The Agueda Basin, north-central Portugal is comparatively wet (rainfall, 1600-1800 mm/yr) with frequent, relatively large storms in autumn and winter yet the summer drought is sufficiently long and consistent for frequent forest wildfires. This paper discusses wildfire impacts in such a wet Mediterranean environment on soil hydrophobicity, infiltration capacity, overland flow coefficients, soil loss, rainsplash detachment and small-scale ground level changes for Eucalyptus globulus and Pinus pinaster forest: (1) 0-2 years after fire ('new' burn); (2) 3-4 years after fire ('old' burn); and (3) 'mature' (or long unburnt) sites. For 'new' burn sites, rainsplash detachment rates are an order of magnitude and soil losses two orders of magnitude higher than for 'old' burn sites and both are two orders of magnitude higher than for 'mature' sites. Soils are hydrophobic in all three categories of sites, but infiltration capacities are lower at 'new' burn and 'old' burn than at 'mature' sites. Overland flow coefficients on long unburnt sites were low while on burnt sites they were high and tended to be higher for summer and autumn than for winter and spring, implying enhanced hydrophobicity under summer drought conditions, causing decreased infiltration capacity and increased overland flow. The distinctiveness of fire effects on soil erosion and hydrology in this wet Mediterranean environment and implications for post-fire management are discussed.

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The principal natural source of fresh water on scattered coral atolls throughout the tropical Pacific Ocean is thin unconfined groundwater lenses within islet substrates. Although there are many threats to the viability of atoll fresh water lenses, salinization caused by large storm waves washing over individual atoll islets is poorly understood. In this study, a mathematical modeling approach is used to examine the immediate responses, longer-term behavior, and subsequent (partial) recovery of a Pacific atoll fresh water lens after saline damage caused by cyclone-generated wave washover under different scenarios. Important findings include: (1) the saline plume formed by a washover event mostly migrates downward first through the top coral sand and gravel substrate, but then exits the aquifer to the ocean laterally through the more permeable basement limestone; (2) a lower water table position before the washover event, rather than a longer duration of storm washover, causes more severe damage to the fresh water lens; (3) relatively fresher water can possibly be found as a preserved horizon in the deeper part of an aquifer after disturbance, especially if the fresh water lens extends into the limestone under normal conditions; (4) post-cyclone accumulation of sea water in the central depression (swamp) of an atoll islet prolongs the later stage of fresh water lens recovery.