Application of Hot Spots Index in the Analysis of Spatial Variations of Heavy Metalsin Anzali International Wetland

Awareness on spatial dispersion of heavy metals allows for planning of appropriate environmental policies. This study aims to monitor the pollution of heavy metals in Anzali International Wetland using GIS and spatial statistics. Sampling of water was done at 10 stations in 2014. The spatial distribution, density, zoning and distribution pattern were used in GIS for interpolation method, kernel function, Moron test, and hot spots index. The zoning maps derived from the density estimates indicated an increase in lead and nickel concentrations from west to east of Anzali Wetland. Based on the moron test and the GI* index, spatial correlation and spherical distribution pattern of heavy metals cluster indicate the accumulation and proximity of high density contaminated areas adjacent to each other. Accordingly, the highest hot spot of cadmium and nickel belongs to the northern parts of the wetland (under the bridge of Anzali port), zinc and lead were in the eastern part, and form the high cluster pattern, it could conclude that in these regions, heavy metal have been shown the positive self-correlation pattern.