Spatial analyses in environmental studies: II. Identification of pollution hotspots in urban soils

The identification of pollution hotspots is an important approach for a better understanding of spatial distribution patterns and the searching for influencing factors in environmental studies. One of the most often asked... [ view full abstract ]

The identification of pollution hotspots is an important approach for a better understanding of spatial distribution patterns and the searching for influencing factors in environmental studies. One of the most often asked questions in an environmental investigation is: Where are the pollution hotspots? This presentation explains one of the popularly used methodologies called local index of spatial association (LISA) and its applications in urban geochemical studies in Galway, Ireland. The LISA is a useful tool for identifying pollution hotspots of Pb pollution in urban soils, and for classifying them into spatial clusters and spatial outliers. The results were affected by the definition of weight function, data transformation and existence of extreme values, and it is suggested that all these influencing factors should be considered until reasonable and reliable results are obtained. The LISA is also found useful in identifying polluted areas in bonfires sites. Soils with elevated metal concentrations, as evident from the spatial distribution maps, coincided with the locations of traditional festival bonfires. The results of hotspots analysis provide useful information for the management of urban soils.