Pub Date : 2024-03-13DOI: 10.1371/journal.pwat.0000184
Kelley Moyers, J. Abatzoglou, A. Escriva-Bou, J. Medellín-Azuara, J. Viers
California’s bountiful San Joaquin Valley (SJV), a critical region for global fruit and nut production, has withstood two severe, multi-year droughts in the past decade, exacerbated by record-breaking high temperature and evaporative demand. We employed climate data and crop coefficients to estimate the crop water demand in the SJV over the past forty years. Our approach, using crop coefficients for Penman-Montieth modeled evapotranspiration, focused on the climate effects on crop water demand, avoiding the confounding factors of changing land use and management practices that are present in actual evapotranspiration. We demonstrate that increases in crop water demand explain half of the cumulative deficits of the agricultural water balance since 1980, exacerbating water reliance on depleting groundwater supplies and fluctuating surface water imports. We call this phenomenon of climate-induced increased crop water demand an invisible water surcharge. We found that in the past decade, this invisible water surcharge on agriculture has increased the crop water demand in the SJV by 4.4% with respect to the 1980–2011 timeframe—more than 800 GL per year, a volume as large as a major reservoir in the SJV. Despite potential agronomic adaptation and crop response to climate warming, increased crop water demand adds a stressor to the sustainability of the global fruit and nut supply and calls for changes in management and policies to consider the shifting hydroclimate.
{"title":"An invisible water surcharge: Climate warming increases crop water demand in the San Joaquin Valley’s groundwater-dependent irrigated agriculture","authors":"Kelley Moyers, J. Abatzoglou, A. Escriva-Bou, J. Medellín-Azuara, J. Viers","doi":"10.1371/journal.pwat.0000184","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000184","url":null,"abstract":"California’s bountiful San Joaquin Valley (SJV), a critical region for global fruit and nut production, has withstood two severe, multi-year droughts in the past decade, exacerbated by record-breaking high temperature and evaporative demand. We employed climate data and crop coefficients to estimate the crop water demand in the SJV over the past forty years. Our approach, using crop coefficients for Penman-Montieth modeled evapotranspiration, focused on the climate effects on crop water demand, avoiding the confounding factors of changing land use and management practices that are present in actual evapotranspiration. We demonstrate that increases in crop water demand explain half of the cumulative deficits of the agricultural water balance since 1980, exacerbating water reliance on depleting groundwater supplies and fluctuating surface water imports. We call this phenomenon of climate-induced increased crop water demand an invisible water surcharge. We found that in the past decade, this invisible water surcharge on agriculture has increased the crop water demand in the SJV by 4.4% with respect to the 1980–2011 timeframe—more than 800 GL per year, a volume as large as a major reservoir in the SJV. Despite potential agronomic adaptation and crop response to climate warming, increased crop water demand adds a stressor to the sustainability of the global fruit and nut supply and calls for changes in management and policies to consider the shifting hydroclimate.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140245886","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 : 2024-03-06DOI: 10.1371/journal.pwat.0000210
B. Malla, Kazuki Yamamoto, Kotomi Furukawa, E. Haramoto
Microbial source tracking (MST) using host-specific Bacteroidales and mitochondrial DNA (mtDNA) markers is an efficient tool to identify the sources of fecal contamination in environmental water. This study evaluated and updated the previously reported performances of seven host-specific Bacteroidales markers (three human-, two cattle-, and two pig-specific). Additionally, the performance of a cattle-specific Bovine mtDNA and a pig-specific Swine mtDNA marker were evaluated and then applied to MST of river water samples collected in Yamanashi Prefecture, Japan. We collected 48 fecal-source samples, including raw sewage, secondary-treated sewage, an effluent of a domestic wastewater treatment tank, pig feces, pig wastewater, and cattle feces, which were quantitatively analyzed using host-specific Bacteroidales and mtDNA markers. BacHum and gyrB markers (human-specific), BacR and Bovine mtDNA markers (cattle-specific), and Pig2Bac and Swine mtDNA markers (pig-specific) were judged the best-performing markers. Then, these selected markers were applied to MST to identify the sources of fecal contamination in 59 river water samples collected at 21 sites. Of them, 20 (95%), 21 (100%), and 16 (76%) sites were positive for at least one human, cattle, and pig marker, respectively, indicating the need for immediate action and monitoring to control fecal pollution.
{"title":"Performance evaluation and application of host-specific Bacteroidales and mitochondrial DNA markers to identify sources of fecal contamination in river water in Japan","authors":"B. Malla, Kazuki Yamamoto, Kotomi Furukawa, E. Haramoto","doi":"10.1371/journal.pwat.0000210","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000210","url":null,"abstract":"Microbial source tracking (MST) using host-specific Bacteroidales and mitochondrial DNA (mtDNA) markers is an efficient tool to identify the sources of fecal contamination in environmental water. This study evaluated and updated the previously reported performances of seven host-specific Bacteroidales markers (three human-, two cattle-, and two pig-specific). Additionally, the performance of a cattle-specific Bovine mtDNA and a pig-specific Swine mtDNA marker were evaluated and then applied to MST of river water samples collected in Yamanashi Prefecture, Japan. We collected 48 fecal-source samples, including raw sewage, secondary-treated sewage, an effluent of a domestic wastewater treatment tank, pig feces, pig wastewater, and cattle feces, which were quantitatively analyzed using host-specific Bacteroidales and mtDNA markers. BacHum and gyrB markers (human-specific), BacR and Bovine mtDNA markers (cattle-specific), and Pig2Bac and Swine mtDNA markers (pig-specific) were judged the best-performing markers. Then, these selected markers were applied to MST to identify the sources of fecal contamination in 59 river water samples collected at 21 sites. Of them, 20 (95%), 21 (100%), and 16 (76%) sites were positive for at least one human, cattle, and pig marker, respectively, indicating the need for immediate action and monitoring to control fecal pollution.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"5 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140262329","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 : 2024-03-06DOI: 10.1371/journal.pwat.0000228
David A. Chin
Conventional designs of infiltration swales either neglect infiltration while the swale is filling or approximate the flow in the swale as being normal instead of gradually varied. The adequacy of these approximations are elucidated, and two common design configurations for infiltration swales are considered. For swales designed to store the water-quality volume behind check dams, the retained volume can be on the order of twice the design water-quality volume depending on the magnitude of the inflow rate normalized by the infiltration rate. In a second configuration, the swale is designed to infiltrate the water-quality flow, where the limiting assumption is that the flow is normal along the infiltration length. The actual required infiltration length can be expressed as a function of the normalized bottom width, and the required infiltration length can be up to 30% longer than derived using the conventional design. Graphical relations are developed that can be used to either quantify the factor of safety of conventional designs or provide credit for in the flood-control function of infiltration swales.
