Suitability Assessment Of Well-facilitied Capital Farmland Construction Based On Flood Disaster

Sanjiang plain is located in the east of Heilongjiang Province,with a total area of 109,000 km2,per capita possession of cultivated land is 0.25 hm2,more than 6 times beyond the average level.It is the national key construction commodity grain base,because of it's great agricultural production potential.The area also destroyed by natural disaster,resulting in reduction of grain production or no harvest.Mainly due to low-lying,inadequate farmland water conservancy facilities and frequent flood disasters,which can hinder agricultural production.In 1984,the flood of Heilongjiang,the flooded area was 158,000 hm2 in Tongjiang at once,in which the farmland without rightful heirs reached 21,000 hm2,and the direct economic loss was nearly 100 million yuan.In August 1998,the Jiamusi section of Songhuajiang was hit by the especially flood from the upstream of Nenjiang,the flood occurred,the flood water level exceeded the alert water level lasted for more than 40 days,which is rare.Because the flood disaster caused great loss of economy,the construction of suitability assessment of well-facilitied capital farmland based on flood disaster has certain practical guiding significance.Thus,the study took Fujin as the research area which on the Sanjiang plain.According to the theory of regional disaster system,analyzing the causes of agriculture flood disaster in Fujin from the disaster-causing factor,disaster-causing condition,disaster-affected area and ability to prevent and mitigate disasters,and then selected assessment factors.Using the American land evaluation and site assessment system,divided the suitability assessment of well-facilitied capital farmland construction based on flood disaster in Fujin into the natural conditions assessment and social conditions assessment;Using the theory and method of natural geography and natural disaster,taking the parcel of cultivated land in the study area as the research object.In the natural conditions assessment of the suitability assessment of well-facilitied capital farmland construction,using the DEM data of Fujin calculated the relative elevation.Using the spatial interpolation tool of ArcGIS mapped the average of the maximum 3 days of rainfall in the last 55 years;Combining the DEM data of Fujin and Hydrology-hydrodynamics model,and then using the hydrology analysis module in ArcGIS simulated and calculated possible flood scope and flood depth;In the social conditions assessment of the suitability assessment of well-facilitied capital farmland construction,using the Near tool calculated the length between parcel of cultivated landfield and ditch as well as drainage facilities in Fujin,then divided level of the distance between them;Using the buffer function to calculate the dams buffer,cutting the buffer with the higher level ditch and drainage facilities,and grading the buffer of different dams according to the dike level;According to the difference of the ability of water-logging resistance,divided the assessment unit into paddy field and dry land.Finally,according to the LESA assessment system,set the assessment model of the suitability assessment of well-facilitied capital farmland construction based on flood disaster,so as to realize the suitability assessment and division of the well-facilitied capital farmland construction of Fujin.This study according to the natural conditions assessment,social condition assessment and comprehensive assessment result in Fujin divided the well-facilitied capital farmland construction area into three levels:priority construction area has poor natural conditions,which has lower flood control and disaster reduction facilities level,the area should be given priority to develop land reclamation in flood control and disaster reduction facilities,it mainly distributed in Erlongshan Town,Dayushu Town,the north of Xiangyangchuan Town and the north and the southeast of Jiansanjiang farms management bureau;Conditional construction area has general level of natural conditions and flood control and disaster reduction facilities,can adopt particular renovate technique and measures direct at the construction influence of limit factor,the area mainly distributed in Xinglonggang Town,Hongsheng Town,Shangjieji Town,Dayushu Town,Xiangyangchuan Town,the north of Yanshan Town,the south of Erlongshan Town,the central and the south of Jiansanjiang farms management bureau and the both sides of drainage facilities;Limited construction area has good natural conditions and high level of flood control and disaster reduction facilities.So it need not renovate the farmland from the view of flood disaster when construct well-facilitied capital farmland.It mainly distributed in JinShan Town,Changan Town,Yanshan Town,Toulin town,the southwest of Shangjieji Town,the northeast of Xinglonggang Town,the southeast of Xiangyangchuan Town and the central of Hongsheng Town and Jiansanjiang farms management bureau.