Characteristics Of Soil Physicochemical Property Changes During The Oasis Of Mu US Desert

The artificial oasis formed through oasisification is the basis for sustaining people’s life and economic development in arid areas,and good soil properties are fundamental for sustainable development.Therefore,it is important to clarify the evolution characteristics of soil properties during the process of oasis formation for the sustainable and rational use of sandy land resources and to promote the improvement of local ecological environment.In order to reveal the characteristics of soil physical and chemical property changes during the oasisification process of Mu US Desert,In this thesis,we use ENVI5.3 and Arc GIS10.7 as the platform to interpret the desertification of the 8-phase remote sensing images of Mu US Desert from 1986-2021,outline the reversal of desertification of Mu US Desert in the past 35 years,and by constructing the desertification index DDI of Mu US Desert in 2021 and classifying the land of Mu US Desert into non-,mild,moderate,severe and very severe according to the natural fracture method The five desertification types represent different stages of desertification reversal,and according to the inversion results,the spatial instead of temporal method is applied to collect samples and perform laboratory analysis on different desertification types of soils,to investigate the soil particle composition,texture type,particle size parameter,effective state Cu,Fe,Mn,Zn,soil crust factor(SCF),organic matter content(OM),and vegetation factor(C),so as to reveal the effects of the oasisification process in the Mawwusu sand on soil physicochemical properties.The results were as follows:1.The overall trend of desertification in the Mu US Desert has reversed in the past 35 years,with the desertified land area shrinking from 47877.81 km~2in1986 to 45914.06 km~2in 2021,reversing at a rate of 56.11 km~2per year.It can be roughly divided into three stages:from 1986 to 2001,the non-deserted and lightly desertified land gradually decreased,the area of moderately,heavily and very heavily desertified land continued to increase,and the degree of desertification gradually intensified;from 2001 to 2011,the reversal rates of non-deserted,lightly and moderately desertified were 104.28km~2/year,1828.4km~2/year and 581.53km~2/year,and the reversal rate of severe and very severe desertification is 1176.55km~2/year and 174.59km~2/year respectively,with significant reversal effect;2011-2021,presenting a stable reversal state with mild and moderate desertification mainly.Moderate,severe and very severe desertification land area shows reversal trend,light desertification land area shows development trend and stable reversal of desertification.It indicates that the implementation of a series of projects has been effective in rebuilding the ecosystem of Mao Wusu Sand.2.With the process of oasis,the percentage content of soil clay grain and chalky sand showed a linear increasing trend with an incremental rate of 1.55%and 7.08%respectively,and the percentage content of soil sand grain showed a linear decreasing trend with a decreasing rate of 8.62%,and the soil texture evolved from sand-chalky sand-sand chalky sand;the average particle size of soils with different degrees of desertification ranged from 1.56 to 3.31Φ,with a mean value of 2.68;non-The particles of non-deserted and very heavily desertified soils are poorly sorted,and the particles of lightly,moderately and heavily desertified soils are poorly sorted;the particles of non-deserted soils are extremely positively skewed,and the particles of lightly,moderately,heavily and very heavily desertified soils are positively skewed;the kurtosis belongs to the sharp-narrow kurtosis;the particle size distribution curves of all desertified soils are bimodal and similar in shape,with the first peak of the non-deserted curve at about 200μm The first wave of non-desertification curve is obtained at200μm,the rest of desertification curve is obtained at 350-400μm,the second wave is obtained at 900μm,and the corresponding particle size components are all sand particles.The effective Cu,Mn and Zn contents showed a linear increasing trend with the process of oasis,with the increment rate of 0.08%,1.03%and 0.24%respectively,and the effective Fe content showed a linear decreasing trend with the decreasing rate of 0.36%.The organic matter content showed a linear increasing trend with an incremental rate of 1.98%,and the crust factor and vegetation factor values showed a linear decreasing trend with decreasing rates of 0.13%and 0.23%,respectively.The above results show that the process of oasis formation in the Mawwusu sandy area has optimized the soil particle composition and soil texture type,improved soil quality,developed crust,increased vegetation,enhanced soil erosion resistance,and played a significant role in suppressing soil wind erosion.3.Due to the heterogeneity of the implementation project,the degree of reversal in the Mu US Desert varies,and the representative areas with significant reversal of desertification are Zhaosi Township in Ertok Banner,Garutu Sumu in Uttarakhand Banner,and Taig Sumu in Iginhoro Banner,where the soil clay grain,powder grain,effective Cu,Mn,Zn and organic matter content increase significantly,and the soil sand grain,effective Fe content and crust factor and vegetation factor values decrease significantly decreased.