Abstract:

To grasp the evolution characteristics of land use structure within the Henan water source area of the Middle Route of the South-to-North Water Diversion Project, using remote sensing images from 1990-2021, the fractal theory was adopted to analyze the changes in various land use areas and the stability of spatial structure, to reveal the transformation and evolution laws of land use structure. The results were as following. During 1990-2021, the areas of cultivated land, shrub land, grassland and unused land had generally decreased, while the areas of forest land, water areas and construction land had shown increasing trend; the average area of patches had been increasing overall, from 1990-2021, it increased by 0.052 square kilometers; the average area of patches in cultivated land, forest land, water area, unused land and construction land had increased, while that in shrub land and grassland had decreased; human activities were the main factor triggering change of land use types in the basin and the overall fractal dimensions in 1990, 2000, 2010 and 2021 were 1.4038, 1.3805, 1.3660 and 1.3580, respectively, showing gradually decreasing trend, indicating that the land use structure was tending to be orderly; the corresponding stability index gradually increased from 0.0962 to 0.1420, but the stability was not high and it was easily affected by external factors. In the future, land use planning of the basin, artificial controls should be implemented to reduce the fractal dimension of land use structure and enhance its stability.

Key words: fractal theory, water source area, land use, evolution