cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7515776.v1
title: Coupling the atmospheric model RAMS 6.0 /ECHAM 4.1 to hydrologic model SMA/HMS for operating a reservoir in Brazil’s semiarid

description: ABSTRACT The planning and the efficiency of water resources are subject to the uncertainties of the input data of climate and hydrological models. Prediction of water inflow to reservoirs that would help decision making for the various water uses, contain uncertainties fundamentally the initial conditions assumed in the modeled processes. This paper evaluates the coupling of a regional atmospheric model with a hydrological model to make streamflow forecast for seasonal operation of Orós reservoir, Ceará State, Brazil. RAMS model, version 6.0, was forced by the ECHAM 4.5 atmospheric general circulation model over Alto Jaguaribe basin to obtain the rainfall data. To remove biases in the simulated precipitation fields was applied the probability density function (PDF) correction on them. Then the corrected precipitation data were inserted in the hydrologic Soil Moisture Account (SMA) model from the Hydrologic Modeling System (HEC-HMS). For SMA calibration, it was used the Nash-Sutcliffe objective function. Finally, decisions to water release from the Orós were evaluated using the Heidke Skill Score (HSS). The SMA model showed a satisfactory performance with Nash-Sutcliffe values of 0.92 (0.87) in the calibration (validation) phase, indicating that it is a rainfall runoff model alternative. For decisions in releasing water from the Orós reservoir, using climate predictions, obtained HSS = 0.43. The results show that the simulated rainfall coupled with a hydrological model is able to represent the hydrological operation of Brazilian semiarid reservoir.
DOI: 10.6084/m9.figshare.7509284
title: Cost-benefit analysis of reservoir operation scenarios considering environmental flows for the lower stretch of the São Francisco River (Brazil)

description: ABSTRACT Environmental water allocation consists in considering the environment as a licit user of water. The importance of meeting the environment’s hydric necessities to assure ecosystem protection is recognized worldwide, however their practical implementation is restricted, requiring impact assessment of the implementation towards the other water users. In this context, this article aims to evaluate the financial impacts on the hydroelectric sector considering environmental flows as reservoir release restrictions. The case study is the lower course of the São Francisco River, a region that presents a strong social and environmental degradation of great importance for Brazilian energy system. The method used to achieve this goal contemplates the construction of reservoir operation scenarios, the mathematical modeling of the water system and the cost-benefit analysis for the energy sector. The simulation points out potential conflicts between the non-consumptive uses. Assessing the cost-benefit analyses for normal and dry periods, it turns out that the first leads to total financial losses for the energy sector, while the second to payoffs, enabling agreements between Brazil’s energy generation and the implementation of environmental flows in the lower stretch of the São Francisco River.
DOI: 10.6084/m9.figshare.7509284.v1
title: Cost-benefit analysis of reservoir operation scenarios considering environmental flows for the lower stretch of the São Francisco River (Brazil)

description: ABSTRACT Environmental water allocation consists in considering the environment as a licit user of water. The importance of meeting the environment’s hydric necessities to assure ecosystem protection is recognized worldwide, however their practical implementation is restricted, requiring impact assessment of the implementation towards the other water users. In this context, this article aims to evaluate the financial impacts on the hydroelectric sector considering environmental flows as reservoir release restrictions. The case study is the lower course of the São Francisco River, a region that presents a strong social and environmental degradation of great importance for Brazilian energy system. The method used to achieve this goal contemplates the construction of reservoir operation scenarios, the mathematical modeling of the water system and the cost-benefit analysis for the energy sector. The simulation points out potential conflicts between the non-consumptive uses. Assessing the cost-benefit analyses for normal and dry periods, it turns out that the first leads to total financial losses for the energy sector, while the second to payoffs, enabling agreements between Brazil’s energy generation and the implementation of environmental flows in the lower stretch of the São Francisco River.
DOI: 10.6084/m9.figshare.7509554
title: Simulation of land use scenarios in the Camboriú River Basin using the SWAT model

description: ABSTRACT Changes in the Earth’s landscape have been the focus of much environmental research. In this context, hydrological models stand out as tools for several assessments. This study aimed to use the Soil and Water Assessment Tool (SWAT) hydrological model to simulate the impact of changes in land use in the Camboriú River Watershed in the years 1957, 1978, and 2012. The results indicated that the SWAT model was efficient in simulating water flow and sediment transport processes. Thus, it was possible to evaluate the impact of different land use scenarios on water and sediment yield in the catchment. The changes in land use caused significant changes in the hydro-sedimentological dynamic. Regarding flow, the effects of land use changes were more pronounced at both ends of the curve representing duration of flow. The worst scenario was identified for the year 2012, which saw the highest peak discharges during flood events and lowest flows during the dry season. Concerning soil erosion, the highest values were identified for sub-basins that were predominantly covered by rice paddies and pastures; this was attributed mainly to surface runoff and changes in land use (represented by C-USLE). Overall, the Camboriú River Basin did not experience severe soil erosion issues; however, it was found that changes in land use related to soil and climate characteristics may increase soil degradation, especially in years with high precipitation levels.
DOI: 10.6084/m9.figshare.7509554.v1
title: Simulation of land use scenarios in the Camboriú River Basin using the SWAT model

