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Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis, a model is developed to predict the related well production rate. This model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales, as well as the flow characteristics in different types of thin layers (tight sandstone gas, shale gas, and coalbed gas). Moreover, a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir. A semi-analytical solution for the production rate is obtained using a matrix iteration method. A specific well is selected for fitting dynamic production data, and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of reservoirs. Moreover, desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production, and the daily production of these two gases decreases rapidly with decreasing reservoir pressure. Interestingly, the gas production from fractures exhibits an approximately U-shaped distribution, indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture control. The coal matrix water saturation significantly affects the coalbed gas production, with higher water saturation leading to lower production. [ABSTRACT FROM AUTHOR]

With renewed interest in the optimisation of the hydraulic performance of new and existing culverts, particularly relevant to South Africa's evolving road network and anticipated climate-induced rainfall changes, this research investigated the benefit of angled wingwall and headwall combinations and considered the installation of a ventilation device in order to improve culvert performances. Through experimental modelling at the University of Pretoria Water Laboratory, the angled wingwall and headwall combinations demonstrated significant flow improvements compared to square inlets. It was also demonstrated that a ventilation device could cause flow through culverts to flow under inlet control conditions where it would otherwise have flowed under outlet control conditions. Additionally, the study proposes design coefficient adjustments for square inlet culverts operating under inlet control conditions. The proposed improvements can be applied during design stages, but the findings also propose prefabricated inlet elements as cost-effective solutions for existing culverts, thereby facilitating quick upgrades without the need for lengthy road closures while potentially enabling benefits for pedestrian traffic. Ultimately, this study underscores the potential of innovative and novel design modifications to enhance culvert performance, offering sustainable and economical alternatives to conventional replacement practices while advancing hydraulic engineering resilience in response to evolving infrastructural and environmental demands. [ABSTRACT FROM AUTHOR]

The first systematic attempts to straighten the River Inn in Tyrol for shipping and land reclamation date back to the middle of the 18th century. A dedicated hydraulic engineering authority—the so-called Main Ark Inspection—was established to realize this challenging task. The one-man authority was unable to straighten the Alpine river through the period of its existence up to 1792. The reasons for this were by no means related to a lack of technical resources and knowledge. On the contrary, a micro- and environmental-historical analysis of the attempts to straighten the River Inn highlights the complexity of the causes, which were mutually reinforcing and multifactorial. In this paper, four key causes are examined in more detail: (1) the social organization of water engineering, (2) social conflicts between riparian communities among themselves and with the hydraulic engineering authority, (3) conflicts between Tyrol and Bavaria at the wet border downstream of Kufstein, and (4) increased bedload discharge into the main river by tributaries. To illustrate the causes mentioned above, historical river maps are analyzed in great detail, drawing on contemporaneous written sources. The approach thereby highlights the overall complexity of pre-modern hydraulic engineering in all its facets, be they social, technical, natural, administrative, or organizational. To conclude, the results of this environmental history research are embedded and discussed in the context of integrated river management in the Anthropocene. [ABSTRACT FROM AUTHOR]

The objective of this study is to carry out a hydrogeological mapping of the study area in order to precisely identify the favorable zones to the implantation of boreholes and water wells. This is with a view to optimizing success with the realization of catchment works and thus solves the problem of water shortage in the locality. The study area is covered by trachyte to the north and biotite granite which largely dominates the site and major NE-SW direction lineaments which correspond to the hydrographic network and are considered as fractures. Geological models from 1 and 2D inversions of electrical resistivity made it possible to visualize deep fractured rocks and consequently the different levels of aquifers. The study area is characterized by three domains, namely, a domain with high hydrogeological potential, characterized by hydraulic conductivity between 9.3817 and 2.7956 m/J, porosity between 35.5 and 28%, transmissivity between 232.34 and 27.36 m2/J, longitudinal conductivity between 0.298 and 0.046 Ω−1, transverse resistance varying between 324.0566 and 2469.663 Ω/m2, reflection coefficient between − 0.976 and − 0.321, and geoelectric anomalies essentially of types H, KH, and HKH; a second domain with average hydrogeological potential, characterized by hydraulic conductivity between 1.054 and 2.795 m/J, porosity between 25.74 and 30%, transmissivity between 27.36 and 16.42 m2/J, longitudinal conductivity varying between 0. 046 and 0.028 Ω−1, transverse resistance lower than 37,460.7 Ω/m2, reflection coefficient between − 0.321 and − 0.016, and geoelectric anomalies essentially of types H, KH, HKH, KHK, Q, and K; and a third range of low hydrogeological potential, characterized by hydraulic conductivity less than 1.45 m/J, porosity less than 24%, transmissivity of less than 16.43 m2/J, longitudinal conductivity less than 0.028 Ω−1, reflection coefficient greater than − 0.16, and characterized by anomalies of types Q, HK, and K. The area with high hydrogeological potential is where the lineaments most closely correspond to fractures. Its characteristics make it a favorable domain for any hydraulic engineering project. [ABSTRACT FROM AUTHOR]

This study performed a sensitivity analysis to correlate the frictional head loss calculated by the Darcy-Weisbach (D-W) and the Hazen-Williams (H-W) formulas. For a broad variety of fluid temperatures, velocities, and pipeline diameters, this study considered an extensive discussion and analysis to determine friction loss within pressurized pipelines using Microsoft Excel. Regression analysis and statistical tools were applied to improve the relationship between the two equations. A more accurate expression was developed to calculate the friction loss in terms of the H-W equation. The estimated values were compared with previous experimental and numerical studies, and a good agreement was observed. The proposed model was evaluated using WaterGEMS software in an application example of a water supply system against the D-W and H-W equations. Good agreements were recorded between predicted values and previous studies, with an error of less than 1%. These findings can be used to improve the hydraulic design of engineering applications. [ABSTRACT FROM AUTHOR]

Una problemática a nivel mundial es la pérdida de cobertura boscosa, por lo que su protección es prioridad en Cuba, además de formar parte del plan del estado para enfrentamiento al cambio climático. El objetivo de esta investigación consistió en evaluar la dinámica espacio-temporal del cambio de cobertura boscosa acontecida entre los años 2015 y 2023 en la cuenca hidrográfica “San Juan”, provincia de Santiago de Cuba. Se realizó el análisis multitemporal y clasificación supervisada de imágenes satelitales Landsat 8, bandas 6-5-4 del sensor OLI-TRS, procesadas en el software profesional QGIS v-3.24. Se catalogó la cobertura en cuatro categorías y se determinó el área de cobertura boscosa. Como resultado se obtuvo que índice de boscocidad disminuyó en 1.32%, con una afectación de 182 ha de cobertura boscosa de la cuenca.

