Study On The Change Of Cultivated Land Use Under The Background Of Climate Change In Sanjiang Plain

Climate change significantly in recent years,climate change has a far-reaching influence on cultivated land planting boundaries,phenological period,potential productivity and planting structure layout by changing the heat and water conditions of cultivated land.Sanjiang plain as an important commodity grain base in our country,the climate and cultivated land layout change significantly.Therefore,analyzing the characteristics of the Sanjiang plain climate change,cultivated land change and the influences of climate change on the cultivated land in recent years has scientific and practical significance.In this paper,analyzing the differences in monthly variability,interannual variability,anomalies and cumulative anomalies,spatial distribution and climate trend coefficients by using the average temperature and precipitation in farming period(may-september)data on Sanjiang plain in 2000-2015,in order to analysis current situation and change of climate in research area.Based on the data of land use in 2000,2005,2010 and 2015,the changes in the quantity and scale of cultivated land,the change of internal structure,the spatial difference and evolution and the landscape characteristics of the cultivated land in the study area were analyzed in order to analyze the changes and current situation of cultivated land in the study area briefly.Then analyze the distribution characteristics of cultivated land under different climatic conditions and the impact of climate change on cultivated land and its internal structure.The main contents and conclusions of this paper are as follows:(1)Analysis of climatic factors change in farming period.The average temperature in farming period was 18.05 ?,the maximum temperature difference was 1.62 ? in the Sanjiang plain from2000 to 2015,The climate tendency was 0.075 ? / 10 a,and the trend of partial cold period-fluctuation period-partial warm period was formed.The average temperature in farming period has small differences in time and large differences in spatial,the low temperature zone is mainly concentrated in the larger area of elevation.The climatic trend coefficient and the inclination rate show a obviously longitude zonality in spatial,and decrease from east to west.The trend of average temperature change in farming area and reclamation area is similar,and the advantage of average temperature in reclamation area is increasing with the going of time.The average precipitation in farming period was 428.25 mm,the maximum difference is 198.51 mm in the Sanjiang plain from 2000 to 2015.The climate tendency was 88.12 mm / 10 a,and the trend of rainy was dry period-rainy period.The spatial difference is significant.There is a significant difference in the longitude zonality.The trend of precipitation change in farming area and reclamation area is similar,and the advantage ofprecipitation in farming area is decreasing with the going of time.Fuyuan County,part of Fujin City,part of Raohe County and part of Baoqing County have a clear increase trends.(2)Analysis of cultivated land use change.There was a slight increase in cultivated land,but it has a rapid adjustment of internal structure in 2000-2015.The total area of cultivated land increased from5.6835 million hm~2 to 5.7991 million hm~2,the arid land area continued to decrease while the paddy field area continued to increase.The ratio of the two change from 3.8: 1 to 1.2: 1.The center of gravity change of paddy field was more significantly than that of arid land and total cultivated land.The change of cultivated land is the smallest and the change of paddy field is the biggest.There were significant differences in the reclaimed index of land between agricultural area and reclamation area,and the mean of reclaimed index of land of reclamation area was 0.75 times higher than that of agricultural area in2000-2015.The ratio of arid land to paddy field in the agricultural area was reduced from 6.35 to 2.43,and the ratio of arid land to paddy field in the reclamation area was reduced from 2.32 to 0.50.During2000 to 2015,the area of arid land change to paddy field in reclamation area is about 1.85 times of that in agricultural area,the difference in the area of paddy field change to arid land is insignificant between reclamation area and agricultural area.Mudanjiang authority and Jiansanjiang authority have a greater tendency for arid land change to paddy field.In terms of reclamation area,it is more agglomerated,human disturbance is lower and patch area is more different in paddy field than in arid land,while farmland area is opposite.(3)Analysis of the impact of climate change on cultivated land use.The effect of temperature on the dominance of cultivated land distribution is greater than that of precipitation,and the lack of precipitation can be compensated by irrigation,while too much precipitation is not conducive to farming,climate conditions are not good(low temperature and rain)areas has less cultivated land.The change of precipitation and temperature has little effect on the dominant planting of arid land,and the change of temperature has a great influence on the dominant planting of paddy field.The reclamation area is higher than the agricultural area in the extent of climate change and cultivated land change.However,the effect of the increase rate of the temperature in farming period on the increase rate of cultivated land area(arid land and paddy field)in agricultural area is higher than that of reclamation area.The difference in the effect of the increase rate of the precipitation in farming period on the increase rate of cultivated land area(arid land and paddy field)is insignificant between reclamation area and agricultural area.With the increase in the increase extent in precipitation(warming)during the farming period,the dynamic degree of cultivated land and paddy field showed an increasing trend,and the increase extent of water field dynamic degree is larger,while the arid land dynamic degree showed a decreasing trend.The effect of the change of temperature on the dynamic degree of cultivated land,arid land and paddy field is greater than that of precipitation in strength and degree.With the increase in the increase extent in precipitation(warming)during the farming period,the area change degree of arid land becoming paddy field showed an increasing trend,and the area change degree of paddy field becoming dry land showed a not significant trend.Study on the status and changes of cultivated land quantity,internal structure composition,changesin climatic factors(temperature and precipitation)and the impact of climate on cultivated land to provide the basis for cultivated land cultivation structure adjustment,crop adaptability planting and reasonable and effective layout of cultivated land.