Study On Dynamic Of Soil Erosion In Red Soil Region Based On Evenly Sample Survey

Soil erosion,called "the peristaltic disaster",is one of the most common and strongest persistent gradual natural disasters faced by human beings.Changting country of Fujian province,a typical degradation region of Red Soil Region and a typical area of water erosion desertification in subtropical granite hilly area,was chosen as study area.And it was also a pilot county which needed to be emphasized for governing.Thus,in this paper,we analyzed the temporal and spatial characteristics of soil erosion,explored the correlation between soil erosion and environmental factors and predicted the future change of soil erosion by using Chinese soil loss equation(CSLE)and sampling survey method which used by the first national water conservancy survey together.So as to scientifically evaluate the results of ecological restoration,provide scientific basis for making government measures,and provide source for establishing the basic design framework of sampling survey method of the key management area.The results indicated that:1)We constructed the basic design framework of 125 small watersheds based on uniform sampling proportion and the spatial data sets of the environmental factors in Changting country.2)The erosion still heavily taken place in Hetian basin and the central and southeastern part of Changting was relatively heavy,but soil erosion in western and northern is the lowest.3)Seen from the time of change,in addition to the sharp increase of micro erosion and slight increase of moderate erosion,other types of erosion decreased in Changting from 2008 to 2013 years,so we concluded the overall ecological environment has improved although the deteriorating type was still 5.67%.Seen from the spatial variation of soil erosion,the center part of the study area fell most obviously and the erosion rate 6.89%in five years,followed by southeastern area,decreased 4.6%.4)Soil erosion was mainly distributed in 300～450m elevation area the slope degree ranged 8～25,where human activity is more frequent and the slope aspect slightly influenced the soil erosion.The plant measures had better soil and water conservation effect,and with the increase of vegetation coverage,soil and water loss rapidly improved.The new places occurred soil erosion was always industrial land,abandoned mine land and traffic land;5)We predicted the development trend of soil erosion in the study area by Markov chain and concluded that the Soil erosion phenomenon still developed benignly and the dynamic change tended to reach stability in 10 years...