El trabajo enfoca la modelación con técnicas de la Mecánica de los Fluidos Computacional del flujómetro de cuña normado por la ISO 5167-6 del 2022. Los buenos resultados obtenidos en la calibración, con valores por debajo del 2,7% para la relación entre la diferencia de presión y el caudal y de menos del 1,9% para las pérdidas de carga permanentes en el conducto, permiten tener un modelo patrón, en cuanto a geometría, mallado y configuración de las condiciones de borde del modelo que permitirán acometer nuevas alternativas de diseño de este y de otros flujómetros para conductos forzados, con principios semejantes al del elemento evaluado. La modelación de las nuevas alternativas en el diseño del flujómetro ha permitido resolver el gran problema del flujómetro original, que son las altas pérdidas de carga permanentes que se producen en la conducción. Los nuevos diseños de cuñas asimétricas han permitido reducir las pérdidas en más de un 80% respecto a la cuña original.

Es ineludible el impacto que puede aportar el uso del tratamiento magnético al agua (TMA) como tecnología innovadora, económica y amigable, importantes aristas del bienestar social y del incremento de la calidad de vida. El estudio de la tecnología del TMA desde un enfoque de Ciencia, Tecnología y Sociedad (CTS) contribuye a elevar la dimensión ética, política y social del trabajo científico imbricado en el proceso de desarrollo e innovación de esta técnica. Por lo que esta investigación argumenta desde un enfoque CTS el impacto socioeconómico del uso del TMA como tecnología ambientalmente amigable para el tratamiento de aguas en Cuba.

ABSTRACT The quality of water distribution and the coefficients that express water use efficiency are evaluated from the distribution of the irrigation depth (I). However, a hypothesis has been proposed that it may be more effective to base these analyses on the water depth stored in the soil profile (H), after irrigation. To evaluate this hypothesis, in a very clayey soil, bean was cultivated under irrigation by conventional sprinkling, with four scenarios of water application uniformity. During the crop cycle, irrigations were carried out, scheduled according to a lower limit of soil-water potential. The four scenarios were associated with 64, 144, 192 and 256 experimental points, which were characterized as having excellent (S1), adequate (S2), inadequate (S3) and unacceptable (S4) uniformity, according to obtained values of Christiansen’s uniformity coefficient (CUC) and distribution uniformity coefficient (DUC). At the end of the cycle, harvest was carried out in each grid, obtaining the crop yield. The uniformity of water distribution in the soil negatively impact crop yield only in S4, with an unacceptable water application pattern. The irrigation quality analysis based on values of H is more consistent with the results observed for the crop than the analysis based on the applied water depth.

ABSTRACT The presence of emerging contaminants in surface water is a growing concern, as these substances are not typically monitored by environmental quality systems, potentially leading to the consumption of contaminated water. In this study, the presence of caffeine, an emerging contaminant that is ingested solely by humans and is present in surface water due to its chemical characteristics, was investigated as a potential indicator of anthropogenic contamination in the Itajaí-Açu River in the southern Brazilian Atlantic Forest biome. Additionally, twelve other emerging pollutants were examined in the Itajaí-Açu River, including estrone (E1), estradiol (E2), ethinylestradiol (EE2), estriol (E3), prednisone (PD), hexestrol (HEX), acetaminophen (ACM), Oxytetracicline (OC). Surface water samples were collected over five months and analyzed using high-performance liquid chromatography. The results revealed that caffeine was present in 84% of the analyzed samples, and emerging pollutants were present in all monitored municipalities. The study also investigated the relationship between an integrated water quality index, the magnitudes and occurrences of caffeine, and land use. The emerging pollutants Estrone, Ethinylestradiol, Hexestrol, Naproxen and Oxytetracycline were not detected in the analyzed samples. However, Ibuprofen, Tetracycline, Prednisone, and Acetaminophen were present in 44% and 36% of the samples, respectively, with Estriol, Ketoprofen, and Estradiol having a lower occurrence. The mean concentrations of Estradiol, Estriol, Ketoprofen, Acetaminophen, and Ibuprofen were 0.08 µg L-1, 0.23 µg L-1, 0.15 µg L-1, 0.42 µg L-1, and 0.44 µg L-1, respectively, and were higher than previously reported. The concentration range of caffeine during the study was

ABSTRACT Environmental monitoring of water is essential for efficient management of water source conservation in river basins. However, there is a lack of studies with this synergy applying unconventional techniques. We evaluated chemical characteristics of surface and underground waters (2021-2022), including for the first time the analysis of the isotopic composition of waters collected from water sources throughout Educandos`s Basin, in the city of Manaus-AM/Brazil, to evaluate chemical-isotopic changes in the view of anthropogenic impacts. Statistical analyzes were used to compare means, graphical analyzes and Principal Component Analysis to identify the main patterns of the data sets. Our results demonstrated a significant increase in pH, electrical conductivity and an increased in nitrates in polluted groundwater and reduced DO in contaminated surface waters. Furthermore, the isotopic signature did not indicate pollution through changes in the isotopic composition of natural and polluted waters, however, it showed more depleted signatures in one of the underground monitoring wells, indicating an impact site vulnerable to the interaction of aquifer waters with Rio Negro and Igarapé. When analyzing chemical parameters with isotopic composition, it can be allowed a better understanding of the mechanisms of circulation and mineralization of underground and surface waters in the Urban Hydrographic Basin.

ABSTRACT The Urucuia Aquifer System (UAS) is an important groundwater source in Brazil, where declining river flows and groundwater table levels were observed in the past years. Changes in actual evapotranspiration due to an increase in atmospheric water demand was among many driving causes that were pointed out to explain lowering observed flows. To assess evaporative demand across the Urucuia Aquifer System, in this study we evaluated possible trends in reference evapotranspiration with the FAO Penman-Monteith method, using the ERA5 atmospheric reanalysis data for the period of 1960-2020 after a comparison with ground-based observed data. Our findings revealed a generally good agreement between ERA5 data and ground-based measurements and significant increasing trends of reference evapotranspiration. This increase seems to be caused by increases in air temperature, surface radiation and wind speed. Within the 1960 to 2020 analyzed period, the last two decades from 2000 onward had the highest evaporative demand across the UAS.

