Hasil untuk "Hydraulic engineering"

RAO Qingyang, YANG Qiongbo, CUI Dongwen

To improve over-fitting of data processing, weak time series modeling, and difficult selection of hyperparameters in the Kolmogorov-Arnold network (Kan), a groundwater level prediction model based on wavelet packet transform (WPT) secondary decomposition and Chinese Pangolin optimizer (CPO) algorithm was proposed to optimize KAN hyperparameters, and WPT-CPO-Transformer, WPT-CPO-LSTM, WPT-CPO-gated circulation unit (GRU), WPT-CPO-least squares support vector machine (LSSVM), WPT-CPO-extreme gradient ascent machine (XGBoost), WPT-CPO-MLP, and WPT-KAN were constructed. These seven kinds of comparative analysis models were verified by the daily average groundwater level time series prediction examples of Xicheng, Wenlan, Lin'an, and Caoba stations in Yunnan Province. Firstly, the WPT secondary decomposition technology was used to decompose the groundwater level time series data and divide the training set and the verification set. Then, the CPO was used to optimize the hyperparameters of KAN to overcome the tedious and inefficient manual debugging and avoid local optimization. Finally, the WPT-CPO-KAN model was established by using the optimal hyperparameters to train, predict, and reconstruct the decomposed components of the groundwater level time series. The results show that: (1) compared with that of the WPT-CPO-Transformer, WPT-CPO-LSTM, WPT-CPO-GRU, WPT-CPO-XGBoost, WPT-CPO-LSSVM, WPT-CPO-MLP, and WPT-KAN models, the prediction accuracy of the WPT-CPO-KAN model is improved by 15.6%, 37.4%, 26.5%, 36.4%, 18.6%, 7.2%, and 26.7%, respectively (MAPE index), which has a smaller prediction error and better universality. (2) Under the same WPT secondary decomposition and CPO, KAN can better capture the complex nonlinear space and time dependence in groundwater level time series data and is more suitable for the distribution of groundwater level time series data. Its performance is better than that of the transformer, LSTM, GRU, XGBoost models, traditional LSSVM, and MLP network. (3) The prediction error of the WPT-CPO-KAN model increases with the increase in the prediction step. Within three days, the prediction accuracy of the WPT-CPO-KAN model is higher. (4) The reasonable selection of hyperparameters is of great significance to improve the performance of the KAN model. By using CPO to optimize KAN hyperparameters, the performance of KAN and the level of prediction automation are significantly improved. The optimization method can provide a reference for improving the performance of KAN. (5) KAN can reveal the variation characteristics of groundwater level time series data with fewer parameters, thus enhancing the interpretability of the WPT-CPO-KAN model.

ZHANG Zhixiang, LIU Songtao, LI Qian et al.

【Background】Soil salinization is a widespread abiotic stress that significantly impacts agricultural productivity and water resource management in the Yinbei region of Ningxia Province. This study explores the inter-annual dynamics of soil salinity and groundwater depth in areas within this region that use surface irrigation and subsurface drainage.【Method】Field investigations were conducted in Huinong, a representative area in northern Yinbei characterized by surface irrigation and subsurface drainage systems. Spatiotemporal variation of soil salinity and groundwater depth were analyzed using measured data with the help of correlation analysis and the inverse distance weighting (IDW) interpolation method.【Result】Temporally, areas with high soil salinity were accounting ting for 23.57% of the study region in April. In contrast, areas with soil salinity greater than 2 g/kg decreased by 52.99% in July and 26.3% in October, compared to April. Soil salinity decreased gradually with increasing groundwater depth, and the relationship between them was well fitted by a proposed model (R2＞ 0.82).【Conclusion】Soil salinity in the region peaks in spring and declines by summer, showing spatial variability influenced primarily by topography and irrigation practices. Salinity in the 40-100 cm soil layer was more responsive to groundwater depth than in the 0-40 cm layer. Maintaining a groundwater depth between 1.8 and 2.2 m can facilitate crop growth and reduce salinization risk.

Yongxiang Zheng, Rui He, Liuke Huang et al.

