The potential of karst aquifers as a drinking water resource is substantial because of their large storage capacity gained in the course of carbonate dissolution. Carbonate dissolution and consequent ...development of preferential paths are also the reasons for the complex behavior of these aquifers as regards surface and underground flow. Hydrological modeling is therefore of paramount importance for an adequate assessment of flow components in catchments shaped on karsts. The cross tabulation of such components with geology, soils, and land use data in Geographic Information Systems helps decision makers to set up sustainable groundwater abstractions and allocate areas for storage of quality surface water, in the context of conjunctive water resources management. In the present study, a hydrologic modeling using the JAMS J2000 software was conducted in a karst area of Jequitiba River basin located near the Sete Lagoas town in the state of Minas Gerais, Brazil. The results revealed a very high surface water component explained by urbanization of Sete Lagoas, which hampers the recharge of 7.9 hm
yr
of storm water. They also exposed a very large negative difference (-8.3 hm
yr
) between groundwater availability (6.3 hm
yr
) and current groundwater abstraction from the karst aquifer (14.6 hm
yr
), which is in keeping with previously reported water table declines around drilled wells that can reach 48 m in old wells used for public water supply. Artificial recharge of excess surface flow is not recommended within the urban areas, given the high risk of groundwater contamination with metals and hydrocarbons potentially transported in storm water, as well as development of suffosional sinkholes as a consequence of concentrated storm flow. The surface component could however be stored in small dams in forested areas from the catchment headwaters and diverted to the urban area to complement the drinking water supply. The percolation in soil was estimated to be high in areas used for agriculture and pastures. The implementation of correct fertilizing, management, and irrigation practices are considered crucial to attenuate potential contamination of groundwater and suffosional sinkhole development in these areas.
Abstract
Despite the promise to increase control and fight against deforestation, the new Brazilian Forest Code (BFC) allowed more flexible dimensioning and land use rules in areas of private rural ...properties intended for native vegetation protection, namely the Legal Reserve (LR) and Areas of Permanent Preservation (APP). Following a decade of BFC implementation, the promise was somewhat flawed, while oversight and monitoring of private rural properties were not as expected. Considering this worrying scenario, the objective of this study was to quantify and map the forest balance of private rural properties listed in the Environmental Rural Registry of Rio das Velhas hydrographic basin (Minas Gerais, 2002), to assess compliance with the BCF and detect potentially illegal deforestation. The total deforested area in 6216 (28.7%) registered private rural properties reached approximately 119,800 ha after 2008, 61,500 ha of which were suppressed without surplus forest of LR. Besides, nearly half of the private rural properties presented forest deficits in the APPs. In a vast majority of cases, the deforestation was potentially illegal, but only a small number of private rural property owners was made responsible for that. The deforested areas were concentrated in small sectors within the rural properties, which would facilitate the control of illegal native vegetation suppression if oversight and law enforcement had been effective. Our results are an alert and a subside to public institutions and rural property owners while developing and executing plans, programs, and projects focused on environmental regularization of rural properties, with the ultimate goal of preventing further land degradation in the basin.
The zoning of groundwater recharge potential would be attractive for water managers, but is lacking in many regions around the planet, including in the Jequitiba River basin, Minas Gerais, Brazil. In ...this study, a physically based spatially distributed method to evaluate groundwater recharge potential at catchment scale was developed and tested in the aforementioned Jequitiba River basin. The data for the test was compiled from institutional sources and implemented in a Geographic Information System. It comprised meteorological, hydrometric, relief, land use, and soil data. The average results resembled the annual recharge calculated by a hydrograph method, which worked as validation method. The spatial variation of recharge highlighted the predominant contribution of flat areas, porous aquifers, and forested regions to groundwater recharge. They also exposed the negative effect of urbanization. In combination, these factors elected the following sectors of the Jequitiba River basin as regions of high recharge potential: the south-southeast part of the headwaters in Prudente de Morais; Sete Lagoas towards the central part of the basin; and the region between Funilândia and Jequitiba, near the Jequitiba river mouth. Some management practices were suggested to improve groundwater recharge. The map of groundwater recharge potential produced in this study is valuable and is therefore proposed as tool for planners in the sustainable use of groundwater and protection of recharge areas.
Diversidade de gênero e inovação nas organizações Monteiro, Adriana; Lima, Fabiana; Fernandes Mesquita, Rafael ...
