Research On The Relation Between Soil Micromorphology And Landuse In Loess Station In Xi'an

The paper studied the soil micromorphology characteristics on different land uses, researched the relation of soil micromorphology and land use, accurate interpretation of micromorphology to land use change instructions. And provided new ideas and opened up a new research avenue to changes in land use studies, provided vital scientific theory on combating ecological problems and improving soil ecological functions .So, this study is of importance and relevance significance.The combination of the National Natural Science Foundation, this paper choose loess station in Xi'an as a study, based on the 3S technology and Leica digital image processing system , analysis the land-use change effects on soil micromorphology. Through field trips to determine the wild sampling locations, the selected soil profile has strong representation. Using Leica Qwin Standard v2.6 image processing system, it is an important experience that quantitative analysis of the relationship of the soil micromorphology and land-use change patterns. Micromorphology data are available to other physical nature of the soil and mutual explanation.This paper is divided into six chapters, the first chapter provides research progress of land-use / land-cover change and soil micromorphology. Chapter II described primarily on study regional options principles, the natural conditions on research region, inspection line, research profiles selection and analysis processing. Chapter III is soil micromorphology research methods. Chapter IV studied on the relationship of the soil micromorphology and land-use change patterns. Chapter V synthetically evaluated on land use patterns involving soil micromorphology response. Chapter VI provides a summary and discussion of the paper.Conclusion drawn in the study were as follows :(1) Under analyzing soil micromorphology quantitative data", different enlarged multiple digital image effect on data analysis, in which images in 10 X 10 times are most suitable for quantitative statistical analysis in Leica Qwin Standard V2.6 image processing systems.(2) Research on relation of the soil micromorphology characteristics and other nature indicators of soil, the results are as follows :The correlation coefficient between average length of hole in soil micromorphology indicators and soil weight is 0.270 (testing 0.05), the correlation coefficient between the maximum length hole and soil pore weight is 0.312 (testing 0.05), indicated that the relationship of soil pore weight and soil hole length was consanguineous;its correlation coefficient is -0.325 (testing 0.05). At the same time, relation analysis on soil micromorphology and soil moisture content showed : soil moisture content is respect on and shape of the soil pore, and is direct proportion. The sponge-shaped structure of farming soil micromorphology not only helps to ventilate water and enhance water performance;And, of course farming cling progress will improve the soil water performance. Relation analysis on soil micromorphology indicators and soil magnetization showed the particle size and shape are related to the degree of strength with mineral weathering. The low frequency and high frequency of soil magnetization in the soil profile is higher than Maran ocher, indicating the Maran loess obviously take place biological wind process. Moreover, different types of land use change impacts on soil organic carbon content changes, farming soil in a shorter period, the organic carbon is low, relative with the material cumulative. Research shows that soil colloidal particle coincide with colloidal particle content changes;the colloidal particle concentration in Long-term farming fields, orchards, woodland and grass is larger.(3) The similarities analysis on Maran loess micromorphology and soil shows soil accelerated soil development with the extension of farming. In addition, topography, environmental conditions have affected the growth of soil.(4) Through factor analysis ,found that 10 integrated factors represent the vast majority of soil micromorphology information. Including : coarse particle shape, coarse particle largest size, pore degrees, pore shape, the number of coarse particle, minimum width of coarse particle, round degrees, the total number of coarse particle, minimum area of coarse particle. According to the contribution rate of 10 factors variables, measured micromorphology composite index, which reflects the total differnce of micromorphology.(5) This study researched in the smaller scale of the space environment by human activities and non-soil areas effects on soil environment, the relationon factors and soil micromorphology in different soil layers is different;But the non- territories factors which impact on soil micromorphology are : land-use time>slope>landusetype>elevation>land-cover change>aspect. On the overall situation, human land use change impact on soil environmental more than non-zone natural factors. (6) Accoding to observering and qualitativly describing soil micromorphology in different soil profile in the land use patterns, summed up the soil micromorphology in response to changing patterns of land use.Namely: different land uses have different characteristics of soil micromorphology, soil micromorphology in woodland and grassland have similarities, and soil micromorphology in the fields and gardens have significant similarities;With depth changes,the soil profile changes are obvious changes;under different types of land use in the same time, its soil micromorphology characteristics have regularity. Along with the length of farming, the overall trend of soil growth is soil sponge micromorphology development;enhance soil cling degree;Rail pollution phenomena and reunion phenomenon has become increasingly evident. This is because the development process is artificial soil mature process. Therefore, it is possible to identify the certain soil characteristics and land-use have counterpart : sponge-shaped micromorphology is the most prominent farming soil micromorphology;under 10 cm surface indicated coarse particles as feldspar, in addition to the sand dust removal ,its sources are from loess manures in artificial fertilization process;the clay nodules cemented with CaCO3 appear that the soil growth in the semi-arid environment . Because the study area precipitation in the 25-35 cm depth, if rail dyed clay in 25-30 cm, which is significant symptoms in loess plateau region.The innovation of the thesis are as following:First, realize the quantitative image analysis on the soil micromorphology , analyze the relationship with soil micromorphology and soil other physical characteristics.Second, make out the soil soil micromorphology composite index and access methods ,and explore human activities and natural factors effect on the soil soil micromorphology. And describe the specific characteristics of soil micromorphology in response to land use change.