Milena Truba, Jacek Sosnowski, Krzysztof Pakuła

The aim of the study was to determine the effect of soil fertilising biopreparations, i.e. compost extract, vermicompost extract and humus extract, used against the background of NPK mineral fertilisation, on the content of manganese, iron, zinc and copper in the biomass of Lolium perenne, Festulolium braunii, and Dactylis glomerata. In the spring of 2019 and 2020, a single dose of the biological preparation was applied. During each vegetation period, the plants were mown three times. During mowing, fresh plant mass was taken from each plot, dried, ground and the content of Cu, Zc, Mn and Fe was determined using the ICP-AES method. The use of a biological preparation with the composition of an extract from compost significantly increased the content of Mn, Fe and Zn in the dry mass of the tested grass species. The grass species that accumulated the highest total content of microelements in its above-ground parts was Lolium perenne. The use of only biological preparations in the cultivation of the analysed grass species gave better production effects, for example in the form of a higher concentration of microelements in the dry mass of plants compared to objects fed only with minerals. This creates the possibility of using the tested biopreparations in organic farms. The Fe:Mn ionic ratio was too wide in relation to the standards on all experimental objects, which resulted from the excess of Fe in the plants. Only the combination of compost extract with mineral fertilisation narrowed the above relationship, but it was still too high.

P. Desmond, K. Huisman, H. Sanawar et al.

The application of membrane technology for water treatment and reuse is hampered by the development of a microbial biofilm. Biofilm growth in micro-and ultrafiltration (MF/UF) membrane modules, on both the membrane surface and feed spacer, can form a secondary membrane and exert resistance to permeation and crossflow, increasing energy demand and decreasing permeate quantity and quality. In recent years, exhaustive efforts were made to understand the chemical, structural and hydraulic characteristics of membrane biofilms. In this review, we critically assess which specific structural features of membrane biofilms exert resistance to forced water passage in MF/UF membranes systems applied to water and wastewater treatment, and how biofilm physical structure can be engineered by process operation to impose less hydraulic resistance ("below-the-pain threshold"). Counter-intuitively, biofilms with greater thickness do not always cause a higher hydraulic resistance than thinner biofilms. Dense biofilms, however, had consistently higher hydraulic resistances compared to less dense biofilms. The mechanism by which density exerts hydraulic resistance is reported in the literature to be dependant on the biofilms' internal packing structure and EPS chemical composition (e.g., porosity, polymer concentration). Current reports of internal porosity in membrane biofilms are not supported by adequate experimental evidence or by a reliable methodology, limiting a unified understanding of biofilm internal structure. Identifying the dependency of hydraulic resistance on biofilm density invites efforts to control the hydraulic resistance of membrane biofilms by engineering internal biofilm structure. Regulation of biofilm internal structure is possible by alteration of key determinants such as feed water nutrient composition/concentration, hydraulic shear stress and resistance and can engineer biofilm structural development to decrease density and therein hydraulic resistance. Future efforts should seek to determine the extent to which the concept of "biofilm engineering" can be extended to other biofilm parameters such as mechanical stability and the implication for biofilm control/removal in engineered water systems (e.g., pipelines and/or, cooling towers) susceptible to biofouling.

Ebrahim Kadivar, M. Timoshevskiy, M. Nichik et al.

Cavitation is a process of liquid evaporation, bubble or vapor sheet formation, and further collapse of vapor structures, which plays a destructive role in many industrial applications. In marine transport and hydraulic machinery, cavitation usually occurs nearby the surface of a ship propeller and rudder, impeller blades in a pump, and distributor vanes and runner blades in a hydroturbine and causes various undesirable effects such as vibrations of frameworks and/or moving parts, material erosion, and noise enhancement. Based on an extensive literature review, this research is aimed at an experimental investigation of a passive approach to control cavitation on a benchmark hydrofoil using a wedge-type vortex generator in different flow regimes with a high Reynolds number. In this study, we employed a high-speed imaging method to explore the spatial patterns and time evolutions of cavitation structures and utilized a hydroacoustic pressure transducer to record and analyze local pressure pulsations due to the collapse of the cavities in the hydrofoil wake region. The results show that the examined control technique is quite effective and capable of hindering the formation of cloud cavities and reducing the amplitude of pressure pulsations associated with unsteady cavitation dynamics. This study provides important experimental information, which can be useful for improving industrial technologies and for promoting new developments in this particular research field.

