Prediction And Evaluation Of Damaged Land In Mines And Research On Restoration Techniques

Mineral resources development has played an important role in the economic and social development,as well as the mining area land resource and ecological environment caused serious damage,adjust measures to local conditions for the damaged land reclamation and reconstruction to the ecological environment system,is the objective demand of the protection of cultivated land,protect the environment,to ensure national food security,ecological security and sustainable economic and social development is of great significance to promote mining area."In order to implement the one who destroyed reclamation,who destroyed governance",clear the obligations of the person in charge of land reclamation and environmental governance to promote land reclamation and ecological rehabilitation of scientific and orderly,the need for new land destroyed in mining and the situation of the damage to ecological environment impact analysis forecast,repair the damaged land suitability evaluation,and formulate a practical and feasible measures and methods of land reclamation and ecological restoration.Based on the mian pool thunder ditch bauxite mine as an example,the geological environment of mining area,water and soil resources endowment,on the basis of field investigation,combined with the mining production plan,for mine construction and production of land resources,geological environment and ecological environmental damage,the link and the timing of the impact,failure mode,extent of damage and strength is analyzed and forecast;The suitability of damaged land reclamation was evaluated and the direction of land reclamation and ecological restoration in different damaged land units was determined.According to the needs of land reclamation and ecological restoration,a technical system of land reclamation and ecological restoration for bauxite mines in the hilly area of leigou is formed by integrating existing technologies.The following research results were obtained:(1)According to the analysis and prediction,the land damaged by mine construction and production in leigou is mainly caused by land expropriation damage and goaf collapse damage.The total area of land damaged is predicted to be 426.78hm~2,including 400.31hm~2 of land to be damaged by project construction and 26.47hm~2 of permanent construction land(excluding 3.69ha of road land)that is no longer retained.In the area of the land to be damaged in the project construction,the damaged land area is 23.87hm~2,and the degree of damage is severe.The area of collapse damaged land in goaf is 376.44hm~2,the area of severe damage is 12.37hm~2,and the area of mild damage is 364.07hm~2.(2)The evaluation index system of land reclamation suitability is established.The method of combining the limit condition method with the weight and index method(comprehensive scoring method)is adopted to evaluate the suitability and quality of land reclamation units.According to the evaluation results,the land to be reclaimed can be divided into four types:suitable for cultivation,suitable for forest,suitable for grass and not suitable for the time being.Among them,the suitable land area is 258.48hm~2,the suitable land area for forest is 20.85hm~2,the suitable land area for grass is 121.04hm~2,and the suitable land area for the time being is 26.41hm~2.The suitable cultivated land is divided into three types:first class suitable cultivated land,second class suitable cultivated land and third class suitable cultivated land.Among them,the first class suitable cultivated land area is 232.01hm~2,and the second class suitable cultivated land area is 26.47hm~2.(3)On the basis of suitability evaluation results,combined with the mining area economic and social development needs,determine the direction of different evaluation unit of land reclamation,the engineering level,terracing,soil reconstruction and ecological restoration and other comprehensive measures to treat reclaimed land to repair,repair after new farmland 25.14 hm~2,new woodland 5.97 hm~2,new grass 17.91 hm~2,new land for rural road 1.32 hm~2.(4)According to the direction and goal of reclamation and the measures to be taken,the quantity of land reclamation and ecological restoration in the mining area was quantitatively estimated,and the estimated quantity of land leveling was 123.93*104m3;In the greening project,there are 3.77*104 trees,1.94*104 shrubs and 17.91hm~2 grass.The total capacity of the water cellar and reservoir is 360m3.