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摘要
In order to monitor effects of ecosystem restructuring project under the government Grain for Green program, this paper, based on the MODIS NDVI time series data and land use change data, explored the regional land use change and consequently vegetation coverage change in Wuchuan county, Inner Mongolia, by using linear regression and remote sensing interpretation. Results showed that from 2000 to 2013, the annual maximum NDVI of study area was not improved progressively at all. But the vegetation coverage change of the whole area showed obvious spatial difference, the vegetation coverage with significant (P<0.05) increase accounted for 33.55% of the total study area, while significant (P<0.05) decrease of vegetation cover area was 30.15%, and the degraded area of the whole area mainly distributed in the northeast of Wuchuan county. The results also showed that from 1999 to 2010, generally speaking, the area of cultivated land in the studied area decreased by 18809.29 h2, which was mainly distributed in slope between 2°and 15°or altitude between 1500 m and 2000 m above sea level, and the proportion of returning farmland to forest and grass increased with slope and altitude within certain range. Overall a majority of steep slope land had been returned to forest and grass. Compared with 1999, there were 13873.48 hm2of the cultivated land converted to grassland, and at the same time, 5429.81 hm2of cultivated land converted to forests. In addition, in the area under Grain for Green program, the areas with degraded vegetation coverage accounted for 20.98%, and those with improved vegetation coverage accounted for 43.89%. In the area without the program, the areas with degraded vegetation coverage accounted for 29.34%, and the percentage of areas with improved vegetation coverage was 34.12%. In all, the vegetation coverage of the area under the program has been better than the area without the program since 2000.Last, from the specific land use change type, in the area under the program, the vegetation coverage of grassland returned from cropland experience improvement, the improved areas and degraded areas accounted for 34.65% and 30.45% of the total area in "cropland-grass"area. The degradation area is 4224.20 hm2, and mainly distributed in slope between 2°and 15°slope or altitude between 1500 m and 1750 m. By contrast, both of the vegetation coverage of forest returned from grassland and cropland experienced great improvement, and the improved proportions respectively accounted for 49.39% of the "cropland-forest"area and 51.14% of the "grass-forest"area. Among which, the improved areas of the forest returned from cultivated land mainly distributed in slope between 2°and 6°or altitude between 1500 m and 1750 m, and the improved areas of forest returned from grass mostly located in slope between 6°and 15°or altitude between 1750 m and 2000 m. Furthermore, in non-ecological area, vegetation coverage of the areas in "cropland-cropland"region, "forest-forest"region and "grass-forest"region experienced great improvement, the proportions of vegetation coverage improved areas among these land use type changes were separately 38.48%, 46.14%, 38.80%. While in other regions of non-ecological area, the vegetation coverage of the areas in "grass-grass"region, "grass-cropland"region and "grass-sand"region degraded markedly, and the proportions of degraded areas among those land use type changes were separately 31.06%, 35.79%, 62.61%.
- 出版日期2015
- 单位中国农业大学
