The Study Of Landscape Pattern Spatio-temporal Transformation And Ecosystem Health Danamic Assessment In Keriya River Basin

Keriya River Basin,located in North Region of Kunlun Mountain, is a typicalwater source region of the Kunlun Mountain, The basin includes special geologicalformations, complex and diverse landforms such as forests, farmland,wetlands,rivers, salin,desert,so there is great ecological significance of the basin protection.The main conclusions of the study are as follows:(1) The classification system of watershed land use/cover types was establishedand the land use/cover information was extracted on the basis of interpreting fourremote sensing images of1990Landsat TM inmage,2000and2011Landsat ETMimage, topographic maps and forest map.(2) Meanwhile the Landscape Pattern Indexes were used to analyze the landscapepattern transformation characters on the type and landscape level. The changes ofbasin landscape pattern and types indicate: the landscape types of Keriya River Basinwere not changed; the main changes were the landscapes proportions and the spatialpattern. The process of landscape evolution was that residential saline-alkali land andarea increased, arbor forest,shrub land,h-grass,m-grass and marshland are declined,l-grass firstly increased and then reduced. desert firstly slightly reduced and thenrapidly increased, glaciers are stabilized, farnland area slightly increased volatility,but not much,Dynamic conversion process indicates that the basin landscape typechanges include the two-way change of increase and decrease. On the landscape level,human activities impact on the landscape pattern made it tends to be shaped becauseof the human aims; on the plaque level, forest,saline-alkali land,l-grass,marshlandfarmland and residential areas changed dramatically, which plaqueshapeare complexand dispersion and interfered obviously.(3) The spatial characteristic changes of the study area during20years weregradually in-deep analyzed by using Markov theory, Conclusions were as follows. Since1990, the study area has appeared desert as matrix, farm land and grassland asmain patches. This pattern almost has not changed. the study area is mainly for theforest-grassland cultivated, farmland-grassland salinization, low coverage grasslanddesertification, the most intense change area located in oasis and the oasis-deserttransitional zone, that oasis was increased, desert was decreased step forward in1990s,and increased in the21st century. The forecast of the trend of landscapechange by Markov Chain Model indicated that farm land; water, saline-alkali land,desert will go on increasing, while wetland, woodland, high-grass, and middle grassand low grass will decline.(4) The comprehensive health assessment of Keriya River Basin ecosystem wasmade by utilizing the pressure-state-response model (PSR model), on the base of thelately research achievement of domestic and foreign scholars on the ecosystem healthassessment. The PSR model include10evaluation indexes,and using the analyticalhierarchy process to weight the sorted indicators, and then calculate comprehensiveevaluation index.(5) According to the index classification level of ecosystem health,the CEI of1990is0.3058,2000is0.3213.the health value of Keriya River Basin is belong the intervalof0.2to0.4, that means, at present its special environment and economicdevelopment is the main influencing factors of the basin ecosystem health; Ecosystemhealth of Keriya River Basin is up to level4, belongs to the poor.(6) The CEI of Keriya River Basin in2010is0.4102,the health value of it is belongthe interval of0.4to0.6,that means, ecosystem structure is integrity, and have somesystem vitality, pressure relatively heavy, system is relatively stable, sensibilityrelatively strong, ecological absormal phenomena is found,but it can develop itsecosystem function of oasis, Ecosystem health of Keriya River Basin is up to level3,belongs to the general, namely the alert.In this paper,which analysed variation characteristics of landscape pattern during 20years in Keriya River Basin, as well as its landscape pattern analysis andcomparison through transverse,explored its variation and mechanisms.By constructingsuitable ecosystem health evaluation system for arid landscape-scale, which evaluatedKeriya River ecosystem health, discussed environmental problems that currently existand made appropriate recommendations. There is a very important empiricalsignificance and reference value for sustainable development of Keriya River basinand ecological environment.