Hasil untuk "Hydraulic engineering"

Kai-Ho Cheng, Chih-Hsun Chang, Yi-Chung Yang et al.

The relationship between wind and waves has been extensively studied over time. However, understanding the local wind and wave relationship remains crucial for advancing renewable energy development and optimizing ocean management strategies. This study used wind and wave data collected by the ten weather buoys in the waters surrounding Taiwan to analyze regional sea states. The relationship between wind speed and significant wave height (SWH) was examined using regression analysis. Additionally, machine learning techniques were employed to assess the relative importance of features contributing to SWH growth. The regression analysis revealed that SWH in the waters surrounding Taiwan was not fully developed, with notable discrepancies observed between the waters east and west of Taiwan. According to the power law formula describing the relationship between wind speed and SWH, the eastern waters exhibited a larger prefactor coupled with a smaller scaling exponent, while the western waters manifested a converse parametric configuration. Through an evaluation of four machine learning algorithms, it was determined that wind speed is the most influential factor driving these regional differences, especially in the waters west of Taiwan. Beyond wind speed, air pressure or temperature emerged as the secondary feature factor governing wind–wave interactions in the waters east of Taiwan.

付瑶瑶

为实现QE300 桥机（额定起重量300 t）安装100%验收合格率，解决大型桥机安装工序复杂、精度要求高及管控漏洞等问题，构建全周期质量管控体系。先明确螺栓扭矩、轨距误差等核心验收标准，组建专业团队并建立质量追溯与责任追究制度；安装前完成设备材料超声波探伤检测、现场地基静载试验及人员专项培训；安装中严控基础标高偏差、主梁水平度偏差及电气接地电阻；安装后实施三级验收，并开展空载、负载及125%超载调试。该管控模式成功达成100%验收合格率，有效规避隐患，保障桥机安全稳定运行。

Zhen Wang, Yunqi Wang, Zhiyi Yan et al.

The excessive phosphorus input generated by human activities has broken the nutritional balance of ecosystem. This study focused on the Three Gorges Reservoir Region, where human activities are concentrated. It involved the innovative selection of county subunits to provide a clearer analysis of different components contributing to net anthropogenic phosphorus input (NAPI) and factors impacting it on a smaller scale, opening up a new horizon for more accurately formulating phosphorus management policies. The results showed that NAPI of the reservoir region maintained a high level (2641.84 kg·km−2·a−1), while showing significant spatial variation due to high input (>4200 kg·km−2·a−1) at an urban agglomeration in the reservoir region. Phosphorus fertiliser made the largest (63 %–64 %) contribution to NAPI in the reservoir region, but different compositions of the component determining NAPI were shown among the counties. The sensitive coefficient (2.36) of phosphorus fertiliser in the reservoir region was the largest, the sensitive coefficients and proportional contributions in counties also varied among the counties. The findings of this study showed that reducing the input of phosphorus fertiliser and improving the utilization rate of phosphorus are direct methods for reducing NAPI in the Three Gorges Reservoir Region. Furthermore, improving the methods of treating human domestic waste and sewage can alleviate the high input pressure of phosphorus. The spatial differentiation of NAPI in the analyzed counties was mainly affected by the increase in phosphorus fertiliser and gross output value of agriculture, along with increasing urbanization, population densification, and greater economic activity in Chongqing compared with the other counties. Moreover, the components, sensitivities, contributions and impact factors in the counties were heterogeneous due to socio-economic, agricultural, and geographical characteristics, so it might be more appropriate to formulate phosphorus management policies on a smaller county-based scale.

