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The monitoring of surface-water quality followed by water-quality modeling and analysis are essential for generating effective strategies in surface-water-resource management. However, worldwide, particularly in developing countries, water-quality studies are limited due to the lack of a complete and reliable dataset of surface-water-quality variables. In this context, several statistical and machine-learning models were assessed for imputing water-quality data at six monitoring stations located in the Santa Lucía Chico river (Uruguay), a mixed lotic and lentic river system. The challenge of this study is represented by the high percentage of missing data (between 50% and 70%) and the high temporal and spatial variability that characterizes the water-quality variables. The competing algorithms implement univariate and multivariate imputation methods (inverse distance weighting (IDW), Random Forest Regressor (RFR), Ridge (R), Bayesian Ridge (BR), AdaBoost (AB), Hubber Regressor (HR), Support Vector Regressor (SVR) and K-nearest neighbors Regressor (KNNR)). According to the results, more than 76% of the imputation outcomes are considered “satisfactory” (NSE > 0.45). The imputation performance shows better results at the monitoring stations located inside the reservoir than those positioned along the mainstream. IDW was the model with the best imputation results, followed by RFR, HR and SVR. The approach proposed in this study is expected to aid water-resource researchers and managers in augmenting water-quality datasets and overcoming the missing data issue to increase the number of future studies related to the water-quality matter.
Rafael Rodríguez; Marcos Pastorini; Lorena Etcheverry; Christian Chreties; Mónica Fossati; Alberto Castro; Angela Gorgoglione. Water-Quality Data Imputation with a High Percentage of Missing Values: A Machine Learning Approach. Sustainability 2021, 13, 6318 .
AMA StyleRafael Rodríguez, Marcos Pastorini, Lorena Etcheverry, Christian Chreties, Mónica Fossati, Alberto Castro, Angela Gorgoglione. Water-Quality Data Imputation with a High Percentage of Missing Values: A Machine Learning Approach. Sustainability. 2021; 13 (11):6318.
Chicago/Turabian StyleRafael Rodríguez; Marcos Pastorini; Lorena Etcheverry; Christian Chreties; Mónica Fossati; Alberto Castro; Angela Gorgoglione. 2021. "Water-Quality Data Imputation with a High Percentage of Missing Values: A Machine Learning Approach." Sustainability 13, no. 11: 6318.
Land use/land cover is one of the critical factors that affects surface-water quality at catchment scale. Effective mitigation strategies require an in-depth understanding of the leading causes of water pollution to improve community well-being and ecosystem health. The main aim of this study is to assess the relationship between land use/land cover and biophysical and chemical water-quality parameters in the Santa Lucía catchment (Uruguay, South America). The Santa Lucía river is the primary potable source of the country and, in the last few years, has had eutrophication issues. Several multivariate statistical analyses were adopted to accomplish the specific objectives of this study. The principal component analysis (PCA), coupled with k-means cluster analysis (CA), helped to identify a seasonal variation (fall/winter and spring/summer) of the water quality. The hierarchical cluster analysis (HCA) allowed one to classify the water-quality monitoring stations in three groups in the fall/winter season. The factor analysis (FA) with a rotation of the axis (varimax) was adopted to identify the most significant water-quality variables of the system (turbidity and flow). Finally, another PCA was run to link water-quality variables to the dominant land uses of the watershed. Strong correlations between TP and agriculture-land use, TP and livestock farming, NT and urban areas arose. It was found that these multivariate exploratory tools can provide a proper overview of the water-quality behavior in space and time and the correlations between water-quality variables and land use.
Angela Gorgoglione; Javier Gregorio; Agustín Ríos; Jimena Alonso; Christian Chreties; Mónica Fossati. Influence of Land Use/Land Cover on Surface-Water Quality of Santa Lucía River, Uruguay. Sustainability 2020, 12, 4692 .
AMA StyleAngela Gorgoglione, Javier Gregorio, Agustín Ríos, Jimena Alonso, Christian Chreties, Mónica Fossati. Influence of Land Use/Land Cover on Surface-Water Quality of Santa Lucía River, Uruguay. Sustainability. 2020; 12 (11):4692.
