Hasil untuk "River, lake, and water-supply engineering (General)"

Agustina Rachmawardani, Budhy Kurniawan, Sastra Kusuma Wijaya et al.

Flooding in Jakarta is a multifaceted issue influenced by a combination of geographical, social, economic, and environmental factors. This study focuses on predicting floods by comparing automatic rain gauge (ARG) ground station data and Climate Hazards Group InfraRed Precipitation (CHIRPS) satellite data using the Adaptive Neurofuzzy Inference System (ANFIS) integrated with principal component analysis (PCA). The dataset includes precipitation measurements from both ARG and CHIRPS along with water level data spanning from 2014 to 2020. ARG provides precise local rainfall data, while CHIRPS offers extensive regional precipitation coverage. To enhance data quality, preprocessing techniques such as mean imputation, data normalisation, and the interquartile range (IQR) method were employed. The ANFIS-PCA model, which integrates fuzzy logic and neural network training, was applied using an 80:20 split for training and validation. When trained with ARG ground station data and water level measurements, the ANFIS-PCA model demonstrated superior accuracy, achieving a root mean square error (RMSE) of 0.13, mean absolute error (MAE) of 0.12, and R2 of 0.82. In contrast, the ANFIS model without PCA yielded higher errors, with RMSE 6.3, MAE 6.2, and R2 0.74. Training with CHIRPS satellite data resulted in significantly higher errors (RMSE 30.14, MAE 24.05, R2 0.42). These findings underscore the superiority of ground-based measurements for flood prediction, given the reduced precision and higher susceptibility to errors in satellite-derived data. While CHIRPS satellite data offers broader spatial coverage, its limitation in precision and higher susceptibility to errors reduce its effectiveness for accurate flood prediction.

DU Boheng, ZHANG Jingwen, KANG Zheng et al.

The acceleration of urbanization has induced a sharp increase in urban water consumption, so the saltwater intrusion has stronger influences on domestic, industrial, and agricultural water use in estuarine areas. To enhance the water supply security of coastal cities, it is necessary to analyze and predict saltwater intrusion. This study aims to further investigate the influence of various factors, including estuary tide level, wind direction and speed, and upstream water flow, on the saltwater intrusion (chlorinity in the estuary) in the Pearl River estuary, providing scientific support for improving water supply security in coastal cities. The study determines the lag time of different influencing factors on saltwater intrusion through correlation coefficients and constructs prediction models for the chloride content at the estuaries of the Guangchang and Pinggang water pumping stations based on various machine learning methods to analyze the saltwater intrusion in the Modaomen waterway of the Pearl River estuary. The established models show a good performance in predicting salinity. According to the analysis of the importance of influencing factors, it is found that upstream water flow has the greatest influence on saltwater intrusion, followed by estuary tide level and wind direction and speed.

Xuanting Ji, Minghai Chen, Zhengheng Pu et al.

Precise value of scheduling decisions forms the cornerstone of water distribution network (WDN) scheduling optimization, which aims at conserving energy and enhancing network operational efficiency. This article proposes a computational methodology for evaluating the value chain of scheduling decisions in WDN. The scheduling process is modeled as a Markov decision process with immediate reward function, action and state space. Due to the periodicity of water supply and sequential nature of scheduling, the calculation quantifies cumulative value of scheduling decisions by incorporating state transition probability with expected value. The effectiveness and applicability of the proposed evaluation method are demonstrated using scheduling data from a real world WDN. The method provides rational values on scheduling period and strategies, offering practical feedback for scheduling decisions.

Fernanda Monicelli, Carlos Alberto Nascimento da Rocha Junior, Stela Lima et al.

ABSTRACT Prolonged drought extreme events can intensify eutrophication symptoms. This study aimed to analyze the trophic state of two semiarid reservoirs (Cruzeta and Dourado) that experience regular periods of drying and reflooding, verifying limnological changes. Two distinct periods were defined: Period I - before water depletion and Period II – after water renewal. To assess the changes in the limnological variables and the trophic state following the reflooding was conducted Wilcoxon test, Pearson's Correlation, and cluster analysis. Despite similar hydro-meteorological conditions, the reservoirs exhibited different outcomes in limnological variables. Due to the prolonged drought, Cruzeta maintained the eutrophic state in both periods, with the reservoir retaining only 2% of its water volume. In the Dourado reservoir, the trophic state change was observed, shifting from mesotrophic to eutrophic. The acceleration of eutrophication may have occurred due to the existence of organic matter in the sediment, coming from plantations inside the reservoir in addition to phosphorus carried from the drainage basin and by internal loading. Thus, reflooding did not improve water quality conditions and may intensify eutrophication. Therefore, it is recommended that effective reservoir and drainage basin management practices be implemented to mitigate eutrophication and aim for improvements in water quality.

