6 results on '"Miralles-Wilhelm, Fernando"'
Search Results
2. Water for Food and Energy Security : An Assessment of the Impacts of Water Scarcity on Agricultural Production and Electricity Generation in the Middle East and North Africa
- Author
-
Miralles-Wilhelm, Fernando, Hejazi, Mohamad, Kim, Song, Yonkofski, Catherine, Watson, David, Kyle, Page, Liu, Yaling, Vernon, Chris, Delgado, Alison, Edmonds, Jae, and Clarke, Leon
- Subjects
ENERGY ,SUSTAINABILITY ,WATER RESOURCE MANAGEMENT ,GROUNDWATER ,IRRIGATION ,FOOD SECURITY ,HYDROPOWER ,CLIMATE CHANGE ,CLIMATE IMPACT ,WATER SCARCITY ,WATER SUPPLY ,RAINFALL - Abstract
Water, energy, and agriculture have been conventionally dealt with separately in investment planning. For each of these sectors, regulatory frameworks, organizations, and infrastructures have been put in place to address sector-specific challenges and demands. As the Middle East and North Africa works towards building a more sustainable future, a nexus approach that considers the risks and synergies among these sectors is needed. To demonstrate the added value of a nexus approach, this report applies scenario analysis and integrated assessment modelling of the water-energy-food nexus to the Middle East and North Africa. The analysis finds that water scarcity increases in all countries in the region over the coming decades, mostly due to growing demands. More importantly, the analysis finds that many countries in the region could run out of fossil groundwater by 2050 unless measures to curb unsustainable abstraction are implemented. The impacts of growing scarcity on agriculture are significant, with production projected to drop by 60 percent by 2050 in some countries. On the upside, reducing the dependence of the agricultural and energy sectors on water and transitioning to renewable energies can reduce water scarcity, at the same time reducing greenhouse gas emissions.
- Published
- 2018
3. The Water-Energy-Food Nexus in the Middle East and North Africa : Scenarios for a Sustainable Future
- Author
-
Borgomeo, Edoardo, Jagerskog, Anders, Talbi, Amal, Wijnen, Marcus, Hejazi, Mohamad, and Miralles-Wilhelm, Fernando
- Subjects
RENEWABLE ENERGY ,SUSTAINABILITY ,GROUNDWATER ,ENERGY SUPPLY ,DEMOGRAPHICS ,CLIMATE CHANGE ,FOOD SECURITY ,WATER SCARCITY ,SURFACE WATER ,WATER SUPPLY ,ELECTRICITY - Abstract
Water, energy, and agriculture have been conventionally dealt with separately in investment planning. For each of these sectors, regulatory frameworks, organizations, and infrastructures have been put in place to address sector-specific challenges and demands. As the Middle East and North Africa works towards building a more sustainable future, a nexus approach that considers the risks and synergies among these sectors is needed. To demonstrate the added value of a nexus approach, this report applies scenario analysis and integrated assessment modelling of the water-energy-food nexus to the Middle East and North Africa. The analysis finds that water scarcity increases in all countries in the region over the coming decades, mostly due to growing demands. More importantly, the analysis finds that many countries in the region could run out of fossil groundwater by 2050 unless measures to curb unsustainable abstraction are implemented. The impacts of growing scarcity on agriculture are significant, with production projected to drop by 60 by 2050 in some countries. On the upside, reducing the dependence of the agricultural and energy sectors on water and transitioning to renewable energies can reduce water scarcity, at the same time reducing greenhouse gas emissions. This report is targeted to policy makers, the academic community, and a wider global audience interested in exploring the interactions between water, agriculture, and energy.
- Published
- 2018
4. The role of recharge and evapotranspiration as hydraulic drivers of ion concentrations in shallow groundwater on Everglades tree islands, Florida (USA).