Chicago/Turabian StyleAngela Gorgoglione; Javier Gregorio; Agustín Ríos; Jimena Alonso; Christian Chreties; Mónica Fossati. 2020. "Influence of Land Use/Land Cover on Surface-Water Quality of Santa Lucía River, Uruguay." Sustainability 12, no. 11: 4692.
Regionalization techniques have been comprehensively discussed as the solution for runoff predictions in ungauged basins (PUB). Several types of regionalization approach have been proposed during the years. Among these, the physical similarity one was demonstrated to be one of the most robust. However, this method cannot be applied in large regions characterized by highly variable climatic conditions, such as sub-tropical areas. Therefore, this study aims to develop a new regionalization approach based on an enhanced concept of physical similarity to improve the runoff prediction of ungauged basins at country scale, under highly variable-weather conditions. A clustering method assured that watersheds with different hydrologic and physical characteristics were considered. The novelty of the proposed approach is based on the relationships found between rainfall-runoff model parameters and watershed-physiographic factors. These relationships were successively exported and validated at the ungauged basins. From the overall results, it can be concluded that the runoff prediction in the ungauged basins was very satisfactory. Therefore, the proposed approach can be adopted as an alternative method for runoff prediction in ungauged basins characterized by highly variable-climatic conditions.
Santiago Narbondo; Angela Gorgoglione; Magdalena Crisci; Christian Chreties. Enhancing Physical Similarity Approach to Predict Runoff in Ungauged Watersheds in Sub-Tropical Regions. Water 2020, 12, 528 .
AMA StyleSantiago Narbondo, Angela Gorgoglione, Magdalena Crisci, Christian Chreties. Enhancing Physical Similarity Approach to Predict Runoff in Ungauged Watersheds in Sub-Tropical Regions. Water. 2020; 12 (2):528.
Chicago/Turabian StyleSantiago Narbondo; Angela Gorgoglione; Magdalena Crisci; Christian Chreties. 2020. "Enhancing Physical Similarity Approach to Predict Runoff in Ungauged Watersheds in Sub-Tropical Regions." Water 12, no. 2: 528.
The Data Scarcity problem is repeatedly encountered in environmental research. This may induce an inadequate representation of the response’s complexity in any environmental system to any input/change (natural and human-induced). In such a case, before getting engaged with new expensive studies to gather and analyze additional data, it is reasonable first to understand what enhancement in estimates of system performance would result if all the available data could be well exploited. The purpose of this Special Issue, “Overcoming Data Scarcity in Earth Science” in the Data journal, is to draw attention to the body of knowledge that leads at improving the capacity of exploiting the available data to better represent, understand, predict, and manage the behavior of environmental systems at meaningful space-time scales. This Special Issue contains six publications (three research articles, one review, and two data descriptors) covering a wide range of environmental fields: geophysics, meteorology/climatology, ecology, water quality, and hydrology.
Angela Gorgoglione; Alberto Castro; Christian Chreties; Lorena Etcheverry. Overcoming Data Scarcity in Earth Science. Data 2020, 5, 5 .
AMA StyleAngela Gorgoglione, Alberto Castro, Christian Chreties, Lorena Etcheverry. Overcoming Data Scarcity in Earth Science. Data. 2020; 5 (1):5.
Chicago/Turabian StyleAngela Gorgoglione; Alberto Castro; Christian Chreties; Lorena Etcheverry. 2020. "Overcoming Data Scarcity in Earth Science." Data 5, no. 1: 5.
