The environmental impacts of human activities and engineering constructions in karst regions

regions, an important issue is how to keep the balance between the necessity for development and preservation of complex and unpredictable hydrogeological systems. Karst terrains have been modified and adapted through a range of human activities as needs for drinking water, hydroelectric power and other resources increase. In many regions, reclamation projects, construction of large dams and reservoirs, deep underground excavations and complex foundation structures have had a detrimental impact on the environment. However, because each karst region is unique, the nature of environmental change is unpredictable, often occurs very rapidly, and similar situations are seldom, if ever, repeated. Changes in karst function can have a profound impact on regional ecological, infrastructure, social and political systems. The majority of impacts can be foreseen and mitigated by appropriate designs. Ecological and environmental protection is more difficult when the changes are unexpected and source of problem is some distance from the impacted area. Optimal environmental protection requires a multidisciplinary approach, a lot of patience and perseverance, and adequate funds. Legal aspects and insurability are also very important basic elements in karst environmental protection. Criteria for determining the environmental protection, as well as regulatory procedures that are applicable for nonkarst regions are generally not suitable for karst terrain. Successful solutions require serious and complex geological/hydrogeological investigation programs and close co-operation of a wide spectrum of scientists and engineers: geologists, civil engineers, biologists, chemists, hydrogeologists, geophysicists, sociologists and many others. In karst areas where interrelations and interactions are inadequately known, the ultimate aim is identification of crucial parameters that define causes and consequences between human activities and the resulting impact (cause-and-effect relations). As a consequence of human activities and engineering construction in karst regions, the common negative environmental impacts are: severe spring discharge change, groundwater quality deterioration, endemic fauna endangering, waste disposal failures, induced seismicity, induced sinkholes, and a number of different secondary uncertainties. In some cases, socioeconomic problems related to migration from submerged regions are very pronounced. Similar problems are related with flooding of cultural and historical monuments and natural rarities. The major aims of proper planning of water resource systems in karst terrain are to minimize negative and to maximize positive environmental impacts. The optimal strategy of water resources development in karst areas is a key requirement for regional socio-economic development.