Spatio-Temporal Pattern Analysis Of Cultivated Land Productivity In Shandong Province Based On NPP Data

Food is a staple of the people,and the stability of grain yield is a major issue related to the national economy and the people’s livelihood.The study of cultivated land productivity and farmland production capacity is of great significance in estimating grain output and ensuring food security.This study selected China’s granary province-Shandong Province as the research object.Using MODIS remote sensing data to construct a VPM model to simulate the NPP of cultivated land in Shandong Province.By combining the data such as Landsat TM/OLI EVI,land use,agricultural divisions,comprehensive agricultural development project area,the study has completed the estimate of farmland production capacity of provincial-scale and agricultural comprehensive development project area scale.In addition,it also evaluates the implementation effects of 959 agricultural comprehensive development projects and 8 key agricultural comprehensive development project areas and.The main conclusions are as follows:（1）In 2000,the total amount of NPP in Shandong Province was 7.05×1013 g C·a^-1.From2000 to 2015,the average and total NPP of farmland in Shandong Province showed a fluctuating upward trend,with a growth rate of 17.25%.In Shandong Province,the total NPP reached8.07×1013 g C·a^-1 in 2015.（2）In the 17 cities of Shandong Province,the average NPP of farmland in Heze City,Liaocheng City,Dezhou City,and Jining City was relatively large,with the values over 800 g C·m^-2·a^-1,and the productivity of farmland in Dongying City was the lowest,just 516.54 g C·m^-2·a^-1.The NPP high value areas are mainly distributed in the northwest plain of Shandong and the plain of southwest Shandong,while the low value areas are mainly distributed in the central-southern mountain of Shandong and the hilly area of Shandong Peninsula,especially in delta saline areas of Yellow River.（3）According to the farmland production capacity,the high,medium and low income farmland in Shandong Province was divided.It was found that Shandong Province was dominated by high-yielding farmland,with the proportions of 52.07%and 33.38%respectively.（4）From 2000 to 2015,the total farmland production capacity in Shandong Province increased.The farmland with more than 14000 kg/hm² of arable land increased significantly,and the area of farmland with a production capacity of less than 12000 kg/hm² gradually decreased.The areas with high farmland production capacity in Shandong Province are mostly located in the Southwest Plain of Shandong,the Northwest Plain of Shandong,the East of Weifang,and the central of Qingdao,which over 13000 kg/hm².The farmland production capacity in the Shandong Peninsula Hilly Region and the central-southern mountain of Shandong is between12000¹3000 kg/hm²,and it is the lowest in the coastal areas around the Yellow River Delta,mostly below 12,000 kg/hm².（5）In the eight project areas surveyed by Shandong Province,the capacity increase ranged from 836.27 to 2710.78 kg/hm².After the completion of the project area,the farmland production capacity has increased substantially,and six of the eight project areas have achieved a higher increase in production capacity over 1000kg/hm².Prior to the implementation of the project,in the eight project areas in Shandong Province,there were 4 project area of 8 project areas in which the area of low-yield farmland was over 20%;after the project,the area of high-yield farmland in the 6 project areas accounted for more than 95%.