Simulation of Seasonally Frozen Soil Freezing-Thawing Processes and the Spatial Distribution of Active Layer Depths Based on Modis Data in the Three-River Source Region, China

Abstract

：The processes of soil freezing-thawing lead to soil water and heat movement in cold regions, which significantly influences the hydrological and energy cycles in the soil-plantatmosphere system. This research presented a soil water content coupled with heat transfer model based on physical processes of water and heat movement in frozen soil. The model was calibrated and validated using the measured data of soil temperature and active soil depths at 19 stations in and around the Three-River Source Region of China. The results showed that the frozen soil model capture the processes of soil freezing-thawing well at this region. The relationship between model parameters and climate and vegetation factors was analyzed using the observation data and remote sensing data obtained by MODIS, and results showed that the model parameter c has a better correlation with longitude and vegetation coverage. A multi-regression model was established to estimate the model parameters in regions without observation data and its determination coefficient R 2 was 0.82. The mean relative error between calibration and inversion parameters of 19 stations is 6.29%. Thus, the proposed method can be applied to cold regions without observation data to obtain the parameters and simulated the soil freezing-thawing processes.

Temporal and Spatial Variation of Vegetation in Net Primary Productivity of the Shendong Coal Mining Area, Inner Mongolia Autonomous Region

“…Researchers have adopted a range of model approaches for studying vegetation or other ecological parameters in coal mining areas [18][19][20][21][22]. Additionally, the research mainly focuses on analyzing the relationship between the temporal and spatial variation characteristics of NPP and coverage in mining areas and their influencing factors.…”