Characteristics And Models Of Soil Moisture Under Different Land Types In Mountainous Area Of ​​Qinling Mountains

This paper studied Xunyang town, Shaanxi County of Ningshan Province at Water Cathment Region of Central Route for South-to-North Water Diversion Project and in medium mountain areas of the Qinling mountains.This place has implemented natural forest protection project since 1998. The forest coverage rate has increased and water sources have conserved. The environment in this district has improve. The purpose of this paper is to more in-depth study soil moisture variability in 0～100cm under different land use types and provide theoretical support for vegetation restoration, ecological construction and forest management.To analyze soil moisture vertical variability in different land use types in Zhongshan district,soil moisture correlation and soil moisture storage capacity prediction this study collected 0～100 cm profile field sampling in Xunyang dam area. 0～100 cm profile soil moisture under five land use types(Pinus tabulaeformis Carr,Walnut orchard,Corylus ferox,Deyeuxia arundinacea,Corn slope farmland) in descriptive statistical analysis was analyzed by statistical software SPSS19.0. Soil moisture vertical distribution and the main different of soil moisture under five land use types was revealed by excel software. Soil moisture vertical variability under different land use types is analyzed by semi-variance function and Gs+7.0 software. Based on 0-20 soil moisture capacity soil moisture vertical model under different land use types was established and tested.(1)Under different land use types 0～100cm soil vertical moisture variability range was between 10.14% and 21.91%. The average content of soil vertical moisture was: Deyeuxia arundinacea>Corn slope farmland>Corylus ferox> Walnut orchard>Pinus tabulaeformis Carr.(2)The main different of soil vertical moisture in Deyeuxia arundinacea was located at 30～40cm, The main different of soil vertical moisture in Corn slope farmland was located at 20～30cm. The main different of soil vertical moisture in Corylus ferox, Walnut orchard and Pinus tabulaefornis was lower than in Deyeuxia arundinacea and Corn slope farmland. Soil moisture in Corylus ferox began to decline from the 40cm and was a downward trend with depth. Therefore The main different of soil vertical moisture in Corylus ferox was in the following 40cm. Soil moisture in Pinus tabulaeformis Carr and Walnut orchard began to decline from the 60cm and was a downward trend with depth. Therefore the main different of soil vertical moisture in Pinus tabulaeformis Carr and Walnut orchard was in the following 60cm.(3)Common feature of soil moisture in Pinus tabulaeformis Carr,Walnut orchard and Corylus ferox is that the upper soil moisture was than those in the lower and there were obvious deffernces between the upper and the lower. The average soil moisture of Deyeuxia arundinacea and Corn slope farmland in the following 70cm was greater than that in 70cm above,this kind of change in Deyeuxia arundinacea is more obvious than change in Corn slope farmland. The average soil moisture of Corylus ferox in 50cm above was the most and was 20.10%,the average soil moisture of Pinus tabulaeformis Carr in 50cm above was the least and was 13.40%, the average soil moisture of Deyeuxia arundinacea in 50cm above was the middle and was 18.36%. The average content of soil vertical moisture in the following 50cm was:Pinus tabulaeformis Carr< Corylus ferox< Deyeuxia arundinacea, the average content of soil vertical moisture in Pinus tabulaeformis Car was 11.34%, the average content of soil vertical moisture in Corylus ferox was 15.40%, the average content of soil vertical moisture in Deyeuxia arundinacea was 19.09%.(4)For the whole profile,C/C+C0 of Deyeuxia arundinacea was 0.19 and had strong spatial correlation; C/C+C0 of Pinus tabulaeformis Carr, Walnut orchard,Corylus ferox and Corn slope farmland were greater than 75%,the four kind of land use types had weak spatial correlation. The range of soil vertical moisture was betreen 0.53 and 0.83,the range in Deyeuxia arundinacea was the most and was 0.83. Under different land use types soil moisture semi-variance function model of the optimal choice is: Pinus tabulaeformis Carr,Walnut orchard,Corylus ferox for the Gaussian model, Deyeuxia arundinacea for linear model,Corn slope farmland for the spherical model.(5)Taking the single factor correlation analysis as a main analytical tool,this paper revealed soil moisture and soil ph in Pinus tabulaeformis Carr and Walnut orchard had a significant positive correlation,however soil moisture and soil ph in Deyeuxia arundinacea had a significant negative correlation.soil moisture and soil grain size in Pinus tabulaeformis Carr had a significant negative correlation. soil moisture and soil organic matter in Pinus tabulaeformis Carr,Walnut orchard and Corylus ferox had a significant positive correlation.(6)According to multiple regression analysis of SAS, Based on 0～20 soil moisture capacity soil moisture vertical model under different land use types is established and tested. The minimum accuracy of soil moisture vertical prediction model was 96.27%,this accuracy was considerable. Thus,the credibility of soil moisture vertical prediction model under different land use types was relative high and forecast the moisture from deep soil well.