Study On The Spatial-Temporal Characteristics Of Cultivated Land Pressure In Heilongjiang Province Based On Food Security

Cultivated land is the basis of grain production,and its change has important impact on grain yield and food security.Reasonable evaluation of the level of cultivated land pressure in the region can not only provide theoretical reference for cultivated land protection and grain security work in the region,but also promote social harmony and sustainable development.Heilongjiang Province is an important grain producing area in China.It plays an important role in safeguarding the national food security strategy and shoulder the arduous task of nation grain supply allocation.The cultivated land resources bear the tremendous pressure of guaranteeing national food security.Reasonable evaluation of the pressure of cultivated land and level of food security in Heilongjiang Province has a certain guidance and reference significance for protection of China’s cultivated land and food production.This paper selected Heilongjiang Province as the study area,and analyzed the change characteristics and reasons of cultivated land resources quantity and grain yield in Heilongjiang Province from 2000 to 2014.Using the minimum per capita cultivated land area and the cultivated land pressure index model,measured and calculated the cultivated land pressure of Heilongjiang Province and its 13 city or region during 15 years,analyzed the temporal change characteristics,spatial distribution and regular pattern of gravity migration center and the spatial variability of cultivated land pressure,and the gray GM(1,1)model was applied to forecast the cultivated land pressure from 2015 to 2020.The results showed that:(1)The amount of cultivated land resources in Heilongjiang Province increased steady and smoothly from 2000 to 2004,and the amount of cultivated land resources increased rapidly from 2004 to 2005,and the amount of cultivated land resources was basically unchanged from 2005 to 2011,and maintain steady growth after a substantial increase from 2011 to 2014.The variation trend of total grain output,grain yield per hectare and grain yield per capita were nearly the same.The change trend of the three kinds of grain yield,on the whole showed an upward trend.(2)From 2000 to 2014,the pressure index of cultivated land in Heilongjiang showed a downward trend,and the cultivated land resources could guarantee the food security of the whole province.In 2003,due to the dry climate,the grain yield was greatly reduced,and the cultivated land pressure increased.(3)In 2009,the cultivated land pressure of every city and region in Heilongjiang Province was the most optimistic.All of the cities were in no pressure area except Yichun in the pre-warning area for cultivated land.In 2003,the pressure level of cultivated land in Heilongjiang Province was the most rigorous.Except Harbin,Jiamusi and Suihua,the cultivated land pressure of the other cities were all higher than 0.8.(4)From 2000 to 2014,the pressure barycenter of cultivated land in Heilongjiang Province shifted from southeast to northwest.The cultivated land pressure in Daxinganling and Yichun had been larger.The barycenter of cultivated land pressure kept moving around the junction of Yichun,Suihua and Heihe.The cultivated land pressure index of Heilongjiang Province in the other years had strong spatial correlation except in the year of 2009.The randomness of cultivated land pressure index variation increased year by year.The spatial heterogeneity first increased,then decreased,and increased at last.The change of cultivated land pressure showed a high correlation in all directions.(5)The cultivated land pressure in Heilongjiang Province will continue to decrease in the next six years,and the cultivated land resources and grain production will ensure the food security of the province.(6)To strengthen the awareness of law enforcement,strengthen the consciousness of cultivated land resources protection,implement the farmland protection system strictly,carry out land consolidation work actively,promote agricultural technology vigorously,implement rural land system reform moderately,can effectively protect the cultivated land and protect the food security of our country.