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Global climatic change intensifies the water crisis, particularly in arid and semi-arid regions. In this regard, the provision of enough water for irrigation is a serious dilemma because the agricultural sector consumes the largest amount of water (70% withdrawal and 90% consumption). In this review, we have summarized recent innovations that have emerged as unconventional techniques to supply adequate water for irrigation purposes. We present the principles and basics of seven approaches: the Sahara Forest Project (SFP), water extraction from the air (WEA), aquifer recharge, the treatment of marginal water using a magnetic field, desalination and wastewater treatment (DWT), electro-agric technology (E-AT), and the Toshka Project. The SFP is currently being utilized in Aqaba, Jordan, and DWT is considered a common practice worldwide, whereas some of these innovations are still under investigation to ensure their feasibility for large-scale applications, such as E-AT. The Toshka Project is considered a wonderful idea that utilizes the water stored behind the High Dam in Lake Nasser, Egypt. Several approaches have been adopted to reduce the amount of water being used for irrigation, as the current amount of freshwater is insufficient for the requirements of increased agricultural consumption, particularly in hot, arid, and semi-arid regions. [ABSTRACT FROM AUTHOR]

The island of Astypalea (Greece), known for its rich and pristine archeological sites, encompasses a semi-enclosed silled basin that has been very susceptible to global sea levels and regional climate changes due to its relatively modern shallow sill of 4.7 m water deep that connects the Vathy bay with the adjacent Aegean Sea. To identify the causal relationship between regional climate, sea-level trajectories, and environmental change and their potential impact on hominine habitats on the island, we investigated a high-resolution seismic profile together with sediment, stable isotope, geochemical, and biotic proxies retrieved from a marine sediment core (ASTC1). Our results show that the basin was once isolated, and a marine inundation occurred at around 7.3 ka BP, which is older than expected, based on global sea level reconstructions. The entire transition from isolation to full marine conditions was accomplished in three major phases: (1) non-marine isolated conditions between 9–7.3 ka BP, (2) semi-isolated hypersaline marsh and lagoonal conditions between 7.3 and 4.1 ka BP, and (3) semi-isolated shallow marine conditions of today (4.1 ka BP to present). High water alkalinity, elevated organic content, and heavier isotopic signals indicate relatively arid conditions in the region that favored Sr-rich carbonate precipitation within the 7.3–6 ka BP interval. On the other hand, freshwater biota, along with a high Corg/N ratio and lighter isotopic signal, showed wetter conditions, at least for the intervals 8–7.3 ka and 6–5.4 ka BP, in contrast to the aridification trend seen as 4.1 ka to present. Finally, the hominine habitat evolution at around 6 ka BP might be attributed to the wetter conditions and the freshwater source provided by the bay at that time. [ABSTRACT FROM AUTHOR]

Enhancing resilience against flooding events is of great importance. Eastern Iberian Peninsula coastal areas are well known for high intensity rainfalls known as DANA or "cold drop". Extreme records in 24 h can exceed the annual average of the historical series. This phenomenon occurs normally in autumn due to convective storms generated by the existence of cold air in the upper layers of the atmosphere combined with warm winds coming from the Mediterranean Sea. In many coastal areas of the Eastern Iberian Peninsula, their flat topography, sometimes of a marsh nature, and the natural (e.g., dune ridges) and man-made (e.g., infrastructures) factors, result in devastating flooding events of great potential damage and risk for urban and rural areas. In this context, this paper presents the case study of the town of Oliva (Valencia, Spain) and how in a flooding event the flow tends to spread and accumulate along the flat coastal strip of this populated area, causing great potential damage. From that point, the paper discusses the particular issues that flood studies should consider in such flat and heavy rainy areas in terms of the hydrological and hydraulic models to be conducted to serve as the key tool of a correct risk assessment. This includes the correct statistical simulation of rainfalls, the hydrological model dependency on the return period and the correct geometry definition of all possible water barriers. An analysis of the disturbance that climatic change effects may introduce in future flooding events is also performed. [ABSTRACT FROM AUTHOR]

Global warming causes rapid shrinking of mountain glaciers. New lakes can, thus, form in the future where overdeepenings in the beds of still-existing glaciers are becoming exposed. Such new lakes can be amplifiers of natural hazards to downstream populations, but also constitute tourist attractions, offer new potential for hydropower, and may be of interest for water management. Identification of sites where future lakes will possibly form is, therefore, an essential step to initiate early planning of measures for risk reduction and sustainable use as part of adaptation strategies with respect to impacts from climate change. In order to establish a corresponding knowledge base, a systematic inventory of glacier-bed overdeepenings and possible future lakes was compiled for the still glacierized parts of the Peruvian Andes using the 2003-2010 glacier outlines from the national glacier inventory and the SRTM DEM from the year 2000. The resulting inventory contains 201 sites with overdeepened glacier beds >1 ha (104 m²) where notable future lakes could form, representing a total volume of about 260 million m³. A rough classification was assigned for the most likely formation time of the possible new lakes. Such inventory information sets the stage for analyzing sustainable use and hazard/risk for specific basins or regions. [ABSTRACT FROM AUTHOR]

The Ionian coast of the Basilicata region, southern Italy, is characterized by a remarkable archaeological heritage, valuable crops, and national and international tourism, contributing significantly to the regional economy. In the last two decades, the area has been affected by the heavy recurrence of flooding events, which caused significant damage to agriculture, tourist infrastructure, and archaeological heritage. Both qualitative and quantitative analyses of pluviometric, hydrometric, and erosion/deposition dynamics of main rivers have been carried out in order to investigate the role played by natural factors, climate changes, and human activity. The results show that flooding events in the Metaponto plain were certainly caused by extreme rainy events, but man has also played an important role. The Metaponto plain has been involved in a reclamation consisting of the building of an extensive channel network, which provided better land cultivation, easy access to the beaches, and archaeological heritage protection. The human impact related to the absence of channel cleaning has proved to be the most relevant factor that greatly amplified the effects of low-intensity rainfall events, thus triggering flooding events. [ABSTRACT FROM AUTHOR]

Wildfires are prevalent in grasslands and shrublands. The objective of this study is to provide land managers with a general overview, by assessing the main impacts of wildfire, including those on plant communities (e.g., secondary succession and species invasion), soil characteristics (e.g., water repellency (hydrophobicity), aggregation and structure stability, and contents of organic carbon and nutrients), and surface processes (e.g., ash deposition, ground surface clogging, water runoff, soil erosion, hillslope debris flow, and dry ravel). Additionally, the study discusses the effects of livestock grazing on the functioning of post-fire grasslands and shrublands. Although mesic regions are mentioned, this review focuses on drylands. The comparatively low-to-moderate fuel loads that characterize grasslands and shrublands generate wildfires of relatively moderate intensity, resulting in moderate burn severity. Yet, it seems that because of decreased soil aggregate stability following burning, the hoof action of livestock that access burnt lands shortly after the fire increases the shearing and detachment of mineral material from the ground surface; this increases soil erodibility, with the possible risk of accelerated land degradation. The review ends with an assessment of general implications for environmental sustainability and health, and provides recommendations on wildfire control in rangelands, and on restoration of burnt lands. [ABSTRACT FROM AUTHOR]