| Cultivated land is the essence of land,which is an important agricultural means of product and material basis to ensure food security in our country.In the process of Social and economic development,urbanization and population growth in our country,the number of cultivated land is decreasing,the quality is declining and the ecology is destroyed,the reserve of cultivated land is seriously deficient,cultivated land system security is seriously threatened.The cultivated land system security includes three aspects:quantity security,quality security and ecological security,of which the quantity is the base,and sufficient quantity of cultivated land can meet the huge demand of China’s 1.3 billion people.Quality is the root,cultivated land can provide all kinds of safe agricultural products with quality assurance.Ecology is the guarantee,the cultivated land in good ecological environment can maintain the quality of cultivated land.It is only when the three aspects are safe that is the cultivated land safe.The comprehensive protection of cultivated land from the perspective of the system is more important than the single aspect protection of cultivated land,such as quantity protection or quality protection.In view of the above reasons,This paper takes Yingtan city as the research area,research on the security change and pattern optimization of cultivated land system,combining the thought of cultivated land,quantity,quality,ecological "trinity".Studying the cultivated land system security evolution trend,driving mechanism and security spatial pattern prediction and optimization with the methods of space analysis,spatial regression,neural network and cellular automata.Achieving the goals of optimizing the allocation of land resources,improving the safety and stability of the cultivated land system.It is of great significance to formulate the countermeasures for the cultivated land protection and promote the sustainable utilization of land resources.The main achievements are as follows:(1)In the study of the evaluation and change of cultivated land system security from 1995 to 2015,considering the discrete situation of the quantity,quality and ecological security of cultivated land,the improved TOPSIS method was used to carry out security evaluation,The results show that:Both the quantity and ecological security of cultivated land system experienced a process of slow change after rapid reduction,its quality security showed a slowly ascent due to the improvement of agricultural infrastructure.After the integration,the trend of cultivated land system security showed a slow rise after a rapid decline.Among them,the critical state of cultivated land system security accounted for 91.32%of the cultivated land area in Yingtan City in 1995,and then down to 48.96%in 2005,but the criticality of cultivated land increased to 37.55%,which was mainly distributed in the central town construction area in the north-central part of Yingtan City.In 2015,the cultivated land area of high and low grade was reduced,and it turned to the middle level.The land area of the critical state increased to 60.72%.From the county level,Guixi City showed a small change.Yuehu District and Yujiang County were less stable,and dropped slowly after a sharp decline.In terms of spatial change,hotspot analysis and stability analysis show that the spatial autocorrelation of cultivated land system security was gradually enhanced,the low-value region extended from the central region to the western region,and the high value region was concentrated in the north-south mountainous area with less human influence.High-stabilized cultivated land was scattered in the east and west and distributed into several nuclear centers distribution to be concentrate in the middle east and the northwest,with the multi-center mosaics.(2)In the research of cultivated land system security change drivers of Yingtan City from 1995 to 2015,the spatial regression model was used to find the driving factors of the cultivated land system security from 26 factors in terms of nature,social economy,location and policy.Compared with the driving force analysis results of the two periods from 1995 to 2005 and 2005 to 2015,the influence degree of natural factors became weaker in the unchanging cultivated land.The environmental load of agricultural inputs in socio-economic factors has increased,and the influence of other socio-economic factors has also weakened.The influence of location factors and policy factors were changed from unsignificant to significant,but the impact of location factors was weak overall,while the impact of policy factors was greater.To improve the security of the arable land system in constant cultivated land,it is necessary to promote scientific farming,apply fertilizer and pesticide scientifically,and to increase production capacity,while prohibiting to destroy the safety of cultivated land ecosystems and controlling industrial pollution.At the same time,policies should applied to increase investment in agricultural investment and environmental governance.The influence of increasing the natural factors of cultivated land is less and less significant.Socio-economic factors have a greater effects,and the influence of locational factors decreased.Therefore,it is necessary to improve the soil conditions of cultivated land and agricultural infrastructure,and increase capital and technical input.the cultivated land system security changing in the decreased space mainly refers to the conversion of cultivated land into non-cultivated land in space.It was mainly because the need of land to meet the social and economic development and population growth,and the natural location conditions of cultivated land resulted in the decrease of cultivated land.In order to reduce the occupation of cultivated land,it is necessary to strengthen the efficient use of the construction land,increase the intensity of the construction land,put an end to the behavior of extensive and idle use,and enforce the protection measures of cultivated land strictly.(3)ANN-CA model was used to predict the cultivated land system security pattern in Yingtan City in 2025.From the prediction results,the stability of cultivated land system security of unchanging space is enhanced,part of the original higher security grade shows a decreasing trend,and the lower grade shows an upward trend generally,Finally,cultivated land system security is increasing,which is better than that of 2015.Construct ion occupation is still the main reason for the reduction of cultivated land in the future of Yingtan City,while the woodland distributed in the north and south is the main source of maintaining the balance of cultivated land.In the space layout,the fragmentation degree of cultivated land is reduced,and the concentration is more contiguous.However,while maintaining the safety and stability of the cultivated land system,it occupies other ecological space,which leads to the decrease of the service value of the regional ecosystem and land degradation problems.In the future development,It is necessary to increase investment in agriculture,carry out land reclamation and other technical measures to increase the cultivated land,manage the occupation of cultivated land behavior strictly,plan the land for construction rationally,improve the level of intensive use of construction land,maintain the safety and stability of the cultivated land system without breaking the regional ecological balance in future.(4)The cultivated land system security pattern optimization model was established through ArcGIS and MATLAB platform.The research of cultivated land system security pattern optimization in Yingtan city was carried out on the premise of grassland and water are not involved in optimization,established the optimization rules,which contains land use suitability,land conversion compatibility,land conversion priority and farmland system security overall control layer,and control the quantity through the land conversion rate.After optimization,the area of cultivated land and woodland was decreased and the area of construction land was increased.The slope with relatively poor cultivated conditions in the hilly region of the north and south was optimized for woodland.The cultivated land located in the surrounding of the central urban construction land,cultivation environment has been greatly affected by people,and low cultivated land system security level,which can bring more economic benefits is optimized for construction land.The low-efficient woodland is optimized for farmland in the surrounding areas of Zhangping township and Tangwan town.After the optimization,the area of middle and high level of cultivated land system security has increased,and the area of lower security level has decreased,the whole cultivated land system security level was improved.it has achieved the goal of optimizing land resource allocation and improving the level of cultivated land system security at the same time.In the process of land use in Yingtan City,it is important deal with the border between cultivated land and ecological forest land in the north and the south hilly mountain region,protect the cultivation environment surrounding the construction land of the central town,so as to prevent cultivated land system security falling and cultivated land losing.(5)According to the security and stability of cultivated land system,the core conservation zone,moderate protection zone,moderate improvement zone,and comprehensive improvement zone of cultivated land system are divided.Different protection modes should be imposed on different protection zones,economic investment should be increased,land management should be strengthened,and land policies should be completed to improve people’s awareness of cultivated land protection,coordinate the relationship between cultivated land and construction,and ecological space,improve the quality security and ecological security of cultivated land,promote the security and stability of cultivated land system,and further regional sustainable development.The main innovations in this study include:(1)The cultivated land system security is researched from the perspective of cultivated land quantity,quality and ecological "trinity".(2)This paper constructs the optimal model of Cultivated Land System Security Pattern Optimization Model(Referred to as CLSSPOM)through MATLAB programming,which combined with the overall control rules for the cultivated land system security,realizing the purpose of optimizing the land resources quantity structure and spatial pattern,and improving the security of cultivated land system. |
PDF Full Text Request