description: ABSTRACT Changes in the Earth’s landscape have been the focus of much environmental research. In this context, hydrological models stand out as tools for several assessments. This study aimed to use the Soil and Water Assessment Tool (SWAT) hydrological model to simulate the impact of changes in land use in the Camboriú River Watershed in the years 1957, 1978, and 2012. The results indicated that the SWAT model was efficient in simulating water flow and sediment transport processes. Thus, it was possible to evaluate the impact of different land use scenarios on water and sediment yield in the catchment. The changes in land use caused significant changes in the hydro-sedimentological dynamic. Regarding flow, the effects of land use changes were more pronounced at both ends of the curve representing duration of flow. The worst scenario was identified for the year 2012, which saw the highest peak discharges during flood events and lowest flows during the dry season. Concerning soil erosion, the highest values were identified for sub-basins that were predominantly covered by rice paddies and pastures; this was attributed mainly to surface runoff and changes in land use (represented by C-USLE). Overall, the Camboriú River Basin did not experience severe soil erosion issues; however, it was found that changes in land use related to soil and climate characteristics may increase soil degradation, especially in years with high precipitation levels.
DOI: 10.6084/m9.figshare.7509305
title: Impact of soil moisture over Palmer Drought Severity Index and its future projections in Brazil

description: ABSTRACT Soil moisture is a main factor for the study of drought impacts on vegetation. Drought is a regional phenomenon and affects the food security more than any other natural disaster. Currently, the monitoring of different types of drought is based on indexes that standardize in temporal and regional level allowing, thus, comparison of water conditions in different areas. Therefore, in order to assess the impact of soil moisture during periods of drought, drought Palmer Severity Index was estimated for the entire region of the territory. For this were used meteorological data (rainfall and evapotranspiration) and soil (field capacity, permanent wilting point and water storage in the soil). The data field capacity and wilting point were obtained from the physical properties of soil; while the water storage in soil was calculated considering the water balance model. The results of the PSDI were evaluated during the years 2000 to 2015, which correspond to periods with and without occurrence of drought. In order to assess the future drought projections, considering the set of the Coupled Model Intercomparison rainfall data Project Phase 5 (CMIP5). Climate projections precipitation in CMIP5 for the period 2071-2100 was extracted generating entitled forcing scenarios Representative Concentration Pathways - RCPs, and referred to as RCOP 8.5, corresponding to an approximate radiative forcing the end the twenty-first century of 8.5 Wm-2. The results showed that the PDSI is directly associated with climatological patterns of precipitation and soil moisture in any spatial and temporal scale (including future projections). Therefore, it is concluded that the PDSI is an important index to assess soil moisture different water conditions, as well as the association with economic and social information to create risk maps for subsidies to decision makers.
DOI: 10.6084/m9.figshare.7509305.v1
title: Impact of soil moisture over Palmer Drought Severity Index and its future projections in Brazil

description: ABSTRACT Soil moisture is a main factor for the study of drought impacts on vegetation. Drought is a regional phenomenon and affects the food security more than any other natural disaster. Currently, the monitoring of different types of drought is based on indexes that standardize in temporal and regional level allowing, thus, comparison of water conditions in different areas. Therefore, in order to assess the impact of soil moisture during periods of drought, drought Palmer Severity Index was estimated for the entire region of the territory. For this were used meteorological data (rainfall and evapotranspiration) and soil (field capacity, permanent wilting point and water storage in the soil). The data field capacity and wilting point were obtained from the physical properties of soil; while the water storage in soil was calculated considering the water balance model. The results of the PSDI were evaluated during the years 2000 to 2015, which correspond to periods with and without occurrence of drought. In order to assess the future drought projections, considering the set of the Coupled Model Intercomparison rainfall data Project Phase 5 (CMIP5). Climate projections precipitation in CMIP5 for the period 2071-2100 was extracted generating entitled forcing scenarios Representative Concentration Pathways - RCPs, and referred to as RCOP 8.5, corresponding to an approximate radiative forcing the end the twenty-first century of 8.5 Wm-2. The results showed that the PDSI is directly associated with climatological patterns of precipitation and soil moisture in any spatial and temporal scale (including future projections). Therefore, it is concluded that the PDSI is an important index to assess soil moisture different water conditions, as well as the association with economic and social information to create risk maps for subsidies to decision makers.
DOI: 10.6084/m9.figshare.7509308
title: Multi-variable SWAT model calibration with remotely sensed evapotranspiration and observed flow

