采空沉陷湿地形成动力过程的初步研究

因采空、沉陷和积水所形成的湿地是采矿沉陷区扰动了区域性地表水和地下水循环而产生了季节性或永久性积水而形成的一种湿地类型。从采空沉陷湿地形成的主要动力过程入手,研究其形成原因,明确其主要湿地特征。结果表明,采空积水沉陷地是在人类对地下矿层开采后,上覆岩层发生弯曲变形、断裂、位移,导致地面塌陷下沉,形成比采矿范围大得多的负地貌(低洼地);同时原有地表水系统因地表沉陷被破坏,使采矿沉陷区演变为局部汇水区,导致季节性或永久性积水;最终使其出现了沼泽化水生生态系统等特征,形成了一种新型人工湿地。

Dynamic Process of Formation of the Mining Subsidence Wetland

There is the new ground subsidence area of 70 km2 by mining every year in China.Now subsidence regions have been over 1 180 sites and the area has been over 1 150 km2.Many ground subsidence not only has changed the ecological and environmental system in mining area,but also came into some wetland characteristics such as soil swamping and aquatic ecosystem.So the place that ground surface has been subsided and water has been accumulated in mining area is regard as a new type wetland that is temporarily named the mining subsided wetland.But the research,introduction and reports,which brought up the mining subsided area was a wetland type,are very few.Based on the main classified wetland criteria,which is used in the RAMSAR classification,including geomorphic origin,broad hydrology and substrate type,the paper analyzed the dynamic process how the mining subsidence wetland is formed and what the mining subsided wetland characteristics are.The research results showed that under the condition that the stratum movement has been caused by mining excavation,rock layers would lose steadiness and begin to move,deform or be discontinuously destroyed,as a result there is the subsidence and deformed area which is lager to the mining area to be formed.Because the precipitation and wastewater discharging system has been destroyed in the subsidence region,or groundwater level has be long term higher than ground surface which had been subsided after the mining,water-accumulated,soil swamping and the existence of hydroids appeared at storm season or all times,besides also the normal agro-ecosystem has been complete died away and changed to the ecological area of semi-close-type wetland.So the mining subsided and water-accumulated region is a new man made wetland type,which isn't similar to any other wetland types of all the main wetland classifications in the world.In addition,the mining subsidence wetland would be suggested as an addition to the wetland types in the RAMSAR classification.Finally suggestions were made about utilization ways of the mining subsidence wetland.The mining subsidence wetland would be turned into the water farmland if the destroyed water systems were repaired.The mining subsidence wetland would be changed into park with water or a fishpond if its area is large and the water is deep.