LI Yexin, LYU Gang, WANG Daohan et al.

【Objective】 Restoring coal mining waste dumps is a way to alleviate their detrimental impact on environment. In this paper, we present the results of an experimental study on distribution and stability of soil aggregates in a reclaimed coal mining overburden dump. 【Method】 The experiment was carried out at a reclaimed coal mine dump site in a grassland region in northern China. We measured the development of fissures from Zone I (GF) to Zone three (GFIII) in the fissure zone. The composition and distribution soil aggregates in these zones were determined using dry-wet sieve method. Aggregate stability and its relationship with the fissures was analyzed. 【Result】 The content of the >0.25 mm air-dried aggregates over the fissure zones was 23.02%~42.70%, and content of the >0.25 mm water-stable soil aggregates was 16.9%~29.52%. There was no significant difference between air-dried aggregates and water-stable aggregates. The content of the >0.25 mm water-stable soil aggregates in the 0~60 cm soil layer in GF, GFⅡ and GF Ⅲ was 25.26%, 26.57%, 23.62%, respectively, while the percentage of aggregate destruction in the three fissure zones was 20.77%~36.17%, 20.52%~25.00%, and 26.58%~40.56%, respectively. The percentage of aggregate destruction in 0~10, 10~20, 20~30, 30~40, 40~50, and 50~60 cm soil layers was 28.81%, 29.96%, 26.19%, 23.50%, 24.91%, and 29.38%, respectively. The fractal dimension of air-dried and water-stable soil aggregates was 2.847~2.919 and 2.898~2.942, respectively. Small aggregates and fine particles are the dominant aggregates. The mean mass diameter (MWD) and geometric mean diameter (GMD) of the air-dried aggregates in three fissure zones were 1.11, 1.05, 1.28 mm, and 0.45, 0.44, 0.49 mm, respectively. The MWD and GMD of water-stable soil aggregates in the three fissure zones were 0.67, 0.73, 0.72 mm, and 0.36, 0.38, 0.37 mm, respectively. Soil in GFⅡ had good structure and aggregate stability. Most of water-stable soil aggregates in the fissure zones were unstable due to the formation and development of fissures. 【Conclusion】 The formation and development of fissures in the reclaimed coal mining overburden dump reduced the stability of soil aggregates, thereby resulting in aggregate segmentation. The larger and wider the fissures were, the less stable the soil aggregates were.

Zongliang Zhang, Xueming Wu, Enshang Xiao et al.

Abstract Based on the emergency rescue, the subsequent disposal, and the development and utilization projects of the Hongshiyan Landside Dam in Ludian, Yunnan, China, research has been conducted on key technical issues facing the development and utilization of landside dams, including the possibilty evaluation of development and utilization, structure analysis of wide gradation material, performance evaluation, investigation and design, dam seepage control, construction technology and equipment, and safe operation assessment. And innovative results has made in all seven aspects mentioned above, writing the history in this field. The achievements were directly applied to the development planning, investigation and design, construction, and operation and maintenance of the Hongshiyan Landside Dam, a comprehensive water conservancy project that integrates flood control, water supply, irrigation, and power generation, with significant comprehensive benefits.

Marta J. Kiraga, Anna Markiewicz

Changes in river channel morphological parameters are influenced by anthropogenic factors, such as climatic changes, river catchment management changes, and hydrotechnical development of rivers. To assess the intensity of individual pressures and the resulting changes in abiotic and biotic factors in the riverbed, water quality monitoring is conducted, including the assessment of the hydromorphological status. The assessment can be based on the River Habitat Survey (RHS) which is a synthetic method that includes the evaluation of habitat character and river quality based on their morphological structure. The input data, which characterise any river include physical features of hydrotechnical structures, bed granulation, occurrence of bedforms, visible morphodynamic phenomena, and a sediment transport pattern. The RHS method allows to determine two quantitative indices used to evaluate the hydromorphological status: Habitat Modification Score ( HMS), which determines the extent of transformation in the morphology of a watercourse, and Habitat Quality Assessment ( HQA), which is based on the presence and diversity of natural elements in a watercourse and river valley. The proposed method can be divided into three stages. The first assesses the river section hydromorphological indices, describing the degree of technical modification ( HMS) and the ecological quality of the reach ( HQA), using the RHS method. The second stage describes morphological changes resulting from the technical regulation and estimates indices for the regulated reach. Finally, we compare HQA and HMS indices before and after the regulation. This comparison is described by numerical indicators and related to reference values.

