Water Availability, Biofuels, and IWRM

August 5, 2013

The following 3 studies have been compiled for the 2013 Sustainable Water Resources site and ISWS Water Resources Site.

Water Availability and Vulnerability of 225 Large Cities in the United States

Padowski, Julie and James Jawitz

Water Resources Research, Vol. 48, 2012

This study presents a quantitative national assessment of urban water availability and vulnerability for 225 U.S. cities with population greater than 100,000. Here, the urban assessments account for not only renewable water flows, but also the extracted, imported,
and stored water that urban systems access through constructed infrastructure. These sources represent important hydraulic components of the urban water supply, yet are typically excluded from water scarcity assessments.
Results from this hydraulic-based assessment were compared to those obtained using a more conventional method that estimates scarcity solely based on local renewable flows. The inclusion of hydraulic components increased the mean availability to cities, leading to a significantly lower portion of the total U.S. population considered ‘‘at risk’’ for water scarcity (17%) than that obtained from the runoff method (47%). Water vulnerability was determined based on low-flow conditions, and smaller differences were found for this metric between at-risk populations
using the runoff (66%) and hydraulic-based (54%) methods.
The large increase in the susceptible population between the scarcity measures evaluated using the hydraulic method may better reconcile the seeming contradiction in the United States between perceptions of natural water abundance and widespread water scarcity. Additionally, urban vulnerability measures developed here were validated using a media text analysis. Vulnerability assessments that included hydraulic components were found to correlate with the frequency of urban water scarcity reports in the popular press while runoff-based measures showed no significant correlation, suggesting that hydraulic-based assessments provide better context for understanding the nature and severity of urban water scarcity issues.


Microalgae Biofuel Production in the Desert Southwest

Becker, Jackson Jae

As evidence of global climate change continues to become more apparent, the world is exploring ways for humans to live sustainable lives on Earth. The combustion of fossil fuels contributes to climate change by introducing greenhouse gases to the atmosphere, and the need for an alternative fuel source is increasingly important.

Biofuels from microalgae may provide a fuel source that could meet energy demands while and be less harmful to the environment than fossil fuels. Microalgae production for the use of biofuels provides a renewable, environmentally friendly, and sustainable alternative to fossil fuels.

Only requiring light, water, and carbon dioxide, algae has the capability to grow virtually anywhere, however the Southwestern region of the United States would make the most suitable environment for microalgae production. With high amounts of solar radiation, very few cloudy days, and consistent annual temperatures suitable for algae cultivation, the desert Southwest would be the most appropriate area for the production of American energy.


Using Modern Decision Support Systems for Evidence Based Policy Making in IWRM in Developing Countries

Giupponi, Carlo

Universita Ca Foscari di Venezia, Dipartimento di Economia, and Euro-Mediterranean Centre for Climate Change (CMCC)

Decision support systems (DSS) tools in the water management sector are usually developed upon hydrologic simulation models, to which they provide at least an interface for facilitated use beyond the restricted group of model developers. They quite often provide also routines for decision analysis and decision making  (e.g., optimization methods). In some cases they also include functionalities targeting the management of participatory processes  (e.g., elicitation of stakeholders’ preferences, group decision making, and conflict resolution).

The EU funded SPLASH project (Coordinating European Water Research for Poverty Reduction, http://www.splash-era.net/) has thus included in its activities the writing of this report on Using modern decision support systems for evidence based policy making in IWRM developing countries with a general objective to harness the potential of modern decision support systems for policy making in the field of integrated water resources management in developing countries.