- Author
-
Sullivan, Pamela L., Price, René M., Miralles‐Wilhelm, Fernando, Ross, Mike S., Scinto, Leonard J., Dreschel, Thomas W., Sklar, Fred H., and Cline, Eric
- Subjects
EVAPOTRANSPIRATION ,CALCIUM carbonate ,GROUNDWATER ,IONS ,HYDROLOGIC models ,HYDRAULIC conductivity - Abstract
Recently, evapotranspiration has been hypothesized to promote the secondary formation of calcium carbonate year-round on tree islands in the Everglades by influencing groundwater ions concentrations. However, the role of recharge and evapotranspiration as drivers of shallow groundwater ion accumulation has not been investigated. The goal of this study is to develop a hydrologic model that predicts the chloride concentrations of shallow tree island groundwater and to determine the influence of overlying biomass and underlying geologic material on these concentrations. Groundwater and surface water levels and chloride concentrations were monitored on eight constructed tree islands at the Loxahatchee Impoundment Landscape Assessment (LILA) from 2007 to 2010. The tree islands at LILA were constructed predominately of peat, or of peat and limestone, and were planted with saplings of native tree species in 2006 and 2007. The model predicted low shallow groundwater chloride concentrations when inputs of regional groundwater and evapotranspiration-to-recharge rates were elevated, while low evapotranspiration-to-recharge rates resulted in a substantial increase of the chloride concentrations of the shallow groundwater. Modeling results indicated that evapotranspiration typically exceeded recharge on the older tree islands and those with a limestone lithology, which resulted in greater inputs of regional groundwater. A sensitivity analysis indicated the shallow groundwater chloride concentrations were most sensitive to alterations in specific yield during the wet season and hydraulic conductivity in the dry season. In conclusion, the inputs of rainfall, underlying hydrologic properties of tree islands sediments and forest structure may explain the variation in ion concentration seen across Everglades tree islands. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
5. Numerical modeling of the effects of water flow, sediment transport and vegetation growth on the spatiotemporal patterning of the ridge and slough landscape of the Everglades wetland
- Author
-
Lago, Marcelo E., Miralles-Wilhelm, Fernando, Mahmoudi, Mehrnoosh, and Engel, Vic
- Subjects
- *
GROUNDWATER flow , *WETLANDS , *NUMERICAL analysis , *VEGETATION & climate , *WAVELENGTHS , *SIMULATION methods & models , *GROUNDWATER , *SEDIMENTATION & deposition - Abstract
Abstract: A numerical model has been developed to simulate the spatiotemporal patterning of the ridge and slough landscape in wetlands, characterized by crests (ridges) and valleys (sloughs) that are elongated parallel to the direction of water flow. The model formulation consists of governing equations for integrated surface water and groundwater flow, sediment transport, and soil accretion, as well as litter production by vegetation growth. The model simulations show how the spatial pattern self-organizes over time with the generation of ridges and sloughs through sediment deposition and erosion driven by the water flow field. The spatial and temporal distributions of the water depth, flow rates and sediment transport processes are caused by differential flow due to vegetation and topography heterogeneities. The model was parameterized with values that are representative of the Everglades wetland in the southern portion of the Florida peninsula in the USA. Model simulation sensitivity was tested with respect to numerical grid size, lateral vegetation growth and the rate of litter production. The characteristic wavelengths of the pattern in the directions along and perpendicular to flow that are simulated with this model develop over time into ridge and slough shapes that resemble field observations. Also, the simulated elevation differences between the ridges and sloughs are of the same order of those typically found in the field. The width of ridges and sloughs was found to be controlled by a lateral vegetation growth distance parameter in a simplified formulation of vegetation growth, which complements earlier modeling results in which a differential peat accretion mechanism alone did not reproduce observations of ridge and slough lateral wavelengths. The results of this work suggest that ridge and slough patterning occurs as a result of vegetation''s ability to grow laterally, enhancing sediment deposition in ridge areas, balanced by increased sediment erosion in slough areas to satisfy flow continuity. The interplay between sediment transport, water flow and vegetation and soil dynamic processes needs to be explored further through detailed field experiments, using a model formulation such as the one developed in this work to guide data collection and interpretation. This should be one of the focus areas of future investigations of pattern formation and stability in ridge and slough areas. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
6. Water source utilization and foliar nutrient status differs between upland and flooded plant communities in wetland tree islands.
- Author
-
Saha, Amartya, da Silveira O’Reilly Sternberg, Leonel, Ross, Michael, and Miralles-Wilhelm, Fernando
- Subjects
TREE islands ,PLANT communities ,HISTOSOLS ,SOIL moisture ,GROUNDWATER ,STABLE isotopes in ecological research ,PLANT-water relationships - Abstract
Tree islands in the Everglades wetlands are centers of biodiversity and targets of restoration, yet little is known about the pattern of water source utilization by the constituent woody plant communities: upland hammocks and flooded swamp forests. Two potential water sources exist: (1) entrapped rainwater in the vadose zone of the organic soil (referred to as upland soil water), that becomes enriched in phosphorus, and (2) phosphorus-poor groundwater/surface water (referred to as regional water). Using natural stable isotope abundance as a tracer, we observed that hammock plants used upland soil water in the wet season and shifted to regional water uptake in the dry season, while swamp forest plants used regional water throughout the year. Consistent with the previously observed phosphorus concentrations of the two water sources, hammock plants had a greater annual mean foliar phosphorus concentration over swamp forest plants, thereby supporting the idea that tree island hammocks are islands of high phosphorus concentrations in the oligotrophic Everglades. Foliar nitrogen levels in swamp forest plants were higher than those of hammock plants. Linking water sources with foliar nutrient concentrations can indicate nutrient sources and periods of nutrient uptake, thereby linking hydrology with the nutrient regimes of different plant communities in wetland ecosystems. Our results are consistent with the hypotheses that (1) over long periods, upland tree island communities incrementally increase their nutrient concentration by incorporating marsh nutrients through transpiration seasonally, and (2) small differences in micro-topography in a wetland ecosystem can lead to large differences in water and nutrient cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.