Evaporation Control in Mediterranean Climates
Hot dry summers and mild wet winters make Mediterranean reservoirs lose most of their water in a concentrated summer window. How to target it.
The Mediterranean climate — hot, dry, sunny summers and mild, wetter winters — concentrates evaporation into a sharp summer peak. Annual loss is moderate-to-high (often 1,200–1,800 mm), but it is heavily summer-weighted, which shapes the whole strategy: get effective coverage in place before summer and you capture most of the year’s savings. The economic stakes are real — studies in Spain’s Segura Basin put a clear monetary value on reservoir evaporation losses (Martínez-Granados et al., 2011).
What works best here
Permanent high-coverage options — modular floating covers and floating solar — give year-round protection and ride through the critical summer. Because loss is seasonal, seasonal measures also have a place: a chemical monolayer applied through the dry months targets the high-loss window at low capital cost, and windbreaks help where regional summer winds drive the loss.
What to watch
The mild winters mean year-round permanent covers earn their keep mostly in summer, so weigh capital cost against the summer-only saving using the cost-benefit page. For calm, radiation-dominated summer conditions, the Priestley-Taylor method gives a good loss estimate to plan around.