Revista Portuguesa de investigação comportamental e social,
05/2024, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Contexto: Embora a relação entre diversidade de gênero e inovação nas organizações seja amplamente discutida em estudos de caso e surveys, ainda carece de uma caracterização descritiva e ...interpretativa da evolução dessa temática na literatura, bem como de uma síntese do conhecimento produzido. Objetivo: Para preencher essa lacuna, o presente estudo buscou caracterizar a relação entre diversidade de gênero e inovação nas organizações. Métodos: O estudo consistiu em uma análise bibliométrica da produção científica no período de 2002 a 2023. Foram analisados 96 artigos coletados na base de dados Web of Science, usando o software Bibliometrix. Resultados: Os resultados principais indicam uma tendência de crescimento na investigação da temática, com destaque para a análise da inovação associada à inclusão de mulheres nos conselhos de administração. Essa inclusão é considerada uma estratégia não apenas para a criação de valor nas organizações, mas também para a promoção de práticas sustentáveis, como parte da inovação verde. Além disso, a representatividade de mulheres nos conselhos de administração ajuda a promover maior inclusão de outros grupos sociais sub-representados. Conclusões: Este estudo oferece insights importantes para a compreensão da relação entre diversidade de gênero e inovação nas organizações, apontando para a necessidade de desenvolver políticas que incentivem a inclusão de mulheres em posições de liderança. Contudo, foi identificada uma limitação na literatura existente, que é a falta de estudos comparativos sobre a inovação associada à inclusão de mulheres em diferentes níveis hierárquicos. Recomenda-se que futuras pesquisas explorem a diversidade de gênero sob a perspectiva de pessoas transgêneras e considerem a interseccionalidade com outros marcadores sociais.
Human actions in the drainage network of hydrographic basins interfere with the functioning of ecosystems, causing negative impacts on the environment. Among these impacts, mass loads with a high ...concentration of phosphorus (P) have a significant potential for point and diffuse pollution of freshwater. The objective of this work was to model P spatially in the Paraopeba River basin, namely in the main water course and 67 sub-basins, and temporally in the years of 2019, 2020, and 2021, after the rupture of B1 tailings dam of Vale, SA company in Brumadinho (Minas Gerais Brazil). The distribution of total phosphorus concentrations (Pt) in relation to environmental attributes (terrain slope, soil class, and land use) and stream flow was assessed with the help of SWAT, the well-known Soil and Water Assessment Tool, coupled with box-plot and cluster analyses. The Pt were obtained from 33 sampling points monitored on a weekly basis. Mean values varied from 0.02 to 1.1 mg/L and maximum from 0.2 to 15.9 mg/L across the basin. The modeling results exposed an impact on the quality of Paraopeba River water in a stretch extending 8.8–155.3 km from the B1 dam, related with the rupture. In this sector, if the contribution from the rupture could be isolated from the other sources, the average Pt would be 0.1 mg/L. The highest Pt (15.9 mg/L) was directly proportional to the urban area of a sub-basin intersecting the limits of Betim town and Belo Horizonte Metropolitan Region. In general, urban sprawl as well as forest-agriculture and forest-mining conversions showed a close relationship with increased Pt, as did sub-basins with a predominance of argisols and an accentuated slope (>20%). There were various moments presenting Pt above legal thresholds (e.g., >0.15 mg/L), mainly in the rainy season.
To compare the degree of debris and friction of conventional and self-ligating orthodontic brackets before and after clinical use.
Two sets of three conventional and self-ligating brackets were ...bonded from the first molar to the first premolar in eight individuals, for a total of 16 sets per type of brackets. A passive segment of 0.019 × 0.025-inch stainless steel archwire was inserted into each group of brackets. Frictional force and debris level were evaluated as received and after 8 weeks of intraoral exposure. Two-way analysis of variance and Wilcoxon signed-rank test were applied at P < .05.
After the intraoral exposure, there was a significant increase of debris accumulation in both systems of brackets (P < .05). However, the self-ligating brackets showed a higher amount of debris compared with the conventional brackets. The frictional force in conventional brackets was significantly higher when compared with self-ligating brackets before clinical use (P < .001). Clinical exposure for 8 weeks provided a significant increase of friction (P < .001) on both systems. In the self-ligating system, the mean of friction increase was 0.21 N (191%), while 0.52 N (47.2%) was observed for the conventional system.
Self-ligating and conventional brackets, when exposed to the intraoral environment, showed a significant increase in frictional force during the sliding mechanics. Debris accumulation was higher for the self-ligating system.
