We use asteroseismic data from the Kepler satellite to determine fundamental stellar properties of the 66 main-sequence targets observed for at least one full year by the mission. We distributed tens ...of individual oscillation frequencies extracted from the time series of each star among seven modeling teams who applied different methods to determine radii, masses, and ages for all stars in the sample. Comparisons among the different results reveal a good level of agreement in all stellar properties, which is remarkable considering the variety of codes, input physics, and analysis methods employed by the different teams. Average uncertainties are of the order of ∼2% in radius, ∼4% in mass, and ∼10% in age, making this the best-characterized sample of main-sequence stars available to date. Our predicted initial abundances and mixing-length parameters are checked against inferences from chemical enrichment laws ΔY/ΔZ and predictions from 3D atmospheric simulations. We test the accuracy of the determined stellar properties by comparing them to the Sun, angular diameter measurements, Gaia parallaxes, and binary evolution, finding excellent agreement in all cases and further confirming the robustness of asteroseismically determined physical parameters of stars when individual frequencies of oscillation are available. Baptised as the Kepler dwarfs LEGACY sample, these stars are the solar-like oscillators with the best asteroseismic properties available for at least another decade. All data used in this analysis and the resulting stellar parameters are made publicly available for the community.
Intense urbanisation in many coastal areas has led to intensification of groundwater consumption, while reducing permeable areas and increasing the frequency and magnitude of flooding. Among the ...potential strategies to compensate for these adverse effects, which are expected to become worse as a result of climate change, rooftop rainwater harvesting (RWH) in combination with managed aquifer recharge (MAR), may be indicated. This work investigated the performance of different configurations of such a system, tested as a twofold sustainable stormwater and domestic water management tool in a tropical metropole (João Pessoa, Brazil). This area located over a sedimentary aquifer system illustrates the water security challenges of densely urbanised areas in southern cities. To that end, several configurations of rooftop catchments and storage volumes were evaluated, by simulating a MAR-RWH system connected to the regional unconfined aquifer (Barreiras Formation) through a 6″ diameter injection well. Rainfall-runoff-recharge processes and water balances were simulated using monitored high-temporal resolution rainfall data. The results showed that catchments ranging from 180 to 810 m2, connected to tanks from 0.5 to 30.0 m³, are the optimal solutions in terms of efficient rainwater retention and peak flow reduction. These solutions provided mean annual estimates of aquifer recharge between 57 and 255 m³/yr from 2004 to 2019. The results of this study highlight the opportunity for MAR schemes to reconcile stormwater management and water supply goals.
•A sustainable stormwater and domestic water management tool was proposed.•RWH systems were simulated in combination with managed aquifer recharge (MAR-RWH).•Catchment area and storage volume were defined to minimise surface runoff.•The MAR-RWH systems can effectively reduce peak runoff after heavy rainfall events.•Mean annual recharge is adequate to use the stored water to meet domestic demands.
Although cosmic‐ray neutron sensing (CRNS) is probably the most promising noninvasive proximal soil moisture measurement technique at the field scale, its application for hydrological simulations ...remains underexplored in the literature so far. This study assessed the use of CRNS to inversely calibrate soil hydraulic parameters at the intermediate field scale to simulate the groundwater recharge rates at a daily timescale. The study was conducted for two contrasting hydrological years at the Guaraíra experimental basin, Brazil, a 5.84‐km², a tropical wet and rather flat landscape covered by secondary Atlantic forest. As a consequence of the low altitude and proximity to the equator low neutron count rates could be expected, reducing the precision of CRNS while constituting unexplored and challenging conditions for CRNS applications. Inverse calibration for groundwater recharge rates was used based on CRNS or point‐scale soil moisture data. The CRNS‐derived retention curve and saturated hydraulic conductivity were consistent with the literature and locally performed slug tests. Simulated groundwater recharge rates ranged from 60 to 470 mm yr–1, corresponding to 5 and 29% of rainfall, and correlated well with estimates based on water table fluctuations. In contrast, the estimated results based on inversive point‐scale datasets were not in alignment with measured water table fluctuations. The better performance of CRNS‐based estimations of field‐scale hydrological variables, especially groundwater recharge, demonstrated its clear advantages over traditional invasive point‐scale techniques. Finally, the study proved the ability of CRNS as practicable in low altitude, tropical wet areas, thus encouraging its adoption for water resources monitoring and management.
Core Ideas
Cosmic‐ray neutron sensing (CRNS) can detect field‐scale soil moisture also at low latitudes.
Soil hydraulic parameters were calibrated using CRNS and inverse simulations.
Daily groundwater recharge rates were simulated using CRNS‐based soil hydraulic parameters.
CRNS‐based recharge was matching independent area average recharge estimates.
