CAJ | 학술논문

为监测半干旱地区退耕还林工程实施的效果，基于MODIS NDVI时间序列数据及土地利用数据，该文对内蒙古武川县的土地利用变化及植被覆盖变化进行了研究。结果表明：1）2000－2013年，武川县植被覆盖呈增加趋势发展的面积占33.55%，呈减少趋势发展的面积占30.15%，无显著变化的占36.30%，植被覆盖变化的空间差异明显，植被退化的区域重点集中于武川县的西北部。2）1999－2010年间，研究区耕地面积净减少18809.29 hm2，耕地转为草地13873.48hm2，转为林地5429.81 hm2，草地转为林地13554.25 hm2；结合地形特征，退耕地重点分布于＞2°～15°坡度与＞1500～2000 m海拔范围，并随着坡度与海拔的增加，退耕的幅度越来越大。3）退耕区中，植被覆盖下降的面积占20.98%，植被覆盖增加的面积占43.89%；在非退耕区，植被覆盖下降的区域面积占29.40%，植被覆盖增加的占34.14%。整体来看，退耕区植被的改善程度要高于非退耕区。4）进一步分析发现，退耕区中，耕地-草地的植被呈退化趋势发展，退化区域集中于＞2°～15°坡度与＞1500～2000 m海拔范围；在耕地-林地与草地-林地区域，其整体植被覆盖均显著提高，其中，耕地-林地的植被改善区域集中于＞2°～6°坡度与＞1500～1750 m海拔范围，草地-林地的植被改善区域重点分布于＞6°～15°、＞2°～6°及＞15°～25°坡度范围与＞1500～2000 m海拔范围。在非退耕区，耕地保持区、林地保持区与林地-草地区域的植被覆盖整体增加，而草地保持区、草地-耕地与草地-沙地区域的植被覆盖整体下降。
위감측반간한지구퇴경환림공정실시적효과，기우MODIS NDVI시간서렬수거급토지이용수거，해문대내몽고무천현적토지이용변화급식피복개변화진행료연구。결과표명：1）2000－2013년，무천현식피복개정증가추세발전적면적점33.55%，정감소추세발전적면적점30.15%，무현저변화적점36.30%，식피복개변화적공간차이명현，식피퇴화적구역중점집중우무천현적서북부。2）1999－2010년간，연구구경지면적정감소18809.29 hm2，경지전위초지13873.48hm2，전위임지5429.81 hm2，초지전위임지13554.25 hm2；결합지형특정，퇴경지중점분포우＞2°～15°파도여＞1500～2000 m해발범위，병수착파도여해발적증가，퇴경적폭도월래월대。3）퇴경구중，식피복개하강적면적점20.98%，식피복개증가적면적점43.89%；재비퇴경구，식피복개하강적구역면적점29.40%，식피복개증가적점34.14%。정체래간，퇴경구식피적개선정도요고우비퇴경구。4）진일보분석발현，퇴경구중，경지-초지적식피정퇴화추세발전，퇴화구역집중우＞2°～15°파도여＞1500～2000 m해발범위；재경지-임지여초지-임지구역，기정체식피복개균현저제고，기중，경지-임지적식피개선구역집중우＞2°～6°파도여＞1500～1750 m해발범위，초지-임지적식피개선구역중점분포우＞6°～15°、＞2°～6°급＞15°～25°파도범위여＞1500～2000 m해발범위。재비퇴경구，경지보지구、임지보지구여임지-초지구역적식피복개정체증가，이초지보지구、초지-경지여초지-사지구역적식피복개정체하강。
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 18,809.29 hm2, which was mainly distributed in slope between 2° and 15° or altitude between 1,500 m and 2,000 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 13,873.48 hm2 of the cultivated land converted to grassland, and at the same time, 5,429.81 hm2 of 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 4224.20hm2, and mainly distributed in slope between 2°and 15° slope or altitude between 1,500 m and 1,750 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%.