Headwater catchments store valuable resources of quality water, but their hydraulic response is difficult to assess (model) because they are usually deprived of monitoring stations, namely ...hydrometric stations. This issue becomes even more pertinent because headwater catchments are ideal for the practice of conjunctive water resources management involving the supply of towns with groundwater and surface water, a solution that can be used to mitigate overexploitation of groundwater resources in densely urbanized and populated areas. In this study, a stepwise approach is presented whereby, in a first stage, a gauged basin was modeled for stream flow using the JAMS J2000 framework, with the purpose to obtain calibrated hydraulic parameters and ecological simulated stream flow records. Having validated the model through a comparison of simulated and measured flows, the simulated record was adjusted to the scale of an ungauged sub-basin, based on a new run of JAMS J2000 using the same hydraulic parameters. At this stage, a second validation of modeled data was accomplished through comparison of the downscaled flow rates with discharge rates assessed by field measurements of flow velocity and water column height. The modeled basin was a portion of Jequitiba River basin, while the enclosed sub-basin was the Marinheiro catchment (state of Minas Gerais, Brazil). The latter is a peri-urban watershed located in the vicinity of Sete Lagoas town, a densely urbanized and populated area. This town uses 15.5 hm3 year−1 of karst groundwater for public water supply, but the renewable resources were estimated to be 6.3 hm3 year−1. The impairment between abstraction and renewable resources lasts for decades, and for that reason the town experiences systemic water table declines and sinkhole development. The present study claims that the storage of quality water in the Marinheiro catchment, in a dam reservoir, would help alleviate the depletion of groundwater resources in the karst aquifer because this catchment could deliver 4.73 hm3 year−1 of quality surface water to the municipality without endangering ecologic flows. The construction of a small dam at the outlet of Marinheiro catchment could also improve aquifer recharge. Presently, the annual recharge in this catchment approaches 1.47 hm3 but could be much larger if the small dam was installed in the water course and the captured stream water managed properly.
Water resources are paramount for the maintenance of the Earth’s system equilibrium; however, they face various threats and need increased conservation and better management. To restore water ...resources, nature-based solutions can be applied. Nevertheless, it is unclear which solution promotes greater water supply resilience: restoring riparian vegetation, improving management practices in key areas for water recharge, or both? In addition, how significant are these results in the face of climate change effects? To answer this, we used the SWAT (Soil and Water Assessment Tool) model to simulate and compare four different land use scenarios under three climate conditions (i.e., observed climate and two of the IPCC’s future climate projections). Focusing on key areas contributed more to increasing water supply resilience than forest restoration. Applying both solutions, however, yielded the greatest increases in resilience and groundwater recharge and the greatest decreases in surface runoff and sediment loads. None of the solutions caused a significant difference in streamflow and water yield. Furthermore, according to both of the IPCC climate projections evaluated, by the end of this century, the average annual streamflow will be lower than the historical mean for the region. Climate adaptation strategies alone will be insufficient to ensure future water access, highlighting the need for implementing drastic mitigation actions.
The deposits of mine tailings can be a source of groundwater contamination by metals. In this study, we simulated the concentrations of iron, manganese and aluminum in groundwater potentially ...affected by drainage from tailings deposits located in Brumadinho (Brazil). The aim was to verify whether the concentrations observed in the region can be attributed to these drainages. The simulation used the FREEWAT graphical interface, which incorporates the MODFLOW model, the hydraulic properties of existing unconfined and confined aquifers, the spatial distribution of the tailings’ deposits, and the dissolved iron concentrations measured in drilled wells. The simulation period was 20 years, starting in 2019 after the collapse of B1 tailings dam of Córrego do Feijão mine of Vale, S.A. The modeling results revealed plumes of metal contamination progressively less dispersed over time, in the unconfined aquifer, and increased metal concentrations in the confined aquifer. The simulated concentrations in both aquifers were generally lower than the legal limits imposed for human consumption, although some areas in the vicinity of the deposits had iron and manganese concentrations higher than those limits, especially in the unconfined aquifer, and these areas widened over time. The most relevant result was the revelation that the contribution of tailings drainage to the iron concentrations observed in the drilled wells might have not exceeded 1%. This is important from a management standpoint, because monitoring of anthropogenic groundwater contamination in these cases (where rock weathering dominates groundwater chemistry) becomes more challenging.
Display omitted
•Iron, manganese and aluminum concentrations were modeled with MODFLOW in Brumadinho.•The simulations started in 2019, after the B1 dam collapse, and lasted for 20 years.•Iron and manganese leached from tailings exceeded legal concentrations in the unconfined aquifer.•The contribution of rock weathering to iron concentration in groundwater is dominant.
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