中国农业气象

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基于NDVI3g数据反演的青藏高原草地退化特征

曹旭娟,干珠扎布,胡国铮,高清竹   

  1. 1.中国农业科学院农业环境与可持续发展研究所/农业部农业环境重点实验室,北京 100081;2.山西省环境科学研究院,太原 030027
  • 出版日期:2019-02-20 发布日期:2019-02-16
  • 作者简介:曹旭娟(1989?),女,硕士,主要从事气候变化与草地生态研究。E-mail:caoxujuan@sina.com
  • 基金资助:

    国家重点研发计划(2016YFC0502003);西藏自治区科技计划项目;国家自然科学基金项目(31570484);中国工程院重点咨询项目(2017-ZD-09-04-02)

Characteristics of Grassland Degradation in the Qinghai Tibetan Plateau, Based on NDVI3g Data

CAO Xu-juan,HASBAGAN Ganjurjav,HU Guo-zheng,GAO Qing-zhu   

  1. 1. Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences/Key Laboratory for Agro-Environment, Ministry of Agriculture, Beijing 100081, China;2. Shanxi?Research Academy of Environmental Sciences, Taiyuan 030027
  • Online:2019-02-20 Published:2019-02-16

摘要:

利用NDVI3g数据反演青藏高原1986-2013年高寒草地植被盖度,并计算草地退化指数,以了解青藏高原高寒草地退化状况及其分布特征。结果表明,2011-2013年青藏高原草地退化指数为1.76,属轻度退化等级;退化面积达到41%,与历史平均水平(1986-2010)相比无显著变化,但中等以上退化面积有所增加。其中,轻度退化面积为22%、中度退化面积为8%、重度和极重度退化面积分别为6%和5%,而历史平均分别为28%、7%、4%和1%。从不同草地类型来看,高寒荒漠退化程度最严重,退化面积78%,退化指数为3.23,达到重度退化等级且表现出持续恶化趋势;而高寒草甸和高寒草原退化面积分别为31%和38%,退化指数分别为1.49和1.57,均属于轻度退化状态。从不同省域看,2011-2013年青藏高原新疆自治区范围内草地退化程度最为严重,退化草地面积所占比例为71%;青海省和西藏自治区草地退化比例也较大,分别达到42%和41%;甘肃、四川和云南草地退化比例较小,分别为25%、10%和12%。总体来看,青藏高原草地退化存在空间差异,与历史平均相比无显著变化,但局部有恶化趋势,尤其是高寒荒漠退化状况较为严重。

关键词: 草地退化, 退化指数, 草地类型, 不同省域, 青藏高原

Abstract:

The Qinghai-Tibetan Plateau is an important ecological security barrier and animal husbandry base in China. Alpine grassland is the largest ecosystem in the Qinghai-Tibetan Plateau, accounting for more than 60% of the total area of the plateau. In recent years, the alpine grasslands in the Qinghai-Tibetan Plateau are experienced large area of degradation, which is restricting the ecological services of the plateau and the sustainable development of animal husbandry. To date, however, it is remaining unclear in the status of grassland degradation on the Qinghai-Tibetan Plateau. In this study, the degradation status was presented by the grassland degradation index, which was retrieved from vegetation coverage, based on NDVI3g data. The results showed that the current situation (2011-2013) of average grassland degradation index in the Qinghai-Tibetan Plateau was 1.76, which indicated light degradation level. The area of degraded grassland reached 41% and has no change compared with the historical average (1986-2010), but the areas of moderate, severe, and extra severe degradation has been increased in the Qinghai-Tibetan Plateau. The areas of slight, moderate, severe, and extra severe degraded grassland were 22%, 8%, 6% and 5%, respectively during 2011 to 2013, while they reached 28% (slight), 7% (moderate), 4% (severe) and 1% (extra severe) during 1986 to 2010. The degradation index in alpine desert was 3.23 during 2011 to 2013, which reached an extremely degradation level. The degradation index in the alpine meadow and alpine grassland steppe were 1.49 and 1.57, respectively during 2011 to 2013, which were characterized as light degradation level. In the Qinghai-Tibetan Plateau, the degraded area of grassland in Xinjiang reached 71%, higher than that in Qinghai and Tibet, which reached 42% and 41%, respectively. The degraded area of grassland in Gansu, Sichuan and Yunnan were relatively small, reached 25%, 10% and 12%, respectively, in the Qinghai-Tibetan Plateau. In summary, there exist spatiotemporal variations in grassland degradation in the Qinghai-Tibetan Plateau. There is no significant change in current grassland degradation status compared with the historical average. However, in some regions on the plateau, i.e. alpine region, the grasslands showed a continuously degrading trend.

Key words: Grassland degradation, Degradation index, Grassland type, Different province, Qinghai-Tibetan Plateau