description: ABSTRACT Although intrinsic, uncertainty for hydrological model estimation is not always reported. The aim of this study is to evaluate the use of satellite-based evapotranspiration on SWAT model calibration, regarding uncertainty and model performance in streamflow simulation. The SWAT model was calibrated in a monthly step and validated in monthly (streamflow and evapotranspiration) and daily steps (streamflow only). The validation and calibration period covers the years from 2006 to 2009 and the study area is the upper Negro river basin, situated in Santa Catarina and Paraná. SWAT-CUP was used to calibrate and validate the model, using SUFI-2 with KGE (Kling-Gupta Efficiency) as objective function. Different calibration strategies were evaluated, considering single-variable and multi-variable calibration, using streamflow and evapotranspiration. Compared to conventional single-variable calibration (streamflow only), multi-variable calibration (streamflow and evapotranspiration, simultaneously) produce better streamflow performance, especially for low flow periods and daily step validation. Despite that, no evidence of reduction of streamflow prediction uncertainty was observed. SWAT model calibration using solely evapotranspiration still requires further studies.
DOI: 10.6084/m9.figshare.7509308.v1
title: Multi-variable SWAT model calibration with remotely sensed evapotranspiration and observed flow

description: ABSTRACT Although intrinsic, uncertainty for hydrological model estimation is not always reported. The aim of this study is to evaluate the use of satellite-based evapotranspiration on SWAT model calibration, regarding uncertainty and model performance in streamflow simulation. The SWAT model was calibrated in a monthly step and validated in monthly (streamflow and evapotranspiration) and daily steps (streamflow only). The validation and calibration period covers the years from 2006 to 2009 and the study area is the upper Negro river basin, situated in Santa Catarina and Paraná. SWAT-CUP was used to calibrate and validate the model, using SUFI-2 with KGE (Kling-Gupta Efficiency) as objective function. Different calibration strategies were evaluated, considering single-variable and multi-variable calibration, using streamflow and evapotranspiration. Compared to conventional single-variable calibration (streamflow only), multi-variable calibration (streamflow and evapotranspiration, simultaneously) produce better streamflow performance, especially for low flow periods and daily step validation. Despite that, no evidence of reduction of streamflow prediction uncertainty was observed. SWAT model calibration using solely evapotranspiration still requires further studies.
DOI: 10.6084/m9.figshare.7511372
title: Monthly streamflow forecast for National Interconnected System (NIS) using Periodic Auto-regressive Endogenous Models (PAR) and Exogenous (PARX) with climate information

description: ABSTRACT This study aims to find a seasonal streamflow forecast model simultaneous to all stations of SIN using periodic autoregressive models with exogenous variables (PARX) using climate indexes. Comparing the results from PAR and PARX Models, this research analyzes the impact on forecasts by using climate information. The proposed models for streamflow forecast has been carried out using natural streamflow data from Operador Nacional do Sistema (ONS) and statistical techniques (such as multiple linear regression and stepwise method to choose explanatory variables). On 27 climate indexes utilized, 4 of them are suggested in this work. The performance analysis methodology is based on the ELECTRE method further the NASH coefficient, the mean absolute percentage error, the multi-criteria distance and correlation. Forecasts with one month lead, the PAR models present better results for most stations of SIN within seasons DJF, MAM, and JJA, while for SON season there is greater efficiency from PARX model. This kind of model shows better performance during dry season in the basins at Northern Brazil – Amazonas and Araguaia-Tocantins; Central-Eastern Brazil – Eastern Atlantic and the most rivers located in the Paraná basin.
DOI: 10.6084/m9.figshare.7509278
title: Water permit integration in the Paraguaçu River Watershed (Bahia)

description: ABSTRACT In Brazil, water regulatory agencies adopt two different methodologies of equating water balance for the purposes of water permits: one that considers the uses for surface water withdrawal and waste water discharge in an integrated way, and one that analyses these two uses as demands that do not relate with each other. In the state of Bahia, this analysis disregards the integration of quantitative and qualitative uses. Furthermore, at the moment, there are not internal procedures that enable the integration of the water permit with other water resources management instruments. In this context, the aim of this work consists of analysing the advantages and limitations of the implementation of the equating methodology that integrates the quali-quantitative analysis of the water balance for purposes of water permit, compared with current procedures in the state of Bahia. For this analysis, a diagnosis of use of the Paraguaçu River Watershed (BHRP) was developed through the Water Balance Control System (SCBH), simulating the two methodologies and comparing potential water use index. The results reinforce that the methodology of equating the quali-quantitative water balance does not represent an advance for water resources management when the other instruments, present in the State Water Resources Policy, are not integrated with the water permit.
DOI: 10.6084/m9.figshare.7509278.v1
title: Water permit integration in the Paraguaçu River Watershed (Bahia)

