Research On Spatial Configuration Of Sunning Water Pool Area In Paddy Fields Of Cold Regions

Under the circumstance of climate warming,breeding and farming techniques,the boundary of paddy field in China continues to move northward^[1].However,low temperature,low water temperature and short growing period have always been the limiting factors for the expansion of paddy fields and the increase of output.The warming of irrigation water during the rice growing season is a necessary measure to prevent cold damage and promote rice production in cold regions.In 2016,"13th Five-Years Plan"formally proposed the strategy of"storing grain in the land",the land remediation projects in various regions of China have continued to advance.The types of land for agricultural auxiliary facilities have gradually diverged.The scale of land use has continued to expand and the distribution has become more and more extensive.It has become an indispensable important land use type in modern agricultural development.The sunning pool,as an ancillary facility for warming rice irrigation water,is getting more and more construction in the current land remediation.It plays an irreplaceable role in ensuring rice production and agricultural modernization in alpine areas^[2-5].It is of great significance to explore the layout of land for sunning pool in order to ensure the high and stable yield of paddy irrigated paddy field in cold area^[6-8],enhance the intensive use of cultivated land,promote scientific and technological innovation in land consolidation and promote the agricultural development in the paddy field in cold region.In this paper,the space data of Remote Sensing Satellite Data of the No.3 satellite and the second land use survey data of the country are used as the main data sources.In combination with the site acceptance survey of Qixing farmland and on-the-spot investigations,the data of the sunning water pool of Qixing Farm of the Sanjiang branch of Heilongjiang Province was collected.Analyze the relationship between the average size of the sunning water pool land and the average nearest distance in each management area,using the nearest neighbor index method to analyze the distribution characteristics of the sunning water pool land,and obtain the irrigation water satisfaction of the sunning water pool in each management area,and put forward the selection of sunning water pool As well as the scale of land use,the NPP index of vegetation net primary productivity was used to analyze the relationship between the satisfaction degree of the sunning water pool and the productivity of the paddy field.The purpose was to provide reference for the spatial distribution of the sunning water pool land in the paddy field.The main research contents and conclusions are as follows:（1）Analysis of Land Use Characteristics of Sunning water pool.There are two main types of sunning water pool in Qixing farmland,constructing a total of 1,886 sunning water pools,covering a total area of 404.92hm² with an average land use of 2146.98m² and an average nearest neighbor distance of 331.87m.Among them,the average size and the average nearest distance of the sunning water pool in the sixth management area were the largest,4062.86m²and 516.86m respectively.There was a significant and positive linear correlation between the average nearest distance of the sunning water pool and the average land use size.The larger the average size of the land,the farther the average nearest neighbor between the sunning water pools.In the spatial distribution characteristics of sunning water pool land use,the nearest neighbor index R of sunning water pool land in Qixing Farm is 0.852458,which is compared with remote sensing images to verify that the spatial distribution of sunning water pools in most management areas of the farm is close to random distribution.And the proportion of sunning water pool in each management area accounts for the proportion of paddy field area,the more obvious the distribution and distribution characteristics;the smaller the proportion,the more obvious the random distribution characteristics.（2）Analysis of the impact of land configuration in sunning water pool on the productivity of paddy field,when the area of the sunning water pool occupies 0.8%of the area of the paddy field served,the water consumption of the sunning water pool and the temperature of the water can meet the peak water demand of the paddy field.Qixing Farm sunning water pool area accounted for paddy field area ratio of 0.62%,irrigation water to meet the degree of 77.5%.However,in the process of arranging land for sunning water pool,the scale of land use is not determined only according to the peak water demand of paddy fields,but also the length of the irrigation channels and the warming effect.There is also a significant linear correlation between water satisfaction of sunning water pool irrigation basin and NPP index.In the absence of overuse of water basin in construction,the higher the water basin irrigation water satisfaction,the vegetation in paddy field The net primary productivity index is higher.Within a certain range,the higher the satisfaction of irrigation water in the sunning water pool within a paddy field region,the more obvious the effect of enhancing the productivity of paddy fields.（3）The layout standard and space optimization analysis of sunning water pool land.The rationality of the layout of the sunning water pool land use space is mainly affected by the two aspects of the site selection of the sunning water pool land and the scale of the sunning water pool land.The sunning water pool land must be at the highest point of paddy field independent irrigation district,and the sunning water pool irrigation radius should be controlled within 300m.According to the maximum and minimum temperature of groundwater in Sanjiang Plain,the proportion of sunning pool area to service paddy field area should be controlled within about0.74%-0.89%.By analyzing the problems in the space allocation of the sunning water pool land in each management area,with the principle of land conservation and utilization and the principle of maximizing paddy field productivity as the optimization principle,the land for the sunning water pool in the management area with low satisfaction of irrigation water shall be expanded,and the sunning water pool shall be used.The proportion of management areas with a high proportion of land is reduced.The proportion of land occupied by sunning water pools in each management area must reach 64%to 68%of the service paddy fields.The entire farm needs to increase the use of the sunning water pool from 29.56 to 42.16 hm²,while the second management area should be reduced by 5.77 to 7.18 hm².