关键词: 惠州梅菜, 惠州梅菜, 亚硝酸盐, 用盐量

Abstract: To realize the harmonious development of human and land, and provide a reference for formulation and implementation of ecological construction policy in Shaanxi, based on MODIS-NDVI image and altitude data, the author analyzed the spatio-temporal variation characteristics of NDVI in Shaanxi from 2011 to 2015 by using MVC and linear regression. The results showed that: (1) the distribution of NDVI in Shaanxi was characterized by“high south and low north”; the forest vegetation was thick in southern Shaanxi, as well as in the south area of northern Shaanxi; the vegetation coverage was poor in the north area of northern Shaanxi, which belonged to sandy area; the vegetation coverage was medium in Guanzhong region, which was mainly dominated by crops; (2) from 2011 to 2015, the NDVI value in Shaanxi fluctuated, the overall change tended to be stable and the trend was improving, mainly in Guanzhong and southern Shaanxi; the NDVI value in northern Shaanxi showed signs of degradation; (3) with the increase of altitude, the NDVI value presented a change of “decrease-increase-decrease”. NDVI value was the highest in the range of 2000-2500 m where the vegetation coverage was better, mainly distributed in Taibai mountain area of Qinling mountains.