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Université du Xinjiang (2019)

Temporal and Spatial Pattern Changes of Grassland Phenology and Grassland NPP in Xinjiang from 2001 to 2014

蔡亚荣;

Titre : Temporal and Spatial Pattern Changes of Grassland Phenology and Grassland NPP in Xinjiang from 2001 to 2014

Auteur : 蔡亚荣;

Grade : Master’s Theses 2019

Université : Université du Xinjiang

Résumé partiel
Vegetation phenology is one of the important indicators reflecting the current growth of vegetation and climate and environmental changes.In recent years,the research on the response of vegetation phenology and primary productivity to meteorological factors has become the focus of research in geography,environment and ecology.As one of the“five pastoral areas”in China,Xinjiang’s grassland ecological environment development will not only directly affect the development of local animal husbandry,but also affect local ecological security.For the fragile ecosystems in Xinjiang and the deteriorating ecological environment,the study of grassland phenology and net primary productivity of grassland will prompt us to understand more about the current status and trends of grassland in Xinjiang.Studying the relationship between grassland phenology and grassland net primary productivity in Xinjiang has important scientific and practical significance for the protection and rational use of natural grassland resources in Xinjiang.Based on MODIS NDVI data and temperature,precipitation and radiation data of meteorological sites,this study combined the Xinjiang grassland type,measured biomass data and Xinjiang elevation data to accurately estimate the net primary productivity of Xinjiang grassland using CASA model.The spatial and temporal distribution patterns of net primary productivity of different grassland types in Xinjiang were analyzed.In addition,using the 2001-2014 MCD12Q2 dataset,the three main parameters of grassland phenology in Xinjiang are extracted from the continuous time series data.The parameters include:growth season start date(SOS),growing season length(LOS),and growing season.End date(EOS).Then the spatial and temporal distribution changes and interannual variation trends of grassland phenological parameters in Xinjiang were analyzed and explored,and the extracted phenological parameters were correlated with grassland NPP to study the impact of grassland phenology on NPP in Xinjiang.Through the above three aspects of research,the preliminary conclusions of this paper are as follows :(1)The research on NPP in Xinjiang grassland found that the annual average variation of NPP in Xinjiang grassland was large.The annual average NPP of the whole Xinjiang region is 158 g C/(m2·a).From the spatial point of view,the northern Xinjiang part and the Ili valley area have the largest value,while the southern part of Xinjiang has the smallest value.

Mots clés : phenology; remote sensing monitoring; grassland net primary productivity; correlation analysis; grassland;

Présentation (CNKI)

Page publiée le 19 mai 2020