HIGHLIGHTS. Large-scale best-siting analyses of traditional Nepalese ponds (pokharis) are lacking despite their importance for water management in Nepal.Uphill

In the Namib Desert, along the South-Western African coast, fog represents the main water input for local flora and fauna. During the last years, changes in the timing of fog occurrence and in the quantity of water that can be harvested from it, have been observed in several areas of the world, including the Namib Desert. A deeper insight into fog presence and fog water yield changes can help to understand to what extent Namib Desert’s ecosystem is being and will be affected in future by climate change. This information can also contribute to local environmental protection and carbon dioxide sequestration strategies, as fog water can be used for reforestation and land restoration. An 8-year-long dataset of harvested fog water rates recorded daily in 13 ground stations along the Namib Desert was statistically analysed to inspect advection fog occurrence evolution. The results show a noticeable intra-annual and inter-annual variability in rates and seasonality of harvested fog water. On the other hand, observed trends in collected fog water time series are generally decreasing, but longer time series are required to confirm the trend since El Niño Southern Oscillation (ENSO) phenomenon presence in the analysed period might have had an impact. The main hypothesis is that changes in fog occurrence and its characteristics are due to climate modifications, given that no extensive human activities are present in the area. However, further analyses on fog-related climatic and meteorological factors, possibly including remote sensing or reanalysis datasets aiming to increase the available data timespan, are envisioned to understand to what extent fog collection in the Namib Desert will be affected in future by climate change.

Water Harvesting Ponds (WHPs) are vital for enhancing irrigation water availability and controlling soil erosion in Mediterranean mountain regions under hydro-climatic stress. In Lebanon's Shouf Biosphere Reserve (SBR), hundreds of WHPs exist, locally known as ”birket”, yet historical siting often lacked integrated assessment, leading to siltation and structural failure. This study proposes an evidence-based methodology combining hydrological and socio-economic factors to identify suitable WHP sites, offering a transferable framework for similar Mediterranean contexts. The approach integrates Geographic Information Systems (GIS), Multi-Criteria Decision-Making (MCDM), and soil erosion modeling via the Revised Universal Soil Loss Equation (RUSLE), alongside participatory research.,The model was calibrated using a spatial inventory of 498 existing ponds, categorized by public and private ownership. Siting decision criteria included land use cover, soil, rainfall patterns, terrain elevation, and proximity to roads and water sources. Consultations with decision-makers and farmers provided essential socio-economic context. Results yielded two suitability maps (for public and private WHPs, respectively) both showing high performance: over 75% of existing ponds fell within the top 25% suitability range. Weighting was refined through sensitivity analysis, balancing expert criteria with local knowledge. Field-based assessments in five high-suitability areas (>7.5) validated the model, identifying several viable implementation sites. Consultations confirmed pond relevance under climate variability but highlighted the critical need for a national cadastral map to facilitate realistic implementation.,As the first research to couple hydrological and socio-economic factors for WHP suitability in the SBR, this study provides a valuable data-based decision support tool. The methodology is scalable to the national level, significantly contributing to climate adaptation strategies in water-stressed Mediterranean regions.

Water Harvesting Ponds (WHPs) are vital for enhancing irrigation water availability and controlling soil erosion in Mediterranean mountain regions under hydro-climatic stress. In Lebanon's Shouf Biosphere Reserve (SBR), hundreds of WHPs exist, locally known as ”birket”, yet historical siting often lacked integrated assessment, leading to siltation and structural failure. This study proposes an evidence-based methodology combining hydrological and socio-economic factors to identify suitable WHP sites, offering a transferable framework for similar Mediterranean contexts. The approach integrates Geographic Information Systems (GIS), Multi-Criteria Decision-Making (MCDM), and soil erosion modeling via the Revised Universal Soil Loss Equation (RUSLE), alongside participatory research.,The model was calibrated using a spatial inventory of 498 existing ponds, categorized by public and private ownership. Siting decision criteria included land use cover, soil, rainfall patterns, terrain elevation, and proximity to roads and water sources. Consultations with decision-makers and farmers provided essential socio-economic context. Results yielded two suitability maps (for public and private WHPs, respectively) both showing high performance: over 75% of existing ponds fell within the top 25% suitability range. Weighting was refined through sensitivity analysis, balancing expert criteria with local knowledge. Field-based assessments in five high-suitability areas (>7.5) validated the model, identifying several viable implementation sites. Consultations confirmed pond relevance under climate variability but highlighted the critical need for a national cadastral map to facilitate realistic implementation.,As the first research to couple hydrological and socio-economic factors for WHP suitability in the SBR, this study provides a valuable data-based decision support tool. The methodology is scalable to the national level, significantly contributing to climate adaptation strategies in water-stressed Mediterranean regions.

In recent years, non-conventional water (NCW) has been providing a promising alternative against increasing water scarcity in the Mediterranean. However, little work is available regarding the socioeconomic effects of its use. The purpose of this study is to present the effects of different levels of availability of irrigation water on four different Mediterranean areas relevant to the valorization of NCW. The analysis is based on technical and economic data from four Mediterranean Living Labs (LLs): one in Italy, one in Spain, one in Egypt and one transboundary between Tunisia and Algeria. The methodological approach is based on different versions of mathematical programming (linear programming, parametric programming, multi-objective programming). The results of the analysis showed that future scenarios of water deficiencies will have serious implications on the cropping pattern and will severely affect certain farm types, equally affecting employment, incomes and input use.