Pub Date : 2024-03-05DOI: 10.1371/journal.pwat.0000217
Lauren D’Mello-Guyett, Camille Heylen, Elsa Rohm, Jane Falconer, Jean Lapegue, R. Dreibelbis, Monica Ramos, Oliver Cumming, Daniele Lantagne
Water, sanitation and hygiene (WASH) interventions should provide access to safe water and sanitation, and promote good hygiene practices with dignity, comfort and security. Multiple systematic reviews have noted evidence gaps and is a paucity of good quality evidence related to the effectiveness and implementation of WASH programmes and interventions in humanitarian crises. The aim of this study was to generate consensus-based actionable research priorities for the humanitarian WASH sector. A research prioritisation exercise was conducted by adapting the Child Health and Nutrition Research Initiative (CHNRI) method. Research questions were compiled from a rapid scoping review, key informant interviews (KIIs) and focus group discussions (FGDs). Questions were reviewed by a technical expert group. An online survey was circulated to score research questions according to five criteria. An overall prioritisation score was calculated and weighted to prioritise questions. A diverse range of 286 global WASH and health experts engaged in the CHNRI process. A list of 128 questions were generated and scored by experts. Prioritised research questions focussed on evaluating existing interventions or programmes, and making iterative changes to current programmes. Other important questions centred on describing WASH conditions and associated health risks in crises contexts. Priorities were also stratified by gender, organisation and region to understand differences globally. The WASH in Crises Research Agenda has identified key research questions of most importance to those implementing WASH in humanitarian crises and has established a list of research priorities. The identified priorities reinforce how more evidence is needed, and underlines the need for research to evaluate current practices in order to improve the quality of humanitarian response. Stakeholders, including donors, international and national organisations, governments and academic institutions, are invited to use this research agenda to encourage, inspire and enable relevant and high-quality research that will be used to inform humanitarian responses.
{"title":"Research priorities for water, sanitation and hygiene (WASH) in humanitarian crises: A global prioritisation exercise","authors":"Lauren D’Mello-Guyett, Camille Heylen, Elsa Rohm, Jane Falconer, Jean Lapegue, R. Dreibelbis, Monica Ramos, Oliver Cumming, Daniele Lantagne","doi":"10.1371/journal.pwat.0000217","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000217","url":null,"abstract":"Water, sanitation and hygiene (WASH) interventions should provide access to safe water and sanitation, and promote good hygiene practices with dignity, comfort and security. Multiple systematic reviews have noted evidence gaps and is a paucity of good quality evidence related to the effectiveness and implementation of WASH programmes and interventions in humanitarian crises. The aim of this study was to generate consensus-based actionable research priorities for the humanitarian WASH sector. A research prioritisation exercise was conducted by adapting the Child Health and Nutrition Research Initiative (CHNRI) method. Research questions were compiled from a rapid scoping review, key informant interviews (KIIs) and focus group discussions (FGDs). Questions were reviewed by a technical expert group. An online survey was circulated to score research questions according to five criteria. An overall prioritisation score was calculated and weighted to prioritise questions. A diverse range of 286 global WASH and health experts engaged in the CHNRI process. A list of 128 questions were generated and scored by experts. Prioritised research questions focussed on evaluating existing interventions or programmes, and making iterative changes to current programmes. Other important questions centred on describing WASH conditions and associated health risks in crises contexts. Priorities were also stratified by gender, organisation and region to understand differences globally. The WASH in Crises Research Agenda has identified key research questions of most importance to those implementing WASH in humanitarian crises and has established a list of research priorities. The identified priorities reinforce how more evidence is needed, and underlines the need for research to evaluate current practices in order to improve the quality of humanitarian response. Stakeholders, including donors, international and national organisations, governments and academic institutions, are invited to use this research agenda to encourage, inspire and enable relevant and high-quality research that will be used to inform humanitarian responses.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"38 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140264762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04DOI: 10.1371/journal.pwat.0000227
J. Unrine, Nina McCoy, W. J. Christian, Yogesh Gautam, L. Ormsbee, Wayne Sanderson, Ricki Draper, Madison Mooney, Mary Cromer, Kelly Pennell, A. G. Hoover
To increase our understanding of the factors that influence formation of disinfection byproducts (DBPs) in rural drinking systems, we investigated the spatial and seasonal variation in trihalomethane (THM) and haloacetic acid (HAA) concentrations in relation to various chemical and physical variables in a rural public drinking water system in Martin County, Kentucky, USA. We collected drinking water samples from 97 individual homes over the course of one year and analyzed them for temperature, electrical conductivity, pH, free chlorine, total chlorine, THMs (chloroform, bromodichloromethane, dibromochloromethane, dichlorobromomethane, and bromoform) and HAAs (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, and dibromoacetic acid). Spatial autocorrelation analysis showed only weak overall clustering for HAA concentrations and none for THMs. The relationship between modeled water age and TTHM or HAA5 concentrations varied seasonally. In contrast, there was strong variation for both HAA and THMs, with concentrations of HAA peaking in mid-summer and THMs peaking in early fall. Multiple regression analysis revealed that THM concentrations were strongly correlated with conductivity, while HAA concentrations were more strongly correlated with water temperature. Individual DBP species that only contained chlorine halogen groups were strongly correlated with temperature, while compounds containing bromine were more strongly correlated with conductivity. Further investigation revealed that increased drinking water conductivity associated with low discharge of the Tug Fork River, the source water, is highly correlated with increased concentrations of bromide. Discharge and conductivity of the Tug Fork River changed dramatically through the year contributing to a seasonal peak in bromide concentrations in the late summer and early fall and appeared to be a driver of brominated THM concentrations. Brominated DBPs tend to have higher toxicity than DBPs containing only chlorine, therefore this study provides important insight into the seasonal factors driving risk from exposure to DBPs in rural drinking water systems impacted by bromide.