Paul Dominique Barrette, Karl-Erich Lindenschmidt

This article addresses the question: What is expected from frazil ice activity in rivers, taking into account the changing climate? It begins with an overview of what frazil ice is and what is required for the occurrence of frazil ice events, namely a supercooled water column. Methodologies to anticipate frazil ice events in the short term are based on air temperature and water discharge, underlining the significance of these two parameters for any predictive methods. Longer-term approaches, calibrated against past events (hindcasting), are used to anticipate frazil ice activity into the future, with indicators such as frazil ice risk, water temperature and frazil volume. Any of these approaches could conceivably be applied to frazil-prone river stretches. To assess climate impact, each location should be treated separately. River ice dynamics can lead to the formation of a hanging dam, a frequent outcome of frazil ice generation in the early winter, causing flow restriction. Flood modeling and forecasting capabilities have been developed and implemented for operational use. More frequent mid-winter breakups are expected to extend the occurrence of frazil ice events into the winter months – the prediction of these will require climate model output to adequately capture month-to-month variability. HIGHLIGHTS Previous modeling endeavors aimed at foreseeing frazil ice generation in rivers are summarized.; Frazil ice risk, water temperature and frazil ice volume are model outputs.; Each frazil-prone location should be the subject of its own climate impact study.; Mid-winter breakups (MWBs) will likely be more frequent in the future, which implies that clogging risks at water intakes will extend well into the winter months.;

SHAO Peiyin, LI Yalong, XIONG Yujiang et al.

【Objective】 Most hilly regions in China are short of freshwater resources and recycling the effluent water in their drainage ditches is a way to relieve this pressure and improve water use efficiency. This paper investigates how reusing the effluent water for irrigation affects leaching of nitrogen (N) and phosphorus (P) from soils. 【Method】 In-situ experiment was set up in a field to measure the change in water flow and N and P concentrations in the ditches and the ditch buckets. We calculated the ratio of recycled water volume to the volume of water pumped for irrigation (i.e., regression rate), as well as the change in N and P pollutant loads and their determinants. 【Result】 The water had been drained and reused for irrigations for 24 cycles during the growing season, and the total regression rate reached 89.93%. The loads of total P, total N, nitrate nitrogen and ammonia nitrogen during the growing season were 0.28, 3.27, 2.35 and 2.35 kg/hm2, respectively. The load reductions of P and N were correlated with the ratio of their concentrations in the effluent and in the irrigation water. The reduction in total P and ammonia was significantly correlated with the regression rate. The reduction in total N and nitrate was significantly correlated with irrigation and rainfall in the second day after the irrigation. Nitrate reduction rate was also significantly correlated with temperature. 【Conclusion】 The cycles of drainage and its reuse for irrigation not only saves water but also improves utilization of water and fertilizers, thereby reducing the risk of N and P pollution to the downstream.

MA Jinghang, XIAN Yongcai, HE Xueping et al.

Flood forecasting is one of the important non-engineering flood control measures and is the main basis for flood control command and decision-making.In order to avoid the uncertainty of the prediction results of a single model,the Majiagou Reservoir in Chenggu County was taken as the object to simulate the daily runoff and flood process from 2019 to 2021 by using the Xin'anjiang model and tank model respectively,and the simulation results and accuracy of the two models were compared by using the model parameters calibrated and optimized by the genetic algorithm.In the daily runoff simulation,the simulation effect of the tank model is better than that of the Xin'anjiang model,with a relative error of flood volume of less than 16%,a relative error of flood peak of less than 4%,a difference of peak time of less than 1 h,and a Nash-Sutcliffe efficiency coefficient of greater than 0.58,all of which meet the evaluation accuracy requirements of the Standard for Hydrological Information and Hydrological Forecasting,and the simulation effect of deluge in the reservoir is ideal.In the flood process simulation,the difference of peak time between the two models is similar;the simulation effect of the Xin'anjiang model is smoother,and the flood volume and flood peak simulated by the tank model are closer to the measured flow process.On the whole,the tank model is more suitable for flood forecasting in Majiagou Reservoir than the Xin'anjiang model.