One of the main causes of water conflicts in transboundary watersheds all over the world is represented by the increasing water demand due to urban, industrial, and agricultural development. In this context, water scarcity plays a critical role since, during a drought period, water supply is not sufficient to cover the demand of all water uses. In this work, we have conceptualized and developed a new scenario-based framework able to improve the sustainability and equity of water allocation among two or more riparian countries. The proposed approach is in accordance with the United Nations Watercourses Convention. It considers a hydraulic/hydrologic model, a water-management model, and combines them with multi-criteria decision analysis (MCDA) and what if scenario analysis (WISA). The suggested framework was applied to the transboundary watershed of Cuareim/Quaraí river (Uruguay/Brazil) to tackle a real water-sharing conflict. It resulted in being very flexible in exploring various policy options and test and quantifying them with different scenarios to reach an objective and impartial decision in a water-sharing issue. This framework can effectively be applied to any other transboundary watershed to resolve any possible conflict related to water-allocation/water-management matter.
Angela Gorgoglione; Magdalena Crisci; Rafael H. Kayser; Christian Chreties; Walter Collischonn. A New Scenario-Based Framework for Conflict Resolution in Water Allocation in Transboundary Watersheds. Water 2019, 11, 1174 .
AMA StyleAngela Gorgoglione, Magdalena Crisci, Rafael H. Kayser, Christian Chreties, Walter Collischonn. A New Scenario-Based Framework for Conflict Resolution in Water Allocation in Transboundary Watersheds. Water. 2019; 11 (6):1174.
Chicago/Turabian StyleAngela Gorgoglione; Magdalena Crisci; Rafael H. Kayser; Christian Chreties; Walter Collischonn. 2019. "A New Scenario-Based Framework for Conflict Resolution in Water Allocation in Transboundary Watersheds." Water 11, no. 6: 1174.
Nowadays no other region on earth is more threatened by natural hazards than coastal areas. However the increasing risk in this area is not just a climate extreme events’ result. Coasts are the places with highest concentration of people and values, thus impacts continue to increase as the values of coastal infrastructures continue to grow. Climate change aggravates chronic social vulnerabilities since social groups may be affected differently both by climate change as well as by risk management actions. Relationships between these groups are often characterized by inequality, with different perceptions, response, or adaptation modes to climate hazards. Misperception of these differences often leads to policies that deepen inequities and increase the vulnerability of the weakest groups. Population affected by climatic extreme events increases dramatically resulting in urgent adaptation intervention. We address the interdependence of risk perception and vulnerability of coastal communities and the relevance of ecosystem services for adaptation. We developed a methodology where risk analysis and communities’ risk perception are linked through key actions at strategic points of risk assessment: (i) initial interviews with qualified local informants to complete an inventory of ecosystem services, (ii) a social valuation of ecosystem services by local people, and (iii) assessment of stakeholders’ social vulnerability. This approach allows a truly socially weighted risk assessment to be validated in three sites: Valle de Itajai (Brazil), Estuary of Lagoa dos Patos (Brazil), and Laguna de Rocha (Uruguay). In this novel approach, risk assessment is forced by social perceptions, thus risk treatment can better contribute to realistic adaptation arrangements to cope with climate forces. Public policies could be improved, recognizing healthy functioning ecosystems as key factor for coastal resilience and well-being.
J. P. Lozoya; D. Conde; M. Asmus; M. Polette; C. Píriz; F. Martins; D. de Álava; R. Marenzi; M. Nin; L. Anello; A. Moraes; M. Zaguini; L. Marrero; N. Verrastro; X. Lagos; C. Chreties; L. Rodriguez. Linking Social Perceptionsocial perception and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America. Handbook of Climate Change Adaptation 2015, 373 -399.
AMA StyleJ. P. Lozoya, D. Conde, M. Asmus, M. Polette, C. Píriz, F. Martins, D. de Álava, R. Marenzi, M. Nin, L. Anello, A. Moraes, M. Zaguini, L. Marrero, N. Verrastro, X. Lagos, C. Chreties, L. Rodriguez. Linking Social Perceptionsocial perception and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America. Handbook of Climate Change Adaptation. 2015; ():373-399.
Chicago/Turabian StyleJ. P. Lozoya; D. Conde; M. Asmus; M. Polette; C. Píriz; F. Martins; D. de Álava; R. Marenzi; M. Nin; L. Anello; A. Moraes; M. Zaguini; L. Marrero; N. Verrastro; X. Lagos; C. Chreties; L. Rodriguez. 2015. "Linking Social Perceptionsocial perception and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America." Handbook of Climate Change Adaptation , no. : 373-399.