ABSTRACT The objective of this study was to determine the concentration, types and characteristics (size, morphology and color, as well as polymer composition) of MPs in surface sediments in two streams in an Andean region of Peru. Surface sediment samples were collected in Ishoj stream (11 sampling sites) and Uyru Rume stream (8 sampling sites), and density separation was performed using high-density saline solution (zinc chloride, ZnCl2) to separate the MPs from the sediment. The concentration of MPs ranged from 0 - 2216 items/Kg (Ishoj stream) and 0 - 6383 items/Kg (Uyru Rume stream). In both streams, the maximum concentration of MPs was in the sites located near the dumps (solid waste collection, downstream) and the minimum value was found in the sites located in the upper zone. The size, morphology and predominant color in both streams were less than 1 mm, fragment and transparent, respectively. No MPs were found in pellet form. PP (polypropylene) was the predominant MPs in Raman analysis. All MPs were secondary. This study report contamination by MPs in streams in Andean zones.

ABSTRACT Protection devices can be used to protect a water transmission system in a hydraulic transient state, such as the Air Chamber, which can dampen both positive and negative pressure waves. This study proposes an optimal sizing of air chambers through genetic algorithms NSGA-II and NSGA-III combined with air valves in the pipeline. A real-life transmission system located in Brasilia-Brazil was simulated and analyzed. The results indicate the effectiveness of both algorithms in seeking optimal solutions and show the influence of guaranteeing safe minimum pressures in decision-making. We generate a Pareto front and highlight the best solutions.

ABSTRACT Water is the most important substance in nature and all known life forms on the planet depend on it. Among aquatic species, microalgae and cyanobacteria stand out as indicators of their quality, as their increase can be harmful for human consumption, and their concentrations should be monitored. This research aimed to identify reflectance patterns of the microalgae Chlorella vulgaris and Raphidocelis subcapitata that allow, through the creation of an algorithm, the estimation of their chl-a concentrations. The R software found that cell density and growth were higher in C. vulgaris Pearson correlation of 0.96 (p-value 0.000041) and Chl-a content was higher in R. Subcapitata Pearson correlation of 0.81 (p-value 0.013778). An algorithm made it possible to edit the dependent variable based on statistical models. The best readings for the microalgae used were in the spectral range of 524.84 nm in R. subcapitata and 671.13 nm in C. vulgaris. The use of the spectroradiometer for such an analysis, previously unprecedented, was due to the best cost-benefit for measuring the reflectance of Chl-a. It is expected that these two equations will be used in satellites to remotely check water quality through the incidence of these microalgae.

ABSTRACT The region of Alto Capibaribe, in the Brazilian semiarid, faces an environmental issue due to contamination from textile activities. Inadequate release of dyes and other toxic substances threatens human health and water resources, such as alluvial reserves. Thus, biochar, a low-cost adsorbent produced by biomass pyrolysis, helps mitigate these problems by increasing soil retention capacity. This study analyzed the effect of applying biochar, produced from coffee husks, a biomass already established in biochar production, at temperature of 530 °C with a pyrolysis time of 10 to 12 hours, in a homemade metallic furnace, resulting in a product with 67.11% carbon. This biochar was applied to evaluate the mobility of the textile dye Red Drimaren, at a concentration of 25 mg.L-1, used for garment dyeing in local industries, in a subsurface layer of an alluvial deposit located in the dry bed of the Capibaribe River. Fourier Transform Infrared Spectroscopy (FTIR) showed that the highest spectral vibrations are in the range of 1400-1800 cm-1, indicating the presence of amine and amide functional groups, favoring the biosorption process. The pH in water is higher than in KCl for all situations, with biochar being basic and the alluvial soil being acidic. The zero charge point values are equal to 6.96 and 7.96 for the proportions Soil+0.25%BC and Soil+1.00%BC, respectively. Layers with 0.25%BC and 1.00%BC added had an increase in adsorptive capacity of 31.68% and 8.62%, respectively, compared to the natural soil sorption capacity. Kinetic data best fit the pseudo-second-order model, and intra-particle diffusion was not the determining mass transfer process nor the occurrence of the adsorption process. Linear and Freundlich isotherm models consistently described the process under varying concentrations, and the Langmuir model did not show a valid physical significance.

ABSTRACT This study characterized the hyporheic zone of a stretch of the Ipojuca River through analysis of the sediments and meiofauna of this environment. Samples were collected at two points (Point 1: 8°17'28.2” S; 35°59'38.6” W and Point 2: 8°17'48.1” S; 35°56'12.2” W) and in three periods: summer (November/2018), transition period (March/2018), and winter (June/2018). The most representative material was classified as silt, varying between coarse, medium, and fine. 678 meiofauna individuals were counted, distributed in four more representative taxa, Rotifera (41%), Nematoda (40%), Annelida (11%), and Copepoda (5%). The PERMANOVA analysis indicated significant differences for the period (p = 0.0009) and space (p = 0.0261) factors. There was no significant relationship between the meiofauna community structure and hyporheic environment variables. The observed differences may be linked to water quality, which also varied between the points and periods studied.

ABSTRACT Simulation of water flow in the soil in semiarid regions is fundamental for managing scarce water resources. Aiming for more accurate results, the sensitivity analysis (SA) of the hydrodynamic parameters involved in the simulations is very relevant. This study aims to evaluate the influence of hydrodynamic parameters on the hydrological response of an alluvial deposit in the dry bed of the Capibaribe River using the Hydrus-1D. A global sensitivity analysis method proposed by Sobol was chosen to evaluate the sensitivity of the soil water infiltration curve. A convergence analysis was carried out to investigate the evolution of the indices with increasing sample size. Values of the sensitivity indices showed gross variations at the beginning of the simulations for the different parameters, but they converged within the set of 10,000 samples. For parameters whose sensitivity indices are closer to 0, it is noted that 1,000 samples (14,000 simulations) were sufficient for the index to converge to their final value. The total and first-order sensitivity index calculated with 10,000 samples present the parameters n and Ks as the most important, being expressly more influential than the others.

