Comparison of index systems for rating water quality in intermittent rivers.

Water quality indexes (WQI) are a practical way to evaluate and compare the level of chemical contamination of different water bodies and to spatially and temporally compare levels of pollution. The purpose of this study was to check if these indexes are appropriate for intermittent rivers under arid and semi-arid climates. A literature review enabled the comparison of 25 water quality indexes to discern their capability to evaluate spatial (inter and intra catchment) and temporal (high and low water flow conditions) variations in water quality in three Mediterranean intermittent rivers: the River Vène (France) and the Oued Fez and the River Sebou (Morocco).