Research On Land Use Change Of Qinghai-Tibet Plateau Based On Multi-Source Data

The Qinghai-Tibet Plateau has complex terrain and unique climate type.It is very important to explore the land use change of the Qinghai-Tibet Plateau to grasp the environmental conditions and environmental protection and restoration.The Qinghai-Tibet Plateau is selected as the research area.Based on a total of seven periods of land use remote sensing monitoring data,socio-economic statistics,meteorological data from 1980 to 2015 by using transfer matrix,trend line analysis and other methods,the changes and driving factors of land use in six different periods are studied.Then the transition probability matrix is calculated based on the current land use situation.The suitability atlas is produced in combination with terrain,climate,socio-economic data,etc.The land use change of the Qinghai-Tibet Plateau is predicted by the CA-Markov model,and reasonable suggestions are put forward.The results show that:(1)The grassland distribution range of Qinghai-Tibet Plateau is the largest,and cultivated land and construction land occupy the least area in the entire region.The distribution areas are mainly near waters and roads and railways.From 1980 to 2015,the distribution range of grassland,arable land,construction land,and unused land continue to expand,while forest and waters decrease.Construction land increase most sharply,mainly transfers from unused land and grassland.The transfer-out contribution rate of waters is the largest.And the proportion of unused land transfer-in area is the largest.There is frequent exchange between these two types.In the secondary classification,other construction land expands sharply,with the area of permanent glaciers and snow decreasing the most.(2)Economy,crop sown area and climate are the main affecting factors of land use change.During the study period,the population increase significantly,and the speed of economic development and urbanization increase rapidly in the Qinghai-Tibet Plateau.The annual average temperature and annual precipitation both show an upward trend.The temperature change trend is significant,but the precipitation change is slow.Climate change,the implementation of national policies,the opening of the Qinghai-Tibet Railway,and the continuous development of economy and population promote the increase in the area of cultivated land and construction land.The increase of precipitation and temperature provides the necessary moisture and heat for the growth of grassland.And the permanent glacier and snowfield transforms into bare rock texture.This is the main reason for the increase in the area of grassland and unused land and the decrease in waters.Rising temperature increases surface evapotranspiration in woodland with good growth condition.And increased intensity of human disturbance leads to a decline in forest.(3)By 2025,the area of grassland and unused land will account for the largest proportion of the overall area of the Qinghai-Tibet Plateau,while farmland and building land will be the smallest.From 2015 to 2025,the changes of forest,grassland,waters and unused land are stable.The area of unused land expands gradually,while woodland and grassland are on the contrary.Cultivated land and construction land expands significantly.The expansion mainly occurs near the Yarlung Zangbo River,Qinghai Lake and along the Qinghai-Tibet Railway.Therefore,the Qinghai-Tibet Plateau should allocate cultivated land and construction land reasonably,strengthen the control of animal husbandry,and optimize the allocation of forest resources.