陕北黄土丘陵区干燥度变化趋势及其对植被恢复的响应(英文)

编号 zgly0001584683

文献类型 期刊论文

文献题名 陕北黄土丘陵区干燥度变化趋势及其对植被恢复的响应(英文)

作者 李旺君  吕昌河 

作者单位 KeyLaboratoryofLandSurfacePatternandSimulation  InstituteofGeographicSciencesandNaturalResourcesResearch  CAS  UniversityofChineseAcademyofSciences 

母体文献 Journal of Geographical Sciences 

年卷期 2015年03期

年份 2015 

分类号 Q948.1 

关键词 aridity  variationtrend  hillyLoessPlateau  Grain-for-Grainprogram 

文摘内容 Detecting variation trend in dry-wet conditions can provide information for developing strategic measures to mitigate the impacts of global warming, particularly in dry regions. Taking the hilly region of northern Shaanxi on the Loess Plateau as a case area, this study analyzed the trend of aridity variation during 1981–2012, and explored the effect of vegetation restoration promoted by the Grain-for-Green(GFG) program implemented in 1999. The results indicated that the aridity in the region was non-significantly increased by 0.88% per year during 1981–2012, showing a drying trend. This drying trend and amplitude were changed by the influence of vegetation restoration promoted by the GFG program, based on two findings. The first one was that the aridity variation tended to increase during 1981–1999 while it turned to decrease during 2000–2012, with the regional mean relative change rate changed from 2.45% to –1.06%. This distinction was more remarkable in the loess gully region, where the vegetation was improved more obviously. The second one was that the mean vegetation coverage as indicated by EVI increased by 0.90% to 4.32% per year at county level, while the aridity decreased by 0.14% to 2.32% per year during 2000–2012. The regression analysis using the mean county data indicated that the change rate of aridity was negatively related to that of EVI with the coefficient of determination(R2) of 0.56, illustrating that around half of the aridity decline was explained by the EVI change. The mechanism of this effect was complicated, but it was found that the wind speed decline induced by the vegetation improvement could be an important contributor. It is concluded that the region became drier during 1981–2012, but the eco-restoration reduced the drying speed. However, this conclusion is involved in uncertainties, and further study based on experiments is needed to confirm the effect of the GFG-promoted vegetation restoration.