Assessing tradeoffs in the design of climate change adaptation strategies for water utilities in Chile.
AuthorsRicalde, Iñigo; email: email@example.com
Vicuña, Sebastián; email: firstname.lastname@example.org
Melo, Oscar; email: email@example.com
Tomlinson, James E; email: firstname.lastname@example.org
Harou, Julien J; email: email@example.com
Characklis, Greg; email: firstname.lastname@example.org
MetadataShow full item record
AbstractClimate change is a challenge to drinking water providers worldwide and to regulatory frameworks that consider long-term investment decisions. Coping with an unstable climate warrants adjustments in regulations and new investments. The investment required to maintain a selected service level needs to balance the potential for high regret stranded assets with the political and socioeconomic consequences of not meeting water demands. In recent years, the City of Santiago in Chile has seen drought events associated with climate change, which could worsen in the future. Chile's drinking water regulatory framework does not account for uncertainty in infrastructure design to cope with the potential impacts of such events. This work presents an adaptation option design process that considers multiple plausible climate change-impacted future scenarios, accommodating both structural and nonstructural measures. In our Santiago case study adaptation measures include extensions to the existing Chilean water market and traditional structural alternatives (e.g., storage infrastructure); all are represented in a simulation model of the water utility. We evaluate and optimize packages of efficient adaptation measures for various climate scenarios. This allows comparing different portfolios of combined institutional and infrastructure interventions via a range of stakeholder measures and comparing their tradeoffs under different plausible climate-impacted hydrological scenarios. Results showed that water supply performance without climate change adaptation is worse under climate scenarios with lower water availability, which are likely to be associated with higher GHG emission scenarios such as RCP 8.5. The optimized portfolios implement various combinations of adaptation strategies to reduce the impacts of this poor performance. Considering the uncertainty on future climate scenarios, the use of nonstructural adaptation measures such as option contracts exhibits the advantage of providing water in critical periods while avoiding large investments such as building reservoirs or the purchase of permanent water rights, which could end up underused if favorable climate scenarios manifest. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]
CitationJournal of environmental management, volume 302, issue Pt A, page 114035
DescriptionFrom PubMed via Jisc Publications Router
History: received 2020-07-21, revised 2021-10-21, accepted 2021-10-28
Publication status: aheadofprint
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Perceptions of Drinking Water Service of the ‘Off-Grid’ Community in Cimahi, IndonesiaPrayoga, Rizky; email: email@example.com; Nastiti, Anindrya; orcid: 0000-0003-4857-5287; email: firstname.lastname@example.org; Schindler, Seth; email: email@example.com; Kusumah, Siska W. D.; email: firstname.lastname@example.org; Sutadian, Arief D.; email: email@example.com; Sundana, Eka J.; email: firstname.lastname@example.org; Simatupang, Elivas; email: email@example.com; Wibowo, Arie; email: firstname.lastname@example.org; Budiwantoro, Bagus; email: email@example.com; Sedighi, Majid; email: firstname.lastname@example.org (MDPI, 2021-05-17)The establishment of decentralized drinking water systems in urban areas is technically and financially feasible, and these ‘off-grid’ systems can complement investment in traditional piped water systems. However, users often see ‘off-grid’ systems as the second-best option, compared to citywide piped water systems. Thus, although they are designed to improve access to water and reduce inequality, they can be perceived by users as infrastructural manifestations of extant inequality. In this paper, we present original research on the perceptions of users in Cimahi, Indonesia, surrounding their access to water and willingness to use and maintain ‘off-grid’ infrastructure. The majority of respondents used groundwater and packaged water as their primary water sources, and paid approximately twice the maximum tariff of piped water service. We interpreted the survey data with the theory of planned behavior framework and determined that respondents demonstrated a willingness to pay fees for ‘off-grid’ water systems, participate in water supply programs, and switch to new water sources. These intentions were affected by their attitude towards the behavior, subjective norm, and perceived behavioral control to various degrees. The findings are useful for those designing strategies to introduce novel water delivery systems aimed at improving water access for diverse and disadvantaged socioeconomic groups in urban areas in the Global South.
Energy-entropy prediction of octanol-water logP of SAMPL7 N-acyl sulfonamide bioisosters.Falcioni, Fabio; email: email@example.com; Kalayan, Jas; Henchman, Richard H; orcid: 0000-0002-0461-6625; email: firstname.lastname@example.org (2021-07-10)Partition coefficients quantify a molecule's distribution between two immiscible liquid phases. While there are many methods to compute them, there is not yet a method based on the free energy of each system in terms of energy and entropy, where entropy depends on the probability distribution of all quantum states of the system. Here we test a method in this class called Energy Entropy Multiscale Cell Correlation (EE-MCC) for the calculation of octanol-water logP values for 22 N-acyl sulfonamides in the SAMPL7 Physical Properties Challenge (Statistical Assessment of the Modelling of Proteins and Ligands). EE-MCC logP values have a mean error of 1.8 logP units versus experiment and a standard error of the mean of 1.0 logP units for three separate calculations. These errors are primarily due to getting sufficiently converged energies to give accurate differences of large numbers, particularly for the large-molecule solvent octanol. However, this is also an issue for entropy, and approximations in the force field and MCC theory also contribute to the error. Unique to MCC is that it explains the entropy contributions over all the degrees of freedom of all molecules in the system. A gain in orientational entropy of water is the main favourable entropic contribution, supported by small gains in solute vibrational and orientational entropy but offset by unfavourable changes in the orientational entropy of octanol, the vibrational entropy of both solvents, and the positional and conformational entropy of the solute.
Effect of layered water structures on the anomalous transport through nanoscale graphene channelsChen, S; orcid: 0000-0002-8118-5849; Draude, A P; Nie, A X C; Fang, H P; Walet, N R; orcid: 0000-0002-2061-5534; Gao, Shiwu; email: email@example.com; Li, J C; email: firstname.lastname@example.org (IOP Publishing, 2018-08-16)Abstract: We analyse the enhanced flow rate of water through nano-fabricated graphene channels that has been recently observed experimentally. Using molecular dynamics simulations in channels of similar lateral dimensions as the experimental ones, our results reveal for the first time a relationship between water structure and the variation of flux in the rectangular graphene channels. The substantial enhancement in the flow rate compared to Poieseuille flow is due to the formation of layered 2D structures in the confined space, which persists up to a channel height of 2.38 nm, corresponding to six graphene layers. The structure of the water shows an intricate crystal of pentagonal and square tiles, which has not been observed before. Beyond six layers we find a sudden drop in flux due to the disordering of the water, which can be understood by classical flow dynamics.