Sh. Shahmansouri, M.R. Mosaddeghi, H. Shariatmadari

IntroductionMonitoring the changes in physical and hydraulic properties and stability of growth media due to root growth effects and wetting and drying cycles is important. Wetting and drying cycles can probably change physical characteristics, availability of water, air and nutrients for the plant and, as a result, might affect the growth and yield of the greenhouse plants. The growth period greatly affects the physical characteristics of the growth substrates; therefore, the watering of growth substrates should be managed according to these changes to avoid improper irrigation.Materials and MethodsIn this study, 14 growth media were prepared from individual substrates with different volumetric ratios. In order to evaluate the changes of growth media over the time (i.e., during consecutive irrigation events) in the greenhouse, 10 wetting and drying cycles were applied on the growth media in the lab. Several physical indicators including easily available water (EAW), air after irrigation (AIR), water buffering capacity (WBC) and water holding capacity (WHC) of the growth media were determined before and after the wetting and drying cycles. Besides, the subsidence, decrease of mass and decomposition of the growth media were determined over the time. Total porosity (TP), bulk density (BD), particle density (PD), pH and electrical conductivity of the mixtures were measured as well.Results and DiscussionThe pH values in the growth media varied from 5.72 to 6.94. The maximum pH value was related to sawdust- sugarcane bagasse biochar produced at 300◦C vermiculite-zeolite, and wheat straw-vermiculite substrates, and the minimum value was related to the cocopeat-perlite substrate. The values of EC in the growth media varied from 0.21 to 1.43 dS m-1. The highest and lowest EC values among the growth substrates were related to date palm bunches-vermiculite-rockwool and rockwool (0.2)-perlite substrates, respectively. The bulk density (BD) values of the growth media varied in the range of 0.163-0.401 Mg m-3. The values ​​of total porosity (TP) of the growth media varied in the range of 64.8-82.8%v/v. The highest TP was related to the cocopeat-perlite substrate. The TP values ​​of most of the substrates were greater than 70%v/v. The average values of EAW in the growth substrates ranged from 0.123 to 0.272 cm3 cm-3. The highest EAW was related to the sawdust-sawdust biochar produced at 500 ◦C vermiculite-zeolite substrate. The application of wetting and drying cycles increased EAW in most of the growth media. Therefore, it can be stated that the time had a positive effect on the EAW in most of the growth media. The average values of AIR before and after the application of wetting and drying cycles for the growth media varied in the range of 0.063-0.240 cm-3 cm3. The highest value of this indicator was observed in the sawdust-date palm bunches biochar produced at 300◦C vermiculite substrate. In all substrates (with the exception of the sawdust-sawdust biochar produced at 500◦C vermiculite-zeolite), the AIR increased after wetting and drying cycles. The range of WHC values before and after applying wetting and drying cycles was 0.453-0.699 cm3 cm-3. The highest WHC belonged to the wheat straw-vermiculite substrate. The WHC values of five growth media, including cocopeat-perlite, decreased due to the application of wetting and drying cycles, and the WHC values of nine growth media decreased. The most stable substrate after the wetting and drying cycles was rockwool-sawdust-vermiculite. The effect of time on the quantity of WBC was positive, so that with the application of wetting and drying cycles, the WBC values of most of the substrates increased. In all substrates, subsidence and dry weight reduction were observed after the wetting and drying cycles. These changes were low for the substrates with a high volumetric ratio of inorganic materials. The least change among the growth substrates in terms of decomposition (dry weight reduction) was related to the completely inorganic substrate rockwool (0.1)-perlite (%0.17). The most stable substrate in terms of subsidence after wetting and drying cycles was the rockwool-sawdust-vermiculite, which has a large volumetric ratio of individual inorganic substrates. The highest subsidence was observed in the substrates containing wheat straw (wheat straw-vermiculite and date palm bunches biochar produced at 300◦C wheat straw-vermiculite). The organic matter content in all the growth substrates decreased over time (after wetting and drying cycles). The decrease of organic matter in the substrates can be related to the decomposition of organic materials as a result of wetting and drying cycles.ConclusionThe BD, TP, EAW and WHC of the majority of growth media were in the optimal ranges and for some mixtures even better than cocopeat-perlite. Wetting and drying cycles could affect the growth media through several processes such as decomposition of organic compounds, displacement and rearrangement of particles, fragmentation of particles, shrinkage, hardening and subsidence. The growth media with a high percent of organic substrates were unstable as compared with those containing a high proportion of inorganic substrates. In general, the wetting and drying cycles increased the frequency of micropores in the growth media. The wetting and drying cycles positively affected EAW, WHC, AIR and WBC of most growth media. These findings imply that wetting and drying cycles may improve the growth media according to the studied extensive variables. However, it is necessary to study the intensive variables such as hydraulic conductivity, oxygen diffusion and pore tortuosity in the growth media for better evaluation of the impact of wetting and drying cycles as well.

XUE Ping, LIU Ling, WANG Yangren et al.

