تغييرات مكاني كيفيت آب و برخي خصوصيات خاك در دشت يزد-اردكان

چكيده انگليسي :

Spatial Variability of Groundwater Quality and Selected Surface Soil Characteristics in Yazd Ardakan Plain Leila Rayat leila rayat@yahoo com February 7 2011 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Hossein Shariatmadari Shariat@cc iut ac ir Hossein Khademi hkhademi@cc iut ac ir Abstract Groundwater is one of the most important sources of water required for life in central Iran In our country because surface water sources are limited the use of groundwater has been very common since long time ago Nowadays the groundwater is highly used for agriculture drinking and industrial activities The objective of this study was to investigate the spatial variability of groundwater quality and selected surface soil characteristics in Yazd Ardakan plain The plain is located in an arid region of central Iran The use of groundwater in this area has been increasing in recent years to meet the drought crisis The study area covering 504 km2 is situated in Yazd Ardakan plain in the center of Yazd province Water samples were randomly collected from 123 wells located in different agricultural industrial and urban land usees Sampling was carried out in 2 stages including September 2009 at the end of dry season and April 2010 at the end of humid season Also 128 composite surface soil samples 0 20 cm were randomly taken Selected chemical parameters were measured in water and soil samples Omni directional variograms were prepared for soil and water characteristics using Variowin 2 2 software The mapping of different variables in soil and water samples was carried out using block kriging in ILLWIS 3 software The geostatistical results indicated that the maximum concentration of fluoride and nitrate was found in agricultural areas The kriging map of fluoride concentration in groundwater for September was well in line with that of Ca 2 Mg 2 and SAR Similar results were also found for April and the proposed block kriging map for fluoride estimation was totally in agreement with that of Ca2 Mg2 and HCO3 The results of this study indicated that the concentration of fluoride in groundwater was closely related to hydro chemical characteristics of the waters The mean fluoride concentration of water samples in the first stage was higher than that of the second sampling Mean nitrate concentration was higher in the second stage of sampling in comparison with the first sampling The average nitrate and fluoride concentration was in the range of non polluted waters According to standards the level of fluoride in irrigation and drinking water is suggested to be 1 5 and 1 mg l 1 Therefore the level of fluoride in the water samples in the study area falls within the suitable range for irrigation but deficient for drinking water Also nitrate concentration of water in the study area is within the standard range for irrigation less than 30 mg l 1 and drinking water less than 45 mg l 1 Since the Yazd Ardakan plain is located in an arid region and also due to rain deficiency and high depth of groundwater in the region characteristics of soil could not justify the changes of fluoride and other chemical parameters in groundwaters during two stages of sampling Keywords Groundwater Fluoride Nitrate Kriging Sodium Adsorption Ratio SAR Yazd Ardakan plain

رعيت، ليلا

تغييرات مكاني كيفيت آب و برخي خصوصيات خاك در دشت يزد-اردكان

آب هاي زيرزميتي , فلورايد , نيترات , كريجينگ , نسبت جذب سديم