مجله آبخوان و قنات
پیاپی 1 (پاییز و زمستان 1396)

Decreases of the qulity of ground waters is due to wasteful harvest of this water resource, which needs to identify the suitable places for ground water extraction for drink pourposes. The aim of current research was to identify the suitable places for ground water extraction in Roshtkhar plain using the Delphi and Topsis methods. In Delphi method the weight of criterias and sub- criterias, and multiplied in their raster layers and therefore the final map was extracted. In Topsis method by using decision-making matrix, the sub inderces were specified and then by ranking the selected sub-criterias carried out. Criterias included water, catchment physiography, geology, economic and social criterion, and sub-criterias included the quality and quantity of water, transmission coefficient, alluvium thickness, distance from the road, distance from power transmission lines, distance from the city and villages, slope of basin and geological formations of the region. The result of comparison of two methods showed that there is no meaningful different in result in the present areas, because the calculated Chi-Square ( 12χ2"> ) was 97.5 which is lower than the Chi of table. So by taking attention to the final map of Roshtkhar plain aquifer, the aptitude of aquifer was classified in five classes included very good, good, average, weak and non-suitable. In Delphi method, the 37.07 percent of area was very good and good, and in Topsis method the 35.27 percent of area which placed in the west of plain were good and very good and in the weast of aquifer has non-suitable extraction situation.

Use of GIS in estimation of the status of aquifer has increased in recent years. Currently, many aquifers in the country, including the Gonabad aquifer, have faced a continuous reduction of trend in groundwater levels and the quantitative and qualitative reduction of their water, which results, reduction in the Qanat discharge and qwality. Therefore, this research was attempted to integrate GIS and multi-criteria decision-making systems, to identify the best area zone for artificial recharge project to increase the discharge rate. For this purpose, the data of six effective parameters contains slope, water quality, aquifer thickness, land use, flood and permeability of the case study area were prepared in GIS environment. Then were calculated by the use of AHP method and with a Paired comparison the weigths and sub weight of each criteri Expertchoice software. The total area designated for each of the criteria and final map with the three regions poor nutrition, appropriate medium were prepared bye the use of the GIS. The results of this study showed that the western part of the aquifer is a suitable place for artificial recharges which is abouts for half of existing Ghanats in this area.

Groundwater resources, as one of the most important factors in sustainable development, need to be intensely considered. Numerical models such as Modflow and MT3D is an applied tool for simulation and management of groundwater flow and solute transport. In this study, Shahrekord aquifer modeling is provided by the use of monthly data’s including hydraulic heads, depletion volume of the wells, springs and qanats, precipitation values. This model has been developed based on the assessment of the hydraulic conductivity and specific yield coefficients in the calibration process. The study year was divided to 12 monthly stress period for calibration (10 periods) and verification (2 periods). The results showed that the hydraulic conductivity from 6 to 16 m/day and specific yield from 0.03 to 0.07 were varied. The predicted water table in calibration process in comparison to observed values of water levels on piezometers with variance of 0.63. These results confirm the need model of groundwater flow prediction. Moreover, Effective molecular diffusion coefficient, longitudinal dispersity and distribution coefficient were calibrated to achieve acceptable variance between observed and calculated nitrate concentration. The most contaminant particles are in the south zone of aquifer where is the nearby urban wastewater wells. Moreover, the central and south parts of plain have the suitable situations for groundwater discharge because of the high amount of transmissivity.

Iran is located in an arid, semi-arid region. The mean annual precipitation of our country is about 250 mm which is less than the mean annual precipitation of Asia and about one third mean annual precipitation of the world. different kinds of climatic, topographic and geographic conditions, uneven distribution of surface streams are the hydrological features in many parts of the country. Iran possesses 37000 Qanats. These Qanats are providing 7 billion cubic meters water a year for agriculture productivities without consuming any kind of fossil fuel or electricity power. In recent years, increasing population has caused more demanding for new water sources such as digging new wells from aquifers, and this leads to accelerate decline in groundwater table. Decline in groundwater table has caused lots of problems, for instance increased number of arid fields, reduced the flow rate of rivers and lakes, decreased the quality of water, increased pumping costs, and the land subsidence. In this article, essential safety requisition and reconciliation of Qanats was studied by investigating the role of Qanats and comparing them with others sources.

Sensitivity analysis is the basic process of modeling that determines how the variation in the output of the model can be attributed to variations of its input factors. In recent decades with the increase in simulation models and the complexity of these models due to increased variables, sensitivity analysis is an essential tool for understanding the role and significance of variables in the modeling process. There are different categorizations for a variety of sensitivity analysis methods, Depending on whether output variability is obtained by varying the inputs around reference (nominal) values, or across their entire feasible space, Sensitivity analysis is either referred to as local or global. Quantitative and qualitative sensitivity analysis and One-At-a-Time (OAT) and All-At-a-Time (AAT) methods are other divisions for a variety of sensitivity analysis methods. In this study, sensitivity analysis methods in simulation models were investigated and capability of GLUE method, a common method for uncertainty analysis based on the Monte Carlo simulations, was presented to analyze the sensitivity of groundwater model in a case study.

The unsustainable exploitation of groundwater resources has reduced the level of stagnation and has caused the crisis of Iran's plains. Given the strategic role of these vital resources, conservation of groundwater resources is one of the most important issues of today's human societies. The study seeks to answer the question by investigating the" legal dimension "of the country's groundwater authority how much the legal dimension of the country's groundwater body has strengthened the framework for cooperation or has led to an intensification of the water conflict? The theoretical framework governing this research is "institutionalism." Based on the "qualitative" research method and using the "content analysis" tool, the text of the laws related to groundwater resources of the country was analyzed. This content analysis was based on the dimensions related to participation and disputes in the institutional matrix. Therefore, the data used in this research are related to the text of the laws established since the Mashroteh Revolution until now (1906-2016) in the groundwater's basin and similarly written documents. The results showed that without the presence of people, the possibility of proper planning and the possibility of operating the programs would not be possible in any way, and the role and position of people in the coordinate axes of the water crisis should be seen, and even the design of this situation also is a need for the participation of civil society institutions.