Knowledge Mining Of The Environment And Properties Of Soil Types In Huangshui River Basin

Soil is the material basis of human survival and can also provide necessary nutrients and places for plants and animals.In order to meet the rapid development of precision agriculture,resource and environment management and eco-hydrological simulation,which require high precision of a large amount of soil information,digital soil mapping method is emerging.Based on the theory of the relationship between soil and environment,the key is to obtain the relationship between soil type and environment and the relationship between soil type and attribute.The specific contents and main conclusions are as follows:Based on the theory of soil genesis,terrain(DEM,slope,aspect,plane curvature,profile curvature,topographic wetness index),climate(annual average temperature,mean annual precipitation),biology(vegetation index),parent material(parent rock),human activities(land-use type)were selected.The correlation analysis of these environmental factors shows that DEM has very strong correlation with annual mean temperature,DEM with annual mean precipitation,and annual mean temperature with annual mean precipitation,and there is strong correlation between slope and topographic wetness index,plane curvature and profile curvature.Then principal component analysis was used to reduce the dimension of the factors.It was found that DEM,annual mean temperature,annual mean precipitation and slope had great influence on soil subtypes in the study area.Therefore,DEM,slope,aspect,plane curvature,vegetation index and parent rock were selected to explore the relationship between soil subtypes and environment.According to the rules excavated by See5 decision tree,the importance of environmental factors on soil subtypes in Huangshui River Basin is DEM,parent rock,vegetation index,slope,aspect and plane curvature.By inference mapping and verification,the rules of anthropogenic-alluvial soil are more reliable.It can be considered that the soil with an elevation less than 2240 m and the parent rocks of mesoproterozoic metamorphic ultrabasic rocks or with an elevation less than 2240 m and a slope less than or equal to 10.39°,a slope direction greater than56.08° and a plane curvature greater than-0.0209 is anthropogenic-alluvial soil.By analyzing the relationship between individual attributes and soil subtypes,it was found that some soil subtypes had thin soil layers and lacked soil attributes at 30-100 cm,so 0-30 cm was selected to explore the relationship between soil subtypes and attributes.It was also found that there was no significant difference in clay content of each soil subtype in the study area.The correlation analysis of soil properties shows that soil clay particles are highly correlated with sand particles.So does sand and cation exchange capacity.There was a strong correlation between silt and sand,clay and cation exchange capacity,and soil silt had a strong correlation with cation exchange capacity.Based on the above analysis,silt,sand,organic carbon and calcium carbonate are selected to explore the relationship between soil subtypes and properties.In the extracted rules,it was found that the soil silt content was the main basis for the classification of soil subtypes,followed by the content of organic carbon and calcium carbonate,and the contribution of sand to soil subtypes was small.By inference mapping and verification,the extracted rules of anthropogenic-alluvial soil,chestnut soil and brown-black felty soil can be used.It can be considered that anthropogenic-alluvial soil with silt content less than or equal to 6.65%and calcium carbonate content less than or equal to 2.7%.Chestnut soil with organic carbon content greater than 1.17% and less than or equal to 1.34%;When the content of powder is less than or equal to 13.31%,the content of organic carbon is less than or equal to 1.7%,and the content of calcium carbonate is less than or equal to 2.7%,it is brown-black felty soil.