Basin Dimensions Research Articles

Solar still basin measurements and liner material variance for improved water desalination efficiency

Access to potable water remains a global challenge, and solar stills offer a sustainable desalination solution. Solar stills however have low desalination efficiencies. The impact of basin measurements and liner material variance on their performance have not been evaluated, and this study sought to investigate this through modelling with the objective of improving the performance of a one-slope solar still. MATLAB is employed in the model development and simulations. The developed model is validated using other experiments in literature. The analysis is done with Machakos (1.52°N, 37.2°E), Kenya climatic conditions as a reference. Various basin liner materials including aluminium, synthetic graphite, brass, galvanized iron and stainless steel are examined based on their thermal properties. Different width-to-length ratios ranging from 0.14 to 0.86 are investigated. Basin liner thicknesses of between 2 mm and 6 mm are evaluated. A parametric study is conducted to determine the correlation between liner material thickness and basin dimensions, and their combined impact on freshwater yields. From the results, synthetic graphite had the best performance, followed by aluminium, brass, galvanized iron and stainless steel with efficiencies of 35.04 %, 24.02 %, 17.02 %, 14.13 % and 12.39 %, respectively. Thus, synthetic graphite outperformed aluminium, brass, galvanized iron and stainless steel by 31.4 %, 51.43 %, 59.675 % and 64.64 %, respectively. A width-to-length ratio of 0.45 yields optimal results, while a liner material thickness of 4 mm is found to be ideal across all materials. The parametric study further reveals that width-to-length ratio has a higher significance on freshwater yields compared to liner material thickness.

Hydrological Verification of Two Rainfall Short-Term Forecasting Methods with Floods Anticipation Perspective

Abstract Flood forecasting remains a significant challenge, particularly when dealing with basins characterized by small drainage areas (i.e., 103 km2 or lower with response time in the range 0.5–10 h) especially because of the rainfall prediction uncertainties. This study aims to investigate the performances of streamflow predictions using two short-term rainfall forecast methods. These methods utilize a combination of a nowcasting extrapolation algorithm and numerical weather predictions by employing a three-dimensional variational assimilation system, and nudging assimilation techniques, meteorological radar, and lightning data that are frequently updated, allowing new forecasts with high temporal frequency (i.e., 1–3 h). A distributed hydrological model is used to convert rainfall forecasts into streamflow prediction. The potential of assimilating radar and lightning data, or radar data alone, is also discussed. A hindcast experiment on two rainy periods in the northwest region of Italy was designed. The selected skill scores were analyzed to assess their degradation with increasing lead time, and the results were further aggregated based on basin dimensions to investigate the catchment integration effect. The findings indicate that both rainfall forecast methods yield good performance, with neither definitively outperforming the other. Furthermore, the results demonstrate that, on average, assimilating both radar and lightning data enhances the performance.

Effect of adverse slope on performance of USBR II stilling basin

Abstract This article focuses on the United States Bureau of Reclamation (USBR) Type II stilling basin, which has chute blocks, an end dentated sill, and a flat floor. USBR provides general design criteria to contain the hydraulic jump within the stilling basin. The sequent depth ratio, energy dissipation ratio, and stilling basin dimensions of the hydraulic jump are changed when the bed slope of USBR II stilling basins is changed. This study aimed to investigate the effects of adverse slope on the performance of USBR II stilling basin in terms of sequent depth ratio and energy dissipation. Six discharges ranging from 8 to 33 lps were applied to the USBR II stilling basin with bed slopes (S) of −0.085, −0.055, −0.035, and 0. Results demonstrated that for Q = 13 and 8 lps, the basin performs better than other models with S = −0.085, increasing energy dissipation by about 10% compared to a typical basin due to the formation of a free hydraulic jump downstream dentated end sill. On the other hand, the floor downstream of the dentated end sill needs more protection against this free jump, and this case becomes economically expensive. In other cases, the downstream jump was submerged, resulting in a counterintuitive current and reverse roller based on the submerged ratio, reducing the effectiveness of the stilling basin. In addition, the modified design of the stilling basin resulted in a shorter effective length that included the hydraulic jump downstream spillway, thereby reducing internal friction. As a result, the standard USBR II with a flatbed is less expensive and more efficient than the adverse slope basin.

