Evaluating Mediterranean Soil Contamination Risks in Selected Hydrological Scenarios.

This paper reports an attempt of predicting the contamination risk of soils and water as they respond to hydrological changes in the agricultural lands of Sevilla province, Spain. Based on land evaluation methodologies, a semi-empirical model (named Pantanal, as module of the integrated package MicroLEIS(TM): Microcomputer-based Mediterranean Land Evaluation Information System) is used for assessing limitations for the use of the land, or vulnerability of the land, to relevant surface and ground water agrocontaminants: phosphorus, nitrogen, heavy metals and pesticides, The input land characteristics refer to soil properties (basically, redox potential and organic matter content) and to the mobility of contaminants. The selected hydrological change scenarios are induced by differences in land use, agricultural management and soil type, such as wetlands/drained-irrigated lands, or irrigated rice lands/dry agriculture/set-aside lands. The evaluation results showed that hydrological changes produced by extensification/intensification methods of production appear to have important effects on land degradation. Also, spatial variability in relation to soil and crop implies significant difference of vulnerability for the four types of soil contaminants considered.