草业学报2016，Vol.25Issue(8)：14-26,13.DOI:10.11686/cyxb2015455
基于 MODIS 逐日地表反射率数据的青南地区草地生长状况遥感监测研究
Monitoring of grassland herbage accumulation by remote sensing using MODIS daily surface reflectance data in the Qingnan Region
摘要
Abstract
Monitoring of grassland herbage accumulation using remote sensing technology has a potentially im-portant role in understanding seasonal changes in grasslands and optimizing animal husbandry and grazing man-agement.In this study above ground biomass (AGB)and its spatial distribution was recorded using in-situ measurements during the growing seasons from 2010 to 2013 in southern Qinghai province,and regression models using in-situ AGB data and the corresponding daily surface reflectance product of Terra MODIS were established.The spatial analysis method was used to calculate four vegetation indices (NDVI max ,EVI max ,ND-VI mean and EVI mean )using MOD09GA data,and the accuracy of the inversion models was then analyzed,and the spatial distribution of the NDVI mean values in the previous 10 years characterized.With the algorithms opti-mized in this way,we estimated the aboveground grassland biomass and its spatial distribution for the previous 10 growing seasons.It was found that the aboveground biomass gradually increases from northwest to south-east,and different grassland types have characteristic biomass differences.The biomass of mountain meadow was highest among the grassland types included in this 10 year study,and reached 1280 kg DW/ha in 2010. The biomass of alpine meadow,warm steppe,warm desert and marsh ranged between 244.9 kg DW/ha and 902.4 kg DW/ha,The biomass values of alpine meadow grassland,alpine desert,and alpine desert grassland were much lower,and were below 65 kg DW/ha.The elevation had a marked effect on biomass,with grass-land biomass decreasing with increasing elevation above 3500 m.At elevations between 3500 and 4000 meters, peak biomass was 1358.8 kg DW/ha;between 4000 and 4500 meters,the biomass was below 920 kg DW/ha, and between 4500 and 5000 meters the biomass averaged approximately 574.2 kg DW/ha.Above 5000 meters elevation,the biomass averaged approximately 94.4 kg DW/ha.The trend of NDVI mean values in last 10 years indicates that most regions in the Three River Headwater region (The Yellow River,The Yangtze River, and The Mekong River),which span different administrative areas,can be categorized as showing ‘mild im-provement’or ‘improvement’.Overall,the trend in grassland vegetation status is positive.关键词
青南地区/草地地上生物量/NDVI/遥感监测Key words
Qingnan region/aboveground biomass of grassland/NDVI/remote sensing monitoring引用本文复制引用
杨淑霞,张文娟,冯琦胜,孟宝平,高金龙,梁天刚..基于 MODIS 逐日地表反射率数据的青南地区草地生长状况遥感监测研究[J].草业学报,2016,25(8):14-26,13.基金项目
国家自然科学基金项目（31372367，31228021，41401472），农业部公益性行业（农业）科研专项项目（201203006），长江学者和创新团队发展计划（IRT13019）资助。 （）
