Impacts Of Land Use And Climate Change On Grain Production Potential And Regional Differences

Grain is one of the hot issues in the world in recent years.Land use and climate change are the main factors affecting crop yield.Many scholars have made extensive research on the impact of climate change and land use on crop yield.However,little research has been done on the regional differences of the impact of land use and climate change on crop yield.Therefore,it is necessary to conduct in-depth research on the impact of land use and climate change on grain production potential in different geographical units.Based on the GAEZ farmland production potential model,taking the three geographical units in Shaanxi Province as the research area,and based on meteorological data,soil data,elevation DEM data and land use data from 2000 to 2015,this paper quantitatively analyzed the impacts of land use and climate change on grain production potential in Shaanxi Province and the three geographical units in the past 16 years.And this paper discussed the main influencing factors and regional differences of grain production potential changes in Shaanxi Province and the three geographical units.Firstly,we discussed the influence of land use types and irrigation rate changes on the grain production potential in the study area.Based on the climatic conditions in 2000,combined with the four stages of land use data and irrigation rate statistical data,we estimated the grain production potential of the four stages in the study area,and we analyzed the influence of the conversion of cultivated land and other land use types and irrigation rate on the grain production potential and regional differences in the study area.The study found that the change of land use types from 2000 to 2015 resulted in a large-scale reduction of grain production potential in the study area,with obvious spatial differences.The decrease in output is mainly concentrated in the northern Shaanxi plateau,the central Guanzhong Basin and the northern Qinba Mountain region.The grain production potential in Shaanxi province has decreased by 93.90kg/ha in the past 16 years.the grain production potential changes in the three geographical units are: Guanzhong Basin > Northern Shaanxi Plateau > Qinba Mountain region.From 2000 to 2015,672,100 hectares of arable land in Shaanxi Province were converted into other types of land,resulting in a decrease of 883,300 tons in the total grain production potential.Due to the ecological protection policy of returning farmland to forest and grassland and the development of urbanization,129,000 hectares,364,000 hectares and 154,900 hectares of high-quality arable land were converted into forest land,grassland and construction land respectively.The grain production potential in the research area showed a significant decrease trend,while the conversion of water and unused land into arable land significantly improved the grain production potential in the research area.Compared with land use types,irrigation rate has little influence on the grain production potential in the study area.From 2000 to 2015,the irrigation rate in Shaanxi Province increased by 1.19%,and the grain production potential increased by 20.95kg/ha.Under the condition of corresponding irrigation rates,the grain production potential of the northern Shaanxi Plateau and the Guanzhong Basin increased by 0.04kg/ha and 52.95kg/ha respectively,while that of the Qinba Mountain region decreased by 0.64kg/ha.Secondly,this paper discussed the impact of climate change on the grain production potential in the study area.Based on the data of land use and irrigation rate in 2000 and the monthly data of climate factors in the study area for 16 years,the grain production potential of the four phases(2000/2005/2010/2015)in the study area was estimated,and the impact of climate change on the grain production potential and regional differences in the study area were analyzed.The study found that the climate change from 2000 to 2015 has greatly improved the grain production potential in the study area.Under the influence of climate change,the grain production potential in Shaanxi Province increased 594.32kg/ha,36.29% higher than that in 2000.Among the three geographical units,the northern Shaanxi Plateau has the largest increase in grain production potential,with an increase of 500.73kg/ha in 16 years,with an increase ratio of 39.44%.Under the condition of climate change,the growth rate of grain production potential in the study area shows significant spatial differences,with the increase mainly concentrated in the northeast of the northern Shaanxi plateau,the Guanzhong Basin and the south-central part of the Qinba Mountain region.Precipitation and average minimum temperature are the main climatic factors affecting the grain production potential in Shaanxi province and northern Shaanxi plateau,while precipitation and average maximum temperature are the main climatic factors affecting the grain production potential in Guanzhong Basin and Qinba Mountain region.Among them,under the influence of precipitation,the grain production potential of Shaanxi Province increased by 15.71%,and the northern Shaanxi Plateau,Guanzhong Basin and Qinba Mountains increased by 9.9%,14.08% and 31.08% respectively.Under the influence of climate change,the grain production potential of different geographical units in the study area has increased significantly.Land use types lead to the reduction of grain production potential;Irrigation rate has little effect on it.From 2000 to 2015,the grain production potential increased by 486.02kg/ha in Shaanxi Province.The impact of climate change on the grain production potential in the study area is significantly higher than that of land use.Precipitation and temperature are the main climatic factors affecting the grain production potential in the study area.