Study On The Spatial-Temporal Patterns And Driving Mechanisms Of Multiple Cropping In Jianghan Plain From 2000 To 2018

Multiple cropping of arable land is one of the effective ways to increase the production of agricultural products in China,and is an important indicator for measuring China’s agricultural development.Multiple cropping refers to the agricultural planting method of more than one season in a field.The multiple cropping index is the ratio of the total area of crops sown in a year to the area of cultivated land in the area,which can effectively reflect the utilization efficiency of cultivated land.In China,due to the large land area,climate resources,cultivated land resources,and socio-economic development are different,and the multiple cropping index varies greatly from place to place.As an important commodity grain base in China,the Jianghan Plain has an important impact on the country’s food security and agricultural production.It studies the changes of the multiple crop index in the region and the driving mechanism of the multiple crop index change,and provides relevant departments to guide agricultural production to formulate agricultural policies The reference basis is also of great significance for promoting the efficient and high-quality development of agriculture in the region and accelerating the development of rural economy.In this paper,the Jianghan Plain is used as the research area.Based on the normalized vegetation index layer data of MOD13Q1,the data is superimposed after preprocessing to construct the normalized vegetation index time series curve.The S-G filtering method is used to smooth the denoising time series The quadratic difference method is used to extract the peaks of the growth curve,and the multiple crop index is calculated.Based on the statistical data of the counties and cities in the Jianghan Plain,the driving mechanism of the change of the cultivated land multiple cropping index was analyzed.The main conclusions of the study are as follows:(1)From 2000 to 2018,the cultivated land in the Jianghan Plain was dominated by multiple crops,mainly one-crop and one-crop one-year crops.There was a significant spatial difference in the multiple cropping situation of the cultivated land.It is mainly distributed in the eastern part of the Jianghan Plain and part of the western part of the Jianghan Plain;the two-crop planting area in the year is mainly distributed in the central area along the Han River and the Yangtze River.(2)The average multiple cropping index of cultivated land in the Jianghan Plain varies significantly.From 2000 to 2010,the average multiple cropping index of the Jianghan Plain showed an increasing trend.From 2010 to 2015,the average multiple cropping index changed little and remained stable.The average multiple cropping index from 2015 to 2018 showed a downward trend.(3)From 2000 to 2005,the average multiple cropping index increased in the northern and southern regions of the Jianghan Plain,and decreased in the northwest and northeast regions.From 2005 to 2010,the average multiple cropping index was basically increasing,especially in the northern region of the Jianghan Plain;2010-In 2015,there were areas where the average multiple cropping index increased and decreased in the Jianghan Plain.The increase was mainly in the east,and the average multiple cropping index decreased in the northwest and some marginal areas in the east.From 2015 to 2018,there were changes in the average multiple cropping index in each area of the Jianghan Plain,and there were fewer areas where the average multiple cropping index increased,mainly in the western Zhijiang.(4)From 2000 to 2018,the multiple cropping index of Qianjiang,Xiantao,Tianmen,Shashi,Songzi,Gong’an,Shishou,and Honghu showed a trend of multiple cropping index rising first and then decreasing;Jiangling’s multiple cropping index remained stable but declined in 2018;Yunmeng,Yingcheng,Hanchuan,Zhijiang,and Dangyang showed a decrease in the multiple cropping index in 2005,and then from 2000 to 2015 The trend of rising year after year and decreasing in 2018.(5)There are differences in the impact factors of the multiple cropping index on the Jianghan Plain.Among them,the total power of agricultural machinery,the amount of agricultural fertilizer application,the proportion of effective irrigation area and other agricultural production conditions have a significant positive impact;the urban and rural residents’ savings deposit balance,and the negative impact of regional GDP are weak;agricultural labor is Jianghan Important factors for agricultural production in the plains.