lightning and wildfire, and high-altitude regions influenced by topography. Permafrost degradation promoted horizontal and/or vertical hydrological connectivity, threatening the succession of high latitude vegetation communities and the transition from high altitude grassland to desert ecosystems, causing regional water imbalances would mitigate or amplify the ability of integrated ecohydrological benefits to cope with climate warming. The never-monitored permafrost area was 1.55×106 km2, but the limitations of using data for the same period remained a ...