Research On Cultivated Land Propection Planning And Countermeasures Under The Background Of Rapid Urbanization

Cultivated land is an important land resource for human survival,which is related to national food security and economic development.As China has the largest population in the world,protecting cultivated land resources is an important way to ensure food security,social stability and sustainable development.This study takes the affected areas of the lower Yellow River as the research object,the use of construction land expansion coefficient,space gini coefficient and land use transfer matrix,the net rate of arable land and the cultivated land change attitude,multi-cropping index analysis and other research methods,urban construction land in the area from 2000 to 2018 and the changes of time and space of cultivated land utilization level of structure and characteristics are analyzed,At the same time,the coupling relationship model between urban land expansion and cultivated land use level was built,and the coupling coordination degree between urban land expansion and cultivated land use level was measured.According to the niche model,the suitability of cultivated land in the study area is comprehensively evaluated by single factor and multi index,so as to realize the research of cultivated land protection planning.The main conclusions are as follows:(1)From 2000 to 2018,the gap of urban construction land area of cities in the affected areas of the lower Yellow River gradually increased,and the variation characteristics were obviously different.In 2000,2005,2010,2015 and 2018,the urban construction land in Zhengzhou and Jinan has always been in a dominant position,and with the development of time,this advantage is more and more prominent.The affected areas of the lower Yellow River in 2000-2018 from city to city construction land expansion velocity changes over time is mainly reflected in the differences between different cities,the construction land expansion intensity changes over time is mainly reflect the differences in the same city,the construction land expansion of scale change over time mainly for the expansion of scale of larger changes,mainly in the same city Small changes in expansion scale mainly occur between different cities.The equilibrium speed of construction land expansion in Shandong is faster than that in Henan.(2)From 2000 to 2018,the amount of cultivated land in the affected areas of the lower Yellow River continued to decrease,the net loss area kept increasing,the stability of cultivated land resources in the whole region weakened,and the spatial and temporal distribution pattern of cultivated land multiple cropping index was significantly different.From 2000 to 2018,the cultivated land in the affected areas of the lower Yellow River was mainly converted into construction land,but less into forest land,grassland and unused land.Grassland and construction land were the main sources of cultivated land conversion.In terms of net change rate of cultivated land area,cultivated land was in a state of net loss on the whole.The change of net change rate of cultivated land was the largest from 2015 to 2018,and the loss of cultivated land was more serious.In terms of dynamic attitude of cultivated land change,the dynamic attitude of cultivated land resource is low and the stability of cultivated land resource is high.Most urban cultivated land dynamic attitude of cultivated land change is less than 1%.From 2015 to 2018,cultivated land change was active in the affected areas of the lower Yellow River,which is consistent with the characteristics of net change rate of cultivated land.From 2000 to 2018,the multiple cropping index of cultivated land in the affected areas of the lower Yellow River was higher in southwest and lower in northeast,and the regional average multiple cropping index remained between 1.31 and 1.40.(3)Urban land expansion and cultivated land use levels of cities in the affected areas of the lower Yellow River from 2000 to 2018 are in constant change,and their ranking order is also changing.In terms of the level of urban land expansion,dongying city has the highest level of urban land expansion,while Shangqiu is basically at the lowest level.In terms of cultivated land utilization level,jiaozuo city is basically at the highest level,Dongying city is basically at the lowest level.From the perspective of comprehensive development level and coordination level,Zhengzhou,Jinan,Tai ’an and Laiwu are basically in the high quality coordination cities,while Zhoukou and Shangqiu are basically in the primary coordination cities and near imbalance cities.From the perspective of coordinated development degree and type,dongying,Jinan,Zhengzhou and Zibo have a high degree of coordination between urban land expansion level and cultivated land utilization level.The coordination degree of urban land expansion and cultivated land utilization is low in Heze and Shangqiu.(4)The cultivated land suitability evaluation in the affected areas of the lower Yellow River was good in 2018,which was conducive to the development of agriculture.At the same time,carrying out the cultivated land protection planning in the affected areas of the lower reaches of the Yellow River is also of great significance to achieve national food security.In terms of single factor evaluation,annual precipitation,soil texture and soil organic carbon content were the main influencing factors of cultivated land suitability evaluation in the affected areas of the lower Yellow River.In the aspect of multi-index comprehensive evaluation,the area of suitable arable land was the largest(50933 km2),accounting for 49.84% of the whole cultivated land area in the study area.The most suitable farmland area is 20188 km2,which is mainly distributed in Jining,Tai ’an and Laiwu of Shandong province and Zhoukou,Shangqiu and Xuchang of Henan Province.The area of basic suitable arable land is the smallest(14140km2),which is mainly distributed in Zhengzhou in the west and Dongying and Binzhou in the north of the affected areas of the lower Yellow River.The unsuitable farmland area was 16,930 km2,mainly distributed in Xinxiang of Henan Province and Heze of Shandong Province.