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Ningxia University (2019)

Landscape Distribution and Biomass Estimation of Caragana Intermedia Plantation in Yanchi Desert Steppe Based on Remote Sensing Technology

郑琪琪;

Titre : Landscape Distribution and Biomass Estimation of Caragana Intermedia Plantation in Yanchi Desert Steppe Based on Remote Sensing Technology

Auteur : 郑琪琪;

Grade : Master’s Theses 2019

Université : Ningxia University

Résumé
Desert grassland ecosystem is a typical ecosystem in arid and semi-arid climate regions,Because of overgrazing and human interference,Large-scale desert grassland ecosystem in northwestern China has been severely damaged in the last centur.Studying the material cycle and energy flow of desert ecosystems has guiding value for maintaining the stability of desert steppe ecosystem and establishing a scientific and rational desertification governance model.Taking Yanchi County of Ningxia as a research area,using GF-1 remote sensing image and Google Earth data,the combination of supervised classification and visual interpretation is used to extract Caragana intermedia Plantation.Based on DEM data and landscape ecology methods,the geographical distribution pattern and landscape characteristics of C. intermedia plantations in Yanchi are analyzed.We did experiments in the wild,established a biomass estimation model for C.intermedia plantation by factor of remote sensing independent variable and above ground biomass in Yanchi County based on Remote Sensing Image.And we calculated the biomass of C.intermedia plantation in Yanchi county.The results show that:1)There are 1885 plaques of Caragana forest in Yanchi County,with a total area of 89234.24 hm2.the total area of C.intermedia plantations in Yanchi accounts for 13.18%of the whole county area,and the distribution of the number and area of plaques varies greatly from north to south.From the geographical distribution pattern,the C.intermedia plantation is widely distributed in areas with low elevation and slow slope.The area with high terrain and steep slope has only a small number of small patches.2)The internal plaque connectivity of Gaoshawo is better,the landscape of Mahuangshan is more fragmented,and the plaque boundaries of Gaoshawo and Mahuangshan are more tortuous.On the whole,the middle and northern parts of the salt pond with a gentle topography and low elevation are mainly used to build sand control type.In the southern gully hilly area with large area and continuous plaques,the southern gully hilly area is mainly composed of C intermedia,which is small in area and broken in landscape.3)We established a regression equation for above ground biomass of C.intermedia shrubs by doing field experiments.Then we calculated the total biomass of C.intermedia plantations in the plot.We extracted the image band information of the plot in the landsat-8 image and calculate the vegetation index.We used regression analysis to select factors,and establish model of biomass of artificial C.intermedia forest in Yanchi County based on remote sensing image was obtained.The optimal estimation model is:y=7126.567*b2-217.903(b2:Band Blue reflectivity)R2=0.454 P=0.046 F=5.8294)Calculated for Landat-8 remote sensing image in Yanchi County,the total amount of salt pool biomass was 280674.45 tons.The biomass of C.intermedia plantation forest varies from town to town.Dashuikeng Town has the most biomass,Mahuangshan Town has the lowest biomass.The average biomass of Mahuangshan Township is lower than the average level of Yanchi County.The average biomass per unit area of other townships is equivalent to the average biomass level of Yanchi county.

Mots clés : Caragana intermedia plantation; biomass; remote sensing; regression model;

Présentation (CNKI)

Page publiée le 21 mai 2020