Temporal and spatial patterns of grassland coverage and responses to hydrothermic factors in Inner Mongolia from 2001 to 2016

The monitoring of remote sensing and research on the grasslands of Inner Mongolia is of great significance for the implementation of the national ecological engineering evaluation and related policy adjustments. In this study, Inner Mongolia is selected as the research scope, based on satellite remote sensing data, ground meteorological observation data and other statistical data. For which, we used the dimidiate pixel model to estimate the grassland coverage, analyze the spatial and temporal pattern of the grassland coverage from 2001 to 2016, and evaluate the responses to the changing climate factors. The restoration of grassland vegetation and the growth trends of the grassland have been quantitatively monitored and dynamically evaluated, which effectively reveals the restoration of grassland vegetation and the improvement of the grassland ecosystem. The results showed that the spatial distribution pattern of the grassland coverage in Inner Mongolia, over a 15 year period, gradually decreased from the northeast to the southwest, and the average annual grassland coverage was 37.90% with obvious meridional zonation. The grassland coverage of the northeast grassland area is the largest, the central steppe area is the second, and the western desert grassland area is the lowest. Overall, the trend increased with fluctuation. The grassland coverage increased from 35% to 38.84% during the study period. The average correlation coefficients between the grassland coverage and temperature is 0.058 (P > 0.05) and between grassland coverage and annual total precipitation is 0.269 (P > 0.05), indicating that grassland coverage was not significantly correlated with temperature and precipitation in Inner Mongolia.