ABSTRACT Along the Algerian-Tunisian border in northeastern Algeria, groundwater is regarded as the primary source of agricultural and drinking water for the local community. This situation is the result of low rainfall and limited surface water. Finding out how wastewater discharges affect the physicochemical and bacteriological quality of alluvial groundwater is the objective of this research paper. Thirty-six wells and boreholes were targeted to collect water samples. The analysis results show that the waters ranged from acidic to neutral (6.46 ≤ pH ≤ 8.3), and moderately to highly mineralized (754 μS/cm < C.E < 11680 μS/cm). The main water types, according to the Piper diagram, are calcic bicarbonate (HCO3- Ca2+) and calcic chloride (Cl- Ca2+). Total coliforms and Escherichia Coli were detected in 60 and 100% of the water samples analyzed, respectively. The geospatial data shows that the chemical and bacteriological pollution progresses from upstream to downstream, from Oued El Kebir river in the South East to Oued Chabro River in the North West. The multivariable statistical analysis (Principal Component Analysis and Closer Analysis) highlighted that water mineralization is controlled by three major phenomena, which are water-rock hydrolysis interaction, leaching of geological formations, and influence of anthropogenic activities.

O presente trabalho teve por objetivo avaliar o desempenho da cobertura dos serviços de saneamento de municípios da Região Metropolitana de Belém (RMB) por meio do Sistema de Informação Geográfica (SIG). A metodologia consistiu em três principais etapas: inicialmente, foram consultados os dados do Sistema Nacional de Informações sobre Saneamento (SNIS); posteriormente, foram calculados os índices de atendimento à população com os serviços de abastecimento de água, esgotamento sanitário e coleta de resíduos sólidos; além da elaboração de mapas temáticos com uso da ferramenta SIG. Os resultados revelaram uma condição sanitária “REGULAR” com pontuação de 47,04% de atendimento aos serviços de saneamento nos municípios. A principal problemática foi o sistema de esgotamento sanitário em virtude da ausência e/ou baixo atendimento à população. Portanto, esse eixo do saneamento deve receber maior atenção do poder público municipal visando reverter o atual quadro de degradação ambiental.

A segurança hídrica da RMSP foi articulada historicamente através do uso de estruturas baseadas na hard engineering, com a implantação de canalizações e de reservatórios de detenção, chamados popularmente de “piscinões”. Os reservatórios de detenção brasileiros apesar de atuarem de forma significativa na atenuação dos picos de vazões, tem pouco ou nenhum efeito sobre a qualidade das águas. Atualmente a Região Metropolitana de São Paulo conta com 53 reservatórios do tipo, que totalizam um volume de amortecimento de 9,95 milhões m³. A maioria dos municípios brasileiros ainda não atingiu a universalização dos serviços de coleta e tratamento de esgotos e, portanto, a carga recebida pelo sistema de drenagem através desta fonte ainda é significativa. Além disso, devido à inexistência de um sistema de controle de cargas difusas, os reservatórios de detenção recebem grandes quantidade de poluentes durante suas operações. Só em 2019 a Prefeitura do Município de São Paulo retirou 170 toneladas dos reservatórios da cidade. Além disso, estes reservatórios são de fato utilizados apenas durante alguns meses do ano, no período chuvoso, permanecendo a maior parte do tempo sem uso. A concepção inicial destas estruturas previa a implantação de equipamentos de lazer em seu interior, que poderiam ser utilizadas no período de estiagem. No entanto devido ao contexto de degradação das águas, tal uso fica inviabilizado. Desta forma é necessária a adoção de novas estratégias que tornem esses reservatórios multifuncionais, permitindo sua utilização para além do controle quantitativo das águas. O presente estudo apresenta estratégias para a conversão dos reservatórios de detenção em unidades de tratamento das águas pluviais através de Soluções Baseadas na Natureza e a integração destas estruturas à paisagem urbana, utilizando, para tanto, técnicas consolidadas nas referências internacionais e adequadas ao contexto brasileiro. Desta forma, pretende-se contribuir para a construção de cidades mais adaptadas e resilientes às mudanças climáticas.

As mudanças climáticas têm como consequência a intensificação de eventos extremos. A caracterização da variabilidade espaço-temporal das precipitações permite quantificar estes eventos. A determinação da variabilidade da precipitação é de grande importância ao conhecimento científico, pois permite compreender tendências e alterações climáticas em variadas escalas. Este estudo avalia a irregularidade temporal da precipitação anual, semestral e mensal no território do Brasil com base no índice de irregularidade temporal. A determinação dos valores do índice foi desenvolvida em 1306 estações pluviométricas com séries superiores a 25 anos, considerando o período de 1990 a 2020. Foi aplicado o método geoestatístico de krigagem ordinária para espacialização e interpolação dos valores para locais desprovidos de dados de pluviometria. Os valores do índice na base mensal encontrados ao longo do território brasileiro variam de 0 a 2,755. No intervalo semestral, os valores de variaram de 0,110 a 1,784, enquanto que na base anual variam de 0,088 a 0,666. As regiões Norte, Centro-Oeste e Sul possuem a menor irregularidade temporal, enquanto que a maior irregularidade temporal predomina no Nordeste brasileiro. Os valores encontrados mostram as particularidades de cada região, influenciadas pelos diferentes sistemas atmosféricos atuantes no território.

O objetivo deste trabalho é avaliar a ocorrência de anomalias no regime de chuva na bacia hidrográfica do rio Cachoeira (BHRC), no sul da Bahia, e analisar sua relação com a ocorrência de desastres hidrológicos e climatológicos relacionados à precipitação visando subsidiar ações de enfretamento de desastres naturais na região. Este estudo utilizou dados mensais de precipitação de cinco postos pluviométricos, no período de 1992 a 2022, fornecidos pela Agência Nacional de Águas e Saneamento Básico – ANA e registros de desastres hidrológicos e climatológicos ocorridos na mesma área e período, fornecidos pelo Sistema Integrado de Informações sobre Desastres. Para caracterizar o grau de severidade dos períodos secos e chuvosos foi feito o cálculo do Índice de Anomalia de Chuva (IAC) e para analisar a relação entre a ocorrência de desastres e as anomalias de chuva, os dados do IAC anual foram confrontados com os dados de desastres coletados, sendo analisada a correspondência entre ambos. Os resultados indicaram uma mudança decadal no padrão das chuvas, com alternância entre períodos mais secos e mais úmidos. As chuvas intensas foram responsáveis por 82% dos desastres hídricos na bacia, com os anos de 2021 e 2022 registrando a maior parte desses eventos e danos significativos.

