Sustainable long-term mitigation of floods and droughts in semiarid regions: Integrated optimal management strategies for a salt lake basin

Abstract

We present a management project for the mitigation of extreme climatic events in the frame of cyclic wet and dry periods in the semiarid Pampean region of Argentina. The developed methodological approach allows quantitative planning of strategies to tackle the effect of recurrent floods and droughts in a salt lake basin through the formulation of an optimal control problem, which constitutes a novel approach to ecohydrological systems management. The control variables correspond to (i) diversion flows from a lake tributary to an artificial freshwater reservoir to damp lake flooding, (ii) freshwater flows from the reservoir to the salt lake to keep its salinity at desired values and (iii) freshwater flows to irrigate crops during drought periods. Further, we address the economic valuation of ecosystem services in the basin. Quantitative results provide useful insights on optimal management strategies and the effects of their implementation, as well as their impact on the valuated services in the watershed under study.