Assessment of potential pollution risk areas in fluvio littoral landscapes through a cumulative index

Abstract

In the last decades, the increases of anthropogenic pressure and related socio-economic development have triggered important changes in the Mediterranean fluvio-littoral landscapes. Among the risks to which these landscapes are exposed, those relating to chemical pollution and their potential impact in soil, water, sediment and aquatic fauna should be highlighted. These fluvio-littoral compartments reflect the conflict between development and conservation of natural resources, mainly by competition in the use of water and soil ones. The use of water quality indices as a tool to assess water quality status at certain times and locations have been adopted by many organizations and agencies. However, few specifications are intended for other important compartments such as sediments, which are the most probable dynamic sink of contaminants in the system. Under changing physico-chemical conditions, chemicals could be incorporated into the water column increasing their availability and impact to biota. The aim of this work is to test the applicability of a cumulative index considering water and sediment samples coming from the irrigation networks, to identify the areas of highest concern in the inter-fluvial area between Turia and Xúquer rivers in Valencia province (Spain). This index allows us to consider the concomitance of different stressors. The parameters used here, as well as the different sub-indices calculated, were chosen to represent a number of key environmental issues that have global relevance, including heavy metal pollution, nutrient pollution (eutrophication), and salinization. Aggregation index was performed after the assignment of weights to obtain the final index value. Preliminary results show that our index is able to identify the areas of concern and it agrees with other indexes (Pollution Load Index and mean Effects Range Median quotient). Moreover, it could be a helpful guideline to the sediment management considering their potential pollution.