{"title":"Spatial and seasonal variation in disinfection byproducts concentrations in a rural public drinking water system: A case study of Martin County, Kentucky, USA","authors":"J. Unrine, Nina McCoy, W. J. Christian, Yogesh Gautam, L. Ormsbee, Wayne Sanderson, Ricki Draper, Madison Mooney, Mary Cromer, Kelly Pennell, A. G. Hoover","doi":"10.1371/journal.pwat.0000227","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000227","url":null,"abstract":"To increase our understanding of the factors that influence formation of disinfection byproducts (DBPs) in rural drinking systems, we investigated the spatial and seasonal variation in trihalomethane (THM) and haloacetic acid (HAA) concentrations in relation to various chemical and physical variables in a rural public drinking water system in Martin County, Kentucky, USA. We collected drinking water samples from 97 individual homes over the course of one year and analyzed them for temperature, electrical conductivity, pH, free chlorine, total chlorine, THMs (chloroform, bromodichloromethane, dibromochloromethane, dichlorobromomethane, and bromoform) and HAAs (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, and dibromoacetic acid). Spatial autocorrelation analysis showed only weak overall clustering for HAA concentrations and none for THMs. The relationship between modeled water age and TTHM or HAA5 concentrations varied seasonally. In contrast, there was strong variation for both HAA and THMs, with concentrations of HAA peaking in mid-summer and THMs peaking in early fall. Multiple regression analysis revealed that THM concentrations were strongly correlated with conductivity, while HAA concentrations were more strongly correlated with water temperature. Individual DBP species that only contained chlorine halogen groups were strongly correlated with temperature, while compounds containing bromine were more strongly correlated with conductivity. Further investigation revealed that increased drinking water conductivity associated with low discharge of the Tug Fork River, the source water, is highly correlated with increased concentrations of bromide. Discharge and conductivity of the Tug Fork River changed dramatically through the year contributing to a seasonal peak in bromide concentrations in the late summer and early fall and appeared to be a driver of brominated THM concentrations. Brominated DBPs tend to have higher toxicity than DBPs containing only chlorine, therefore this study provides important insight into the seasonal factors driving risk from exposure to DBPs in rural drinking water systems impacted by bromide.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"30 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140265911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-13DOI: 10.1371/journal.pwat.0000153
Zahirul Haque Khan, Md Saiful Islam, Shume Akhter, Md Raqubul Hasib, A. Sutradhar, J. Timsina, T. Krupnik, U. Schulthess
In Bangladesh’s south-central coastal zone, there is considerable potential to intensify crop production by growing dry winter season ‘Boro’ rice, maize, wheat, pulses and oilseeds using irrigation from southward flowing and predominantly freshwater rivers. However, the impacts of surface water withdrawal for sustained irrigation and its safe operating space remain unclear. We used field measurements and simulation modeling to investigate the effects of irrigation water withdrawal for Boro rice–the most water-consumptive crop–on river water flow and salinity under different climate change and river flow scenarios. Under the baseline conditions, about 250,000 ha could potentially be irrigated with river water that has salinity levels below 2 dS/m. The impact on river water salinity would be minimal, and only between 0.71 to 1.12% of the cropland would shift from the 0–2 dS/m class to higher salinity levels. Similarly, for the moderate climate change scenario (RCP 4.5) that forecasts a sea level rise of 22 cm in 2050, there would be a minor change in water flow and salinity. Only under the extreme climate change scenario (RCP 8.5), resulting in a sea level rise of 43 cm by 2050 and low flow conditions that are exceeded in 90% of the cases, the 2 dS/m isohaline would move landward by 64 to 105 km in March and April for the Tentulia and Buriswar Rivers. This would expose an additional 36.6% of potentially irrigable cropland to salinity levels of 2 to 4 dS/m. However, Boro rice will already be well established by that time and can tolerate greater levels of salinity. We conclude that there is considerable scope to expand irrigated crop production without negatively exposing the cropland and rivers to detrimental salinization levels while preserving the ecosystem services of the rivers.
