Research On Land Use Change And Ecological Security Evaluation In Daqing City Based On GIS And R

This study focuses on Daqing City,a resource city in Heilongjiang Province,using Landsat TM and OLI8 remote sensing image data from 2000,2010,and 2020 as the main supporting data,in conjunction with social,economic,and natural statistical data.The study analyzes the spatio-temporal evolution characteristics of land use in Daqing City from 2000 to 2020,including changes in quantity,land use dynamics,land type transitions,and land use intensity changes.Based on the Pressure-State-Response(P-S-R)model,an ecological security evaluation system was constructed,using natural resources,social and economic factors,and human factors as evaluation indicators.The study explored the spatio-temporal changes of ecological and environmental security in Daqing City,qualitatively analyzed the interrelationships and impacts between land use change and ecological security,and used the entropy weight method and analytic hierarchy process to determine the weight of each indicator.The study also calculated the land ecological security index and its changes in different time periods,identified the ecological security level,and proposed measures and recommendations for the study of land ecological security in Daqing City.The study found that the main land use types in Daqing City are arable land and grassland.The areas of arable land,forest land,water areas,construction land,and unused land have increased,while the areas of grassland and wetland have decreased.The comprehensive land use dynamics have increased from 0.418 in 2000 to 0.506 in2010 and to 0.8616 in 2020,indicating that land use has been accelerating.The single land use dynamics of the seven land types from high to low are: grassland(-3.014%),construction land(2.509%),forest land(2.504%),wetland(-2.274%),unused land(2.089%),arable land(1.167%),and water area(0.320%).There is a significant land transfer phenomenon between various land use types,and land use intensity has increased,rising year by year.The comprehensive land ecological security value in Daqing City has been continuously increasing over the past 20 years,and the region has recently increased efforts to improve ecological environment governance,achieving some results.The land ecological security level has transitioned from level IV to level III to level II,from a less secure level to a more secure level,indicating an improvement in land ecological security.Based on the results of the analysis of land ecological security,the study proposes the following measures and recommendations:(1)reduce the intensity of fertilizer and pesticide use,optimize the land use structure through ecological agriculture,and vigorously develop ecological agriculture;(2)afforestation and increase forest coverage,strengthen land desertification and soil erosion control;(3)strengthen the protection of wetland resources and pay attention to their impact on the ecological environment;(4)strengthen intensive land use and protection of ecological land;and(5)optimize the industrial structure and establish a new economic model.