应用科学学报 ›› 2016, Vol. 34 ›› Issue (6): 702-712.doi: 10.3969/j.issn.0255-8297.2016.06.006

• 信号与信息处理 • 上一篇    下一篇

基于AVHRR和MODIS NDVI数据的黄土高原植被覆盖时空演变分析

张春森, 胡艳, 史晓亮   

  1. 西安科技大学测绘科学与技术学院, 西安 710054
  • 收稿日期:2016-04-28 修回日期:2016-06-02 出版日期:2016-11-30 发布日期:2016-11-30
  • 作者简介:张春森,教授,研究方向:摄影测量与遥感,E-mail:zhchunsen@qq.com
  • 基金资助:

    国家自然科学基金(No.51409204);陕西省教育厅科学研究项目基金(No.15JK1473)资助

Analysis of Spatial-Temporal Evolution of Vegetation Cover in Loess Plateau in Recent 33 Years Based on AVHRR NDVI and MODIS NDVI

ZHANG Chun-sen, HU Yan, SHI Xiao-liang   

  1. College of Geomatics, Xi'an University of Science and Technology, Xi'an 710054, China
  • Received:2016-04-28 Revised:2016-06-02 Online:2016-11-30 Published:2016-11-30

摘要:

黄土高原自退耕还林还草工程实施以来,区域植被覆盖发生了很大变化. 为有效监测其变化程度,基于像元一元线性回归模型,利用该地区2001~2014年MODIS归一化植被指数(normalized difference vegetation index,NDVI)数据对1982~2006年GIMMS NDVI数据进行扩展. 扩展数据通过了一致性检验,获得1982~2014年长时间序列植被NDVI数据集,分析该地区近33年植被NDVI的时空变化特征. 研究结果显示:33年间黄土高原植被NDVI年际整体呈现显著的增加趋势,区域植被覆盖空间分布差异明显. 其中南部和西部大部分地区植被覆盖轻微退化,中部地区植被覆盖基本不变,内蒙古边界、甘肃兰州以及陕西榆林等地区的植被覆盖均呈改善趋势. 研究区各坡度等级植被覆盖良好,各坡度植被覆盖变化程度由强到弱依次为> 28°、20°~28°、14°~20°、9°~14° 、4°~9°. 其中黄土高原中部的坡地植被改善效果最为明显,甘肃与青海的交界处以及陕西南部、山西部分地区坡地植被覆盖呈轻微改善趋势.

关键词: 黄土高原, 归一化植被指数, 植被覆盖, 时空特征

Abstract:

Since implementation of the project of returning farmland to forest and grassland in the Loess Plateau, vegetation cover of the region has been greatly changed. To effectively monitor variation of the vegetation cover, this paper constructs a yearly maximum normalized difference vegetation index (NDVI) sequence covering Loess Plateau from 1982 to 2014 using the per-pixel unary linear regression model (LRM). The work is based on AVHRR GIMMS NDVI datasets from 1982 to 2006 and MODIS NDVI datasets from 2001 to 2014. The constructed NDVI has passed consistency check, and is used to analyze spatial-temporal characteristics of vegetation NDVI in the past 33 years. The following results are obtained. The overall vegetation NDVI of the Loess Plateau in the past 33 years has been increasing. Spatial distribution of the vegetation cover in the regions is significantly different. Vegetation cover has slightly degraded in most southern and western parts of the area under study, and that in the central region is almost unchanged. The vegetation cover shows an improving trend in some areas including the border of Inner Mongolia, Lanzhou, Gansu and Yulin region of Shaanxi. Vegetation covers of different slopes are good. Degrees of changes in areas with different slopes are ranked in a descending order as above 28°, 20°~28°, 14°~20°, 9°~14°, 4°~9°. The vegetation cover in sloping fields of middle part of the Loess Plateau is most improved. Slight improvement of the vegetation cover has been found in areas including eastern Gansu, junction of Gansu and Qinghai provinces, southern Shaanxi, and the cities Linfen, Yuncheng and Sanmenxia of Shanxi, showing positive results in controlling loss of water and soil.

Key words: characteristics of time and space, vegetation cover, normalized difference vegetation index (NDVI), Loess Plateau

中图分类号: