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干旱区地理 ›› 2022, Vol. 45 ›› Issue (4): 1186-1199.doi: 10.12118/j.issn.1000-6060.2021.507

• 地球信息科学 • 上一篇    下一篇

气候变化和人类活动对盐池县植被净初级生产力的影响

李诗瑶1(),丛士翔1,王融融1,余海龙1(),黄菊莹2   

  1. 1.宁夏大学地理科学与规划学院,宁夏 银川 750021
    2.宁夏大学生态环境学院,宁夏 银川 750021
  • 收稿日期:2021-11-01 修回日期:2021-12-25 出版日期:2022-07-25 发布日期:2022-08-11
  • 通讯作者: 余海龙
  • 作者简介:李诗瑶(1996-),女,硕士研究生,主要从事农业遥感、生态遥感等方面的研究. E-mail: nxulsy@163.com
  • 基金资助:
    宁夏重点研发项目(2019BEG03029);国家自然科学基金项目(41961001)

Effects of climate change and human activities on net primary productivity of vegetation in Yanchi County

LI Shiyao1(),CONG Shixiang1,WANG Rongrong1,YU Hailong1(),HUANG Juying2   

  1. 1. School of Geography and Planning, Ningxia University, Yinchuan 750021, Ningxia, China
    2. School of Ecology and Environment, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2021-11-01 Revised:2021-12-25 Online:2022-07-25 Published:2022-08-11
  • Contact: Hailong YU

摘要:

为定量区分退耕还林还草背景下北方典型农牧交错带植被变化过程中气候变化和人类活动的相对贡献率,以宁夏盐池县2000—2020年植被变化为研究对象,基于MODIS13Q1-NDVI数据、地表覆盖数据和气象数据,采用Thornthwaite纪念模型和CASA(Carnegie-ames-stanford approach)模型分别估算了逐年的潜在净初级生产力(Potential net primary productivity, PNPP)和实际净初级生产力(Actual net primary productivity, ANPP)。综合运用趋势分析、相关分析和差值比较法分析了2000—2020年盐池县净初级生产力(Net primary productivity, NPP)时空变化特征及其驱动力,并定量确定了气候因子和人类活动对盐池县植被变化的相对贡献率。结果表明:(1) 在2000—2020年盐池县NPP总体呈上升趋势,但存在着显著的空间异质性,主要表现为植被NPP改善区面积远大于NPP退化区面积,且改善或退化程度也存在显著的空间分异。植被改善区主要分布于荒漠、荒漠草原等退耕还林还草工程区域和灌溉区,而植被退化区则分布于荒漠和荒漠草原的边缘地带。(2) 植被变化归因分析表明,在植被改善区,气候变化和人类活动共同主导驱动了植被的改善,但气候变化的相对贡献率(59.77%)大于人类活动的相对贡献率(40.23%),而在植被退化区,人类活动的相对贡献率(91.77%)则显著高于气候变化的相对贡献率(8.23%)。(3) 驱动力分析表明,研究区植被NPP变化与降水量呈显著正相关,而与气温的相关性较弱;而人类活动是驱动植被退化区NPP下降的主要原因,但负向影响力有所减弱。总体而言,气候变化是植被改善区的主要驱动力,而人类活动是植被退化区的主要驱动因素,两者共同作用则使盐池县整体生态环境得以改善。

关键词: 净初级生产力, 荒漠草原, 植被变化, 驱动力, 盐池县

Abstract:

This study aims to quantitatively differentiate the relative contribution rate of climate change and human activities during the vegetation cover change in the typical agricultural pastoral ecotone of Northern China under the background of the “grain to green project”. Taking vegetation change from 2000 to 2020 in the Yanchi County, Ningxia Province as the study object and using MODIS13Q1-NDVI, land cover data, and meteorological data from 2000 to 2020, the annual potential net primary productivity and actual net primary productivity were simulated using the models of Thornthwaite Memorial and Carnegie Ames Stanford Approach. The spatial and temporal change characteristics of the net primary productivity (NPP) in the Yanchi County and its driving force were analyzed, and the relative contribution rates of meteorological factors and human activities in the process of vegetation cover change were quantitatively calculated using trend analysis, correlation analysis, and difference comparison. The results showed the following: (1) The NPP totally presented an increasing trend, but there was an obvious spatial heterogeneity in the NPP change trend and degree, mainly manifested when the vegetation NPPs of the improved areas were far greater than the those of the degraded areas, and the extents of improvement and degradation showed significant spatial heterogeneity. The vegetation-improved areas were mainly distributed in the desert and desert steppe (where the “grain to green project” was conducted) and in irrigated areas, whereas the vegetation-degraded areas were mainly distributed in the edge zones of the desert and desert steppe. (2) The vegetation change attribution analysis results indicated that in the vegetation-improved areas, the relative contribution rate of climate change (59.77%) was higher than that of human activities (40.23%). Meanwhile, in the vegetation-degraded areas, the relative contribution rate of human activities (91.77%) was higher than that of climate change (8.23%). (3) The driving force analysis results indicated that the vegetation NPP was positively correlated with precipitation but weakly correlated with temperature. Human activities were the main driving force that drove the NPP decrease in the vegetation-degraded areas. In summary, climate change was the main driving force that drove the NPP improvement in the vegetation-improved areas, whereas human activities were the main driving factors that led to the NPP decrease in the vegetation-degraded areas. Climate and human activities jointly dominated the improvement of the total ecological environment in the Yanchi County.

Key words: net primary productivity (NPP), desert steppe, vegetation change, driving force, Yanchi County