Joseph Onwona Ansong; Francisco Miranda Avalos; Alioune Ba; Juan Baztan; Anastasie Beye Mendy; Kenny Black; Anne Blanchard; Kieran Bowen; Scott Bremer; Ruth Brennan; Elisabetta Broglio; Ana Carrasco; H. Caymaris; Omer Chouinard; C. Chreties; Colleen Mercer Clarke; John D. Clarke; D. Conde; Elizabeth Cook; Loreta Cornacchia; Charlotte Da Cunha; Keith Davidson; D. De Álava; Raimonds Ernšteins; Awa Fall Niang; François Galgani; M. García-León; Joaquim Garrabou; Ndickou Gaye; Judith Gobin; Sathya Gopalakrishnan; V. Gràcia; Thierry Huck; Arnaud Huvet; Alejandro Iglesias-Campos; Bethany Jorgensen; Mélanie Jouitteau; Matthias Kaiser; Alioune Kane; Jānis Kauliņš; Andrew G. Keeler; X. Lagos; Craig E. Landry; Daniel E. Lane; Anita Lontone; Dylan McNamara; Andrus Meiner; Aquilino Miguelez; Laura J. Moore; A. Brad Murray; Michelle Mycoo; Sabine Pahl; D. Panario; Ika Paul-Pont; G. Piñeiro; Steve Plante; Grégory Quenet; Jacques Quensière; Tiavina Rivoarivola Rabeniaina; L. Rodriguez-Gallego; A. Sanchez-Arcilla; Aichetou Seck; L. Seijo; Martin D. Smith; S. Solari; Philippe Soudant; Céline Surette; Andrea Taramelli; L. Teixeira; Paul Tett; Diatou Thiaw; Richard Thompson; Mariano Gutiérrez Torero; Emiliana Valentini; Jean-Paul Vanderlinden; Liette Vasseur; N. Verrastro; J. Vitancurt; Sebastian Weissenberger; Ilga Zīlniece. Contributors. Coastal Zones 2015, 1 .
AMA StyleJoseph Onwona Ansong, Francisco Miranda Avalos, Alioune Ba, Juan Baztan, Anastasie Beye Mendy, Kenny Black, Anne Blanchard, Kieran Bowen, Scott Bremer, Ruth Brennan, Elisabetta Broglio, Ana Carrasco, H. Caymaris, Omer Chouinard, C. Chreties, Colleen Mercer Clarke, John D. Clarke, D. Conde, Elizabeth Cook, Loreta Cornacchia, Charlotte Da Cunha, Keith Davidson, D. De Álava, Raimonds Ernšteins, Awa Fall Niang, François Galgani, M. García-León, Joaquim Garrabou, Ndickou Gaye, Judith Gobin, Sathya Gopalakrishnan, V. Gràcia, Thierry Huck, Arnaud Huvet, Alejandro Iglesias-Campos, Bethany Jorgensen, Mélanie Jouitteau, Matthias Kaiser, Alioune Kane, Jānis Kauliņš, Andrew G. Keeler, X. Lagos, Craig E. Landry, Daniel E. Lane, Anita Lontone, Dylan McNamara, Andrus Meiner, Aquilino Miguelez, Laura J. Moore, A. Brad Murray, Michelle Mycoo, Sabine Pahl, D. Panario, Ika Paul-Pont, G. Piñeiro, Steve Plante, Grégory Quenet, Jacques Quensière, Tiavina Rivoarivola Rabeniaina, L. Rodriguez-Gallego, A. Sanchez-Arcilla, Aichetou Seck, L. Seijo, Martin D. Smith, S. Solari, Philippe Soudant, Céline Surette, Andrea Taramelli, L. Teixeira, Paul Tett, Diatou Thiaw, Richard Thompson, Mariano Gutiérrez Torero, Emiliana Valentini, Jean-Paul Vanderlinden, Liette Vasseur, N. Verrastro, J. Vitancurt, Sebastian Weissenberger, Ilga Zīlniece. Contributors. Coastal Zones. 2015; ():1.
