Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Estimation and Uncertainty of Aboveground/Belowground Biomass of Desert Grassland in Xinjiang Based on RS

Auteur : 王公鑫

Grade : Master 2022

Université : Xinjiang Agricultural University

Résumé partiel
Grassland is the most widely distributed system of natural ecosystem.Grassland biomass is an important parameter to measure grassland productivity and carbon sequestration capacity.Therefore,it is necessary to accurately estimate grassland biomass and carry out analysis and researc h on the change pattern and influencing factors of desert grassland in Xinjiang.It is of great significance to the sustainable utilization and carbon storage capacity of natural grasslands in Xinjiang.Based on a variety of remote sensing product data and grassland biomass data,by constructing the optimal inversion model of desert grassland biomass,this study analyzes the uncertainty of temporal and spatial distribution and estimation of desert grassland biomass in Xinjiang,supplemented by trend analysi s,correlation analysis and precision evaluation,and reveals the relationship between the evolution trend of desert grassland biomass and temperature and precipitation.The main conclusions are as follows :（1）Based on a variety of remote sensing product data and measured biomass data,the correlation coefficient and accuracy of the index inversion model are the highest,which is suitable for the monitoring and research of aboveground biomass change of desert grassland in Xinjiang.The precision of the power function model of the belowground biomass of desert grassland is higher than that of the measured root shoot ratio,the uncertainty of desert grassland biomass estimation comes from the estimation accuracy of different remote sensing data sources,root shoot ratio data and allometric growth model.（2）The distribution of desert grassland is concentrated in Northern Xinjiang and scattered in southern Xinjiang.From 2000 to 2019,the NDVI of desert grassland in Xinjiang generally sh owed a trend of gradually increasing from south to north.The NDVI of desert grassland appeared the maximum value（0.15）in 2019 and the minimum value（0.12）in 2010.Among them,the average NDVI of desert grassland was 0-0.2,accounting for 85.43%.Based on the change trend of NDVI,it is found that the desert grassland in Xinjiang is mainly stable and improved,and the area reaches 97.22%.

Mots clés : desert grassland ;aboveground biomass ;belowground biomass ;temporal and spatial distribution ;multi source remote sensing data ;

Présentation (CNKI)