Xin-zhi Wang, H. Ding, Qingshan Meng et al.

M. S. H. Ruslan, M. Bilad, M. Noh et al.

Abstract Implementation of student-centered learning has shown wide global acceptance within institutes of higher learning. Some methods, such as active learning, project-based learning, problem-based learning, and experiential-based learning, have significantly impacted the students’ understanding of a particular subject. However, students will still have problems integrating the materials learned from one course to other courses. Thus, this is where the proposed initiative comes in. This paper discusses the implementation of integrated project-based learning (IPBL) to assist students in integrating the knowledge gained from one course to the other for first-year chemical engineering students of Universiti Teknologi PETRONAS. The mapping of assessments and learning domains to the learning activities are also shown in detail. This study was conducted on two courses offered in the same semester, namely, Principles of Chemical Engineering and Chemical Engineering Fluid Mechanics, in January 2019. A total of 214 students grouped in 43 teams were asked to develop a Do-It-Yourself (DIY) hydraulic jack, which uses the fundamentals taught in these two courses. The results show that 100 % student was able to come up with a working prototype within 5 weeks and 90 % of the students agree that the initiative increased their understanding in chemical engineering fundamentals and developed their leadership, problem-solving, communications and time management skills.

Mojtaba Pakparvar, Gholamali Nekooeian, Gholamreza Ghahari et al.

Introduction Water scarcity due to climate change and growing water demand in different consumption sectors is a major environmental crisis that drives arable lands to a state of degradation, especially in dry regions. Artificial recharge of groundwater (ARG) through floodwater spreading (FWS) which is a potential measure for reversing this emerging trend is investigated in this research. Floodwater harvesting has become an increasingly important technique to improve water security and caused a renewed interest in research and implementation. According to the diverse objectives and methods of implementing artificial recharge of groundwater (ARG) systems, various factors must be considered when choosing a method for quantifying recharge. Therefore, the rate of aquifer recharge is one of the most difficult items to measure in groundwater (GW) resources evaluation. In the soil water balance method (and in the Zero Flux Plane method), soil water movement is inferred by measuring the changes in water content of the soil profile by gravimetric sampling or automatic devices. These methods have not been proven satisfactory in low flow conditions, as there is often insufficient resolution to detect the movement of small quantities of water. Therefore, other methods, based on hydraulic conductivity, potential gradients, and directly calculated water fluxes for unsaturated flow were developed. The Buckingham-Darcy law can be used under the steady flow condition where water contents and fluxes change with depth but do not vary as a function of time. It has been employed in arid and semiarid conditions for recharge estimation. or for assessing the exchange flow between the surface water reservoir and GW. The method requires measurements or estimates of the vertical total head gradient and the unsaturated hydraulic conductivity at the ambient soil water content following the Buckingham-Darcy equation. The overall objective is to evaluate a floodwater spreading system that was installed in 1981 at the Gareh Bygone Plain, southern Iran for recharging the groundwater table.   Materials and Methods To assess the artificial recharge of groundwater through turbid floodwater spreading, three wells, ~30 m deep, were dug in a 37-year-old recharge basin in planted Acacia forest, bare soil, and pasture land uses, respectively. Soil hydraulic parameters of the vadose zone layers (30 m thickness) were measured in the field and laboratory. One well was equipped with pre-calibrated TDR sensors throughout the well profile for measuring the changes in soil water content along the vadose zone. The volumetric soil-water content was measured continuously from Sep. 2010 to Sep. 2020 with closer temporal increments after floodwater spreading events. Rainfall, ponding water depth, and duration were also measured. Recharge through the vadose zone was assessed by the soil-water balance (SWB) method, as measured in the field as well as by calibrating the Hydrus-1D (H1D) model through the inverse solution.   Results and discussion Results showed that the wetting front was interrupted at a layer with fine soil accumulation over a coarse-textured gravely layer at a depth of ~4 m. The large differences in hydraulic conductivity of the two successive layers seemed to cause the transformation of the wetting front water movement into fingering flow. The changes in downward water flux complicated TDR measurement after the depth of 4 m. However, noticeable but temporary changes in the soil water content were detected in some of the layers below the 4 m was evidence for fingering flow after the flood events. Validation of the simulated flow by the H1D model vs. the one observed by SWB (with RMSE 3.45; R2 0.994) showed that the model performed well in flux estimation. The recharge ratio was calculated for the 2010 to 2020 events as 26 to 84 average of 55 % for all events and 63 to 84 average of 75 % for large impounded floodwater in the basin, respectively.   Conclusion Although a reliable set of data is obtained for calculating recharge at the very location of this study, up-scaling of the results for the entire floodwater systems and for the other flooding events with extreme volume and flow rate needs an extended investigation period and thorough identification of the underlying layers. The determined hydraulic properties of the RLs obtained in this study will be utilized in future research works in the FWS systems in our study site. The contributions of this thesis can be summarized as a) development of approaches for application, calibration, and validation of existing models with limited available data, b) the incorporation of new concepts into the models used, c) generating a unique and robust field data set to support the modeling approaches and d) provision of new information in the context of floodwater harvesting and its impact on groundwater recharge. Floodwater harvesting, especially in the form of FWS, is an emerging issue in water management in dry regions, which needs a better understanding and evaluation of its impact on the surrounding environment. Small-scale but nature-friendly water management plans, such as FWS systems, are seriously criticized since there are numerous methods, which are more attractive in terms of investments and money return to investors. However, they are rarely investigated. This study provided quantitative evidence that proves the effectiveness of FWS systems.

