Iranian Journal of

Background and Objectives: Dez dam located on Karun River is one of the largest Iranian dams. In a field study, EC, NO₃, NH₄, PO₄, turbidity, TS, alkalinity, coli, temperature, chlorophyll a, DO, BOD₅, and Secchi disk (at depths of 0, 2.5, 5, 10, 25, and 50 m)were measured at five sampling points during 2011-2012 water year. Materials and Methods: Water Quality Index and TSI were calculated for all sampling points and quality zonation was conducted in GIS. Results: It was found that the best water quality index for reservoir water is at second sampling point with amount of 61 situated at the center of reservoir, and the worst index is at entering point to the reservoir with amount of 46 in April. The main reason of changes was turnover of thermal stratification. Conclusion: The laboratory analysis and assessing the quality indices revealed that the Dez reservoir water is suitable for variety of public uses, however, it needs advanced treatment for drinking purpose. Moreover, in the case of continuity of pollutant entrance into the reservoir, the eutrophication risk would threaten the reservoir water quality. Eutrophication occurrence will cause serious limitations in water use applicability, increase turbidity, produce toxic materials, and increase sedimentation regime.

Background and Objective: The role of groundwater has always been an important issue in order to provide drinking water especially in desert areas. However, studies and decision-making on water supply from the water source is more costly and difficult rather than surface water. Therefore, it is important to note the newest methods like zoning. Due to the effects of water chemical parameters on the quality, application of AHP, ANP, FAHP, and FANP methods lead to more accurate results.  The aim of this research was to zone groundwater quality using ANP and FANP models and comparison of the results obtained by those achieved, by AHP and FAHP models.

Materials and Methods: For this purpose, the study was conducted to zone groundwater quality in Tabas aquifer located at the east of Iran with latitude between 33˚ 19’-33˚ 50’ and longitude between 60˚ 42’-63˚ 12’. In this study, the parameters studied were Mg, Ca, SO₄, Cl, total dissolved solids (TDS), electrical conductivity (EC),  and total hardness (TH). Raster maps for each parameter were prepared and these maps were converted to fuzzy maps. Then, the maps were integrated together using the weights from AHP and ANP methods.

Results:  The research indicated that the most weighted parameters using ANP method were Cl (0.172), Mg (0.161) and EC (0.159). Cl (0.457), TDS (0.163) and EC (0.141) were the most weighted parameters using AHP methods. In addition, the concentration of each parameter was increased from the east and southeast to the northeast.

Conclusion: Based on the results and groundwater flow path, water quality was reduced due to water flow in aquifer (from the east and southeast to northeast). Hence, the east and the southeast were the best location to provide drinking water. The area of these regions were 22.12, 25.08, 57.35 and 58.24% out of total area as determined using AHP, ANP, FAHP, and FANP, respectively.