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sur le développement des zones arides et semi-arides

Titre : Ecosystem Service Value of Kubuqi Desert Based on Ca-Markov Model Evaluation and Prediction Research

Auteur : 陈宏芳

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé
Land use pattern is not only an important part of ecosystem service value（ESV）,but also an important guarantee for the sustainable development of ecological environment.Kubuqi Desert is an important ecological security barrier in northern China.In recent years,frequent human activities have led to a certain degree of change in the regional land use structure,making the ecological environment more fragile.Therefore,China has successively implemented a series of key ecological environment projects,which not only promoted the transformation of the regional land use structure,but also had a positive effect on the ecological service function.Based on the Landsat TM / oli images of Kubuqi Desert with an interval of five years from 2000 to 2020,thesis first interprets and analyzes the dynamic change characteristics of land use in recent 20 years,and predicts the land use pattern from 2020 to 2035 through CA Markov model ;Secondly,the equivalence factor is adjusted regionally,and the temporal and spatial dynamic characteristics of ESV are analyzed.Finally,the relationship between them is analyzed through the variation contribution rate and ecological coordination degree,and the following conclusions are drawn :（1）From 2000 to 2020,the unused land in the study area showed continuous contraction,and other land use types showed the coexistence of expansion and contraction.Except that the water area showed contraction greater than expansion,other land types showed expansion greater than contraction,in which the area of cultivated land and construction land changed sharply ;In addition,the area of cultivated land,forest and grassland and unused land is transferred in and out frequently,which not only speeds up the land transfer,but also improves the degree of land use.From 2020 to 2035,the land use types in the study area are mainly forest and grassland,unused land and cultivated land in space.Among them,forest and grassland are in the state of continuous expansion,and other land use types are in the state of contraction,but the expansion is dominant on the whole ;In terms of time,except that the area of forest and grassland showed an increasing trend,other land use types showed a decreasing trend.（2）From 2000 to 2020,ESV first increased and then decreased,among which forest,grassland,water area and cultivated land contributed more service value.In2020,the contribution rate of hydrological regulation service value is the highest（36.14%）,followed by climate regulation（18.74%）,and the contribution rate of water resources supply is the lowest（-0.10%）.From 2020 to 2035,ESV showed a trend of continuous increase,but the increase rate slowed down,in which forest and grassland contributed the most service value.Among the secondary ESV components in 2035,the contribution rate of hydrological regulation service value is the highest（32.96%）,followed by climate regulation（20.58%）,and the contribution rate of water resources supply is the lowest（0.63%）.（3）ESV sensitivity coefficients are less than 1,that is,the service value coefficient has high reliability.The relationship between land use and ESV is analyzed by using variation contribution rate and coordination degree.From 2000 to 2020,the variation contribution rate of forest,grassland and cultivated land ESV in the study area is large,which is the main land use type affecting ESV in the study area ;The degree of ecological coordination changes from moderate coordination to low conflict,that is,the transfer of land use area is relatively frequent and has a certain negative effect on the ecological environment.

Mots clés : Land use ;Kubuqi Desert ;CA-Markov model ;Ecosystem service value ;

Présentation (CNKI)