Study on Change of Landscape Pattern and Construction of Ecological Security in Shiyang River Basin

Author:Qiao Zuo Qiang

Supervisor:liu xue lu

Database:Doctor

Degree Year:2019

Download:51

Pages:154

Size:4224K

Keyword:

Qilian mountain plays an irreplaceable role in the construction of ecological security in northwest of China,and is an important ecological security barrier in the western and even the whole country.However,using the landscape ecology to study the changes of Qilian mountain ecological environment,the development direction in the following years,and the ecological safety regulation is a lack of comprehensive,systematic research.At present,there is no reference literature available.Therefore,based on the analysis of the dynamic of the landscape pattern dynamics,we use the CA-Markov model,P-S-R model and the minimum cumulative resistance(MCR)research methods to clarify the characteristics and driving factors of landscape pattern changes in Shiyang River Basin from 1988 to 2016,and to study the future landscape ecological simulation status,on the basis of which optimization and optimization are carried out.Constructing the ecological security pattern of Shiyang River Basin.The research shows that:(1)In the analysis of the number,structure and morphological changes of landscape pattern,the landscape fragmentation of shiyang river basin from 1988 to 2016 is obvious,with uneven spatial distribution of various landscape components,complex patch geometry and low degree of spatial heterogeneity.In the research of landscape speed change,and structure change Shiyang River Basin lower ecological value landscape components increase area is large,and speed from 1988 to 2016 and occupy land of high ecological value landscape,landscape composition and low ecological value center of gravity towards the south migration,increase the effect of southern headwater.Luckily downstream sand sediment control engineering of eng grass planting achieved some results.In the analysis of driving factors of landscape components,different landscape components were driven by different influencing factors from 1988 to 2004 and from 2004 to 2016,but there was also a consistency of driving factors.On the whole,natural factors and population status were the general driving factors of landscape changes during the study period.(2)Driven by Landscape Components,the area of cultivated land,woodland,grassland,water body and sandy land in the landscape ecological simulation of Shiyang River Basin in 2022 and 2028 increased year by year compared with 2016,while glaciers and permanentsnow land and construction land and unused land area is reducing year by year,which shows the area of most landscape components with high ecological value increased,while part of the low ecological landscape components reduced.In the forecast of future landscape pattern,the degree of landscape fragmentation in 2022 and 2028 is lower than that in 1988-2016,and the spatial distribution tends to be centralized from dispersion,the spatial distribution is more compact,and the distribution of landscape components is clustered to dominant landscape.(3)In the landscape ecological evaluation,the comprehensive index of landscape ecological security of Shiyang River Basin from 1988 to 2028 is low,and there is great potential to improve ecological security.From 1988 to 2016,the landscape ecological security experienced three stages of sensitivity--risk--sensitivity,but most years the ecological security grade was in the sensitive stage.The comprehensive index of landscape ecological security predicted for 2017-2028 increased year by year,and the ecological security level increased from the sensitive state in 2017 to the general state in 2022 and2028,compared with the ecological security level from 1988 to 2016.The ecology improved,but the severity of the ecological environment did not change fundamentally.(4)In the landscape security pattern of optimization and building,1988-2016 in Shiyang River Basin landscape security level to level of security is given priority to,accounting for 60% of the total area of the basin,while low security level area increase first and then decrease,accounting for about 30% of the total area of the basin,which indicate that the optimized most scientific and reasonable land use distribution.And there are more advantages to the land ecological function.In further improve the ecological quality,high security level of land continue to expand the construction of high ecological value landscape,optimize the construction of ecological barriers and protection mode.The medium safe level of land use further coordinates the relationship between human and natural environment,guides the large-scale development of land use,and improves the ecological compensation mechanism of natural resources in the whole basin.Low security land use through the establishment of sound nature reserves,the implementation of the strictest spatial control strategy on the region,and the implementation of ecologicalmigration policy.