欢迎访问林业科学,今天是

林业科学 ›› 2022, Vol. 58 ›› Issue (3): 10-19.doi: 10.11707/j.1001-7488.20220302

•   • 上一篇    下一篇

基于NDVI的2009—2018年黄河流域林草植被覆盖变化

郝家田,胡云云,杜一尘,侯晓巍,向安民*   

  1. 国家林业和草原局西北调查规划设计院 旱区生态水文与灾害防治国家林业和草原局重点实验室 西安 710048
  • 收稿日期:2021-06-16 出版日期:2022-03-25 发布日期:2022-06-02
  • 通讯作者: 向安民
  • 基金资助:
    黄河流域典型区域森林演变过程回溯研究(GLXD-2021-QT-13)

NDVI-Based Coverage Changes of Forest and Grass Vegetation in Yellow River Basin during 2009 to 2018

Jiatian Hao,Yunyun Hu,Yichen Du,Xiaowei Hou,Anmin Xiang*   

  1. Northwest Surveying, Planning Institute of National Forestry and Grassland Administration Key Laboratory of National Forestry and Grassland Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an 710048
  • Received:2021-06-16 Online:2022-03-25 Published:2022-06-02
  • Contact: Anmin Xiang

摘要:

目的: 研究黄河流域2009—2018年间林草植被覆盖的时空分布及变化特征,预测林草植被覆盖的未来发展趋势,为流域林草植被科学保护和精准修复、促进生态系统正向演替提供参考依据。方法: 以2009-2018年SPOT/VEGETATION的NDVI时间序列数据集为数据源,采用年均值法、Theil-Sen median趋势分析和Mann-Kendall检验方法,研究黄河流域林草植被覆盖的时空分布及变化特征,利用Hurst指数方法分析林草植被覆盖的可持续性特征和未来发展趋势。结果: 黄河流域林草地面积中,高植被覆盖度(NDVI≥0.7)面积占42.34%,呈聚集状分布于流域上游的祁连山、三江源东部、若尔盖草原,中游的秦岭北麓、黄土高原胡焕庸线以南地区,以及下游的济南市区周边区域;中植被覆盖度(0.3 < NDVI < 0.7)面积占44.92%,主要分布于流域上游的三江源西部和中游的宁夏、内蒙、陕西3省(区)交界处;低植被覆盖度(NDVI≤0.3)面积占12.74%,主要分布于流域上游的毛乌素沙地、陇中黄土高原、阴山南麓。2009—2018年间黄河流域林草地年均NDVI总体呈增加趋势,增速为0.007 4 a-1;10年间流域林草植被覆盖变化趋势以改善为主,改善区域面积占81.62%,其中显著改善面积占33.36%,集中分布在林草高植被覆盖度区域;林草植被覆盖退化区域面积占13.86%,集中分布在林草低植被覆盖度区域。未来林草植被覆盖良性发展区域面积占林草地总面积的61.89%,恶性发展区域面积占33.60%,发展方向稳定不变和不确定区域面积占4.51%。结论: 黄河流域林草植被覆盖度整体呈现东南部和西北高山地区高、北部低的特征。2009—2018年间林草植被覆盖改善区域面积远大于退化区域面积,改善区域主要集中在上游的祁连山林区、若尔盖草原,中游的六盘山林区、子午岭林区、黄龙山林区、吕梁林区及秦岭北麓,退化区域主要分布在林草低植被覆盖度的毛乌素沙地、陇中黄土高原等,退化区域应作为重点治理修复区。黄河流域林草植被覆盖未来发展趋势整体较好,预测良性发展区域远大于恶性发展区域,恶性发展区域中三江源地区和毛乌素沙地的林草植被覆盖虽有轻微改善,但持续性较差,未来林草植被覆盖可能呈退化趋势,在流域生态保护治理中应重点关注。

关键词: 黄河流域, NDVI, 植被覆盖, 时空变化, 林地和草地

Abstract:

Objective: This research was aimed to investigate the spatiotemporal distribution and coverage changes of forest and grass vegetation in the Yellow River Basin during 2009 and 2018, and to forecast future development trend of the forest and grass coverage in order to provide a basis for scientific protection and precise restoration of forest and grass vegetation, and for the promotion of positive ecosystem succession in the Yellow River Basin. Method: Based on the SPOT/VEGETATION NDVI time series data from 2009 to 2018, the spatial distribution and temporal changes of the vegetation coverage of forest and grass in the Yellow River Basin were studied by using annual mean method, Theil-Sen median trend analysis and Mann-Kendall test. The sustainability characteristics and future development trend of vegetation coverage were analyzed using Hurst index method. Result: In the total area of forestland and grassland in the Yellow River Basin, the area with a high vegetation coverage (NDVI≥0.7) accounted for 42.34%, distributed in aggregation in the Qilian Mountains, the east of Three-Rivers' Origin and Zoige grassland in the upper reaches of the basin, the northern foot of Qinling Mountains in the middle reaches, the south of Huhuanyong line in the Loess Plateau, and the surrounding area of Jinan City in the lower reaches; The area with a medium vegetation coverage area (0.3 < NDVI < 0.7) accounted for 44.92%, mainly distributed in the west of Three-Rrivers' Origin in the upper reaches of the basin and the junction of Ningxia, Inner Mongolia, and Shaanxi in the middle reaches. The area with a low vegetation coverage (NDVI < 0.3) accounted for 12.74%, mainly distributed in the Mu Us sandy land, the Loess Plateau in central Gansu Province, and the southern foot of Yinshan Mountains in the upper reaches of the basin. From 2009 to 2018, the annual mean NDVI of vegetation in forestland and grassland of the Yellow River Basin showed an overall increasing trend, with a growth rate of 0.007 4 a-1. In the past 10 years, the area with improved vegetation coverage accounted for 81.62% of the total area of forest and grass, of which the area of significant improvement accounted for 33.36%. The area with vegetation degradation accounted for 13.86%, which was basically the same as the area with a low vegetation coverage. In the future, 61.89% of the vegetation coverage will develop in a positive direction, 33.60% in a negative direction, and 4.51% in a stable and uncertain direction. Conclusion: The vegetation coverage in forestland and grassland in the Yellow River Basin is high in the southeast and northwest mountain areas, and low in the north. From 2009 to 2018, the improved area is much larger than the degraded area, mainly concentrated in the Qilian mountain forest area and Zoige grassland in the upper reaches, Liupanshan forest area, Ziwuling forest area, Huanglongshan forest area, Luliang Mountain forest area and the northern foot of Qinling Mountain in the middle reaches.The degraded areas are mainly distributed in the Mu Us sandy land and the Loess Plateau in central Gansu Province with low vegetation coverage, where is the priority area for harness and restoration. The future development of vegetation coverage in the Yellow River Basin tends to be good in general. It is predicted that the positive development area is much larger than the negative development area. In the negative development area, although the vegetation coverage in Three-Rivers' Origin and Mu Us sandy land has slightly improved, the sustainability is poorer, and there is a possibility of degradation in future, therefore it should be given great attention in the ecological conservation and restoration of the Yellow River Basin.

Key words: Yellow River Basin, NDVI, vegetation coverage, spatiotemporal variation, forestland and grassland

中图分类号: