Soil Erosion And Soil Particle Distribution Characteristics Under Different Land Use Types In Jianghuai Hilly Region

In order to further explore the relationship between land use types and soil erosion in Jianghuai Hilly Area and soil particle composition characteristics of different land use types,This research has chosen Jianghuai Hilly Region of Huaihe River Basin as the study area.This study used a combination of remote sensing surveys,sample plot surveys,and sample tests to study the characteristics of soil erosion and soil particle distribution under different land use types in the Jianghuai Hilly Region.Based on the remote sensing images of the two phases of the study area?2007 and 2015?,this paper analyses the distribution of land use types and the dynamic characteristics of soil erosion in the key areas of soil erosion under the support of ArcGIS.Based on the soil fractal theory and model,using the laser diffraction technology?laser particle size analyzer?of soil particle size analysis,this paper studied the distribution and fractal characteristics of soil particles under different land use types.The results can provide reference and basis for understanding the characteristics of soil particles in key areas of soil erosion and their land use types in the Jianghuai Hilly Region.Main results are as follows:1 Erosion characteristics of different land use types?1?Land use types and erosion distribution in Jianghuai Hilly RegionThe land use type of Jianghuai Hilly Region in Huaihe River Basin is dominated by farmland,which accounts for 49.21%of the total area of Jianghuai Hilly Region.The proportion of orchard land,forest land,grassland,urban village and industrial and mining land,transportation land,Water and water facilities land and other land is 8.21%,13.3%,4.19%,8.48%,2.64%and 13.96%respectively.The area of soil erosion in 2015 is1409.58km²,which accounts for about 10.21%of the total area of the Jianghuai Hilly Region.The erosion intensity is mainly light erosion.From the spatial distribution,the Hilly of Fengyang,Dingyuan,Mingguang in Anhui Province,and Xuyi in Jiangsu Province,are serious soil erosion areas,and the soil erosion area accounts for about 79.87%of the total soil erosion area.Among different types of land use,the farmland erosion area is the largest,followed by the forest land,the grassland.Erosion mainly occurs in sloping farmland with larger undulating underlying surface and worse conditions.Erosion also occurs in sparse forests,sloping economic forests and barren slopes with relatively large slopes and poor vegetation coverage.?2?Dynamics of soil erosion in different land use types in key areasThe land use structure in the interpreting area is the same as that of the entire Jianghuai Hilly Region,but the main land is farmland and forest land.The farmland is mostly sloping farm land except for some measures for farmland.The soil erosion area decreased by 1.85%in 9 years between 2007 and 2015,decrease of 0.21%annual.In view of different types of land use,compared with the year of 2007,the soil erosion areas of all types of land use in2015 have declined,and the soil erosion areas of slope grassland and forest land have changed by a wide margin.The reduction area accounts for the total area of the study area respectively.1.11%and 0.55%.It shows that soil erosion control has been carried out in the region,and a series of measures have been implemented.However,the effect was not obvious,and the intensity and area of soil erosion decreased slowly.2 Soil particle distribution characteristics of different land use types?1?Characteristics of soil particle composition in different land use typesThe soil PSD showed obvious heterogeneity among different sizes of plots under different land use types.The distribution of soil particles in Dingyuan county is large,and the variation of the curve is small.More than 80%of the soil particles in the study area were concentrated in the range of 0.01-0.2 mm.The soil particles in Xuyi county are mainly concentrated in the powder range of 0.02⁰.05mm,and the soil particles in Dingyuan county are mainly concentrated in the range of 0.002-0.25mm powder and medium fine sand grains.The clay content of each land use type in Dingyuan county is significantly higher than that in Xuyi county.?2?Fractal features of soil particles in different land use typesThe range of single soil fractal dimension??under different land use types in Xuyi County is 2.4156².4625,and slope farmland>forest land>slope orchard>slope grassland;In Dingyuan County,the range ofis 2.4555².4993,and forest land>slope grassland>slope orchard>slope farmland.The fractal dimension of slope farmland in Xuyi County is greater than that of other land use types,and the soil texture is also better than other types.And all the various fractal parameters of the sample showed trends in₀>₁>₂ under different and use type.The value range of₀ is 0.8001⁰.9364?R²>0.9947?.The value range of₁ is 0.7008⁰.9531?R²>0.9852?.And the value range of₂ is 0.6722⁰.9052?R²>0.9805?.In the sampling point of the two counties,all the multifractal parameters almost follow the same order.But the order is not the same between these two counties.The order of Xuyi county is slope orchard>forest land>sloping farmland>slope grassland.The order of Dingyuan county is sloping farmland>slope grassland>forest land>slope orchard.?3?Correlation between fractal dimension and particle composition of soil particlesThe correlation betweenand soil size of different grain sizes is obviously different.There is a significant positive correlation between the content ofand the content of clay particles.Soil clay,silt and sand have a very significant correlation with₀?₁?₂.Moreover,there is a consistent correlation between clay silt and multifractal dimension.And the sand is the opposite.?4?Correlation between soil particle fractal dimension and soil physical and chemical propertiesSoil bulk density?the total porosity and non capillary porosity was correlated with soil particle fractal dimension,but the correlation was not significant.The soil steady infiltration rate is significantly negatively correlated with?P<0.01?.And it has a very significant positive correlation with multifractal dimension.Organic carbon and total phosphorus were significantly negatively correlated with?P<0.01?.And It is also related to other multiple dimensions,but the correlation is not significant.