| Desertification is one of the greatest environmental challenges facing the world today.It has a serious impact on human life and production,resulting in land degradation,reduced vegetation coverage,and frequent occurrence of natural disasters such as sandstorms,which has a great impact on social and economic development.Climate change is the main factor affecting desertification,and the impact process is very complex.How does climate factor change affect desertification? How is the impact? It is an important basic research content urgently needed in the research of improving desertification.Inner Mongolia Autonomous Region is a typical region seriously affected by desertification.Improving desertification has an important role in promoting local economic development.Taking Inner Mongolia Autonomous Region as the research area,based on the NDVI data of the research area and the precipitation,average temperature,average maximum and minimum temperature,wind speed,and ground temperature data of meteorological stations,this thesis uses correlation analysis,regression model,residual analysis and other methods to carry out the research on the impact of key climate factor changes on desertification.The main conclusions are as follows:(1)From 1982 to 2020,the situation of desertification in Inner Mongolia improved and the scope of desertification decreased.In 2020,the desertification area was 634300 km,45700 km less than in 1982.The severe and moderate desertification areas in Inner Mongolia are mostly concentrated in the western region of Inner Mongolia,while the mild desertification areas are mainly located in the central region of Inner Mongolia and the western region of Hulunbeier.Over time,the severe and moderate desertification in the western region has improved significantly.The period of severe desertification occurs from January to May,which is greatly related to the frequent occurrence of sandstorms,blowing sand,and floating dust in Inner Mongolia during this period.Severe desertification areas are more severely affected.The trend test analysis results of the Sen+Mann-Kendall method show that the area with serious vegetation degradation accounts for 5.05%,5.28%of the area with slight vegetation degradation,23.66% of the area with insignificant vegetation change,and 45.78% of the area with obvious vegetation improvement.In general,the desertification situation in Inner Mongolia has improved from 1982 to 2020.(2)From 1951 to 2021,the annual precipitation of the region showed a downward trend for many years.Summer is the main season with the most rainfall,followed by spring and winter has the least rainfall.In space,it showed a downward trend from west to east.The annual average evaporation has been declining for many years,with the largest evaporation in summer,which is lower in the east and higher in the west spatially.The annual average temperature has shown a significant upward trend for many years,and the warming trend in different seasons is quite different.The warming in spring and winter is the most obvious,showing a low in the east and a high in the west in space.The annual variation trend of the average maximum and minimum temperatures is basically consistent with the average temperature.The annual average wind speed has shown an upward trend for many years,with a relatively sharp range of change and a large seasonal difference.In space,it mainly shows an increasing trend from the middle to the four sides.The annual average ground temperature changes steadily over the years,with obvious seasonal differences.The temperature increase in spring and winter is the most obvious,and it mainly decreases from southwest to northeast in space.(3)The trend towards desertification in the Inner Mongolia Autonomous Region is increasing in most areas,due to the combined effects of climate change and Human-induced.About 30% of the regional desertification has improved under the influence of human activities,mainly concentrated in light desertification areas;About 70%of regional desertification under the influence of human activities has increased,mainly concentrated in severe and moderate desertification areas.Human activities have improved mild desertification areas and aggravated severe and moderate desertification areas.Effects of climate change,the degree of desertification in Inner Mongolia gradually decreases from west to east.Severe desertification areas are less affected by climate change,followed by moderate desertification,while areas with mild desertification are more affected by climate change.Climate change has made the desertification areas in Inner Mongolia better,especially in areas with low desertification have the greatest positive impact.(4)The trend of desertification in the Inner Mongolia Autonomous Region is increasing in most areas due to the combined effects of climate change and human activities.In the desertification improvement area,75% of climate change in the region is above 50%,and about 25% of the regional desertification improvement is mainly affected by human activities,mainly distributed in the west of Inner Mongolia.In the desertification aggravation areas,about 30% of regional climate change is the main influencing factor of desertification aggravation,occurs mainly in the south-western part of the Alxa League,and about 70% of regional desertification aggravation is mainly affected by human activities,mainly distributed in Ordos and Hohhot and other regions.This study reveals the desertification in Inner Mongolia,the spatiotemporal variability of key climate factors,and the qualitative and quantitative impact of the change of key climate factors on desertification in Inner Mongolia,which enriches the basic results of desertification research,has certain scientific significance,and provides a reference for China to improve the desertification environment. |
