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

Titre : Comprehensive Evaluation of Ecological and Environmental Quality of the Hetao Plain Oases based on Remote Sensing Index

Auteur : 刘璐

Grade : Master 2022

Université : Northwest Normal University

Résumé partiel
The ecological environment is the prerequisite and basis for human survival.With the development and progress of human society,ecological and environmental problems have become increasingly prominent.Protecting of ecological environment has become a challenge faced by the world.As an important measure to protect the ecological environment,comprehensive and objective evaluation of ecological environment quality has gradually developed into a strategic demand of ecological civilization construction in various countries,and is of great significance to global changes and sustainable development.The Hetao Plain Oases,as the most famous oases in the Yellow River Basin,is also an important ecological barrier in the northwest of China.Understanding the ecological status and development trend of the Hetao Plain Oases can better improve the local ecological environment.It also can provide scientific decisions for maintaining regional ecological balance and high-quality development.In this paper,Landsat remote sensing images of the Hetao Plain Oase in 1990,1995,2000,2005,2010,2015 and 2020 were used as the basic data source to extract the Normalized Vegetation Index（NDVI）,Humidity Index（WI）,Surface Albedo Index（Albedo）,Salinity Index（SI）and Desertification Index（DI）,which characterize five indexes of greenness,humidity,albedo,salinity and sandiness,respectively.Construct a comprehensive index of ecological environment quality（P）based on principal component analysis.Using P to comprehensively evaluate the changes of ecological environment quality in the Hetao Plain Oases,and also combined with meteorological data,land use data and socioeconomic data to explore the main factors affecting the changes of its ecological environment quality.The main conclusions are as follows.（1）NDVI and Albedo in the Hetao Plain Oases showed an increasing trend in 1990,1995,2000,2005,2010,2015 and 2020 with values of 0.430,0.393,0.524,0.373,0.490,0.620,0.636 and 0.515,0.522,0.509,0.564,0.573,0.634,0.635.WI,SI and DI showed a decreasing trend.The mean values of WI were 0.514,0.488,0.531,0.462,0.513,0.348 and 0.410.The mean values of SI were 0.450,0.457,0.364,0.468,0.412,0.387 and 0.373.The mean values of DI were 0.691,0.609,0.603,0.666,0.604,0.559 and 0.535.The P showed upward trend with its mean values of 0.470,0.532,0.624,0.382,0.450,0.553 and 0.583.It shows that the vegetation and albedo of the Hetao Plain Oases increased,humidity decreased,salinization and desertification area decreased,ecological environment improved and ecological quality became better in general.（2）In the spatial distribution,the high NDVI areas are mainly located in agricultural planting areas.The high WI area is mainly located in the irrigated area.High Albedo areas are concentrated in areas with bare soil.The areas with severe salinization and desertification are mainly concentrated in Ulan Buh Desert in the Dengkou County of the Hetao Plain Oases,the western edge of the Ningxia Hetao Plain Oases and the Mu Us Desert Land on the eastern edge.The areas with better ecological quality are mainly distributed in the agricultural planting areas within the oasis,while the areas with poor ecological environment quality are mainly located in the areas with serious salinization and desertification

Mots clés : Remote sensing index ;Ecological environment quality ;Comprehensive evaluation ;Principal component analysis ;Factor contribution ratio ;Hetao plain Oases ;

Présentation (CNKI)