The study of rainfall properties at various spatiotemporal scales is deeply important for understanding a large range of socio‐environmental processes and variables (e.g., water resources, ...agriculture, socio‐ecosystemic services, natural risk assessment). However, such studies on rainfall characteristics, especially at sub‐hourly resolutions, are scarce in large areas of South America due to the lack of a high‐resolution temporal database. The Brazilian National Centre for Monitoring and Early Warning of Natural Disasters (CEMADEN) has gradually implemented, starting in 2013, a sub‐hourly monitoring network composed of approximately 3500 automated rain gauges distributed across Brazil, enabling access to new hydrological studies in this vast tropical country featuring a range of biomes. This study analysed the characteristics of rainfall events for the whole of Brazil on sub‐daily and sub‐hourly timescales, using 7 years of data (from 2014 to 2021) provided by CEMADEN. Rainfall events were defined by the minimum inter‐event time (MIT) and the minimum depth (1 mm). Seven MITs (30, 60, 120, 180, 360, 720, and 1440 min) were considered to evaluate the behaviour of rainfall event characteristics and their relationships. The Gaussian mixture model method was applied to identify regions with similar rainfall patterns according to the MIT. Six groups with homogeneous characteristics were identified, evidencing the climatic diversity of Brazil. The results show that the MIT strongly influences precipitation properties (especially the dry time and the number of events). The highest number of events occurred in the North‐east Coast region, which exceeded 200 events per year (MIT < 60 min), while the lowest number of events was observed in the Semiarid region, which reached only 38 events per year with an MIT of 1440 min. Moreover, the events with the highest rainfall intensities were found in the Central region. The results found in this study provide a better understanding of precipitation and its characteristics in Brazil, highlighting the climatological diversity of this country.
Evaluates the characteristics of sub‐daily precipitation in Brazil.
MIT criteria and minimum depth were used to define independent events.
Six precipitation groups with homogeneous characteristics were identified in Brazil.
Semi-arid regions often face severe drought events that reduce agricultural and livestock production. In recent years, some international studies have used multicriteria decision analysis (MCDA) ...approaches combined with geographic information systems (GIS-MCDA) to support decision-makers in assessing the suitability of agricultural land for irrigation in semi-arid regions. Unlike previous studies, which have only considered a single source of water for crop irrigation, this study proposes a GIS-MCDA approach that considers all potentially available local water sources (e.g., groundwater, surface water, and wastewater) as possible alternatives for better multisource water resource management (MWRM) in regions facing water shortages. The geospatial multicriteria evaluation implemented in this study considers a series of technical, environmental, and agricultural productivity criteria using the analytical hierarchy process (AHP) method. Three independent baseline maps were generated, showing the spatial distribution of suitable areas for crop irrigation for each considered water source in the studied area. Surface water, groundwater, and wastewater offered suitable crop irrigation for 83%, 70%, and 26% of the study area, respectively. Overlapping these areas produced a final map showing all the feasible areas for each crop irrigation alternative at the same time. The MWRM approach considering all water sources increased the coverage of suitable areas to be irrigated in the study area by 2.2%, 20.4%, and more than 225% compared to considering surface water, groundwater, and wastewater, respectively, independently. The GIS-MCDA framework proposed in this study provides better support for decision-makers and stakeholders, favouring a reduction in possible conflicts over water scarcity, the diversification of irrigated crops, and an improvement in the quality-quantitative management of water resources in semi-arid regions.
•A GIS-MCDA approach to assess the suitability of agricultural lands for irrigation.•Three sources of water were considered in the approach for better water management.•Analysis of combined water resources increased the resulting areas suitable for irrigation.•The proposed analytical approach provides better support for irrigation in semi-arid regions.
Abstract
In order to clarify the properties of the secondary clump star HD 226808 (KIC 5307747), we combined four years of data from Kepler space photometry with high-resolution spectroscopy of the ...High Efficiency and Resolution Mercator Échelle Spectrograph mounted on the Mercator telescope. The fundamental atmospheric parameters, radial velocities, rotation velocities, and elemental abundance for Fe and Li were determined by analyzing line strengths and fitting-line profiles, based on a 1D local thermodynamic equilibrium model atmosphere. Second, we analyzed a photometric light curve obtained by Kepler and we extracted asteroseismic data of this target using Lets Analysis, Use and Report of Asteroseismology, a new seismic tool developed for the study of evolved FGK solar-like stars. We determined the evolutionary status and effective temperature, surface gravity, metallicity, microturbulence, and chemical abundances for Li, Ti, Fe, and Ni for HD 226808, by employing spectroscopy, asteroseismic scaling relations, and evolutionary structure models built in order to match observed data. Our results also show that an accurate synergy between good spectroscopic analysis and asteroseismology can provide a jump toward understanding evolved stars.
