Reason: Some chapters of the dissertation are currently under review or will be submitted soon to peer review journals
until file(s) become available
Application of a Food-Energy-Water (FEW) Nexus Approach to Water Resources Management in the Colombian Andean Region
Water resources are currently under high pressure due to population growth, urbanization, and changes in climate patterns. Therefore, there is a need for strategies to improve water resources management at all scales. The Food-Energy-Water (FEW) nexus approach has emerged as an alternative for water resources management since it provides a comprehensive management strategy through which interactions among components of food, energy, and water systems can be evaluated. In the Latin American and Caribbean region, studies and reports evaluating the FEW nexus are limited in comparison to other regions in the world. The aim of this work was to investigate the potential for applying a FEW nexus approach to improve water resources management in the Colombian Andean region. In this study, an urban FEW nexus framework was developed for the Otun River Watershed (ORW), a pilot study site located in the Colombian Andean region, based on a characterization of the watershed’s climate, land use land cover, streamflow, and water quality. Results from the characterization revealed that the Pereira/Dosquebradas urban area had the greatest impact on watershed water resources owing to its high water and energy demand. Additionally, the Otun River water quality is mostly affected by this urban area due to the lack of a wastewater treatment facility to decontaminate urban sewage water. The Pereira/Dosquebradas urban area is primarily dependent on food coming from outside of the ORW, thus food production does not have as large an impact on water resources in the watershed. A FEW nexus analysis for 2035showed that water and energy demand could increase by 16% and 30%, respectively, except where a reduction in food production in the ORW is considered, in which case the water demand would remained unchanged. Hydrological modeling of the watershed showed potential changes ranging between -35%and 53%in watershed runoff and -29%and25% in overall water yield for the period 2030to2039, in response to anticipated changes in average annual precipitation ranging from -29% to 6% when comparing to a baseline scenario (2007-2012). Thus, changes in precipitation could affect the volume of water available for residential, industrial, and agricultural activities in the ORW. Moreover, an increase in the number of extreme weather events could cause more floods and landslides. Therefore, recommendations for water resources management in the ORW include reducing water losses in the water distribution systems, adopting water conservation practices, developing GI and decentralized wastewater systems, and implementing urban and peri-urban farming practices. Finally, as water quality is of high concern in the ORW, an assessment was conducted to determine suitable water quality sampling frequencies to meet different water quality monitoring objectives. This analysis used the Western Lake Erie Basin (WLEB) as a case study site as it has long-term, continuous water quality records with data available at least ona daily basis. Daily concentrations for select constituents (suspended solids, total phosphorus, soluble reactive phosphorus, and nitrates+nitrites) were used to create weekly, bi-weekly, monthly, and seasonal subsamples following distinctive rules for day, week, or month of sampling. Results from this evaluation indicate that monthly and seasonal sampling would be sufficient if the objective was to assess the stream’s water quality status. However, if the monitoring objective was related to the examination of water quality trends, weekly and bi-weekly sampling would give better results. Furthermore, differential sampling could be adopted in areas with distinctive characteristics, prioritizing high-resolution sampling (daily, weekly, and bi-weekly) in subareas where the constituents of concern have a high variability (sediments and nutrients)or non-point source pollution has been identified as an issue. The remaining subareas could be sampled on a seasonal or annual basis, with sampling conducted at random to reduce bias. Overall, this study provided an urban FEW nexus framework for the Colombian Andean Region, illustrated the application of this framework in a pilot study site (ORW) under current and future conditions, and presented recommendations for water quality sampling frequency on sites with limited resources to implement a high-resolution water quality monitoring plan.