Study On The Construction Of County Ecological Security Pattern Based On Habitat Quality

Since the 20th century,social and economic development has promoted the continuous expansion of production and living space,resulting in the continuous use of ecologically functioning land use/cover types.The ecological and environmental problems have become increasingly prominent,and the normal structure and function of ecosystems were difficult to maintain,seriously threaten the sustainable development of the region.Therefore,in order to avoid ecological protection from entering inefficient protection,the habitat quality and ecological security are organically combined,and the county ecological security pattern is constructed and relevant recommendations are put forward,which is not only an effective way to ensure the ecological security of the county,but also a strong basis for rationally formulating ecological environmental protection measures.In view of this,this paper took Tang County as an example to analyze the characteristics of land use/cover change,combined threat attribute,habitat type sensitivity to threat factors and threat factor accessibility,and used InVEST model to evaluate habitat quality and obtained habitat quality change law.The results of habitat quality assessment were used to identify the ecological source,and the resistance evaluation system was established as one of the resistance factors.The resistance threshold method was used to carry out the ecological safety division.Finally,the MCR model was used to determine the ecological corridor,and ecological security pattern that effectively balance the contradiction between economic development and ecological protection was constructed and relevant countermeasures were proposed.It is intended to provide theoretical reference and practical guidance for the county's construction of county ecological security pattern and land planning layout.Research indicated:(1)During 2009-2016,the land use/cover type of the research area was dominated by grassland and cultivated land.The land remediation project reinstated a small number of rural settlements,increasing the area of cultivated land by 138.10hm~2,in order to meet the needs of urbanization development,the construction land area increased by 633.41hm~2,and some areas of cultivated land,garden land,forest land,grassland,waters and other land were converted into construction land,the area of other land increased by 312.29hm~2,which was derived from the adjustment of internal structure of agriculture,the areas of forest land,grassland and waters decreased by 309.93hm~2,309.80hm~2,374.18hm~2,respectively,including the occupation of construction land,the area of the garden reduced by 89.89hm~2,which was partly due to the internal structural adjustment of agriculture.(2)The InVEST model was used to evaluate the habitat quality.According to the Habitat Quality Index,Tang County was divided into five habitat type regions:low habitat quality,lower habitat quality,medium habitat quality,higher habitat quality and high habitat quality.And the result of habitat quality assessment was the basis for the selection of ecological sources.During 2009-2016,the proportion of low habitat quality was above20%;the proportion of lower habitat quality was above 10%;the proportion of medium habitat quality was above 15%;the proportion of higher habitat quality was above 35%;the proportion of high habitat quality was above 10%.Judging from the overall situation of the county,the quality of habitat in Tang County was at a higher level.The proportion of ecological source area was 3.33%.(3)The MCR model was used to construct the ecological security pattern.The ecological source area accounted for 3.33%of the total area of the county,mainly distributed in forest land and waters;the residential source area accounted for 2.50%of the total area of the county,and consisted of villages and established towns within the threshold.The ecological security zone included four areas:prohibited development zone,restricted development zone,optimized development zone and key development zone.The area of the prohibited development zone was 26708.21hm~2,it was mainly distributed in grassland,woodland and waters in the northern part of Tang County,the area of the restricted development zone was 61728.63hm~2,it was distributed in grassland,cultivated land,other land and a small amount of forest land and waters;the area of the optimized development zone was 38971.24hm~2,it was mainly distributed in a large number of cultivated land and part of grassland and construction land in the southeast direction of restricted development zone,the area of the key development zone was 14027.68hm~2,it was mainly distributed in a large amount of cultivated land and part of construction land in the southeast of Tang County.As the same time,11 ecological corridors were obtained using the MCR model with a total length of 263.91km.In this paper,considering the natural,economic and ecological conditions of the study area,from the perspective of data accessibility,the InVEST model was used to evaluate the habitat quality.and the safety pattern was constructed by MCR model.It aimed to provide a basis and method reference for the selection of ecological source and the construction of ecological security patterns at the county scale.