Introducing a New Method for Evaluation of Karst Springs Discharge Concerning Human and Natural Factors

Global climate change and anthropic activities have various associated impacts on groundwater, surface water, and natural ecosystems. Lack of understanding of the impact of climate regime by taking into account the characteristics of the aquifer and uncontrolled exploitation of the aquifer has caused many problems including changes in groundwater flow, intense and irreversible decline in water level, and ultimately leading to drying of springs. For example, many karst springs occur in Kermanshah province (west of Iran). Many show a significant decrease in discharge in the last three decades. Available methods are based on the relation between spring discharges and rainfall data. The proposed approach combines the effects of anthropogenic activity and natural parameters (precipitation, karst development, and aquifer characteristics), grounded on statistical correlations between the monthly and annual series of spring discharge values and corresponding rainfall values and anthropogenic activity, and finally introduces an equation to determine the contribution and effect of each of these factors. The equation was introduced that is very closely consistent with the actual data of the springs. Results show that the contribution of anthropogenic activities varies from less than 5% to more than 95% in the selected karst springs. This method can be adopted in other karstic areas and would aid as a powerful tool in water resource management and planning, especially for minimum flow rates related to rainfall and anthropogenic activity variations.