The present work attempts to characterize Robusta coffee producing properties located in the São Miguel do Guaporé– RO river basin and analyze water quality. Collections were carried out on 20 properties and the following parameters were evaluated: Calcium, Electrical Conductivity; Total Hardness; Total Phosphorus; Magnesium; pH; Sodium, Sodium Adsorption Ratio, salinity and sodicity. The pH ranged from 5.2 to 6.5 and 55% of the samples presented results within the limit established by CONAMA 357/2005, and around 70% of these waters presented a phosphorus content outside the recommended levels. The water classification regarding salinity and sodicity was C1S3, where C1 means that it does not present any risk of salinity and S3 indicates a severe problem when there is infiltration into the soil due to the sodicity of the water. The results obtained may add technical knowledge on the São Miguel do Guaporé river basin, assisting in sustainable management of soil and water.

No Brasil, a Lei n° 9.433/97 direciona a regulação os múltiplos usos da água tendo como principais ferramentas os instrumentos de gestão. Entretanto, a efetividade da gestão depende do desempenho dos instrumentos, para os quais ainda se verifica a necessidade de objetivos mais concretos no caso da cobrança pelo uso da água. Este estudo traz uma contribuição para essa lacuna ao propor critérios e diretrizes que subsidiam a formulação de modelos de cobrança já integrados a metas de enquadramento e critérios de outorga, tendo como base o valor econômico da água, os diferentes usos e as diferenças na escassez ao longo da bacia. Um modelo hidroeconômico foi desenvolvido para avaliar a distribuição de outorgas e seus efeitos econômicos e de qualidade da água. O modelo representa as externalidades decorrentes da alocação de água, identifica áreas com escassez, potencial para novas outorgas e necessidade de melhorias na qualidade. Essa combinação permitiu a diferenciação espacial dos valores econômicos da água na bacia, servindo de diretriz para um modelo de cobrança capaz de buscar objetivos específicos de internalizar custos de poluição e diferenciar valores conforme diferenças na escassez na bacia. O modelo foi aplicado na bacia hidrográfica do rio dos Sinos, no estado do Rio Grande do Sul.

A segurança hídrica é ampla, ainda assim tem sido modelada como sinônimo de escassez hídrica. No Brasil, a ANA criou o Índice de Segurança Hídrica (ISH) que seguiu este mesmo viés. Como ainda há poucos modelos que considerem outros fatores igualmente importantes, como as inundações, em suas análises de segurança hídrica, neste trabalho se propôs a desenvolver um modelo (denominado ISHajustado) a partir do ISH, incorporando inundações para torná-lo mais coerente com o conceito de segurança hídrica. Metodologicamente, modificou-se a dimensão resiliência do ISH, adicionando-se o “índice de vulnerabilidade às inundações” (IVI) em sua composição. O ISH ajustado foi aplicado em uma projeção para 2035 da segurança hídrica na Região Hidrográfica do Rio Jucu (RHJ), no estado do Espírito Santo. O novo modelo apontou que algumas áreas com maior vulnerabilidade a inundações passaram a apresentar menor segurança hídrica do que no ISH original. Esses resultados se mostraram sensíveis ao contexto da segurança hídrica na RHJ e coerente com percepções locais. Conclui-se que o aprimoramento realizado aponta para a necessidade de modelos que abordem mais representativamente a segurança hídrica da forma como ela é conceituada.

A Lei N° 14.026/2020 instituiu mudanças à Lei do Saneamento (Nº 11.445/2007), como as metas de universalização para abastecimento de água potável e esgotamento sanitário, e designou à Agência Nacional de Águas e Saneamento Básico (ANA) a responsabilidade de edição de normas de referência para regulação dos serviços de saneamento. Para a drenagem e manejo de águas pluviais urbanas (DMAPU), a referida legislação não especificou os resultados desejados. Este artigo apresenta a proposta de regulação deste serviço e a atuação do Governo Federal, baseada nas leis federais de Recursos Hídricos (Nº 9.433/1997) e de Saneamento, seguindo os aspectos institucionais, de planejamento, e de colaboração entre os entes Federais/Estaduais e Municípios. O objetivo é que a gestão minimize os impactos das inundações nos municípios brasileiros, propondo padrões sustentáveis dos serviços de DMAPU no Brasil. Para implementação desta proposta foi desenvolvido um Plano de Ação, impulsionando as ações dentro das cidades. Este é um processo longo e complexo, mas que disciplinado dentro de normas e procedimentos sustentáveis minimizará os impactos que problemas relacionados a DMAPLU causam no Brasil.

RESUMO: O objetivo do estudo é discutir a governança comunitária indígena dos recursos hídricos e a relação com a saúde e doenças na região do Baixo São Marcos, em Boa Vista – Roraima. Trata-se de estudo descritivo e qualitativo, conduzido com 23 lideranças indígenas, de ambos os sexos, idade de 23 a 92 anos. Os participantes foram investigados quanto à governança comunitária dos recursos hídricos e a relação com a saúde e doenças em suas comunidades. Os dados foram analisados conforme a metodologia de análise de conteúdo de Bardin. O estudo foi aprovado pelos Comitês de Ética em Pesquisa, regional e nacional. A amostra identificou que a compreensão do termo governança pelas lideranças, significa: zelar, cuidar e evitar possíveis contaminações da água. O estudo evidenciou queixas em relação a qualidade de água que foram investigadas, tomadas de decisões e iniciativas para resoluções de problemas. Embora existam vulnerabilidades sociais, ambientais e de saúde dos povos indígenas dessa região, a governança comunitária indígena se apresenta efetiva, destacando a não aceitação de imposições externas em suas decisões e mostrando seu posicionamento quanto à governança de sua terra.