{"title":"Design of infiltration swales","authors":"David A. Chin","doi":"10.1371/journal.pwat.0000228","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000228","url":null,"abstract":"Conventional designs of infiltration swales either neglect infiltration while the swale is filling or approximate the flow in the swale as being normal instead of gradually varied. The adequacy of these approximations are elucidated, and two common design configurations for infiltration swales are considered. For swales designed to store the water-quality volume behind check dams, the retained volume can be on the order of twice the design water-quality volume depending on the magnitude of the inflow rate normalized by the infiltration rate. In a second configuration, the swale is designed to infiltrate the water-quality flow, where the limiting assumption is that the flow is normal along the infiltration length. The actual required infiltration length can be expressed as a function of the normalized bottom width, and the required infiltration length can be up to 30% longer than derived using the conventional design. Graphical relations are developed that can be used to either quantify the factor of safety of conventional designs or provide credit for in the flood-control function of infiltration swales.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"14 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140263088","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 : 2024-03-05DOI: 10.1371/journal.pwat.0000230
Claire McDonald, Kara Cunningham, Grace Kerr, Belle Lu, M. H. Tarek, Christopher Anderson, Emily Garner
Multiple threats to surface water quality, including both fecal pollution and acid mine drainage (AMD) are frequently coincident in mining regions, such as parts of the Appalachian region of the U.S. While it has been established that AMD can have toxic effects to fecal bacteria in surface waters, there is also evidence that AMD may induce a viable but non-culturable (VBNC) state, leaving fecal bacteria undetectable by common standard methods. This study aims to better understand the occurrence of VBNC Escherichia coli in mining-impacted waters (MIW) through three objectives: (1) assess the relationship between MIWs and concentrations of culturable fecal bacteria, (2) compare standard methods for quantification of E. coli in MIW, and (3) investigate whether MIW can induce a VBNC state in E. coli. An analysis of historic data from the Deckers Creek and West Run Watersheds of West Virginia revealed a moderate correlation between pH and E. coli abundance determined via culture and enzyme-based methods. In samples collected from sites within the two watersheds impacted by historic mining activities, the E. coli uidA gene was measured via quantitative polymerase chain reaction (qPCR) and found to be significantly more abundant than E. coli concentrations measured via culture or enzyme substrate coliform test. However, this discrepancy between methods was greatest in samples with a low pH. Further, experiments in which an environmental strain of E. coli was dosed into samples of MIW diluted with saline at different concentrations confirmed that the culturability of E. coli significantly decreased with increasing MIW concentration, while the total number of intact cells, determined via "live/dead” staining and microscopy, remained high. This finding suggests that culture and enzyme methods may underestimate viable E. coli levels in AMD-impacted waters.
{"title":"Assessing viability of Escherichia coli in mining-impacted surface waters","authors":"Claire McDonald, Kara Cunningham, Grace Kerr, Belle Lu, M. H. Tarek, Christopher Anderson, Emily Garner","doi":"10.1371/journal.pwat.0000230","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000230","url":null,"abstract":"Multiple threats to surface water quality, including both fecal pollution and acid mine drainage (AMD) are frequently coincident in mining regions, such as parts of the Appalachian region of the U.S. While it has been established that AMD can have toxic effects to fecal bacteria in surface waters, there is also evidence that AMD may induce a viable but non-culturable (VBNC) state, leaving fecal bacteria undetectable by common standard methods. This study aims to better understand the occurrence of VBNC Escherichia coli in mining-impacted waters (MIW) through three objectives: (1) assess the relationship between MIWs and concentrations of culturable fecal bacteria, (2) compare standard methods for quantification of E. coli in MIW, and (3) investigate whether MIW can induce a VBNC state in E. coli. An analysis of historic data from the Deckers Creek and West Run Watersheds of West Virginia revealed a moderate correlation between pH and E. coli abundance determined via culture and enzyme-based methods. In samples collected from sites within the two watersheds impacted by historic mining activities, the E. coli uidA gene was measured via quantitative polymerase chain reaction (qPCR) and found to be significantly more abundant than E. coli concentrations measured via culture or enzyme substrate coliform test. However, this discrepancy between methods was greatest in samples with a low pH. Further, experiments in which an environmental strain of E. coli was dosed into samples of MIW diluted with saline at different concentrations confirmed that the culturability of E. coli significantly decreased with increasing MIW concentration, while the total number of intact cells, determined via \"live/dead” staining and microscopy, remained high. This finding suggests that culture and enzyme methods may underestimate viable E. coli levels in AMD-impacted waters.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"110 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140079205","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 : 2024-03-05DOI: 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}