Recife Metropolitan Region (RMR, NE Brazil) lies over a multi-layered aquifer system located in an estuarial area. The region has experienced fast population growth and repeated droughts in the last ...three decades, which led to unprecedented anthropogenic pressure on groundwater resources because of intense water pumping. Accordingly, scientific and stakeholder communities have been challenged to ensure the maintenance of sustainable groundwater resource by managing all water cycle. Because controlling pumping rates is difficult due to the large number of illegal wells, the Managed Aquifer Recharge (MAR) strategies are now under consideration. The RMR presents a tropical climate and an annual average rainfall rate of approximately 2450 mm year−1, providing great potential volumes of water to be used for piezometric level recovery. However, MAR implementation requires a detailed and in-depth knowledge of the human-impact on the hydrogeological behavior of the resource over the long-term, in order to find out the most appropriate recharge strategy. Therefore, the present study illustrates how routine data monitoring, i.e., piezometric level and electrical conductivity (EC), in combination with the geological knowledge, may allow proposing further MAR strategies. Two contrasted behaviors were observed in RMR: (i) groundwater level decrease and stable EC in the North and Southernmost areas of Recife; and (ii) stable groundwater level and high/varying EC values next to the estuarial zone. Although aquifers are undergoing over-abstraction, this spatiotemporal heterogeneity suggests that a recharge is possibly locally favored next to the estuarial area of the RMR thanks to hydraulic connections between surface and deep aquifers throughout extended paleo-channels. Thus, based on this typology, MAR implementation through controlled infiltration close to the estuarial area seems to be more appropriated, whereas the direct deep injection appears to be more relevant in more distant zones.
Display omitted
•Routine monitoring data and geological knowledge may help the proposition of MAR.•MAR strategies were considered to be implemented in a coastal metropolis of Brazil.•Connections between surface and deep waters were observed through paleo-channels.•Controlled infiltration close to the estuarial area seems to be more appropriate.•Direct deep injection appears to be more relevant in zones distant from the estuary.
hydrological monitoring is essential for a proper decision-making process and modelling. Efforts have been made in Brazil to carry out field activities at the basin scale, but how complete and ...comprehensive are those studies? Where are they located? How long have they been carried out? What are the main findings? To answer these questions, an overview of experimental monitoring basins in Brazil is presented, listing their geographical locations, monitored variables, operational status, monitoring periods and main publications. We identified 60 monitored sites, spread across most Brazilian biomes, with an average monitoring period of 12 years. However, some publications from these monitoring studies are not fully accessible to the international community. Field hydrology activities in Brazil contribute to a better understanding of hydrological processes in humid and semi-arid regions and inform us about the impacts of land-use change on water quality and quantity.
Considering the great economic and environmental interests in the capture and separation of CO
2
and the wide availability of faujasites zeolites (FAU), we propose a set of parameters based on ...classical force fields that has good transferability among Na-FAU sieves and CO
2
. In addition to CO
2
, the parameterization strategy was tested for H
2
S, O
2
, N
2
and CH
4
gases. For these gases, the force field adequately predicts the adsorption isotherms at low pressure. The force field was also tested for N
2
in the FAU framework with different monovalent and divalent cations, resulting in quantitative agreement for monovalent cations and qualitative agreement for divalent cations. The good tradeoff between the reliability and ease of implementation will enable rapid evaluation of the adsorption properties of gaseous mixtures of industrial relevance. The reasoning of the re-parameterization strategy is also discussed in detail.
•This study evaluates the capability of IMERG in defining sub-daily rainfall events and their properties.•The MIT criterion was used to define the independent rainfall events determined by dry ...periods.•IMERG effectively captures the sub-daily rainfall depth for all MIT considered in this study.•Considerable errors of IMERG are evidenced for rainfall duration and intensity.
Sub-daily rainfall information is essential for many hydrological applications, but ground-based data availability is still an issue in poorly gauged regions worldwide. Satellite remote sensing missions, such as the Global Precipitation Measurement (GPM) mission, have been playing a key role in estimating sub-daily rainfall data globally. However, the quality of such information needs to be carefully evaluated. Previous studies evaluating sub-daily data from the Integrated multi-satellitE Retrievals for GPM (IMERG) product considered only the rainfall depth over pre-defined periods (e.g., hourly or half-hourly), with no analysis of the ability and quality of the product in defining the actual rainfall events and the associated properties. Thus, the objective of this study is to evaluate the performance of the IMERG Final Run Version 06B (V06B) product in capturing sub-daily rainfall events and their properties (depth, duration and intensity) over Brazil. The analysis consisted of comparing the satellite estimates against the ground-based data from 1757 sub-daily rainfall gauges for a period of three years (2015–2017). This study used the minimum inter-event time (MIT) criterion to define independent rainfall events determined by dry periods: 1, 6 and 24 h. Results show that IMERG can properly estimate the sub-daily rainfall depth for the three MITs considered, with the best results found in the southern part of the country. This means that the IMERG product represents a good source of sub-daily rainfall depth data for hydrological and hydroclimatic applications in Brazil. On the other hand, the evaluation shows large overestimations and underestimations of the IMERG product for rainfall duration and intensity properties, respectively. The results obtained from this study provide a reference for IMERG users who require sub-daily rainfall data based on events and further knowledge about its properties.
PDF
