Study On Landscape Patterns And Driving Mechanisms Of Paddy And Dryland In Heilongjiang Province

Heilongjiang Province is an important commodity grain base in China.In the past 30 years,under the influence of policies,population,climate and other factors,the internal pattern of cultivated land has changed significantly.Understanding the change of the internal pattern of cultivated land in Heilongjiang Province and discussing the mechanism of influencing the internal pattern of cultivated land in Heilongjiang Province are of great significance for promoting the sustainable development of cultivated land environment and maintaining the security of cultivated land resources.Therefore,this study takes Heilongjiang Province,a major grain-producing province,as the research area,and takes paddy field and dry land as the research object.Based on the combination of longitude and latitude zoning statistics and GIS spatialization,the spatial and temporal pattern change characteristics of paddy field dry land in Heilongjiang Province from 1980 to 2015 are discussed,and the landscape pattern space of dry land and paddy field is constructed by combining landscape index with Freedman-Diaconis law.The overall pattern and local regional changes of Dryland and paddy fields in Heilongjiang Province in the past 35 years were discussed from different scales.On this basis,the spatial panel data model is constructed,and the response mechanism of paddy field and dry land in Heilongjiang Province is analyzed from the aspects of climate,social economy,input and output,topographic location factors,etc.The main conclusions are as follows:(1)In Heilongjiang Province,the paddy field area has shown a continuous upward trend in the past 35 years,while the dry land area has experienced a process from increasing to decreasing.The increase of paddy field area mainly concentrated in the Northeast Sanjiang Plain(132-135 degree E,47-49 degree N);the dry land was bounded by 2000,showing an increasing trend in the early stage,and the net area of dry land began to increase in the southwest and decrease in the Northeast in the later stage.After 2010,the net area of paddy field began to decrease in an all-round way,and the reduction area mainly concentrated in the Northeast(132-135 degree E,46-49 degree N).From 1980 to 2015,the spatial changes of paddy fields and Dryland in Heilongjiang Province experienced a process from decentralization to concentration.The spatial variations of paddy and dry land are mainly concentrated in Sanjiang Plain and Songnen Plain.(2)The overall fragmentation of paddy fields in Heilongjiang Province accelerated from 1980 to 2015.During this period,paddy fields were disturbed by human beings,and the invasion was serious.The shape of paddy patches gradually tended to be slender and irregular.The overall change of Dryland in 1980-2015 is more complex.The number of patches in the dryland area decreases first and then increases during the process of increasing to decreasing.In the early stage(1980-2000),human disturbance was serious.At the same time,large patches were invaded.Small and medium patches began to merge.In the later stage(2000-2015),the invasion degree of large patches was eased,and the small and medium patches were further divided.(3)The paddy field in Heilongjiang Province has changed from agglomeration mode to fragmentation mode in 35 years.The area of Sanjiang Plain and Songnen Plain,the main paddy producing areas,has also changed from agglomeration mode to fragmentation mode.However,compared with Songnen Plain,the paddy field area in Sanjiang Plain has increased relatively steadily,and the stable fragmentation mode is the main one.In the past 35 years,dryland has undergone a process from agglomeration to fragmentation.The Songnen Plain has developed from stable agglomeration mode to reduced-stable fragmentation mode,while the Sanjiang Plain has mainly shifted from increased agglomeration mode to reduced fragmentation mode.(4)During these 35 years,paddy fields were mainly affected by temperature,industrialization and agricultural input.Affected by global warming,the continuous northward migration of rice planting line in the past 35 years has gradually made Heilongjiang Province an important grain-producing area for rice crops,with the contribution rate of temperature reaching 29.6%.The industrialization of the main paddy field producing areas also has a negative effect on paddy field cultivation,and the contribution rate of the secondary industry output value reaches 35.2%.From 1980 to 2015,dryland was mainly affected by population,income of rural residents,output value of secondary and tertiary industries and fertilizer application.The total population and the income of rural residents have significant positive effects on the growth of dryland,with the contribution rates reaching 60.2%and 46.5%respectively.The rapid development of industrialization and urbanization in Heilongjiang Province has a tremendous impact on dryland.The construction of factories and infrastructure not only occupies a large number of Dryland areas,but also poses a huge threat to the living environment of dryland.The paddy field area of Heilongjiang Province expanded rapidly from 1980 to 2015,the demand for water resources increased sharply,and the degree of fragmentation of arable land increased,which also made the ecological balance of Heilongjiang Province suffer tremendous test.This paper examines the relevant influencing factors and contribution degree to the spatial distribution of paddy field and dry land in Heilongjiang Province through relevant models,and further explores the influencing factors in the future.The causes of spatial distribution and transfer of paddy and Dryland in Heilongjiang Province.