三江源区高寒草地地上生物量遥感反演模型研究

发布时间：2018-02-02 22:46

本文关键词： 三江源区高寒草地地上生物量遥感反演模型回归分析　出处：《环境科学研究》2017年01期 　论文类型：期刊论文

【摘要】：为了发展适用于三江源区高寒草地(包括高寒草甸和高寒草原)地上生物量(aboveground biomass,AGB)模拟的遥感反演模型,基于2006—2014年逐年7—8月三江源区高寒草地70个采样点地上生物量数据与同期MODIS-NDVI和MODIS-EVI数据,通过回归分析方法建立高寒草地地上生物量遥感反演模型,并利用长时间序列MODIS数据对2005—2014年三江源区高寒草地地上生物量的时空格局进行模拟分析.结果表明:基于EVI建立的乘幂模型对三江源区高寒草地地上生物量的拟合效果最好,其判定系数(R2)最大,达到0.654;均方根误差(RMSEP)最小,仅为27.86 g/m~2.根据三江源区70个采样点的地上生物量数据最终确立的估算模型为y=348.769x0.783(R2=0.655,P0.001).估算模型模拟结果显示,2005—2014年三江源区高寒草地地上生物量空间特征基本一致,总体表现为从东南到西北逐渐减少的变化趋势,这与该区域的降水量、气温、海拔和植被类型等因素有关;2005—2014年三江源区高寒草地地上生物量平均值为169.25 t/a,最高值为2010年的178.36 t/a,最低值为2008年的162.80t/a,年际变化趋势表现为2005—2008年逐年下降、2008—2014年则在波动中逐年有所上升.研究显示,三江源区高寒草地地上生物量遥感反演模型及其确定的模型参数可对该区域草地地上生物量进行有效评估.
[Abstract]:In order to develop a remote sensing inversion model suitable for simulating aboveground biomass in alpine grassland (including alpine meadow and alpine steppe) in the source region of the three rivers, Based on the aboveground biomass data of 70 sampling points of alpine grassland and MODIS-NDVI and MODIS-EVI data from July to August of 2006 to 2014, a remote sensing retrieval model of aboveground biomass of alpine grassland was established by regression analysis. The temporal and spatial patterns of the aboveground biomass of alpine grassland in the source region of the three rivers from 2005 to 2014 were simulated and analyzed by using the long time series MODIS data. The results showed that the power model based on EVI had the best fitting effect on the aboveground biomass of the alpine grassland in the source region of the three rivers. The R2) is the largest, and the root mean square error (RMSEP) is the smallest. Based on the aboveground biomass data of 70 sampling points in the source area of Sanjiang River, the estimated model is yjing348.769x0.783R2O0.655P0.001. The simulation results show that the spatial characteristics of aboveground biomass of alpine grassland in the source area of Sanjiang River from 2005 to 2014 are basically the same. The overall performance is a decreasing trend from the southeast to the northwest, which is associated with the precipitation and temperature in the region, The above ground biomass of alpine grassland was 169.25 t / a from 2005 to 2014, the highest was 178.36 t / a on 2010, and the lowest was 162.80 t / a on 2008. The trend of interannual variation was decreased from 2005-2008 to 2008-2014. Activity has increased year by year. Research shows that, The inversion model of aboveground biomass of alpine grassland and its determined model parameters can be used to evaluate the aboveground biomass of alpine grassland in the source region of the three rivers.
【作者单位】：中国环境科学研究院环境基准与风险评估国家重点实验室;中国环境科学研究院国家环境保护区域生态过程与功能评估重点实验室;安徽理工大学测绘学院;
【基金】：中央级公益性科研院所基本科研业务专项(2014-YKY-003) 中国工程院重点咨询项目(2014-XZ-31)
【分类号】：S812
【正文快照】： 草地生态系统作为陆地生态系统中分布面积最为广泛的生态系统类型之一,不仅是草地畜牧业发展最重要的物质基础,而且对全球碳循环、气候调节等具有重要作用[1-3].三江源区地处青藏高原腹地,是我国重要的水源涵养区和重点草原草甸生态功能区,高寒草地(包括高寒草甸和高寒草原)是

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