Research On Land Use And Land Cover Change Of District Of Northern Henan Province In The Past 25 Years

District of Northern Henan Province that is a representative type of Yellow River alluvial plain is abundant of sandlot and alkali land.However,after years of governance,much sandlot and alkali land has been changed to Shelterbelt and farmland.For this reason,the quality of ecological environment was significantly improved.Therefore,through combining the research on reduction of sandlot and alkali with research on land use / cover change,while giving dynamic analysis on local ecological environment,this paper contributes to reconstruction of local ecological environment.In addition,this paper provides a scientific foundation to sustainable use of land resources.Based on the RS data source,application of GIS technology,combined with the GPS survey,with Neihuang county as an example,this paper gets layers of land use / cover change of 1979,1990, 2003,which represent three different periods.Through GIS spatial data analysis,this paper gets data of all land-use types and data of transfer between different land-use types.This paper also analyzes change of land quantity and change of space characteristics of different land types.Moreover,it calculates the value of ecosystem services in the region.Besides,it analyzes the regional ecological environment quality evolution.The paper gets hold of conclusions as following:(1) situation of land useCultivated land is the majority type for Land use.The second most land type is sandlot and alkali land in 1979,woodland in 2003 instead however.The least land type is garden plot in 1979,water land in 1990 and 2003 instead.Therefore,acreage of cultivated land,water land,unused land is declining through 1979 to 2003.On the other side,woodland,garden plot,transportation and construction land is increasing through 1979 to 2003.(2) Changes on vegetation cover indexIn 1979,the main vegetation coverage type of Neihuang County was common coverage rate land. Acreage of common coverage rate land was 59682.172 hektare.This was followed by the very low coverage rate land.Acreage of the very low coverage rate land was 25488.236 hektare.The high coverage rate land was the least.In 1990,the main vegetation coverage type of Neihuang County was also common coverage rate land.Acreage of common coverage rate land was 55026.295 hektare. This was followed by the comparatively high coverage rate land.Acreage of the comparatively high coverage rate land that mainly in the form of sand wasteland was 35421.354 hektare.In 2003,the main vegetation coverage type of Neihuang County was also common coverage rate land.Acreage of common coverage rate land was 51482.672 hektare.This was followed by the comparatively high coverage rate land.Acreage of the comparatively high coverage rate land was 45682.702 hektare. The rule of vegetation coverage changes is that Acreage of land of high coverage and by the high coverage is increasing year by year.Acreage of land of lower coverage is declining year by year. What's more,Acreage of land of the lowest coverage declined most.(3) Analysis on the value of ecosystem servicesIn 1979,the value of ecosystem services of Neihuang County was 987,082,480 CNY.In 1990, the value of ecosystem services of Neihuang County was 1,178,860,671 CNY.In 2003,the value of ecosystem services of Neihuang County was 1,248,431,186 CNY.From 1979 to 2003,the value of ecosystem services of Neihuang County had increased by 261,348,710 CNY.Data indicates a growing trend of the service value that provided by Neihuang County ecosystem.Through the research it can be found that the quality of the ecological environment is becoming better and better with environmental quality improved significantly.