【Objective】 The Jensen formula is a nonlinear model for calculating the response of crop yield to water and nutrient applications. It contains a number of parameters which need calibration against experimental data. The aim of this paper is to present a method to inversely estimate these parameters using experimental data. 【Method】 The method is based on the tuna swarm optimization algorithm (TSO). A distribution estimation (ITSO) was used to form the tuna swarm optimization algorithm (TSO), and the performance of the proposed tuna swarm optimization algorithm was verified against other algorithms based on the CEC2017 test. The accuracy and efficiency of the method were compared with other methods based on experimental data obtained from the Xiaohe Irrigation Experimental Station in Shanxi province. 【Result】 Comparing the performance of ITSO, TSO, GWO, WOA, SSA and BOA methods shows that the proposed algorithm is the best. Comparing ITSO with the nonlinear regression analysis in the SPSS software and TSO shows that the relative error of the proposed method is 7.79%, 8.13% and 7.79%, respectively. The TSO algorithm converged in 50 iterations, while the ITSO algorithm found the optimal solution in just 35 iterations. 【Conclusion】 The tuna swarm optimization algorithm combined with the distribution estimation (ITSO) is efficient for estimating the parameters in the Jensen model. It is highly accurate and converges fast.

Julia Derx, Katalin Demeter, Rita Linke et al.

Riverine wetlands are important natural habitats and contain valuable drinking water resources. The transport of human- and animal-associated fecal pathogens into the surface water bodies poses potential risks to water safety. The aim of this study was to develop a new integrative modeling approach supported by microbial source tracking (MST) markers for quantifying the transport pathways of two important reference pathogens, Cryptosporidium and Giardia, from external (allochthonous) and internal (autochthonous) fecal sources in riverine wetlands considering safe drinking water production. The probabilistic-deterministic model QMRAcatch (v 1.1 python backwater) was modified and extended to account for short-time variations in flow and microbial transport at hourly time steps. As input to the model, we determined the discharge rates, volumes and inundated areas of the backwater channel based on 2-D hydrodynamic flow simulations. To test if we considered all relevant fecal pollution sources and transport pathways, we validated QMRAcatch using measured concentrations of human, ruminant, pig and bird associated MST markers as well as E. coli in a Danube wetland area from 2010 to 2015. For the model validation, we obtained MST marker decay rates in water from the literature, adjusted them within confidence limits, and simulated the MST marker concentrations in the backwater channel, resulting in mean absolute errors of < 0.7 log10 particles/L (Kruskal–Wallis p > 0.05). In the scenarios, we investigated (i) the impact of river discharges into the backwater channel (allochthonous sources), (ii) the resuspension of pathogens from animal fecal deposits in inundated areas, and (iii) the pathogen release from animal fecal deposits after rainfall (autochthonous sources). Autochthonous and allochthonous human and animal sources resulted in mean loads and concentrations of Cryptosporidium and Giardia (oo)cysts in the backwater channel of 3–13 × 109 particles/hour and 0.4–1.2 particles/L during floods and rainfall events, and in required pathogen treatment reductions to achieve safe drinking water of 5.0–6.2 log10. The integrative modeling approach supports the sustainable and proactive drinking water safety management of alluvial backwater areas.

Asril Zevri

This study aims to analyze the requirement for the storage capacity of Danau Asam Reservoir as one of the solutions in increasing the availability of water to meet the needs of raw water due to population growth and climate change which is quite extreme. The study was conducted in the Danau Asam Reservoir with source of water from two watersheds that flow into the reservoir, namely the Lopo River Basin with a catchment area of 11.81 Km2 and Kamat Bay with a catchment area of 12.42 Km2 in Kotawaringin Lama District in the West Kotawaringin Regency. The method used is a quantitative approach based on a simulation of the water balance between the inflow and outflow. The inflow parameter is calculated based on 90% probability reliable discharge using the FJ Mock method in two watersheds and the outflow parameter is based on the raw water demand discharge which is calculated based on the population growth rate. The result of the research indicate that the capacity of the Danau Asam Reservoir is 391,842.72 m3 to meet the raw water needs in Kotawaringin Lama District with a population of 35397 people.

YANG Fang, YANG Pan, LU Lu et al.

