Mapping Total Lead Concentration in Soil Particle Size Classes Using IRS-P6 LISS-III Data in Southern Isfahan

Areas surrounding mines are severely vulnerable to pollution due to mine explorations, excavations and transportations. Nowadays spectrophotometers and spectral reflectance are applied for estimating the concentration of pollutants due to high costs of sampling and laboratory measurements. This research was carried out to determine spatial distribution of lead concentration in soil particle size classes using IRS LISS III reflectance in southern Isfahan city. To reach this goal, 100 composite surface soil samples were randomly collected from the area. The samples were air dried and soil particle size classes 250-500, 125-250, 75-125, 50-75 and <50 μm were determined using appropriate sieves after dispersion the bulk soil samples using ultrasonic apparatus. Total Pb concentration were measured using an atomic absorption spectrophotometer after wet digestion of samples with nitric acid. Results showed that Pb concentration increases by decreasing soil particle size. Significant negative correlation coefficients were found between Pb concentration in soil particle size classes and soil spectral reflectances in visible and near infrared bands of IRS LISS-III satellite. Stepwise multiple regression models were used for estimating Pb concentration in soil particle classes through satellite data and spatial distribution of Pb was mapped using stepwise multiple regression equations. Results showed possible estimation of Pb concentration to certain ranges of concentrations through multiple regression models and satellite data. The results also indicated an increase in Pb concentration in all soil particle size classes by approaching the mines.