Dynamic Change Characteristics Of Land Use Landscape Pattern And Its Eco-environmental Effects In Bayuquan District

Land is a complex of natural economy,a link connecting various elements of the ecological environment,and an indispensable material basis for social development.With the rapid development of social economy,in order to gain greater economic benefits,human beings have increased the intensity of land development and utilization,such as urban expansion,infrastructure construction,and unreasonable deforestation,excessive grazing,lake reclamation and so on.This not only changes the surface cover,but also destroys the stability of the ecological environment system,and then affects the overall ecosystem structure.Land use/cover change is an important part of global environmental change research,which affects ecosystem structure and service function at different scales.Studying the characteristics of land use distribution and the problems of land ecological environment and exploring its evolution law has far-reaching significance for strengthening the protection of ecological environment and improving the quality of ecological environment.Based on the land use data of squid enclosure from 2010 to 2017,the spatial and temporal characteristics of land use landscape pattern and its ecological environment effects were studied by using land use dynamics,landscape pattern index,ecosystem service value and ecological environment quality,and spatial autocorrelation analysis.The main conclusions are as follows:(1)From the perspective of land use types and dynamic attitudes,construction land is the main type of land use in squid enclosure,and garden land type is the second.From 2010 to2013,the net increment of construction land was 19.14 km~2,the percentage increased by5.55%,mainly distributed in the western coastal areas,the terrain was low;the net area of garden land decreased by 8.65 km~2,the percentage of area decreased by 3.78%;the area of other land types was basically in a stable state,and there was no significant change.From2014 to 2017,the net increase of construction land was 9.58 km~2,mainly from reclamation projects.During the past eight years,the construction land area of squid pen changed the most,and the transfer of cultivated land and garden land to construction land area was the largest,which were 1.79 km~2 and 9.17 km~2,respectively.The dynamic degree of land use showed a gradual decline on the whole.(2)From the change of land use landscape index,the number of cultivated land,forest land and grassland patches increased greatly,while the number of construction land patches decreased;except forest land,the landscape separation degree of other land use types was basically stable;the landscape shape index of garden land and grassland showed an increasing state,while other land use types showed a decreasing trend.From the view of landscape level changes,patch number,patch density,maximum patch index,spreading degree and aggregation index of the Spanish mackerel enclosure increased.(3)From the perspective of ecosystem service value,the ecosystem service value of squid enclosure decreased by 0.44×10~6 yuan from 2010 to 2017,and the ecosystem service value of grassland,arable land,woodland and garden decreased except that the ecosystem service value of waters increased.Moran'I of ecosystem service value index in 2010,2014and 2017 were 0.5653,0.5540 and 0.5539,respectively,which indicated that there was a significant positive correlation between them,showing a state of aggregation distribution in space and a greater degree of aggregation.The high value areas of ecosystem services are mainly distributed in the eastern part of the study area,and the main types of land use are forest land and garden land;the low value areas are mainly distributed in the central part of the study area,and the main types of land use are construction land.(4)From the point of view of ecological environment quality and ecological contribution rate,there are great differences in spatial distribution of ecological environment quality in Spanish mackerel enclosure.The high value area mainly distributes in the Northeast area,which mainly consists of garden land and woodland,while the low value area mainly distributes in the west coast and South area,which mainly consists of construction land.The high value areas of land use transfer are Wanghai Agricultural Village and Wanghai Fishery Village,with values of 0.03 and 0.08 respectively,while the low value areas are Yuanzi Village,Datiecun Village,Guotun Village,Xiguancun Village and Volcano Village with values of-0.06,-0.06,-0.05,-0.05,-0.08 respectively.