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草业学报 ›› 2020, Vol. 29 ›› Issue (12): 5-16.DOI: 10.11686/cyxb2020240

• 研究论文 • 上一篇    下一篇

基于MODIS数据的青海省草地地上生物量估算及影响因素研究

赵慧芳1,2(), 李晓东1,2(), 张东1,2, 校瑞香1,2   

  1. 1.青海省气象科学研究所,青海 西宁 810001
    2.青海省防灾减灾重点实验室,青海 西宁 810001
  • 收稿日期:2020-05-26 修回日期:2020-08-05 出版日期:2020-12-28 发布日期:2020-12-28
  • 通讯作者: 李晓东
  • 作者简介:Corresponding author. E-mail: lixd16@lzu.edu.cn
    赵慧芳(1986-),女,青海西宁人,工程师,学士。E-mail: zhaohuifang.china@163.com
  • 基金资助:
    第二次青藏高原综合科学考察研究项目(2019QZKK0106);国家自然科学基金项目(41961012);青海省科技厅基础研究计划项目(2019-ZJ-7036);青海省科技计划项目(2017-HZ-801)

Aboveground biomass in grasslands in Qinghai Province estimated from MODIS data and its influencing factors

Hui-fang ZHAO1,2(), Xiao-dong LI1,2(), Dong ZHANG1,2, Rui-xiang XIAO1,2   

  1. 1.Qinghai Institute of Meteorological Science,Xining 810001,China
    2.Qinghai Provincial Key Laboratory of Disaster Prevention and Reduction,Xining 810001,China
  • Received:2020-05-26 Revised:2020-08-05 Online:2020-12-28 Published:2020-12-28
  • Contact: Xiao-dong LI

摘要:

利用EOS/MODIS植被指数产品(NDVI)、实测草地地上生物量和气象监测资料,结合实测资料和NDVI之间的关系建立了青海省草地地上生物量卫星遥感估算模型,并通过研究青海省气温和降水量变化特征分析了影响草地地上生物量的主要因素。结果表明:在草地生长季,生态监测站草地地上生物量与NDVI之间具有较好的正相关关系(P<0.01)。利用模型估算的青海省草地地上生物量在2003-2017年表现出弱的增加态势,2003年平均草地地上生物量最低,仅为2622 kg·hm-2,2010年最大,达3252 kg·hm-2; 2003-2017年,青海省草地地上生物量变化表现出明显的空间分布特征,从东南向西北逐渐递减;其中,青海省果洛州东南部、玉树州南部、黄南州东南部和海北州东南部草地地上生物量最高;西北部的柴达木盆地最低;2003-2017年青海省绝大多数地区草地地上生物量均呈现保持不变或者趋好的变化特征,其中曲麻莱、都兰以及甘德等地区部分草地地上生物量明显减少。气温升高热量条件充足的背景下,青海省草地受降水量增多带来的水分条件趋好的有利影响,对高寒地区草地植被的生长发育起到了促进作用,最终导致草地NDVI升高,地上生物量增加。

关键词: 青海省, 草地, NDVI, 草地地上生物量, 遥感估算

Abstract:

According to the principles of satellite remote sensing estimation, the relationships between vegetation index and biomass were analyzed to produce a method to assess biomass in Qinghai Province based on satellite data. These analyses were based on the normalized difference vegetation index (NDVI) monitored by the EOS/MODIS satellite, aboveground biomass measured on the ground, and meteorological monitoring data (temperature and precipitation), and revealed the factors affecting aboveground biomass in Qinghai Province. We detected a significant positive correlation (P<0.01) between forage yield (aboveground biomass) and NDVI at ground monitoring sites in different grassland types during the grassland growing season. The average aboveground biomass in Qinghai Province tended to slightly increase from 2003 to 2017. The minimum average biomass was 2622 kg·ha–1 in 2003, and the maximum average biomass was 3252 kg·ha–1 in 2010. The aboveground biomass decreased gradually from the southeast to northwest. The areas with the highest biomass were in the southeastern part of Guoluo Prefecture, Yushu Prefecture,Huangnan Prefecture, and Haibei Prefecture, and the area with the lowest biomass was in the northwest of the Qaidam Basin. The aboveground biomass in most areas of Qinghai Province tended to remain unchanged or increase from 2003 to 2017. The grassland biomass significantly decreased in Qumalai, Dulan, and Gande. Against a background of high temperature and sufficient heat conditions, grassland in Qinghai Province was favorably affected by greater water availability resulting from increased precipitation. Greater water availability played a role in promoting the growth and development of grassland vegetation in alpine regions, which eventually led to an increase in NDVI and biomass in those regions.

Key words: Qinghai Province, grassland, NDVI, aboveground biomass in grasslands, remote sensing estimation