| Land consolidation is a result of civilized land use of human beings, an approach to utilize and transform the nature by human, and an inevitable choice to solve the problem of land use when economy developed into a certain degree. From the point of view of the practice of land development and land consolidation in our country, there commonly exist problems of preferring quantity to quality and ecologic environment; consolidation planning, feasibility study, calculation of consolidation engineering volume, soil quality assessment after consolidation are done by hand, rarely with advanced and effective technologies and methods such as remote sense, geographic information system etc. Soil quality acceptance and result management after consolidation lack advanced and effective methods; and if the consolidated land is of inferior quality, it will not own certain production capacity and in the contrary will result in land lying waste. This kind of consolidation has not realized the real consolidation and development of cultivated land and even resulted in destruction of resources and wasting of development fund.With the development of land consolidation practice, at present, the acceptance of a great number of completed projects has entered the operational phase. It is still unclear whether these projects are correct and whether the anticipatory goals and benefits can be achieved. Hence, post-evaluation is urgently needed.Remote Sense provides quick access to vast amounts of high-resolution information. Application of "RS" in the acquisition, processing and analysis of land development information and consolidation information can further standardize the compiling of land development and consolidation plan, and greatly increase the technical contents in land development and consolidation design, implementation of dynamic monitoring, acceptance of projects, particularly, appraisal of project achievements, thus improving the quality and efficiency of the projects. Motivated by the research subject of "Evaluation of Land Development and Consolidation Based on RS", a key project sponsored by The Land and Resources Department of Hunan Province, we applied advanced method-RS to evaluate land development and consolidation for the first time in China.By comprehensively employing multi research approaches, including evaluation system study which combines static analysis with development forecasting, policy regulations with practical engineering needs, and scientific integrated analysis approach which combines RS qualitative analysis with quantitative analysis, traditional technology with modern new technology, the systematic study comes to fruition:(1) In conformity with the relevant laws and regulations, such as the Land Administration Law of the PRC and The Acceptance Codes of Land Development and Consolidation Project, combined with the actual situation of experimental areas and the land development and consolidation of Hunan, the research, based on the features of the high-resolution remote sensing information and the remote sensing interpretation system, proposes quantitative remote sensing method, which can evaluate the engineering quantity of the land development and consolidation project according to land-leveling project, water conservancy and irrigation, crisscross footpaths project and other projects (windbreak forest project etc.). The experiment in project area shows that this method has such characteristics as high speed, high efficiency, high degree of accuracy, extremely low labor intensity, etc; also it can reflect the performance of the project in a complete way. And the extracted index information of classification closely meets the actual conditions.(2) When studying soil moisture, soil organic matter content, land surface temperature, vegetation index, vegetation condition index and vegetation-temperature condition index through remote sensing, soil quality is evaluated directly or indirectly. This fact can speak volumes for the ability of inaugurated applicable remote sensing technology to evaluate or assess the quality and agriculture potential of soil. Based on this conclusion, the reserch shows that there is neither any evaluation system which can systematically assess the land development and consolidation project through the organic combination of the land development and consolidation project with the improvement of the soil quality, nor any evaluation system to evaluate land development and consolidation project by means of remote sensing. Based on the previous application of remote sensing, this research proposes engineering quantity evaluation of land development and consolidation project by using remote sense, starting with the pretreatment and analysis of multi remote sensing data sources. This research makes relatively scientific and objective evaluation on the influence of the land development and consolidation project towards the soil quality through the utilization of the relatively critical indexes such as the MSAVI, vegetation coverage, soil moisture, soil gleying index, LBV transformation.