{"title":"Can crop production intensification through irrigation be sustainable? An ex-ante impact study of the south-central coastal zone of Bangladesh","authors":"Zahirul Haque Khan, Md Saiful Islam, Shume Akhter, Md Raqubul Hasib, A. Sutradhar, J. Timsina, T. Krupnik, U. Schulthess","doi":"10.1371/journal.pwat.0000153","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000153","url":null,"abstract":"In Bangladesh’s south-central coastal zone, there is considerable potential to intensify crop production by growing dry winter season ‘Boro’ rice, maize, wheat, pulses and oilseeds using irrigation from southward flowing and predominantly freshwater rivers. However, the impacts of surface water withdrawal for sustained irrigation and its safe operating space remain unclear. We used field measurements and simulation modeling to investigate the effects of irrigation water withdrawal for Boro rice–the most water-consumptive crop–on river water flow and salinity under different climate change and river flow scenarios. Under the baseline conditions, about 250,000 ha could potentially be irrigated with river water that has salinity levels below 2 dS/m. The impact on river water salinity would be minimal, and only between 0.71 to 1.12% of the cropland would shift from the 0–2 dS/m class to higher salinity levels. Similarly, for the moderate climate change scenario (RCP 4.5) that forecasts a sea level rise of 22 cm in 2050, there would be a minor change in water flow and salinity. Only under the extreme climate change scenario (RCP 8.5), resulting in a sea level rise of 43 cm by 2050 and low flow conditions that are exceeded in 90% of the cases, the 2 dS/m isohaline would move landward by 64 to 105 km in March and April for the Tentulia and Buriswar Rivers. This would expose an additional 36.6% of potentially irrigable cropland to salinity levels of 2 to 4 dS/m. However, Boro rice will already be well established by that time and can tolerate greater levels of salinity. We conclude that there is considerable scope to expand irrigated crop production without negatively exposing the cropland and rivers to detrimental salinization levels while preserving the ecosystem services of the rivers.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"54 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139839822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-13DOI: 10.1371/journal.pwat.0000153
Zahirul Haque Khan, Md Saiful Islam, Shume Akhter, Md Raqubul Hasib, A. Sutradhar, J. Timsina, T. Krupnik, U. Schulthess
In Bangladesh’s south-central coastal zone, there is considerable potential to intensify crop production by growing dry winter season ‘Boro’ rice, maize, wheat, pulses and oilseeds using irrigation from southward flowing and predominantly freshwater rivers. However, the impacts of surface water withdrawal for sustained irrigation and its safe operating space remain unclear. We used field measurements and simulation modeling to investigate the effects of irrigation water withdrawal for Boro rice–the most water-consumptive crop–on river water flow and salinity under different climate change and river flow scenarios. Under the baseline conditions, about 250,000 ha could potentially be irrigated with river water that has salinity levels below 2 dS/m. The impact on river water salinity would be minimal, and only between 0.71 to 1.12% of the cropland would shift from the 0–2 dS/m class to higher salinity levels. Similarly, for the moderate climate change scenario (RCP 4.5) that forecasts a sea level rise of 22 cm in 2050, there would be a minor change in water flow and salinity. Only under the extreme climate change scenario (RCP 8.5), resulting in a sea level rise of 43 cm by 2050 and low flow conditions that are exceeded in 90% of the cases, the 2 dS/m isohaline would move landward by 64 to 105 km in March and April for the Tentulia and Buriswar Rivers. This would expose an additional 36.6% of potentially irrigable cropland to salinity levels of 2 to 4 dS/m. However, Boro rice will already be well established by that time and can tolerate greater levels of salinity. We conclude that there is considerable scope to expand irrigated crop production without negatively exposing the cropland and rivers to detrimental salinization levels while preserving the ecosystem services of the rivers.
