基于MODIS NPP的2006-2015年三江源区产草量时空变化研究

Spatio-temporal Changes of Grassland Production Based on MODIS NPP in the Three-River Source Region from 2006 to 2015

草地既是高原地区重要的生态屏障,也是维系当地人民生产生活的自然资源,准确估算本区域的产草量,可为区域资源开发利用、社会经济可持续发展决策提供科学参考。论文基于MODIS遥感影像获得不同分辨率的NDVI、EVI和NPP产品,结合三江源区监测点的产草量地面实测数据,利用统计分析方法分别建立多种产草量遥感估算模型。利用择优选取的估产模型进行区域适用性评价和模型反演,研究三江源区产草量在2006—2015年的时空分布情况。研究结果表明,基于MOD17A2H NPP的一元线性模型的估算精度相对较高,三江源区的产草量(单产)呈东多西少、自东南向西北逐渐减少的空间分布特点。2006—2013年的产草量(总量)整体呈上升趋势,2013年的产草量(总量)达到3 869.43×10~4t,产草量(总量)自2014年开始降低,2015产草量(总量)为2 069.07×10~4t。

Abstract： The grassland is not only the important ecological barrier in plateau region, but also the natural pasture to maintain the local people＇ s living. The accurate estimation of grass production could provide scientific basis for informed decision-making on regional resource exploitation and socio-economic sustainable development. In this paper, the Three-River Source Region in Tibetan Plateau was selected as the research area. Estimation models of grassland production were established using statistical analysis method based on NDVI, EVI and NPP from NASA＇ s MODIS remote sensing products and measured data. The general grassland production in the Three-River Source Region from 2006 to 2015 was retrieved with these models. The result shows that the linear model based on MOD17A2H NPP is the best model. In the Three-River Source Region, the grassland production （per unit yield） decreases from east to west and from southeast to northwest gradually. The grassland production （total yield） was increasing from 2006 to 2013 and then began to decrease. The annual grassland production （total yield） in 2013 was the highest and that in 2015 was the lowest. The annual grassland production （total yield） was 3 869.43x 104 t in 2013, while the annual grassland production （total yield） was 2 069.07x104 t in 2015.