(3) After analyzing information mechanism, interpretation theory of remote sensing image processing, features and extraction characteristics of remote sensing information of soil, this research first studies the high-resolution Quickbird image, which is used to sort the evaluation of the engineering quantity, through cutting the images on the home-produced software TITAN Image 6.5 (according to the regions of evaluation) and blending the images through the 2-D cubic convolution (4 monochromatic bands and 1 panchromatic band ); second, in order to assure the accuracy, this research adopts the GPS-measured ground control points, uses the polynomial as the geometric correction model to change the images spatial pixel position of the blended images, then utilizes the bi-cubic interpolation to calculate the pixel lightness value after the change of position, namely resampling of pixel lightness value. According to the results of calculation, the position errors of points are less than 1m; after converted into pixel, the errors are about 1 pixel, so they can meet the requirements of the information extraction of consolidation engineering quantity. Third, the research proposes and adopts the method of ISODATA (self-organizing classification) to effectively extract the area value of different areas in the project area and the length of threads such as ditches and roads. The accuracy of extracted area is above 97%; the accuracy of the extracted length is above 98%. Using classification map and onsite data, rationality analysis of irrigation and drainage systems layout, rationality analysis of windbreak forest distribution and rationality analysis of road network distribution can be made.(4) The paper analyzes the correlation between soil water content and soil quality, spectral signatures of soil moisture, soil moisture and relative reflection; probes into adaptability of extracting soil moisture content by using such remote sensing methods as crop water stress index method, average vegetation index method, microwave remote sensing orientation method, thermal inertia approach and data assimilation method; puts forward the idea of analyzing soil moisture with optical vegetation coverage remote sense; builds TM model of optical vegetation coverage and regression model between soil moistures at different depths and greenness indexes of remote sensing vegetation by using the approach of combining sample statistics with correlation analysis; makes information extraction and analysis of soil moisture content in three different layers on TM image of experimental area at different time. Meanwhile, IKONOS image in project area and soil moisture content information in three different layers of CBERS-1 satellite image are extracted with the help of this model. According to the information extracted, the improvement and promotion state of soil quality after land development and consolidation are analyzed. And the results of analysis are corresponding with the actual situation, thus quantizing the soil consolidation effects.(5) This paper studies the quantitative relationship among vegetation index, vegetation coverage and soil quality ; comprehensively analyzes the relationship characteristic between soil quality and such indexes as ratio vegetation index (RVI), normalized difference vegetation index (NDVI), difference vegetation index (DVI), soil adjusted vegetation index (SAVI), enhanced vegetation index (EVI) and vegetation coverage ; establishes MSAVT (called 'modified soil adjusted vegetation index') model and dimidiate pixel model of vegetation coverage. By analyzing MSAVI index of various remote sensing images in experimental area and dimidiate pixel model parameter, this paper testifies that these indexes are suitable for soil quality evaluation in experimental area.(6) By studying the nature of correlation between gleying process of soil and soil quality, thermodynamic characteristics of gleyed soil as well as remote interpretation mechanism, this paper puts forward thermal inertia conceptual model of water-logging disaster soil, number resolution model, and points out the theoretical and practical feasibility of using remote sense to study the phenomenon of water-logging disaster leading to soil gleying.The study points out that there are three important remote characteristics of surface features on satellite remote sensing imaging map, namely overall radiation level of surface features—L, the direction and speed of change of visible light-infrared radiation balance B and surface features radiation with band change—vector V; further proposes to adopt IKONOS and other remote sensing images transformation and information extraction in experimental area through remote sensing image LBV data transformation. The established LBV transformation equation is also testified by experiments. The serious degrees of land barrenness, standing water and gleying of soil before the reclamation in the experimental area are identical with the actual situation.Through systematic research in this paper and actual inspection in project area, it is verified that quantitative RS is well applicable for the evaluation of project quantity of land development and consolidation as well as soil quality assessment. The research findings can be forceful support of the acceptance of land reclamation project run by Land and Resources Bureau or relevant departments. This paper fully proves that applying RS retrieve technique to evaluate the performance of the engineering quantity of land development and consolidation project is true, reliable and feasible. This approach is a new way for RS application. This paper also forcefully proves that the approach of employing quantitative RS--RS retrieve monitoring to evaluate land consolidation quality is characterized by accuracy, effectiveness, strong dynamics and timeliness. This study has great development potential in the evaluation of large-scaled land development and consolidation projects.
|
PDF Full Text Request