There are many reasons for the destruction of cultivated land, generally including natural and man-made destruction. This paper mainly studies the destruction of cultivated land caused by natural causes. The destruction of cultivated land mainly refers to the destruction of irrigated land and dry land, in which the destruction of dry land is the most serious, especially the flood caused by heavy rain, which directly washes cultivated land, not only destroys crops and irrigation and drainage facilities, but also washes the topsoil and destroys the soil, resulting in the decline of nutrients in the soil, which in turn leads to poor land; After the flood transits, sediments such as sediment and pebbles brought by flood transportation cover the soil surface, which also plays a role in destroying cultivated land to some extent.

Geological disasters such as landslide, collapse and debris flow directly destroy dry land, resulting in the destruction or even loss of cultivated land. Temporary facilities such as board houses built for disaster relief and resettlement of affected residents after the disaster occupy a large area and scale, which also pollutes and destroys cultivated land to some extent; In addition, due to the flood discharge of the dammed lake, the water level of the dammed lake rose, and some irrigated paddy fields were flooded and damaged.

According to the Notice of the State Council on Printing and Distributing the Overall Plan for Recovery and Reconstruction after Lushan Earthquake (Guo Fa [2013] No.26), the "4.20" Lushan earthquake * * * caused serious damage to 989.67 hectares of cultivated land and slight damage to 67,766.67 hectares. At the same time, in order to ensure the housing reconstruction of urban and rural residents after the earthquake, 342 hectares of temporary land will be arranged, and the newly-added construction land will not exceed 7400.00 hectares (including 400 hectares of mobility index), including 3900 hectares of urban and rural construction land and 3 100.00 hectares of infrastructure and other construction land. A large number of damaged cultivated land and new land have brought great pressure to the balance of occupation and compensation.

According to the Yushu Earthquake Disaster Assessment Report compiled by the Expert Committee of the National Disaster Reduction Committee, after the Yushu earthquake, the damaged cultivated land area in Yushu Prefecture alone reached 409 1.00 hectares, including 2,996.00 hectares in Yushu County, 746.00 hectares in many counties and 349.00 hectares in Nangqian County.

According to the Special Land Use Plan for Post-Wenchuan Earthquake Recovery and Reconstruction jointly issued by the National Development and Reform Commission and the Ministry of Land and Resources, the cultivated land area damaged by earthquake and secondary geological disasters in Beichuan County is 1, 664.7 1 hectare, and the average cultivated land destruction rate is 3.32%. The cultivated land in qushan town is the most seriously damaged, and the damage rate is 13.29%. Next is Chenjiaba Township, with the damage rate of11.08%; The original cultivated land area in Tangjiashan area is 982.8 1 hectare, and the cultivated land area damaged by earthquakes and secondary disasters is 86.88 hectares, accounting for 8.84% of the total cultivated land area, including 69.09 hectares damaged by landslides and 17.79 hectares submerged by dammed lakes. There are 40 townships 18 townships in jiangyou city, accounting for 45.3 1% of the city's total land area. Cultivated land is seriously damaged, mainly distributed in the hilly areas in the west and middle of the county and the transition zone between mountains and hills. Among them, 7.76% of the affected cultivated land cannot be reclaimed. There are 10 townships, accounting for 22. 17% of the city's total land area. Cultivated land is moderately damaged, mainly distributed in the northwest mountainous area and the transitional area between mild damage and severe damage. Among them, 4.39% of cultivated land in the affected areas cannot be reclaimed. There are 12 towns, accounting for 32.52% of the total land area of the city. The cultivated land is slightly damaged, mainly distributed in the transition zone between flat dam and hills and the eastern flat dam, and the area of cultivated land loss only accounts for 0.76% of the affected area. The total amount of cultivated land damaged in the Wenchuan earthquake in Pengzhou reached 236 1.78 hectares, of which 553.90 hectares could be reclaimed, with a loss area of 1.807.88 hectares. The cultivated land loss area in Wenchuan is 107. 13 hectares, and that in Maoxian county is 254.80 hectares. Lixian, Songpan and Jiuzhaigou also have the phenomenon of cultivated land loss.