description: ABSTRACT In Brazil, water regulatory agencies adopt two different methodologies of equating water balance for the purposes of water permits: one that considers the uses for surface water withdrawal and waste water discharge in an integrated way, and one that analyses these two uses as demands that do not relate with each other. In the state of Bahia, this analysis disregards the integration of quantitative and qualitative uses. Furthermore, at the moment, there are not internal procedures that enable the integration of the water permit with other water resources management instruments. In this context, the aim of this work consists of analysing the advantages and limitations of the implementation of the equating methodology that integrates the quali-quantitative analysis of the water balance for purposes of water permit, compared with current procedures in the state of Bahia. For this analysis, a diagnosis of use of the Paraguaçu River Watershed (BHRP) was developed through the Water Balance Control System (SCBH), simulating the two methodologies and comparing potential water use index. The results reinforce that the methodology of equating the quali-quantitative water balance does not represent an advance for water resources management when the other instruments, present in the State Water Resources Policy, are not integrated with the water permit.
DOI: 10.6084/m9.figshare.7510970
title: Longitudinal distribution of extreme pressures in a hydraulic jump downstream of a stepped spillway

description: ABSTRACT The overflow system of a dam safely controls the water level of a reservoir. The design of these structures should predict the damage caused by the action of the turbulent flow to which they are subject to. The combination formed by a stepped spillway followed by a stilling basin promotes a considerable portion of the energy dissipation in the actual chute of the stepped spillway but it is not sufficient to completely avoid the risk of damaging the basin. In this paper, we analyze the longitudinal distribution of extreme pressures in a stilling basin downstream of a stepped spillway. The study was based on the instant pressure data from the tests carried out in a physical model in the Laboratório de Obras Hidráulicas in IPH/UFRGS. Thus, it was found that the pressure behavior is similar to that observed in studies involving smooth chute spillways, except in the area surrounding the base of the stepped spillway, where high pressure fluctuations may occur. This happens as a result of the impact caused by the flow in the dissipation structure, which is not observed downstream of smooth chute spillways due to the existence of a vertical concordance curve between the spillway and the stilling basin.
DOI: 10.6084/m9.figshare.7510970.v1
title: Longitudinal distribution of extreme pressures in a hydraulic jump downstream of a stepped spillway

description: ABSTRACT The overflow system of a dam safely controls the water level of a reservoir. The design of these structures should predict the damage caused by the action of the turbulent flow to which they are subject to. The combination formed by a stepped spillway followed by a stilling basin promotes a considerable portion of the energy dissipation in the actual chute of the stepped spillway but it is not sufficient to completely avoid the risk of damaging the basin. In this paper, we analyze the longitudinal distribution of extreme pressures in a stilling basin downstream of a stepped spillway. The study was based on the instant pressure data from the tests carried out in a physical model in the Laboratório de Obras Hidráulicas in IPH/UFRGS. Thus, it was found that the pressure behavior is similar to that observed in studies involving smooth chute spillways, except in the area surrounding the base of the stepped spillway, where high pressure fluctuations may occur. This happens as a result of the impact caused by the flow in the dissipation structure, which is not observed downstream of smooth chute spillways due to the existence of a vertical concordance curve between the spillway and the stilling basin.
DOI: 10.6084/m9.figshare.7509269
title: Assessment of water-saving equipment to support the urban management of water

description: ABSTRACT The objective of this study was to analyze the environmental and economic impacts of the implementation of water-saving equipment in residences in the municipality of Caruaru-PE as a measure of water conservation and mitigation of the drought effects that have been devastating the region along the past five years. For this purpose, eight neighborhoods were selected and their populations were estimated along the years of 2015 and 2035. Subsequently, the water consumption per capita, water volumes consumed with the use of conventional sanitary equipment and with the use of water-saving equipment were calculated, obtaining the volume of water saved. For the estimates of cost for the services and material required for the installation of water-saving equipment, tables of price compositions for budgets were consulted and adapted. The results demonstrated that it is possible to save up to 40% of consumed water only with the implementation of water-saving equipment, with a mean return time of six and a half years. Therefore, it is possible to understand that the use of water-saving equipment represents an important instrument of water management.