关中地区植被覆盖变化及其人为影响的对比分析

Comparative analysis of vegetation cover change and its human effects in Guanzhong area

目的 分析关中地区植被覆盖与植被覆盖人为影响的相互关系。方法 基于2001-2018年MODIS-NDVI数据,应用Sen趋势法、Hurst指数等方法分析关中地区植被覆盖的过去、现状及未来演变特征,应用残差法获取植被覆盖的人为影响,并从时间特征、空间特征、变化趋势及未来演变4个维度对比分析。结果 关中地区植被覆盖18 a呈改善趋势,但在未来演变中呈退化趋势,尤其植被覆盖改善转为退化区域面积占42.48%。植被覆盖人为影响18 a呈正作用趋势,但其未来演变呈负作用趋势,尤其人为影响正作用转负作用占比高。植被覆盖改善区域和人为影响的正作用区域主要分布在关中地区南北两侧,植被覆盖退化区域和人为影响负作用区域主要分布在关中地区中东部。结论 关中地区植被覆盖的改善和退化区域与植被覆盖人为影响的正作用和负作用区域具有一致性,应着重防范植被改善区域的植被返恶化问题重演。

Purposes—To explore the relationship between vegetation cover and human effects on vegetation coverage in Guanzhong area.Methods—Based on the MODIS-NDVI data from 2001 to 2018,the Sen trend method,Hurst index and other methods are used to analyze the past,current and future evolution characteristics of vegetation cover in Guanzhong area,and the residual method is adopted to obtain the human effects on vegetation cover,which is compared from the temporal and spatial changes,changing trends and future evolution.Results—Vegetation coverage in Guanzhong area has shown an improvement trend in the past 18 years,but it will be degraded in the future evolution.In particular,the improved area turning into the degenerated one in vegetation cover accounts for 42.48%.The human effects on vegetation cover showed a positive trend in the past 18 years,but its future evolution will show a negative trend,especially the high proportion of positive human effects to the negative one.The areas where vegetation coverage has improved and where human activities have positive effects on vegetation cover are mainly distributed on the north and south sides of the Guanzhong area,while the areas where vegetation coverage has improved and where human activities have negative effects on vegetation cover are mainly distributed in the central and eastern Guanzhong area.Conclusions—The improved and degraded areas of vegetation coverage in Guanzhong area are consistent with the positive and negative effects of human effects.Emphasis should be placed on preventing the recurrence of vegetation deterioration in vegetation improvement areas.