Rainfall is the main source of water resources in Xiangjiang River, so the research on its changing trend is of great significance to the development, utilization and rational allocation of water resources. Based on the rainfall series data of Zhuzhou Hydrological Station in Xiangjiang River from 1955 to 2016, this paper analyzes the regional rainfall characteristics by the mathematical statistics, linear trend, 5 year moving average method, Mann-Kendall test, sliding t test and wavelet analysis. The following conclusions are drawn: (1) In the past 60 years, the annual distribution of rainfall at Zhuzhou Hydrological Station in Xiangjiang River was uneven, but in regularity. The annual average rainfall of many years mainly presents the alternating process of high and low, with significant increase trend. (2) Although the average number of rainy days in many years fluctuates, the overall trend is stable. (3) The periodic oscillation of annual average rainfall and annual average rainy days is the strongest in the time scale of about 14 year and 20 year.In a short period of time after 2016, the amount of rainfall and the number of rainy days will decrease relatively, and then increase, which can provide data support for the study of water resources change characteristics, water resources planning and management, waterlogging and drought control, agriculture, animal husbandry and forestry production in Xiangjiang River Basin.

I. A. Koznacheev, K. V. Dobrego

The one-dimensional axisymmetric problem of initiation of a combustion wave in an oil-saturated reservoir is solved numerically. Two combustible components, viz. liquid (oil) and solid (kerogen, oil sorbate) were considered. The influence of the abovementioned components on time of the hot site ignition and combustion front speed was simulated and analyzed. It was demonstrated that growth of the mass fraction of liquid component (the total heat content being preserved) results in retard of formation of the hot site near the well and in reduction of the maximum temperature of the combustion wave, disregarding of the higher reactivity of liquid combustible. Simulation revealed existence of the two “peaks” of thermal front velocity. The first one corresponds by time to ignition of combustion site. The second one corresponds to a moment when the solid component combustion front overrides the oil displacement front. Calculations shown, that thermal wave propagation velocity, at least after passing the “peaks” and transition to quasi-steady regime, does not considerably depend on mass traction of the fluid component in the system. A typical term of the exothermic reaction site formation may increase from 50 to 200 days in case of growth of the liquid component content from 30 to 80 mass % at the considered thermal conditions in the oil reservoir. Thus, the implementation of the thermo-gas method in high-productive layers increases the likelihood of difficulty of initiation of a fire. Therefore, the study of the regularities of intra-combustion in such cases is of a particular interest. For instance, the task of combustion site ignition may be resolved by increase of oxygen content in blowing-gas or by means of non-steady (periodical) blowing. It is found that taking into consideration of highly reactive liquid component results in widening (diffusion) of the thermal front, which may play positive role in its spatial thermo-hydrodynamic stabilization. The results of simulation may be utilized for development of technical projects of oil recovery via in-situ combustion, for designing of furnaces utilizing multicomponent fixed layer fuels and for thermochemical investigation of multicomponent fuels.

JOSÉ AUGUSTO COSTA GONÇALVES, ELIANE MARIA VIEIRA

As águas subterrâneas têm importante papel no abastecimento público e na irrigação das lavouras no norte do Espírito Santo. A área estudada, com 3.568,4 Km2, está assentada na bacia sedimentar do Espírito Santo, entre as cidades de Linhares, São Mateus, Jaguaré e Nova Venécia. Para realizar este trabalho, em toda região foram cadastrados 107 poços tubulares, dando uma ótima densidade de 33,4 poços por Km2, cuja disposição contempla todo terreno estudado e que explotam concomitantemente expressivas vazões dos mananciais subterrâneos. O Grupo Barreiras é constituído por sedimentos detríticos terciários inconsolidados de origem continental, dispostos em estreita faixa ao longo da costa, desde o estado do Rio de Janeiro até o Pará. No Espírito Santo, este grupo está presente em toda porção do leste e nordeste, com largura aproximada de 30 km. O Aquífero Barreiras é poroso, livre, em determinados locais pode ser semiconfinado, com grande distribuição espacial. Apresenta geralmente boa porosidade e permeabilidade. É composto por sedimentos aluvionares e fluviais em complexa associação de estratos permeáveis/impermeáveis. A grande heterogeneidade existente é proveniente da descontinuidade dos aquíferos (geometria lenticular) associados com barreiras de permeabilidade que são ocasionadas por fácies mais argilosas. Os valores médios para os parâmetros hidráulicos encontrados foram: profundidade dos poços de 100,81 m, nível estático de 14,18 m, nível dinâmico de 51,48 m, rebaixamento de 37,30 m, vazão de 43,52 m3/h, capacidade específica de 2,3681 m3/h.m e transmissividade de 175,54 m2/dia, gradiente hidráulico de 0,25%. A vazão do escoamento natural subterrâneo foi calculado em 296.106 m3/ano. Taxa de Infiltração Anual - Ti = 0,82%, Volume anual infiltrado – VAI= 321.106 m3/ano, Volume da Reserva Reguladora - VRR = 321.106 m3, Volume da Reserva Permanente - VRP = 1,27. 1010 m3, Potencialidade do Aquífero - PO = 346. 106 m3/ano.