{"title":"Can crop production intensification through irrigation be sustainable? An ex-ante impact study of the south-central coastal zone of Bangladesh","authors":"Zahirul Haque Khan, Md Saiful Islam, Shume Akhter, Md Raqubul Hasib, A. Sutradhar, J. Timsina, T. Krupnik, U. Schulthess","doi":"10.1371/journal.pwat.0000153","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000153","url":null,"abstract":"In Bangladesh’s south-central coastal zone, there is considerable potential to intensify crop production by growing dry winter season ‘Boro’ rice, maize, wheat, pulses and oilseeds using irrigation from southward flowing and predominantly freshwater rivers. However, the impacts of surface water withdrawal for sustained irrigation and its safe operating space remain unclear. We used field measurements and simulation modeling to investigate the effects of irrigation water withdrawal for Boro rice–the most water-consumptive crop–on river water flow and salinity under different climate change and river flow scenarios. Under the baseline conditions, about 250,000 ha could potentially be irrigated with river water that has salinity levels below 2 dS/m. The impact on river water salinity would be minimal, and only between 0.71 to 1.12% of the cropland would shift from the 0–2 dS/m class to higher salinity levels. Similarly, for the moderate climate change scenario (RCP 4.5) that forecasts a sea level rise of 22 cm in 2050, there would be a minor change in water flow and salinity. Only under the extreme climate change scenario (RCP 8.5), resulting in a sea level rise of 43 cm by 2050 and low flow conditions that are exceeded in 90% of the cases, the 2 dS/m isohaline would move landward by 64 to 105 km in March and April for the Tentulia and Buriswar Rivers. This would expose an additional 36.6% of potentially irrigable cropland to salinity levels of 2 to 4 dS/m. However, Boro rice will already be well established by that time and can tolerate greater levels of salinity. We conclude that there is considerable scope to expand irrigated crop production without negatively exposing the cropland and rivers to detrimental salinization levels while preserving the ecosystem services of the rivers.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"5 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139779795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-12DOI: 10.1371/journal.pwat.0000226
Francisco Rodrigues do Amaral, Thierry Pellarin, Tin Nguyen Trung, Tran Anh Tu, Nicolas Gratiot
The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.
{"title":"Enhancing discharge estimation from SWOT satellite data in a tropical tidal river environment","authors":"Francisco Rodrigues do Amaral, Thierry Pellarin, Tin Nguyen Trung, Tran Anh Tu, Nicolas Gratiot","doi":"10.1371/journal.pwat.0000226","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000226","url":null,"abstract":"The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"22 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139782117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-12DOI: 10.1371/journal.pwat.0000226
Francisco Rodrigues do Amaral, Thierry Pellarin, Tin Nguyen Trung, Tran Anh Tu, Nicolas Gratiot
The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.
{"title":"Enhancing discharge estimation from SWOT satellite data in a tropical tidal river environment","authors":"Francisco Rodrigues do Amaral, Thierry Pellarin, Tin Nguyen Trung, Tran Anh Tu, Nicolas Gratiot","doi":"10.1371/journal.pwat.0000226","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000226","url":null,"abstract":"The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"225 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139842106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1371/journal.pwat.0000181
Helen Y. Buse, Jatin H. Mistry
A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.
{"title":"Microbial and physicochemical water quality changes within distribution and premise plumbing systems during a chlorine conversion","authors":"Helen Y. Buse, Jatin H. Mistry","doi":"10.1371/journal.pwat.0000181","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000181","url":null,"abstract":"A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"85 2-3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139851329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1371/journal.pwat.0000181
Helen Y. Buse, Jatin H. Mistry
A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.
{"title":"Microbial and physicochemical water quality changes within distribution and premise plumbing systems during a chlorine conversion","authors":"Helen Y. Buse, Jatin H. Mistry","doi":"10.1371/journal.pwat.0000181","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000181","url":null,"abstract":"A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":" 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139791234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000125
Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña
Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.
{"title":"The invisibility of health effects associated with water pollution within disease burden estimates: Analysis from a Colombian Andean watershed","authors":"Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña","doi":"10.1371/journal.pwat.0000125","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000125","url":null,"abstract":"Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"18 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139804988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000127
Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright
Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.
{"title":"Household, neighbourhood and service provider risk factors for piped drinking-water intermittency in urban and peri-urban Zambia: A cross-sectional analysis","authors":"Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright","doi":"10.1371/journal.pwat.0000127","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000127","url":null,"abstract":"Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"97 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139804553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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