L. J. E. Bouaziz, L. J. E. Bouaziz, F. Fenicia et al.

<p>Streamflow is often the only variable used to evaluate hydrological models. In a previous international comparison study, eight research groups followed an identical protocol to calibrate 12 hydrological models using observed streamflow of catchments within the Meuse basin. In the current study, we quantify the differences in five states and fluxes of these 12 process-based models with similar streamflow performance, in a systematic and comprehensive way. Next, we assess model behavior plausibility by ranking the models for a set of criteria using streamflow and remote-sensing data of evaporation, snow cover, soil moisture and total storage anomalies. We found substantial dissimilarities between models for annual interception and seasonal evaporation rates, the annual number of days with water stored as snow, the mean annual maximum snow storage and the size of the root-zone storage capacity. These differences in internal process representation imply that these models cannot all simultaneously be close to reality. Modeled annual evaporation rates are consistent with Global Land Evaporation Amsterdam Model (GLEAM) estimates. However, there is a large uncertainty in modeled and remote-sensing annual interception. Substantial differences are also found between Moderate Resolution Imaging Spectroradiometer (MODIS) and modeled number of days with snow storage. Models with relatively small root-zone storage capacities and without root water uptake reduction under dry conditions tend to have an empty root-zone storage for several days each summer, while this is not suggested by remote-sensing data of evaporation, soil moisture and vegetation indices. On the other hand, models with relatively large root-zone storage capacities tend to overestimate very dry total storage anomalies of the Gravity Recovery and Climate Experiment (GRACE). None of the models is systematically consistent with the information available from all different (remote-sensing) data sources. Yet we did not reject models given the uncertainties<span id="page1070"/> in these data sources and their changing relevance for the system under investigation.</p>

Christian Edgardo Saravia Solares

La quema del diablo se celebra cada año el 7 de diciembre a las 18:00 horas en Guatemala, tradición que en hacer fogatas en la calle. La contaminación del aire en la ciudad de Guatemala se ha evaluado cualitativamente o basado en estimaciones, por lo que es necesario cuantificar la contaminación del aire cuando se presenta el evento. Se instalaron sensores que miden las partículas con diámetro aerodinámico de 2.5 micrómetros (PM2.5) y 10 micrómetros (PM10).  La medición se inició a las 00:00 y se concluyó a las 24 horas. El rango para PM2.5  con valores promedio se encuentra entre 15 a 8 µg m-3 y máximo de 152 µg m-3 y para PM10 promedio 26 a 14 µg m-3 y máximo de 267 µg m-3. Los resultados indican que en el periodo entre las 18:00 a las 21:30 horas, se incrementaron los niveles de partículas de PM2.5 y PM10, a partir de las 22:40 horas, se tuvo picos de las concentraciones de PM2.5 y PM10 debido probablemente a la contaminación arrastrada de los vientos predominantes del noreste y estenordeste, con promedios que superan los límites permitidos de las guías de la Organización Mundial de la Salud del 2005, para material particulado PM2.5  25 µg m-3 y PM10 50 µg m-3.