O saneamento básico promove saúde e inibe a propagação de doenças de veiculação hídrica, sendo essencial à dignidade e sobrevivência humana. Apesar disso, globalmente, bilhões de pessoas ainda carecem de acesso a serviços de saneamento, principalmente em áreas rurais. A presente pesquisa tem como objetivo analisar dados sobre a qualidade da água fornecida em estabelecimentos de saúde em áreas rurais, a fim de possibilitar o planejamento de soluções adaptadas para saneamento da população rural. Foram consideradas informações acerca do Sistema de distribuição de água de instituições cadastradas no Sisagua, considerando a Portaria GM/MS n.º 888/2021. O pH ácido obtido nas amostras da região Centro-Oeste pode ter contribuído com a baixa incidência de coliformes e de E. coli na região, enquanto nas demais regiões foram encontrados valores de pH maiores que sete reduzindo a efetividade do cloro residual livre como agente desinfetante, sendo o pior cenário nas regiões Norte e Nordeste. Sendo assim, os dados compilados na presente pesquisa podem fomentar tomadas de decisões em relação à implementação de políticas públicas de abastecimento de água mais justas para as diferentes regiões geográficas do país, especialmente Norte e Nordeste.

Bimrocks are characterized by their geotechnically significant blocky structure, presenting complex shear behavior. This study investigates the shear behavior and dilatancy of bimrocks featuring a rock-like matrix, such as conglomerates. The study addresses a gap in current research, which has predominantly examined the shear behavior of soil-matrix bimrocks (bimsoils). Laboratory direct shear tests were performed on idealized models with varying volumetric block proportions (VBPs). The results highlight that blocks exert both positive and negative effects on shear strength, dilation, and block breakage factor (BF), depending on VBP. Results indicate 40% and 60% as critical VBPs, revealing distinct shear strength trends within this range, contrary to the dominant downward trend. Blocks positively impact dilation and BF between 20% and 50% VBP, while negatively affecting them beyond this range. Blocky skeleton inherently promotes stable dilatancy under normal stress increments and intensifies stress dependency of shear strength. Variations in dilation angle concerning normal stress and VBP suggest the potential for characterizing this factor using equivalent strength and roughness, akin to rockfill materials. Indirect assessments of equivalent strength revealed positive effects of blocks when VBP was between 30% and 70%. Lastly, the findings indicate that blocks notably impact pre- and post-peak behaviors by reducing shear stiffness and inducing local hardening phases. This study also discusses the similarities and distinctions in the function of blocks within soil-like and rock-like matrices. It offers new insights into the exact role of blocks in bimrock shear behavior beyond the traditional interpretation through the variation of friction and cohesion.

Cyclic shear tests on rock joints serve as a practical strategy for understanding the shear behavior of jointed rock masses under seismic conditions. We explored the cyclic shear behavior of en-echelon and how joint persistence and test conditions (initial normal stress, normal stiffness, shear velocity, and cyclic distance) influence it through cyclic shear tests under CNS conditions. The results revealed a through-going shear zone induced by cyclic loads, characterized by abrasive rupture surfaces and brecciated material. Key findings included that increased joint persistence enlarged and smoothened the shear zone, while increased initial normal stress and cyclic distance, and decreased normal stiffness and shear velocity, diminished and roughened the brecciated material. Shear strength decreased across shear cycles, with the most significant reduction in the initial shear cycle. After ten cycles, the shear strength damage factor D varied from 0.785 to 0.909. Shear strength degradation was particularly sensitive to normal stiffness and cyclic distance. Low joint persistence, high initial normal stress, high normal stiffness, slow shear velocity, and large cyclic distance were the most destabilizing combinations. Cyclic loads significantly compressed en-echelon joints, with compressibility highly dependent on normal stress and stiffness. The frictional coefficient initially declined and then increased under a rising cycle number. This work provides crucial insights for understanding and predicting the mechanical response of en-echelon joints under seismic conditions.

With the growing prominence of recycling projects of groundwater, the attention towards subsidence concerns in geological formations is intensifying. However, due to the long evolutionary time and complex underground discontinuities, the deformation field and subsidence mechanism are difficult to obtain. To this concern, this study implemented the Hydro-Mechanical Coupled Discontinuous Deformation Analysis (HM-DDA) in a groundwater recycling project located at a goaf mining site. The method for establishing numerical stratigraphic models and determining the required numerical parameters is introduced. This contributes to the comprehensive reconstruction of changes in in-situ stress within the goaf area, encompassing the initial stress equilibrium state, as well as the processes of water pumping and injection. The results indicated that the water injection process mitigated stress concentrations at both ends of the goaf area. Specifically, a 30-m rise in water head resulted in a corresponding elevation of the ground surface by 3.94 ​cm.

For solving the computationally intensive problem encountered by the discrete element method (DEM) in simulating large-scale engineering problems, it is essential to establish a numerical model that can effectively simulate large-scale rocks. In this study, the coarse-graining effect of a linear-Mindlin with bonding model was studied in the unconfined compression strength (UCS) and Brazilian tensile strength (BTS) tests. We found that the main reason for the coarse-graining effect of the BTS tests is that the type I fracture toughness is positively correlated with the size of the particles. Based on the results analysis and fracture mechanics, the coarse-grained (CG) modeling theory was combined with a bonded particle model (BPM) for the first time and a coarse-grained bonded particle model (CG-BPM) was developed, which can be effectively used to model the tensile strength of large-scale rocks with different particle sizes. The excavation damage zone (EDZ) in an underground research laboratory (URL) was selected as an application case, which shows that the coarse-grained bonding model presented in this paper is more accurate and reliable than the traditional one in large-scale rock simulation, at least in the scenario where tensile failure is dominant.

