فهرست مطالب iman karimirad

Evaluation of a system needs a combination of indicators that can show their current situation and future. Multilayer aquifers are more complicated due to different recharge and discharge processes of each layer. This paper aims to evaluate sustainability of phreatic and confined layers of an alluvial aquifer in Golestan province. The relevant data includes monthly precipitation of 19 rain gauges, groundwater level of the phreatic layer in 19 observational wells and piezometric level of 19 wells in the confined layer. In this paper combination of eleven indices that selected according to available data in the region, is used to assess sustainability. Results show in spite of detecting no significant trend in the precipitation data, there is descending trend in the water table of phreatic layer and piezometric level of confined one. Aquifer sustainability index of phreatic and confined layers are 0.89 and 1.01, respectively, that means unsustainability of both layers and worse condition of confined layer. Of course unsustainability of the confined layer has been covered by existed non-renewable groundwater resources. According to groundwater abstraction development index equal to 0.26, implementation of water resources development plans is allowed with considering limitations in terms of water quantity and quality. Also 2.82 as the aquifer recovery potential index revealed if driver factors change toward providing sustainable conditions, both layers can be recovered soon. It can be concluded that the region is facing water scarcity that is a limitation to economic development and human health and well-being.

Aquifer overexploitation can cause problems such as salt water intrusion and land subsidence. This condition drives the necessity for the optimal management of aquifers which requires an understanding of aquifer hydrodynamics. In this regard radioisotope dating is one of the useful methods. This paper presents a practical method to determine the age of groundwater using tritium radioisotope. The tritium dating of groundwater includes sampling, initial distillation, enrichment, secondary distillation, measurement of tritium radioactivity, calculation of device parameters, and age of the samples. The electrolytic enrichment method and radioactivity measurement using LSC, which is introduced in this paper, make it possible to measure tritium below 1 TU that means dating water up to 50 years and can overcome the problem of tritium concentration decline in the atmosphere to some extent. The results of a study performed using this method during spring 2012, with interior facilities of the country, showed that the age of the samples were divided into two groups of 5 to 10 years and the mixture of modern recharge and recharged before 1952. Therefore the young parts of aquifer are influenced more readily by qualitative and quantitative climatic and factors. On the contrary, territories with older water reserves are less affected by these changes and have a higher degree of reliability. In the allocation of such resources only the renewable volume should be considered. To achieve this objective imposition of restrictive policies of exploitation seem to be necessary in aquifer management plans.

In recent years, the water quality of Karun River, IRAN, has been affected by different pollutant loads such as agricultural drainages, municipal and industrial wastewaters.Water Quality Index (WQI) and GIS as an efficient tool can be used to provide necessary support for decisions of the management actions in this river and also capability of time series models can be beneficial for forecasting future changes. Therefore this paper aims to evaluate the water quality of Karun River, according to WQI and using GIS and modelling water quality time series. In this research, monthly data including pH, temperature, DO, BOD, TDS, PO43-, NO3-, turbidity and fecal coliform were analyzed during years 2008 to 2013. All the calculated indices were classified in medium class that means the river water can be used only by applying advanced treatment. Spatio-temporal distribution of WQI values and non-significance of its fluctuations indicate balance between the pollutants input and self-purification capacity. Modeling revealed adequate coefficients of determination of selected autoregressive models that vary between 0.69 and 0.85. Also man-made conditions realized as the dominant factor affecting river water quality. According to the results, Karun river water quality has increased slightly comparing to the past and after Dez river junction, relatively high decrease in WQI occurred that can indicate Dez River’s lower quality because of entering pollutant loads in Dezful station downstream and calls for control measures on the river.

The aim of this study was to evaluate the effects of mechanical watershed management ýmeasures implemented across the Boostan Dam Watershed on reduction of flood peak. To this ýend, the Watershed Modeling System (WMS) was used to compare peak flow before and after ýof implementation of the measures. The mechanical measures have been implemented during ýý2000–2007. The major soil and water conservation measures in the Boostan Dam Watershed ýwere mechanical and biological measures implemented in a limited area. To determine the ýeffect of these measures, the watershed has been modeled in WMS environment. Five flood ýevents occurred before implementation of the measures were used for calibration and validation ýof the model. Three other flood events occurred after completion of the measures were then ýused for the evaluation. The results showed that the mechanical measures, despite the fact that ýtheir reservoirs are full of sediment, decrease the average peak flow 1.79 % compared to the ýabsence of these measures and if some structures would not be destructed, the reduction would ýreach 5.95 percent. It should be noted that if the structures were out of sediment, the average ýpeak flow rate would decrease 3.25 % in comparison with current situation and 7.64 % when ýcompared to absence of structuresý.

In many arid and semi-arid regions, groundwater resources exploitation is inevitable to meet water demands for different sectors. This paper aims to study the response of phreatic and confined aquifers in a multilayer groundwater system to climate variability. To achieve this aim, Gorgan plain multilayer aquifer has been investigated using different meteorological (DI, PNI and SPI) and hydrological (GRI) drought indices, involving the correlation analysis method. 19 rain gauge stations and 19 observation wells data with the time period of 38 years and also 14 years data of 19 piezometric wells has been used. The results show that the SPI index has a better performance in monitoring of climate variability and detecting drought events in the studied area. Therefore, the mentioned index has been used in comparing with GRI, to investigate groundwater response. Also, the results indicate difference between aquifers response to meteorological droughts. In this case, long-term 18-month and 48-month SPI indices are the most correlated parameters to the groundwater in both phreatic and confined aquifers and the effect of fluctuations in rainfall remained up to 15 months and 5 months in each zone, respectively. This reflects this fact that, if the principles of sustainable exploitation be followed, confined aquifer has a high reliability and only when prolonged drought or wet condition occurs, it could be affected.