(b) Destruction of forest land

Refers to the destruction of all kinds of forest land, including forest land, shrub land and other forest land, mainly due to earthquakes and geological disasters, such as flash floods, landslides and collapses. , resulting in mountain destruction, displacement, forest land was destroyed. For example, the Wenchuan earthquake caused serious damage to forest land in Sichuan. The whole province * * destroyed 328,666.34 hectares of forest land, and the forest coverage rate decreased by 0.5 percentage points, destroying forest stock 1.947× 1.04 cubic meters, especially the main habitat of giant pandas. The Zhouqu mudslide also damaged 365,438+08.40 hectares of forest land.

(3) The garden was damaged.

Mainly aimed at the destruction of various orchards, tea gardens and other gardens. Floods, mudslides, collapses and meteorological disasters will all cause damage to the garden. For example, after the Wenchuan earthquake, the garden area of Dujiangyan City was 3,846.2 hectares, which was 869.2 hectares less than that of 47 15.4 hectares in 2004. In June of 20 1 1, continuous heavy rainfall caused flash floods in xiushui county, Jiangxi Province, which damaged more than 6,666.67 hectares of tea gardens in the county and caused direct economic losses of more than 53 million yuan.

(4) The grassland was destroyed.

Including the destruction of natural grassland, artificial grassland and other grasslands. The natural disasters that have the greatest impact on grassland destruction are mainly drought, snowstorm, fire, desertification and salinization. For example, the Wenchuan earthquake damaged 3,395.00 hectares of grassland.

(five) other acts of damage to agricultural land.

Refers to the destruction of rural roads, pits, irrigation and drainage facilities and fields, of which rural roads and irrigation and drainage facilities are destroyed in a large proportion. At the same time, the damage of roads blocked the passage between many villages and even towns.

(6) Damaged industrial, mining and storage land

Refers to the destruction of industrial and mining land, mainly caused by floods, earthquakes and their secondary geological disasters. For example, Wenchuan earthquake caused devastating damage to Hanwang Dong Qi industrial plant in Mianzhu, and Sichuan Huafeng Phosphorus Chemical Co., Ltd. and Sichuan Mianzhu Inorganic Salt Chemical Co., Ltd. were also seriously damaged. Because they are close to the dammed lake, once they burst, they will cause serious pollution to the water body and soil environment.

(seven) damage to public facilities.

Refers to the damage of water, electricity, gas, postal services, communications, places of interest, tourist attractions, etc. It is mainly a secondary geological disaster that is further destroyed during the disaster and after the earthquake. For example, the Wenchuan earthquake severely damaged the Erwang Temple in Dujiangyan, the Ape King Cave in Beichuan and Qiangzhai Village in Tao Ping, Lixian County. The Lushan earthquake caused the middle part of Fan Minque, a Han Dynasty relic in the county, to break and the top to collapse, and the historic sites in Mengding Mountain Scenic Area in the famous mountain area were seriously damaged. In addition, floods will also cause great damage to public facilities. For example, in July of 20 13, there was a flood disaster in Quxian County, Dazhou City. About one third of the county's urban area was flooded, and more than 20 township streets along the river were flooded, resulting in huge losses.

(eight) damage to public construction land.

Refers to the damaged teaching, cultural, medical and health land, such as Dujiangyan Juyuan Middle School, Beichuan Middle School and Lushan People's Hospital, which were seriously damaged in the earthquake.

(9) Damage to residential land

Mainly refers to the damage of various residential land, such as the residential, industrial or commercial mixed areas of Beichuan old county and town damaged in Wenchuan earthquake; Debris flow in Zhouqu County caused debris flow to accumulate more than two meters in the main streets of Zhouqu County. Many buildings in the county were damaged and a village with more than 300 families was buried.

(10) Damaged traffic land.

Mainly manifested as highway deformation, cracking, pavement settlement, slope collapse, subgrade damage, bridge damage.

(eleven) the land damaged by water conservancy facilities.

Including damage to reservoirs, dams, hydropower stations, irrigation stations, ditches and other land.

(twelve) other acts that damage the land.

It mainly includes the destruction of rivers and beaches, and the diversion of some rivers in the disaster area has washed away the beaches.