Chicago/Turabian StyleJoseph Onwona Ansong; Francisco Miranda Avalos; Alioune Ba; Juan Baztan; Anastasie Beye Mendy; Kenny Black; Anne Blanchard; Kieran Bowen; Scott Bremer; Ruth Brennan; Elisabetta Broglio; Ana Carrasco; H. Caymaris; Omer Chouinard; C. Chreties; Colleen Mercer Clarke; John D. Clarke; D. Conde; Elizabeth Cook; Loreta Cornacchia; Charlotte Da Cunha; Keith Davidson; D. De Álava; Raimonds Ernšteins; Awa Fall Niang; François Galgani; M. García-León; Joaquim Garrabou; Ndickou Gaye; Judith Gobin; Sathya Gopalakrishnan; V. Gràcia; Thierry Huck; Arnaud Huvet; Alejandro Iglesias-Campos; Bethany Jorgensen; Mélanie Jouitteau; Matthias Kaiser; Alioune Kane; Jānis Kauliņš; Andrew G. Keeler; X. Lagos; Craig E. Landry; Daniel E. Lane; Anita Lontone; Dylan McNamara; Andrus Meiner; Aquilino Miguelez; Laura J. Moore; A. Brad Murray; Michelle Mycoo; Sabine Pahl; D. Panario; Ika Paul-Pont; G. Piñeiro; Steve Plante; Grégory Quenet; Jacques Quensière; Tiavina Rivoarivola Rabeniaina; L. Rodriguez-Gallego; A. Sanchez-Arcilla; Aichetou Seck; L. Seijo; Martin D. Smith; S. Solari; Philippe Soudant; Céline Surette; Andrea Taramelli; L. Teixeira; Paul Tett; Diatou Thiaw; Richard Thompson; Mariano Gutiérrez Torero; Emiliana Valentini; Jean-Paul Vanderlinden; Liette Vasseur; N. Verrastro; J. Vitancurt; Sebastian Weissenberger; Ilga Zīlniece. 2015. "Contributors." Coastal Zones , no. : 1.
Nowadays no other region on earth is more threatened by natural hazards than coastal areas. However the increasing risk in this area is not just a climate extreme events’ result. Coasts are the places with highest concentration of people and values, thus impacts continue to increase as the values of coastal infrastructures continue to grow. Climate change aggravates chronic social vulnerabilities since social groups may be affected differently both by climate change as well as by risk management actions. Relationships between these groups are often characterized by inequality, with different perceptions, response, or adaptation modes to climate hazards. Misperception of these differences often leads to policies that deepen inequities and increase the vulnerability of the weakest groups. Population affected by climatic extreme events increases dramatically resulting in urgent adaptation intervention. We address the interdependence of risk perception and vulnerability of coastal communities and the relevance of ecosystem services for adaptation. We developed a methodology where risk analysis and communities’ risk perception are linked through key actions at strategic points of risk assessment: (i) initial interviews with qualified local informants to complete an inventory of ecosystem services, (ii) a social valuation of ecosystem services by local people, and (iii) assessment of stakeholders’ social vulnerability. This approach allows a truly socially weighted risk assessment to be validated in three sites: Valle de Itajai (Brazil), Estuary of Lagoa dos Patos (Brazil), and Laguna de Rocha (Uruguay). In this novel approach, risk assessment is forced by social perceptions, thus risk treatment can better contribute to realistic adaptation arrangements to cope with climate forces. Public policies could be improved, recognizing healthy functioning ecosystems as key factor for coastal resilience and well-being.
J. P. Lozoya; D. Conde; M. Asmus; M. Polette; C. Píriz; F. Martins; D. de Álava; R. Marenzi; M. Nin; L. Anello; A. Moraes; M. Zaguini; L. Marrero; N. Verrastro; X. Lagos; C. Chreties; L. Rodriguez. Linking and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America. Handbook of Climate Change Adaptation 2014, 1 -22.
