土地整治对耕地细碎化影响评价指标适用性分析.

Land consolidation is an important measure for solving land use problems in the process of socio-economic development in many countries (regions) in the world. But cultivated land fragmentation has a negative effect on raising agricultural productivity, promoting agricultural mechanization and developing agricultural modernization for many years. Land consolidation is regarded as an effective mode to control the fragmentation of cultivated land, which has achieved remarkable results. As for the applicability of the index in the impact assessment of land consolidation on cultivated land fragmentation, the integrated existing research results found that landscape index is a quantitative research method that can highly concentrate landscape pattern information, and reflect some aspects of its structure composition and spatial configuration. And using landscape index to evaluate the impact of land fragmentation by land consolidation is helpful to highlight the improvement of land consolidation on land fragmentation in the scale of time and space. Landscape index is the main source for selecting evaluation index of cultivated land fragmentation. This paper adopted the general idea of “integrating index system, quantitatively evaluating index, statistical analysis and extracting index”. This study used land use data and village land ownership information, selected 27 evaluation indices based on the view of landscape index, and analyzed the fine fragmentation of cultivated land before and after land consolidation under different data sources, data types and granularity levels. By using ArcGIS and FRAGSTATS software, all alternative indices under different grid granularity levels were calculated. A statistical analysis was made on the significance, sensitivity, and difference of the calculation results of the indicators. Finally, according to the characteristics of the results, the evaluation indicators that can effectively represent the fragmentation status of the cultivated land were screened from the aspects of index connotation, method, and granularity. The results are as follows: 1) Evaluation results of cultivated land fragmentation under the project area scale are quite different from each other, which are affected by the basis data, the selected analysis methods and different grid granularity levels. If the land use data are directly used for evaluation like this, it is difficult to fully reflect the changes in the fragmentation of cultivated land, and at the same time, the impact of land consolidation on improving the fragmentation of cultivated land will also be underestimated. 2) In the terms of data types and grid granularity levels, vector landscape indices have a strong ability to characterize the cultivated land fragmentation. However, considering the comprehensiveness of evaluation indices, it is still necessary to calculate with grid data. No matter which data type is taken, the analysis results show that in the project area the suitable grain size is 10 m. 3) The common landscape indices are applied to the problems of cultivated land fragmentation evaluation, such as connotation repetition, method dependence, granularity sensitivity and result ambiguity, and the indicators which can effectively represent the fragmentation of cultivated land include the number of patches, mean patch size, edge density, patch density, patch size’s coefficient of variation, Shannon evenness index, and so on. 4) Land consolidation has obvious effect on improving the fragmentation of cultivated land. The number of patches and the degree of shape irregularity indices were decreased, NP, PD and ED were respectively decreased by 997, 0.16 and 141.73. While the indices representing patch scale and spatial distribution equilibrium were increased, MPS, PSCOV and SHEI were respectively increased by 0.118, 23.56 and 0.004. These results provide an important guide for deeply understanding the impact of land consolidation on the cultivated land fragmentation, and effectively analyzing and evaluating the status and problems of cultivated land fragmentation in project area. [ABSTRACT FROM AUTHOR]