N. N. Grinchik, K. V. Dobrego, M. A. Chumachenko

Operational control of parameters of electrolytes (first of all–of specific electric conductivity), is an important electrochemical technology. The methods of measurement of electric conductivity of electrolytes is a subject of permanent discussions because of complexity of physical-and-chemical processes accompanying ion transport and of electrolyte polarization near surfaces of electrodes and of electrochemical processes on the electrodes surfaces. Actual highand low-frequency conductometric methods require relatively expensive equipment and are not free of methodological flaws. In this paper a new method of electric resistance of liquid electrolytes is described and substantiated. It is based on automatic performance of a series of measurements of electrolyte resistance at DC, data processing and extrapolation of an appropriate dependence to threshold voltage at measurement cell plates. The character of functions approximating resistance-applied voltage dependence and method of resistance determination are substantiated. The measurements of specific resistance of some electrolytes were performed. The advantages of the proposed method and measuring device are their simplicity, cheapness, reliability and, consequently, wider possibility to utilize it at technological lines and processes, even at such sites of production processes where such a control was impractical earlier. The method can be widely used for express-diagnostics of electrolytes in such areas as electrochemical energy storage, medicine, agriculture, chemical industry, food production.

Lyndemberg Campelo Correia

O presente trabalho tem como área de estudo o município de São João da Barra/RJ, o qual é abrangido integralmente pelo aquífero Emborê, principal aquífero do Estado. Foram selecionados 28 poços tubulares profundos. Teve-se como objetivo a análise dos dados de vazão e vazão específica desses poços avaliando a produtividade dos poços que captam água do Emborê e, ainda, a produtividade desse aquífero. A produtividade dos poços, expressa em termos da vazão, apresentou valor médio de 52,81 m3 /h, o que de uma forma geral classifica esses poços como de Produtividade Alta, considerando os intervalos de vazões estabelecidos neste estudo. A produtividade do aquífero, expressa em termos da vazão específica, apresentou valor médio de 5,43 m 3 /h/m, o que de uma forma geral o enquadra na classe de Produtividade Elevada, para os intervalos de vazões específicas estabelecidos neste trabalho.

何际斌

Ozorio Mont’Alverne Silva, Antonio Carlos F. N. S. Tancredi, Eduardo Marechal Tagliarini

A Água Mineral Mar Doce, localizada no Município de Paço do Lumiar, na Ilha de São Luiz (MA) tem clima tropical úmido e situa-se na bacia do Rio Paciência próximo ao interflúvio com a bacia do Rio Santo Antonio. A geologia na Ilha de São Luiz apresenta rochas da Bacia do Parnaíba e de bacias marginais cretáceas, de Barreirinhas e São Luiz, sobrejacendo ao embasamento. A Formação Itapecuru da Bacia do Parnaíba com arenitos, siltitos e folhelhos aflora em grande parte da Ilha, sendo recoberta por sedimentos pelíticos do Paleógeno e pela litologia de areias, siltes e argilas do Grupo Barreiras. Depósitos pleistocênicos ocorrem na parte sul e os depósitos holocênicos nas faixas costeiras e aluviões dos rios. As pesquisas possibilitaram a determinação das características hidrogeológicas na área da Água Mineral, sendo perfurados poços para pesquisas, monitoramento e captação; realizados ensaios de bombeamentos, amostragens e análises da qualidade da água mineral. A composição química em diversas épocas apresentou pequenas variações dos constituintes dissolvidos, indicando não haver interferência de outras águas. A vulnerabilidade do aqüífero capado é baixa com boa proteção, estando as zonas de contribuição, influência e transporte na área da Água Mineral Mar Doce.

