Study On The Criteria For Determining The Degree Of Farmland Destruction In Shenyang

Cultivated land refers to the land where crops can be planted,which is the basis of human survival and sustainable development.However,under the background of rapid urban development and rapid expansion of construction land,cultivated land resources have suffered a lot of damage.Illegal occupation of cultivated land for construction,sand excavation,soil extraction and other destructive practices are common.Since the introduction of the crime of destroying cultivated land in 1997,the state has successively promulgated relevant policies and regulations to stop the destruction of cultivated land,appraised the extent of the destruction of cultivated land,and transferred it to conviction and sentencing according to law.However,the destruction of cultivated land has not been effectively curbed.The reason is that there is not a complete set of criteria for assessing the extent of cultivated land destruction.Therefore,it is necessary to study the criteria for evaluating the degree of cultivated land damage applicable to this region.This study is based on the analysis and mastery of the current research progress on the identification of cultivated land damage and degree of cultivated land damage.Guided by the basic concepts of excavation,hard cover and serious damage to planting conditions,investigation and analysis of typical cases of cultivated land destruction in 2008?2018,combined with the actual conditions of local cultivated land cultivation,analyzes the factors affecting the degree of cultivated land destruction.From the two aspects of the influence of different destruction forms on cultivated land planting conditions and the difficulty of restoring planting conditions,analyses the degree of cultivated land destruction in three forms:excavation,hard cover and occupation,and determines the basis for dividing the damage degree of each damage type.Finally,a quantitative and retrievable criterion for determining the damage degree of cultivated land is put forward for three damage types:excavation,hard cover and occupation.The main conclusions are as follows:(1)There are 62 cases of cultivated land destruction in Shenyang in the past 10 years,involving the destruction area of 125.33 hm~2,mainly distributed in Xinmin,Hunnan,Sujiatun,Liaozhong and Kangping.The destroyed cultivated land has a wide distribution span and a large number,covering three types of destruction,namely,occupation,excavation and hard cover.(2)The degree of cultivated land damage caused by excavation,hard cover and occupation in Shenyang is serious,and a small amount of damaged area involves slight damage.The excavation damage depth of various forms of excavation damage is 1-3 m,and the sand excavation damage depth is larger,up to 10 m;the hard cover type of destroyed cultivated land is mainly hard cover type,such as plain soil compaction,sand,square brick,cement,buildings;the compaction type of destroyed cultivated land includes soil compaction;sand,sand and ore,sand and gravel compaction;the compaction of brick,wood building materials and brick products;and the compaction of hard cover type of destroyed cultivated land.There are four types of occupants in garbage.(3)According to the soil conditions of cultivated crops and the difficulty of restoring the cultivation conditions in different forms of cultivated land destruction,the degree of cultivated land destruction is divided into mild damage,moderate damage and severe damage.(4)Following the principles of scientificity,standardization,operability,qualitative analysis and quantitative analysis,the criteria for determining the degree of cultivated land damage are put forward,and a retrieval system is established.