Han Zhang, Jungang Luo, Jingyan Wu et al.

Flash floods show strong regional differentiation in spatial–temporal distribution and driving forces, thereby hindering their effective prevention and control. This study analyzed the spatiotemporal characteristics of flash floods in Shaanxi Province, China, differentiated among the northern Shaanxi (NS), Guanzhong (GZ), and southern Shaanxi (SS) regions based on the Mann–Kendall, Theil–Sen Median, and standard deviation ellipse methods. The main factors driving disasters and their interactions in each region were then identified within the three categories of precipitation factor (PPF), surface environment factor, and human activity factor (HAF) based on a geographical detector. Finally, the differences in flash flood characteristics among the NS, GZ, and SS regions were analyzed. The results showed that flash floods in Shaanxi Province are greatly affected by the PPF and the HAF, although the spatial–temporal characteristics and disaster-causing factors were significantly different in each region. The regions were ranked according to the number and growth trends of flash floods as follows: SS > GZ > NS. Furthermore, flash floods were affected by multiple factors, with the interaction between factors acting as a driving force of flash floods. The results of this study can provide a reference for the management of flash floods under regional differentiation. HIGHLIGHTS Taking Shaanxi Province as a typical region of regional differentiation, the temporal and spatial characteristics of flash floods are evaluated.; The main disaster-causing factors and their interaction of flash floods in each region are discussed.; Results are helpful to put forward the flash flood prevention and control measures according to local conditions in the same administrative region and reduce the potential risks.;

Masaki Ohno, Yuki Kobayashi, Risa Sohma et al.

Calcium (Ca)-loaded biochar was produced from rice husks by loading the Ca source with subsequent carbonization and was examined from the evaluation of P adsorption capability about the loading method, the availability of oyster shells as the alternative, and the effect of carbonization temperature. Ca-loaded biochar prepared at 650°C had the CaCO3 form, and that at 400°C had unconverted Ca(OH)2 with less CO2 generation. Moreover, silicon in the rice husks might have existed as an amorphous structure of calcium silicate hydrate by reacting with Ca. As the loading method of the Ca source, the powder mixing method was as effective as the conventional impregnation method. It was clarified that oyster shells can be used by decarboxylation and hydration in the powder mixing method, and that the chemical form of the Ca source is important for improving P adsorption capability. Furthermore, the Ca-loaded biochar prepared at 400°C as the condition that could be performed at the paddy field location was higher P adsorption capability than that at 650°C, even though the pores were not developed. The formation of Ca(OH)2 by low-temperature carbonization of rice husks with Ca affected the improvement of P adsorption capability.

Heidar Ghafari, Manouchehr Gorji

Introduction Although soil erosion in natural ecosystems takes place very slowly, yet its cumulative effects on soil productivity are significant in the long term, and even very low rates of erosion cause loss of considerable amounts of soil during the course of many years. Based on statistics presented during the past 40 years, about 30% of agricultural lands in the world have lost their fertility due to erosion and have turned into non-arable lands (Pimentel and Burgess, 2013), and approximately 75 million tons of fertile agricultural soil is lost every year (Eswaran et al., 2001). In another report, it has been stated that about 10 million hectares of agricultural lands in the world lose their productive capacity annually and become non-cultivable lands (Lal, 2001).Materials and MethodsSWAT model was used to simulate the effect of soil erosion on dry wheat yield. For this purpose, after model calibration and validation, the following five scenarios were defined to quantify the effects of erosion on rainfed wheat yield: (1) current soil depth, (2) removing 5 cm, (3) removing 10 cm, (4) removing 15 cm, (5) and removing 20 cm of current topsoil depth in soil database.Accordingly, a regression relation was established between surface soil erosion and wheat yield.Results and Discussion Regression analysis showed that for each centimeter of soil erosion, the yield of rainfed wheat was reduced by 15.1 kg equal to 0.5%. The model results showed that the average specific erosion in the agricultural lands of the region is about 10 t/ha (0.77 mm/year). Assuming that the erosion rate is constant over 100 years, about 77 mm of soil is destroyed, equivalent to a loss of 116 kg/ha of dryland wheat yield. Considering the area under wheat cultivation (about 50,000 ha) in the study region, it is estimated that 580 tons of wheat per year will be destroyed by erosion.Conclusion SWAT model was used to assess the effect of erosion on crop yield. The gradual decrease in horizon A depth of input soil data to the model showed that with a decrease in the soil depth per 10 cm, the average yield decreased by 5%. It is suggested that in subsequent studies, the results of this method can be compared and validated with the comparative plot method, as the best field method in evaluating the effect of erosion on yield.

HE Ruxu, PEI Xiangjun, ZHONG Chuangui et al.