Govind Gopakumar

Public-private partnerships (PPP) are an important governance strategy that has recently emerged as a solution to enhance the access of marginalised residents to urban infrastructures. With the inception of neo-liberal economic reforms in India, in Indian cities too PPP has emerged as an innovative approach to expand coverage of water supply and sanitation infrastructures. However, there has been little study of the dynamics of partnership efforts in different urban contexts: What role do they play in transforming existing infrastructure regimes? Do reform strategies such as partnerships result in increased privatisation or do they make the governance of infrastructures more participative? Reviewing some of the recent literature on urban political analysis, this article develops the concept of water supply regime to describe the context of water provision in three metropolitan cities in India. To further our understanding of the role of PPP within regimes, this article sketches five cases of water supply and sanitation partnerships located within these three metropolitan cities. From these empirical studies, the article arrives at the conclusion that while PPP are always products of the regime-context they are inserted within, quite often strategic actors in the partnership use the PPP to further their interests by initiating a shift in the regime pathway. This leads us to conclude that PPPs do play a role in making water supply regimes more participative but that depends on the nature of the regime as well as the actions of partners.

Francisco Lages C. Filho, Adson Brito Monteiro, A. Reinaldo Soares Filho et al.

A área situa-se no extremo sudeste do Estado do Piauí, próximo às fronteiras com os Estados da Bahia e Pernambuco, na borda da Bacia Sedimentar do Parnaíba. O objetivo deste trabalho foi à caracterização hidroquímica do aqüífero Cabeças quanto ao íon dominante, a parâmetros físicos e ao uso. Aflora na maior parte da área e seu comportamento hidrodinâmico é predominantemente de aqüífero livre. Apenas no canto noroeste da área, na região de Canto do Buriti, se comporta como confinado, uma vez que é recoberto por sedimentos argilosos da formação Longá. Sua caracterização hidroquímica foi realizada utilizando-se os resultados de análises de amostras de água de 54 poços selecionados, cadastrados pelo Projeto Cadastro de Fonte de Abastecimento por Água Subterrânea do Estado do Piauí. Foi efetuado um balanço químico entre cátions e ânions, uma análise de consistência dos dados e, realizado um estudo estatístico dos parâmetros físico-químicos. Os resultados mostram uma predominância de água bicarbonatada mista, branda, doce, levemente ácida, adequada para consumo humano (desde que sejam observados os parâmetros bacteriológicos), consumo animal e irrigação. Indústrias de suco de frutas, laticínios e alimentícias podem ser instaladas sem muita restrição. Para as demais tipologias devem ser feitas pesquisas específicas.

I. A. Bokun

The paper shows an influence of forced pulsations on the character of gas flow in the channel of underground gasification and their efficiency in the processes.

E. P. Zabello, A. N. Evseev

The method is proposed to make a correction in payment for consumption of reactive energy and power which is attributed to deviation of actual activation energy losses for reactive power compensation from their standard value. It is recommended to calculate standard loss values for every voltage level and actual loss values are to be determined with the help of application of remote electronic accounting means in the current mode of power consumption.

FU Xia-bi, YANG Lei-qi, CHEN Yong-Li

Beatriz Helena Minari, Íria Vendrame

As precárias condições de saneamento básico ainda são os grandes responsáveis pela degradação ambiental nos paises desenvolvidos. A falta de saneamento básico impacta fortemente a qualidade da água utilizada para abastecimento e são freqüentemente responsáveis pela disseminação de doenças de veiculação hídrica. Recentemente, doenças causadas pela presença da alta concentração de nitratos na água têm ampliado os estudos a respeito dos efeitos deste componente na saúde humana. Diversos artigos citam associações entre a alta concentração de nitratos e a methemoglobinemia infantil. A alta concentração deste componente também afeta o meio ambiente por meio da eutrofização dos estuários e dos ecossistemas costeiros. O objetivo deste estudo é investigar as condições de saneamento básico do conjunto habitacional 22 de Abril, localizado no município de Jacareí, São Paulo, Brasil e analisar os impactos do ciclo do nitrogênio na água subterrânea local e na saúde humana.