AMA StyleJ. P. Lozoya, D. Conde, M. Asmus, M. Polette, C. Píriz, F. Martins, D. de Álava, R. Marenzi, M. Nin, L. Anello, A. Moraes, M. Zaguini, L. Marrero, N. Verrastro, X. Lagos, C. Chreties, L. Rodriguez. Linking and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America. Handbook of Climate Change Adaptation. 2014; ():1-22.
Chicago/Turabian StyleJ. P. Lozoya; D. Conde; M. Asmus; M. Polette; C. Píriz; F. Martins; D. de Álava; R. Marenzi; M. Nin; L. Anello; A. Moraes; M. Zaguini; L. Marrero; N. Verrastro; X. Lagos; C. Chreties; L. Rodriguez. 2014. "Linking and Risk Analysis to Assess Vulnerability of Coastal Socio-ecological Systems to Climate Change in Atlantic South America." Handbook of Climate Change Adaptation , no. : 1-22.
C Chreties; S Solari; G Lopez; L Teixeira. Analysis of the Solís Chico river mouth migration. River Flow 2014 2014, 1331 -1336.
AMA StyleC Chreties, S Solari, G Lopez, L Teixeira. Analysis of the Solís Chico river mouth migration. River Flow 2014. 2014; ():1331-1336.
Chicago/Turabian StyleC Chreties; S Solari; G Lopez; L Teixeira. 2014. "Analysis of the Solís Chico river mouth migration." River Flow 2014 , no. : 1331-1336.
This work presents results on riprap sizing for pile group protection against local scour. Shear failure mechanism is addressed, avoiding edge, bed-form undermining, and winnowing modes. The influences of the flow conditions and the distance between the piles are analyzed. As a result of a laboratory experimental campaign, and within a detailed dimensional analysis framework, the writers propose expressions for riprap block size to resist shear failure. The influence of the distance between the piles on the block size is shown to be small, and the proposed expressions compare well to some of the literature expressions for single piers.
Gonzalo Simarro; Christian Chreties; Luis Teixeira. Riprap Sizing for Pile Groups. Journal of Hydraulic Engineering 2011, 137, 1676 -1679.
AMA StyleGonzalo Simarro, Christian Chreties, Luis Teixeira. Riprap Sizing for Pile Groups. Journal of Hydraulic Engineering. 2011; 137 (12):1676-1679.
Chicago/Turabian StyleGonzalo Simarro; Christian Chreties; Luis Teixeira. 2011. "Riprap Sizing for Pile Groups." Journal of Hydraulic Engineering 137, no. 12: 1676-1679.
A new methodology for the experimental analysis of the equilibrium scour depth at bridge piers is introduced and validated for clear-water conditions. The proposed experimental methodology determines the flow conditions for a given equilibrium scour instead of determining the equilibrium scour for given flow conditions, which is the usual practice. The basic hypothesis is that the shape of the scour hole is essentially related to the scour depth and sediment properties, but not to flow conditions. This hypothesis is checked experimentally. The proposed methodology may drastically reduce the time period required for experiments (from weeks to hours), and avoids the uncertainties due to the equilibrium scour being usually achieved asymptotically. Some preliminary results of the equilibrium scour obtained with the proposed methodology are compared to the expressions given in the literature, showing fair agreement.
Christian Chreties; Gonzalo Simarro; Luis Teixeira. New Experimental Method to Find Equilibrium Scour at Bridge Piers. Journal of Hydraulic Engineering 2008, 134, 1491 -1495.
AMA StyleChristian Chreties, Gonzalo Simarro, Luis Teixeira. New Experimental Method to Find Equilibrium Scour at Bridge Piers. Journal of Hydraulic Engineering. 2008; 134 (10):1491-1495.
Chicago/Turabian StyleChristian Chreties; Gonzalo Simarro; Luis Teixeira. 2008. "New Experimental Method to Find Equilibrium Scour at Bridge Piers." Journal of Hydraulic Engineering 134, no. 10: 1491-1495.