According to the seepage characteristics of fractured rock mass of hydropower slope insouthwest mountainous area,and taking the sandstone at left bank slope of Jinping HydropowerStation as an example, this paper tests and studies the permeability characteristics of rocksamples prefabricated with artificial fracture in different tips under different confining pressuresand osmotic pressures by high pressure rock permeameter, and statistically analyzes thepermeability coefficients obtained from the tests. The test results show that with the increase ofosmotic pressure from 0.1 MPa to 0.5 MPa, the dissolution and scouring of hydrophilic minerals infractured sandstone increase gradually, resulting in new seepage channels and the increase ofpermeability coefficient. With the increase of confining pressure from 2 MPa to 4 MPa, thefracture and pore in the rock are closed by compression, leading to the reduction of permeabilitycoefficient. The overall permeability coefficient of fractured sandstone with tips of 0°, 30° and45°decreases in turn, and the increase of fracture dip changes the angle between fracture seepagechannel, initial seepage direction and confining pressure, which weakens the response ofpermeability coefficient to confining pressure and osmotic pressure.

周建平, 刘杰, 王伟

Lauro César Zanatta, Larissa Ramage

Foram analisados os impactos ambientais causados pela infiltração do efluente tratado na recarga do aquífero, tendo como principal parâmetro os impactos na balneabilidade na área de descarga da Lagoa da Conceição. O monitoramento foi realizado por 9 piezômetros construídos próximos a área de influencia do lançamento do efluente. Na ETE Lagoa da Conceição, das 237 análises em 44 campanhas realizadas no efluente final da estação verifica-se que 99,6% das amostras coletadas estão em conformidade com os padrões de lançamento, relacionado à Resolução CONAMA 430/2011, que “Dispõe sobre as condições e padrões de lançamento de efluentes”. O modelo aplicado apresenta uma série de vantagens para atender a demanda cada vez mais crescente na localidade da Lagoa da Conceição no município de Florianópolis, onde está implantado o sistema de tratamento de esgoto. Os principais indicadores de poluição avaliados foram N-NO2, NNO3, Coliforme total e Fecal. A redução dos coliformes fecais foi significativa demonstrando a eficiência da remoção de Escherichia coli, devido às características do processo de infiltração.

CARLOS BENEDITO BAPTISTA LEITE, JOSÉ LUIZ ALBUQUERQUE FILHO, ANA MACIEL DE CARVALHO et al.

Apresenta-se breve comparação entre resultados obtidos com dois métodos de mapeamento da vulnerabilidade à contaminação das águas subterrâneas, em porção da área de afloramento do Sistema Aquífero Guarani (SAG), na Bacia do Tietê/Jacaré (estado de São Paulo). O zoneamento da vulnerabilidade foi consubstanciado em escala 1: 250.000, utilizando-se os Métodos GOD e DRASTIC. Pode-se concluir que os resultados dos dois métodos guardam semelhanças significativas entre si, mas o Método GOD sugere resultados mais conservadores. Avalia-se que para melhor comparação entre os dois métodos, o mapeamento da vulnerabilidade deva ser objeto de pesquisa exclusiva e que se utilize da mesma base de dados.

Manuel Arce Montejo, Miguel Ángel García Lapresta, Irina Maidanskaya

A poupança de água e energia associada ao incremento na produção de alimentos é um dos grandes desafios que a agricultura actual enfrenta. Actualmente dispõe-se de modelos de simulação, sensores de humidade e outras ferramentas TIC recentes que permitem, mediante a geração de sistemas de operação simples, o acesso dos agricultores e pessoal com qualificação média ás novas tecnologias em áreas de uma maior habilidade na gestão agrícola. Apresenta-se o sistema integral GESTIRRIEGO, que baseado em aplicações TIC, permite realizar recomendações sobre estratégias de rego, aumentando a eficiência do uso da água e da energia.

ANTÓNIO PEDRO Said Aly de PINA

Inexistente

LUO Cheng-ping, ZHU Shi-kang

Carlos Magno de Souza Barbosa, Arthur Mattos

As soluções para os problemas relacionados com a gestão das águas requerem ações integradas, sensatas e participativas, com vistas ao aperfeiçoamento dos instrumentos que garantam a preservação dos recursos hídricos. As tendências mais modernas apontam para uma visão holística da água, isto é, um entendimento que considere não só as águas superficiais, mas também as subterrâneas. Estas, mais do que uma reserva de água, devem ser consideradas como um meio de acelerar o desenvolvimento econômico e social de regiões extremamente carentes no Brasil. O presente trabalho tem como objetivo apresentar os princípios básicos de gestão integrada de recursos hídricos, a importância da gestão das águas subterrâneas dentro desse contexto, e enfatizar a relevância da participação popular no processo de gestão.

林周成, 林国良

A. Celligoi, U. Duarte

indisponível

田茂连