In this study, laboratory testing and numerical simulation methods are used to investigate the mechanical behavior and perform fracture prediction of a novel high-strength and high-toughness steel with a negative Poisson's ratio (NPR) effect under combined tensile-shear loading conditions. A test device capable of meeting different tensile-shear combination test angles is designed and manufactured, wherein the mechanical experiments on the NPR (Negative Poisson's Ratio) steel specimens are carried out at various testing angles. Q235 steel and MG400 steel are used as experimental control groups. The results show that the mechanical deformation of NPR steel is significantly better than that of Q235 steel and MG400 steel. Its tensile-shear test curve has no yield plateau and it has quasi-ideal elastic-plastic mechanical properties. The loading direction gradually changes from tension-dominated to shear-dominated as the tension-shear angle increases, and the strength and deformation of the specimens show a decreasing trend. Based on the laboratory test results, a finite element numerical model of NPR steel is established. A series of numerical simulations are carried out under the conditions of different tension and shear angles and the average stress triaxiality and fracture strain data are obtained. The fracture data of NPR steel are fitted using the Johnson-Cook fracture criterion, and the Johnson-Cook fracture parameters under the tensile-shear test conditions of NPR steel are thus obtained. The numerical simulation verifies that the fracture model can accurately predict the tensile-shear fracture behavior of NPR steel.

A simplified two-stage method was employed to provide an explicit solution for the time-dependent tunnel-rock interaction, considering the generalized Zhang-Zhu strength criterion. Additionally, a simplified mechanical model of the yielding support structure was established. The tunnel excavation is simplified to a two-stage process: the first stage is affected by the longitudinal effect, while the second stage is affected by rheological behavior. Two cases are considered: one is that the rigid support is constructed during the first stage, and the other is that constructed at the second stage. Distinguished by the support timing at the seconde stage, different kinds of the “yield-resist combination” support method are divided into three categories: “yield before resist” support, “yield-resist” support, and “control-yield-resist” support. Results show that the support reaction of “control-yield-resist” is much higher than that of “yield before resist” if the initial geostress is not very high, but the effect is not obvious on controlling the surrounding rock deformation. So, the “yield before resist” support is much more economical and practical when the ground stress is not very high. However, under high geostress condition, through applying relatively high support reaction actively to surrounding rock at the first stage, the “control-yield-resist” support is superior in controlling the deformation rate of surrounding rock. Therefore, in the high geostress environment, it is recommended to construct prestressed yielding anchor immediately after excavation, and then construct rigid support after the surrounding rock deformation reaches the predetermined deformation.

An hourly hydrological forecasting model (GRP), used for flood forecasting in France, has been enhanced by developing a semi-distributed version (GRPS). This new model addresses some limitations of the original lumped approach by integrating flow observations from upstream stations to improve downstream flood predictions. A comparison of GRP and GRPS was conducted on a large set of flood events in nested catchments in France. Results indicate that GRPS slightly outperforms GRP up to the lead time of the last upstream flow observations reaching the downstream station, though performance gains vary widely across events. Event classification identified detrimental interactions between data assimilation methods and river routing model errors. A sensitivity test suggested that enhancing both the propagation model and the assimilation scheme could reduce poor performance at short lead times for some events. The study also demonstrated that upstream forecast quality significantly impacts downstream forecast accuracy. Overall, the findings confirm the benefits of incorporating multiple flow observations into a semi-distributed model and suggest several avenues for further improvement.

During the construction and operation of a pumped storage power station in an abandoned mine, the soft rock-coal body structure, comprising the roof and the residual coal pillars, encounters a complex stress environment characterized by cyclic loads. The study of its failure mechanism under cyclic dynamic loading holds significant theoretical and practical importance to stay the safety and stability of the abandoned mine pumped storage power station. In this paper, we take “roof-residual coal pillar” soft rock-coal combinations with different percentages of rock as the research object, and study their mechanical properties, failure mechanism, energy evolution characteristics and acoustic emission distribution characteristics through cyclic dynamic loading experiments. The results of the experiment indicate that: (1) Both weak cyclic dynamic loading and high rock percentage enhance the deformation resistance of soft rock-coal combinations. Under low-disturbance horizontal cyclic loading, its peak strength and modulus of elasticity increase with increasing rock percentage. (2) Under low-disturbance horizontal cyclic loading, an increasing trend is observed in the average total strain energy density, dissipation energy density, and elastic energy density of the combinations as the percentage of rock increases. (3) Under low-disturbance horizontal cyclic loading, as the percentage of rock increases in the soft rock-coal combinations, the degree of failure in the rock body part progressively intensifies, while the destruction of the coal portion progressively decreases. (4) The large number of acoustic emission signals are generated at the instant of destabilization and destruction of the coal-rock combinations, mainly dominated by the signals generated by the destruction of the coal body. Acoustic emission counts and absolute energy at key point N2 decrease as the percentage of rock increases. The b value is primarily distributed in the cyclic dynamic loading stage and the failure stage, both displaying zones of sudden increase and sudden decrease in b value.

Landslides are one of the geological disasters with wide distribution, high impact and serious damage around the world. Landslide risk assessment can help us know the risk of landslides occurring, which is an effective way to prevent landslide disasters in advance. In recent decades, artificial intelligence (AI) has developed rapidly and has been used in a wide range of applications, especially for natural hazards. Based on the published literatures, this paper presents a detailed review of AI applications in landslide risk assessment. Three key areas where the application of AI is prominent are identified, including landslide detection, landslide susceptibility assessment, and prediction of landslide displacement. Machine learning (ML) containing deep learning (DL) has emerged as the primary technology which has been considered successfully due to its ability to quantify complex nonlinear relationships of soil structures and landslide predisposing factors. Among the algorithms, convolutional neural networks (CNNs) and recurrent neural networks (RNNs) are two models that are most widely used with satisfactory results in landslide risk assessment. The generalization ability, sampling training strategies, and hyper-parameters optimization of these models are crucial and should be carefully considered. The challenges and opportunities of AI applications are also fully discussed to provide suggestions for future research in landslide risk assessment.

Blasting test research was conducted on iron ore specimens with variable line density charging structures. Computer tomography (CT), digital image processing, and three-dimensional model reconstruction techniques were used to analyze the damage characteristics of iron ore specimens after blasting based on the calculated number of box dimensions. The results show that increasing the variable line density section charge uncoupling coefficient reduces the overall damage to the specimen by up to 1.73%, indicating that the overall damage size negatively correlates with the size of the variable line density section charge uncoupling coefficient. The damage characteristics of iron ore specimens from different layers (uncoupled charging section, transition section, coupled charging section) have some variability; when the uncoupling coefficient of the uncoupled charging section was reduced, the uncoupled section of the center of the damaged layer increased and then reduced. In contrast, the transition section shows a trend of increase, and the coupled section shows a minor difference, fully demonstrating the change in the variable line density section of the uncoupling coefficient of the specimen blasting damage effects. This study concludes that in the actual blasting project, choosing a reasonable variable line charge density structure can make the release of explosive blast energy more uniform to efficiently and thoroughly use explosive power to improve the iron ore crushing effect.

