عنوان مقاله [English]
Background and Objectives: Groundwater resources in Syahtalu- Garmabdsht region are important sources for drinking water supply for Gorgan City. In this region, there are a number of water wells in a small area which indeed forms a well field. Intersection of cone of depressions of these water wells causes the large decline in their water levels. Decline of water level in these water wells results in the considerable decrease of flowrate of water wells and some of them destroyed. Considering to the limited surface water resources to supply new needs of drinking water resources, the main focus is on groundwater resources of Gorgan. Since the groundwater basins that supply drinking water for the region is located in a small area, the quantity of groundwater in this area are affected. So far، comprehensive study on the well field on reducing water discharge has not been done. For this purpose, in this study the effects of well field within a small area (Garmabdasht) on the amount of water extracted is investigated.
Materials and Methods: Uncontrolled exploitation of groundwater can cause a sharp drop in groundwater levels that reduce the discharges of the factors affecting the well field are wells adjacent to each other, This means that the wells are closer to interfere cone drops more. As a result of an increase in decline and reduce discharges and another agent that is effective in reducing the discharge of water from well field. Based on the above factors and impact on reducing discharge wells Syahtalu- Garmabdsht area, a number of statistical indicators used. Distance index and discharge- Distance index are based on the factors affecting the capacity reduction defined. Another factor that played a significant role in reducing the discharge of wells in well field, structure wells. Using the evaluation of statistical indicators presented in this study, a simple and practical method to determine the impact of structure wells to reduce water discharge has been introduced.
Results: After reviewing the discharge rates and reduce water discharge, it was found that the discharge of the index changes, DQI shows the highest correlation. And to determine the distance between the wells can minimize the impact of these factors on capacity reduction. As for the structure of wells, the results of this research indicate that the impact of structure wells to reduce water discharge varied from zero to 75 percent.
Conclusion: Indicators can be defined using a suitable space to create cone drop created around the wells to prevent interference cone drops and changes in the discharges wells in which the harvest is reduced to a minimum. DQI index the best statistical indicators for the lowest rate of decline is known discharges. In order to assess the impact of structure wells to reduce water discharge in this paper is a new way which the discharge index to the distance (DQI), the greater the percentage is even higher water discharge.