| چکیده انگلیسی مقاله |
Groundwater resources in fractures media, unlike porous media aquifers, have very little self-remediation. In other words, any contamination in the karst aquifer spreads rapidly. High hydraulic conductivity, transmissivity and heterogeneity, and extreme anisotropy of karst aquifers increase their vulnerability to contaminants (physical, chemical, and biological) so that in a short time, significant volumes of water resources in such aquifers are at risk of pollution. On the other hand, abstraction of karst aquifers in some areas has led to imbalances in karst aquifers and drying of springs. This issue has now reduced the quality or volume of karst reservoirs in many plains of Iran. In some areas of Iran, the catastrophe has been determined by creating karst collapses; a clear example of this can be seen in the karst sinkholes of Famenin plain and Kaboudar Ahang in Hamadan province. Construction of residential buildings on karst formations has also led to karst water pollution; For example, on the slopes of Babakohi Mountain in Shiraz, a large number of Constructions have been built on the karst formation while Shiraz drinking wells are located downstream. Another example is the abandonment of remains of sheep and other lost animals on high karst formations or in sinkholes. The selection of landfill in karst areas close to carbonate aquifers has also greatly increased the risk of contamination of these aquifers. Since the optimal management and protection of natural resources especially water resources is essential for future generations designating safe areas for drinking water is considered a very important tool. The aquifer sensitivity and vulnerability mapping provides a clear depiction of the potential status of groundwater resources. According to which, any management decision that directly or indirectly affect these important water resources of the country will be made consciously; also the necessity of applying water resources management methods in each region is specified. In other words, the risk of groundwater pollution is highly dependent on the vulnerability map. Vulnerability mapping is done as a tool to assess the sensitivity of the karst aquifers and has been proposed the basis for zoning conservation and land use planning. In fact, vulnerability mapping is one of the methods that is mainly used in complex hydrogeological research; as an augmented method for groundwater protection studies, landscaping programs, or assessment of impact projects and pressure on the aquifer. The most important application of the aquifer vulnerability mapping can be considered as the protective zoning of the aquifer. So that, by determining and explaining each of the protection zones, according to the vulnerability of the aquifer, different levels of the desired area are assigned to special uses. In other words, depending on the environmental, economic, social, political, etc. conditions in each region, the number of specific zones and areas can be determined; so that, special restrictions apply in each zone to prevent any contamination of the aquifer and the movement of pollutants towards valuable water resources |