Bench blasting is commonly used in open-pit mining. Some design parameters such as positions of hole packing and caving holes have great influences on the blasting effects. In this work, with a hybrid discrete-finite element method, numerical simulations of bench blasting are conducted, capturing the whole continuous-discontinuous processes. Considering two engineering cases, the influences of hole packing and caving holes are evaluated. The numerical results not only lead to some improved designs by relocating the packing positions and caving holes but also indicate the reliability of the adopted numerical tools.

En este trabajo se realiza una revisión de los paradigmas existentes y las técnicas más usadas en la detección de rupturas súbitas, profundizando en las que emplean Machine Learning como herramienta principal para la interpretación de datos. Se comparan la relación entre la efectividad de la detección y los parámetros de cada algoritmo, así como el nivel de procesamiento requerido. Para la Máquina de Soporte Vectorial la efectividad en la detección de ruptura súbita está relacionada de forma exponencial. El árbol de decisión expuesto aumenta su precisión mientras más información del estado de la red tenga. La red neuronal analizada demuestra una efectividad en la detección al nivel del resto de algoritmos tratados manteniendo el compromiso con el nivel de procesamiento.

Se caracteriza la infraestructura hidráulica de esta empresa, identificando problemáticas que afectan su productividad y uso eficiente del agua de riego, a partir de entrevistas a directivos y personal técnico, para establecer criterios de selección de técnicas de riego en áreas potencialmente agrícolas en secano. Del levantamiento realizado en la infraestructura de riego y drenaje, fondo de tierra de unidades productivas y análisis del complejo Agua, Suelo, Planta, el 58.6 % de las máquinas de Pivote Central están en explotación y se aprovecha, menos del 50 % del agua para el riego, por pérdidas por infiltración y otras causas, en los canales que conducen el agua. De la superficie agrícola, el 35 % del área está bajo riego y las instalaciones funcionan sin previa evaluación de los parámetros de manejo.

El creciente déficit de agua potable ha motivado a la comunidad científica a incorporar nuevos métodos y tecnologías para elevar su calidad. El tratamiento magnético se presenta como una tecnología innovadora, económica, eficiente, amigable con el medio ambiente y de fácil aplicación. A partir de las características físico-químicas presentadas por las aguas analizadas, se evidencian efectos favorables y significativos con la aplicación del tratamiento magnético para la conductividad, el pH y la turbidez. Se observó que el pH a modo general aumenta sus valores hasta un 11.03 %, mientras que la turbidez disminuye hasta 44.44 %. En el caso de la conductividad los valores de la misma manifiestan aumentos y descensos reportando valores de 0.31 % y 2.79 % respectivamente. Estos resultados podrían ser el preámbulo para el estudio de los procesos de coagulación floculación.

El abasto de agua en Cuba se ve afectado por limitaciones económicas y financieras, además de los efectos del cambio climático, que han incrementado la sequía, afectando los servicios básicos a la población. Los sistemas de saneamiento resultan ineficientes debido a su insuficiencia. Para enfrentar estos desafíos, el gobierno cubano, con apoyo del Fondo de Cooperación para Agua y Saneamiento (FCAS), implementó el proyecto “Mejora y Ampliación de los Sistemas de Agua Potable y Saneamiento de Pequeñas Ciudades Cubanas” (2010), que incluyó la construcción y rehabilitación de plantas potabilizadoras, redes, metrocontadores y plantas de tratamiento. Se diseñó una metodología para evaluar los impactos sociales y técnicos del proyecto, permitiendo corregir deficiencias y lograr los objetivos planteados.

El desarrollo del pensamiento científico-técnico constituye una exigencia de la formación de los profesionales universitarios de especialidades de las ciencias técnicas. El objetivo de este artículo es exponer las manifestaciones peculiares de las características del pensamiento científico-técnico que deben formarse en estudiantes de Ingeniería Hidráulica de acuerdo a los estilos de aprendizaje activo, reflexivo, teórico y pragmático. Se utilizaron los métodos de la sistematización de la teoría y la práctica, el inductivo-deductivo, el hipotético-deductivo, el test de estilo de aprendizaje de Honey-Alonso y técnicas experimentales basadas en la solución de problemas. La utilización de técnicas de correlación permitió establecer relaciones entre los estilos de aprendizaje y las características del pensamiento científico-técnico en la muestra de sujetos estudiada.

Tradicionalmente la información relacionada con el comportamiento de las bombas rotodinámicas ha sido brindada de forma gráfica, mediante sus cuatro curvas características: carga-capacidad, eficiencia-capacidad, potencia-capacidad y NPSHr-capacidad. En la actualidad y estimulados por la extensión del uso de la computación, los fabricantes de bombas rotodinámicas han comenzado a generalizar el empleo de ecuaciones matemáticas en sustitución de la forma gráfica para brindar la información relacionada con sus bombas y como medio más expedito para el estudio del comportamiento hidráulico de los sistemas de bombeo. De esta manera, resulta imprescindible definir los métodos para obtener las expresiones matemáticas representativas de las curvas características de las bombas, a partir de los gráficos y/o datos proporcionados por el fabricante, ya que estos no brindan esta información de forma analítica. Se presentan las tres técnicas más empleadas para realizar el proceso de matematización de las curvas características para su posterior digitalización.

El objetivo de la investigación es exponer los cambios en la gestión de la cuenca hidrográfica para el uso sostenible de los recursos naturales teniendo en cuenta el desarrollo del territorio. Se caracteriza la misma en cuanto a localización, población, producción y conservación para comprender los resultados y lograr un uso eficiente de los recursos naturales teniendo en cuenta las problemáticas ambientales identificadas. Se acerca a sus funciones, al proceso de gestión de las aguas y se plasman los resultados en la transformación como parte del Programa Integral de Desarrollo e implementación de la legislación ambiental del país enfocado al desarrollo utilizando herramientas técnicas y administrativas. Se propone dar seguimiento a la gestión para mitigar los efectos del cambio climático, lograr adaptación y contribuir al desarrollo sostenible en la región.