| Land Use/Cover Change(LUCC),as the result of the joint action of human activities and natural factors,can reflect changes in regional ecological eco-environment objectively,so it's important to study on LUCC and its ecological effect.Panxi area,where the natural environment is complex and the socio-economic is different,with rapid urbanization and unreasonable land use,has brought about a series of problems,such as ecological deterioration and the increasingly prominent contradiction between human and land.In this background,summarizing the status of Land Use/Cover in Panxi area,studying the temporal and spatial evolution of LUCC,and analyzing the driving mechanism of LUCC,and the study of the eco-environmental effects of the LUCC in Panxi area was conducted from three aspects:landscape pattern,ecological services value,and ecological risk assessment.Provide scientific basis for economic transformation and industrial upgrading in Panxi.The main research results obtained in this study are as follows:(1)Woodland,grassland,and cultivated land has always been the main types of the Panxi area,and the woodland is most.during the 25 years from 1990 to 2015,the LUCC in the Panxi area was intense,and many cultivated lands and grasslands transform to the woodlands.The woodland,water body,construction land and unused land increased,and the water body grew rapidly after 2010,showing a nonlinear characteristic.From the four internal divisions in the Panxi area,the difference is large,The trend of LUCC in the southern area is different.From 1990 to 2010,the LUCC trend in the southern area is similar to the Panxi area,but during the five years from 2010 to 2015,the area of cultivated land and grassland in the Southern area began to increase,and the area of cultivated land recovered to the level of 1990,the woodland in the area was reduced and converted into cultivated area;the woodland was increased rapidly in Liangshan area after 2010,increasing by 1673.38 square kilometers in 5 years,with a proportion of 18.82%.(2)Slope has enormous influence on the LUCC in the Panxi,the LUCC is most severe in the area more than 25° in slope degree,many grasslands and cultivated lands are transform to the woodland and unused land.The altitude has a greater impact on the LUCC,in the 3000m-4000m,77.28%of the cultivated land is transform to others,and many grasslands is transformed in middle and high altitudes.The soil has a greater impact on cultivated land and grassland,and the cultivated land in yellow-brown soil is particularly reduced,the grassland in paddy soil and red soil area is reduced more.Among the social and economic factors,the factors such as agricultural population,agricultural output value and grain yield have a significant impact on the land use change in the Panxi area,The southern area's cultivated land increased from 2010,it was affected by the policy.(3)From the view of landscape pattern,the grassland patch fragmentation is the highest in Panxi,which is most disturbed by human activities,the woodland was in an important position of absolute superiority.from the regional point of view,the level of urbanization is low in the Yanyuan and Muli,and the level of urbanization is hgh in the Anning valley and Southern area;the Southern area and the Liangshan area are disturbed by human activities highly,and the MuliYanyuan area is affected by human activities less.In terms of the value of ecological services,the total value of ecosystem services has continued to increase in the past 25 years in the Panxi area,but the overall trends in the Southern is different,and the value of ecological services has decreased.In terms of ecological risks,the overall pattern of ecological risks in the Panxi is relatively stable and continues to decrease.Although the area of low ecological risk areas continued to increase,the area of higher ecological risk areas and high ecological risk areas also increased,mainly due to the large increase in the area of unused land in central Yanyuan area. |
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