| Land resources are the material basis for human survival and the core of economic development.The quantity,quality and ecological status of land resources are crucial to human survival and development.With the increasingly intensified utilization of land resources by human beings,the situation of land ecological security and quality restricts and affects the sustainable development of regional society,economy and environment to some extent.The research on the situation of land ecological environment has become an important research topic for the sustainable utilization of land resources and the construction of ecological civilization.This paper selects Qing'an county of Suihua city,Heilongjiang province as the research object.Qing'an county is China's grain production base and the country's first green agricultural ecological demonstration county,which is typical of heilongjiang province.Using Qing'an survey data of land use change from 2009 to 2017,DEM data,remote sensing image,the agricultural land classification and gradation,statistical yearbook and related statistical data,The main line is "Building index system-index extraction and standardization-static evaluation on spatial scale-dynamic analysis on time scale",with the aid of remote sensing and GIS technology,using the comprehensive index model,the hot spot analysis model and the ecological impact assessment,spatial differentiation principle and method,Carry out study on land ecological quality evaluation and spatial temporal differentiation in Qing'an County,on this basis,put forward strategies and suggestions for land ecological construction.The main conclusions are:(1)Through the investigation of the land ecological environment in the study area,combined with the research focus and the objective conditions of the region,a land ecological quality evaluation index system of Qing'an County is constructed from natural factors,social factors and economic factors that affect the land ecological environment.Using the comprehensive index evaluation model,the comprehensive score of the research area is 0.263-0.621,and the natural breakpoint method is used to divide the land ecological quality status into excellent,good,and general three levels.Among them,the "excellent" area contains 8 evaluation units,accounting for 36.36%,mainly distributed in the mountainous forest areas in the north and south;the "good" area contains 5 townships,accounting for 22.73% of the evaluation units,mainly scattered.In the plain agricultural areas in the middle,such as Fengshou Township and Qinlao Township;the “general” area contains 9 townships,accounting for a maximum of 40.9%,mainly distributed in the central plain urban and rural areas and the southern mountainous areas Townships such as Minxiang,Ping'an Town and Qing'an Town.The ecological quality is higher than that in the south-central part.The Daqingshan forest farm in the north has the highest ecological quality and the Jubaoshan township has the lowest.Forest farms are superior to other townships.(2)The spatiotemporal differentiation characteristics of land ecological quality.From the static analysis of land ecological quality evaluation results,the spatial hot spot analysis model is used to analyze the spatial distribution characteristics of land ecological quality status,showing that the median and higher-level aggregation areas account for a larger proportion,and the north and south are superior to the central space.The proportion of each cluster area from high to low is in order of median cluster area> higher cluster area> very high cluster area> lower cluster area> polar cluster area.Differentiated characteristics,that is,the hotspot gathering area of forest farms in the north and south,Qing'an Township and Huansheng Township in the west are cold spot gathering areas.The results of the analysis and the comprehensive index evaluation model are consistent,that is,the north and south are superior to the land ecological quality of the middle towns.From the analysis of time-scale dynamic changes,the dynamic analysis of land ecological quality in Qing'an County from 2009 to 2017 was carried out.From 2009 to 2017,the state of land ecological quality in Qing'an County first changed slightly and then improved in a “V”-shaped change trend.That is,the land ecological quality has deteriorated in 2009-2013,and the curve has reached the lowest boundary point.From 2013 to 2017,the land ecological quality has shown an improvement trend,and the curve has reached a high point.The spatial characteristics of the region are still better than that of the central and southern parts.The overall change shows an increase in the improvement area and a decrease in the worsening area,and the overall ecological environment is changing to a better direction.(3)Use the principal component analysis method to identify the main control factors of different types of areas in Qing'an County.The main control factors are different.The main control factors of the first-level ecological agglomeration area are the proportion of ecological land and the degradation rate of cultivated land.The second and third level ecological agglomeration areas have the most main controlling factors,involving the most towns and villages,mainly affected by human and nature.And the fourth and fifth-level ecological agglomeration areas are greatly affected by natural factors.The main controlling factors are slope and precipitation.The indicators that affect the land ecological quality of Qing'an County mainly include vegetation coverage rate,NPP,land use pattern diversity,patch diversity,annual average degradation rate of forest land,comprehensive index of land use,and proportion of ecological land.The research results put forward suggestions to improve the land ecological quality of Qing'an County,such as establishing a land ecological monitoring system to achieve real-time dynamic supervision;real-time cold soil black soil protection,increasing soil environment monitoring;implementing safeguard measures according to local conditions,and establishing a regional management and control model;Improve the ecological compensation mechanism to achieve a winwin situation of ecology and economy;accelerate the transformation and upgrading of regional industries and coordinate the development of ecological industries. |
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