Multidisciplinary Approach to Address Water Scarcity in Informal Settlements in Lima, Peru: Fog Water Collection, The Fog Resource and the Health Context

Thesis (Ph.D.)--University of Washington, 2014Many arid regions of the world have very limited and shrinking water availability, which puts vulnerable populations such as informal settlement (slum) dwellers at risk for having the least access to clean drinking water. This is particularly a concern in coastal Peru, where many informal settlements already experience water scarcity that will be exacerbated by both shrinking water supply and a continuously growing population. In Lima, the capital city, rapid growth of the population has resulted in large informal settlements forming up the hillsides surrounding the city. Given the projected growth of Lima, the public water supply has already been found to be inadequate to supply the current water needs of Lima. In order to address this complex problem of inadequate water resources in the informal settlements in Lima, Peru, this dissertation focused on relevant technological, social and environmental factors. The first study demonstrated the improved effectiveness of a nonwoven three-dimensional turf mesh in a passive fog collection system that captures the abundant wind-blown fog that surrounds the city. The material increased yields over traditional fog collection materials by 50% to 150% in field testing. The second focus was on the impact on health and social factors that could be affected by improved water access, as well as have an influence on the ability to develop and sustain any water resource system. Therefore, the second study evaluated demographic, physical and mental health, and social relationship factors of individuals in the community that would be benefit from the fog water collection. We found nearly half of the participants in the community were overweight or obese, yet the prevalence of non-communicable disease was low, and the mental health and social relationship surveys did not indicate significant impacts for the well-being of the community, which may positively contribute to the likelihood of a fog collection system's success. Finally, the fog resource can be assessed by the coastal low cloud conditions. Knowledge about the availability and predictability of these conditions along coastal Peru was explored as the third component of this dissertation. Reduced quantities of stratus clouds were observed with increased temperatures in the El Niño 3.4 region, the El Niño 1+2 region and along coastal Peru. While annually greater quantities of stratocumulus clouds were generally observed with increased El Niño 3.4 temperatures, we observed a negative correlation between seasonal stratocumulus in many coastal Peruvian stations and SST in the El Niño index regions and along coastal Peru. With projected increases in equatorial sea surface temperatures, and warming coastal Peruvian currents, we could see reductions in low cloud cover. In conclusion, by testing efficiency improvements to a method to acquire atmospheric water, exploring individual and social conditions within the type of community where this system could be used, and evaluating conditions that would affect the availability of water throughout the year, this dissertation has contributed to our understanding of many aspects of the problem of water resources in this under-served community. Furthermore, this series of studies has provided direction to the development of community-based water solutions in Lima, Peru