Research On Temporal And Spatial Pattern Changes Of Cultivated Land Area Based On Remote Sensing Technology

Cultivated land is an important resource for human survival and development.The use of cultivated land is a combination of cultivated land and long-term,continuous restoration and production activities.At present,the change of cultivated land use has gradually become a new trend in global change research.The development of the economy,the rapid growth of the population,and the acceleration of the urbanization process have all made changes in the use of cultivated land.At the same time,the long-term effects of natural factors will also change the structure of cultivated land use,which also has a certain impact on the ecological environment.In order to coordinate the development of population,economy and environment,the research on the change of cultivated land use has important value.Monitoring the ten-year change of cultivated land area in Mudanjiang City,and combining the socio-economic information to analyze the factors affecting the change of cultivated land use in Mudanjiang City and suggesting to promote the sustainable use of cultivated land resources,in order to coordinate the contradiction between people and land in Mudanjiang City,and rationally plan the land for utilization.To provide a basis for the formulation of land-related policies,taking Mudanjiang City as an example,it can provide ideas for other developing cities to resolve the contradiction between economy,population,socialization process and cultivated land resources,and apply remote sensing technology to farmland area dynamic monitoring and resource information management.Provide reference.With the support of remote sensing technology and the Remote Sensing Center of Heilongjiang Academy of Agricultural Sciences,this paper conducts multi-band remote sensing image data in2008 and 2018 in four urban areas of Mudanjiang City(Dong'an District,Xi'an District,Yangming District,and Aimin District).Fusion,mosaic,geometric precision correction,cropping according to 1:25 million county boundaries,obtaining land use vector graphics,using the same region two-time difference method to extract change information.Marking and distinguishing the paddy field and the dry land in the cultivated land and non-cultivated land in the study area,extracting the change map,marking the change position of the cultivated land and analyzing the change factors,and obtaining the following conclusions:(1)Compared with the area of cultivated land in Mudanjiang City in 2008 and 2018,the area of cultivated land decreased from 126,800 hectares to 93,400 hectares,and the area decreased by2,9387.5 hectares.Xi'an District has the largest reduction area of 1,6214.7 hectares..(2)Compared with the paddy fields in four urban areas in 2008 and 2018,the area of paddy fields was reduced,from 30,500 hectares to 26,000 hectares.The area of paddy fields in Xi'an District increased by 5,599 hectares.The reason for this is that the coastal areas along the coast of Xi'an are flat and rich in water resources.Suitable for rice cultivation.(3)In 2008 and 2018,the distribution of dry land in four urban areas was concentrated and distributed in mountainous areas,while the total area of dry land decreased sharply,decreasing by24,700 hectares.The total area of dry land decreased by 26.79%.The changing factors included the conversion of dry fields into paddy fields and urban construction.Invasion of cultivated land and other factors.(4)Through the extraction of cultivated land change maps,there are 423 cultivated lands with an area of 3,562.42 hectares.It is found that the disappearance of cultivated land mainly occurs around the surrounding areas where the population is relatively concentrated,while the area of cultivated land in mountainous areas has increased.It may be to plant more crops as wasteland for reclamation.The analysis of cultivated land resources is mainly caused by social and human factors,followed by natural factors such as river diversion and vegetation degradation.