Study On The Ecological Environment Of Land In Changwu County In Recent 30 Years

The Loess Plateau is one of the important cradles of human civilization in our country.Because of its special climate,terrain conditions and the unreasonable development and utilization of human beings in history,resulting in serious soil erosion and deterioration of the ecological environment.In order to manage the fragile ecological environment and develop the regional economy,the ecological and economic projects such as Grain for Green Project and Western Development Strategy have been carried out after 1999.The regional land use situation has changed greatly and the ecological environment has changed obviously.Changwu county is located in the hilly gully region of the Loess Plateau and representative in the central and southern region.Studying on land use change and its impact on ecosystem services value,ecological security in Changwu County,can realize the influence of human activity on regional environment.For local government,it is helpful for optimizing relevant policies to promote the sustainable development of the regional economy.In this study,1990,2000,2005,2010 and 2015 were selected as five time points during past thirty years.Based on the TM/OLI images,using the human-computer interaction,got the five phase of land use data.Then using land use dynamics,transfer matrix,land use degree and landscape index,analyzed the trend of land use types change,the rate of land use types change,the transition of land use types,the land using degree and the spatial variation trend of land use types change.According to the actual situation of Changwu County,calculated the ecosystem service values and analyzed the change of ecosystem service values.Based on above analysis and the socioeconomic data,13 evaluation indexes were selected to construct the PSR evaluation model.Then using the PSR evaluation model evaluated the ecological security status in Changwu County.The results showed that:(1)Cultivated land and grassland expressed a decreasing trend,while forest land,orchard,industrial land,mining land,residential land showed an increasing trend.Water,unused land area change is relatively small.The comprehensive utilization index change is small,which means the land use was in a state of adjustment.(2)The land use change makes the landscape shape complicated,the structural diversified and the landscape pattern fragmentation increased.(3)The total value of ecosystem services is increasing,and the value of individual ecological services is increased except for food production,and the ecological environment has improved.(4)The ecological security status of the land has changed from moderate warning to good.The current land use and ecological protection policy is beneficial to the ecological restoration of the land.However,considering the particularity of the ecological environment of the Loess Plateau,we should constantly optimize the current policy to promote regional sustainable development.