Qian Deru, Zheng Junhua, Gao Runfeng et al.

The MWD tool for formation pressure is composed of mechanical, electronic and hydraulic components. The internal installation space is small, the structure is complex, and the integration is difficult. In order to reduce the research and development risk of the tool, the formation pressure simulation gauging nipple was developed firstly. The 3D visualization technology was used to establish the virtual digital prototype of the simulation gauging nipple. The hydraulic valve insertion technology was used to study the key modules such as the micro hydraulic system with an output pressure of 20 MPa. Meanwhile, a formation pressure simulation test apparatus was developed as a platform for indoor high-temperature and high-pressure test and test principle verification of simulation gauging nipple. Actual measurement shows that the simulation gauging nipple runs stably at 120 ℃ and 60 MPa. Cores with permeability of 1&#215;10^-3 μm² and 320&#215;10^-3 μm² were selected to investigate the gauging nipple test principle, obtaining the formation pressure test curve, with measurement accuracy reaching 96%. The laboratory test verified the correctness of the measurement principle of the simulation gauging nipple and the accuracy of the measurement data. The research results lay a solid foundation for the development of formation pressure MWD engineering prototype.

José Alberto Espinosa-López, Laura Alicia Ibáñez-Castillo, Ramón Arteaga-Ramírez et al.

En México es necesaria la explotación y el control de los recursos hídricos, ya sea para cubrir las diversas carestías o para protegerse del daño causado por eventos extremos. Esta investigación tuvo como objetivo modelar y calibrar los hidrogramas de una cuenca, calculados con datos de lluvia y medidos con imágenes de satélite GPM-IMERG en la cuenca del río Huaynamota, México, así como comparar los resultados con un modelo hidrológico alimentado con datos de lluvia de estaciones meteorológicas automáticas. Esta investigación se realizó en un tributario de la cuenca del río Huaynamota, el cual es parte de la región hidrológica Lerma-Chapala-Santiago. La cuenca se ubica en los estados de Zacatecas, Durango, Jalisco y Nayarit. Para el análisis de los hidrogramas a la salida de la cuenca se evaluaron eventos de lluvia máximos ocurridos en los periodos del 21 al 26 de julio de 2016, del 14 al 24 de agosto de 2017, y del 1° al 16 de septiembre de 2017. El modelo se desarrolló en HEC-HMS, con base en métodos como el número de curva de escurrimiento y el hidrograma unitario de Clark. La comparación de los hidrogramas medidos y aparentados mostró un buen ajuste de lo simulado con la realidad. En la mayoría de los eventos modelados, el coeficiente de Nash-Sutcliffe fue mayor a 0.5, que se considera aceptable. Se concluyó que la modelación hidrológica a partir de imágenes de satélites meteorológicos es una buena opción para su implementación en regiones donde se carece de datos de lluvia horaria medida con instrumentos en tierra.

Xiaoke He, Yingchong Zhang, Chuan Wang et al.

The numerical method on a double-channel sewage pump was studied, while the corresponding experimental result was also provided. On this basis, the influence of wall roughness on the pump performance was deeply studied. The results showed that there was a critical value of wall roughness. When the wall roughness was less than the critical value, it had a great influence on the pump performance, including the head, efficiency, and shaft power. As the wall roughness increased, the head and efficiency were continuously reduced, while the shaft power was continuously increased. Otherwise, the opposite was true. The effect of wall roughness on the head and hydraulic loss power was much smaller than that on the efficiency and disk friction loss power, respectively. With the increase of wall roughness, mechanical efficiency and hydraulic efficiency reduced constantly, leading to the decrement of the total efficiency. With the increase of flow rate, the effect of wall roughness on the head and efficiency gradually increased, while the influence on the leakage continuously reduced. The influence of the flow-through component roughness on the pump performance was interactive.