Numerical modeling of hydraulic jumps at negative steps to improve energy dissipation in stilling basins

The performance of stilling basins including a negative step was analyzed addressing its effect on the energy dissipation efficiency, dimensions and structural properties of the hydraulic jump, streambed pressures and pressure fluctuations. Six different cases were simulated, considering two possible relative heights for the step and three possible Froude numbers. The results show that the step yields to lower subcritical depths, allowing smaller basin dimensions. Nevertheless, it tends to slightly increase the roller length of the jump. Concerning the relative energy dissipation, results confirm the improvement derived from the step presence. The internal flow occurring in the jump was also analyzed, and more specifically the subzones generated upstream and downstream the impingement point. The results prove the contribution of the negative step in the stabilization of hydraulic jumps in the stilling basin. In particular, a general decrease of the streambed pressure is observed. In addition, pressure fluctuations are significantly reduced due to the negative step size influence on the hydraulic jump. Furthermore, the effectiveness of the computational fluid dynamics (CFD) techniques to simulate stilling basin flows and to adequately characterize the hydraulic jump performance was confirmed.

A review on use of mechanical measures in in-situ moisture conservation techniques in agriculture

In this article an effort has been made to review the approaches made on conserving the moisture through in-situ conservation techniques and mechanical measures employed to conserve soil and water with different conservational practices such as basin listing, compartmental bunding, tie ridging, ridge formation, check basin formation etc. has analyzed and the effect of these conservational practices on yield of crop, effect of mechanical machine parameters on basin dimensions and its performance and finally, advantage of these conservational practices in terms of net returns to farmers has been highlighted.

Agriculture mechanization, farm machinery accidents and safety

In this article an effort has been made to review the approaches made onconserving the moisture through in-situ conservation techniques and mechanical measures employed to conserve soil and water with different conservational practices such as basin listing, compartmental bunding, tie ridging, ridge formation, check basin formation etc. has analyzed and the effect of these conservational practices on yield of crop, effect of mechanical machine parameters on basin dimensions and its performance and finally, advantage of these conservational practices in terms of net returns to farmers has been highlighted.

Measuring The Use of Detention Basin as Flood Control System at Campus I Lambung Mangkurat University Banjarmasin, Indonesia

South Kalimantan Province has experienced floods during the rainy seasons due to high intensity of precipitation. In mid-January 2021, flood inundated the Banjarmasin Campus I area of Lambung Mangkurat University (ULM Campus I). In mid-December 2021, other flood case inundated Campus I ULM. The research aims to measure the effectiveness of using detention basin as flood control in Banjarmasin campus area of ULM. Data collection is based on hydrological analysis of rain data to obtain a designed flood discharge with a return period of 20 years using the Der Weduwen method. The hydraulic analysis of the transverse and longitudinal sections on the river section of Campus I ULM was analyzed using the HEC-RAS. Based on the value of the flood volume, an analysis of the volume of the detention basin is carried out, where the volume of the detention basin must be greater than the volume of the flood. Spatial data is used to obtain contours using ArcGIS, to determine the optimal location of the detention basin. Based on the simulation, cumulative planned flood volume was 36,010 m3 with a discharge value of 89.30 m3/s. It was designed two detention basin. First detention basin dimension is 160 m x 130 m x 1.5 m located closed to General Building. The second one, located at Master of Law Building with dimension is 120 m x 35 m x 1.5 m First detention basin dimension is 160 m x 130 m x 1.5 m located closed to General Building. The second one, located at Master of Law Building with dimension is 120 m x 35 m x 1.5 m.

Numerical Investigation of the Effect Dimensions of Rectangular Sedimentation Tanks on Its Hydraulic Efficiency Using Flow-3D Software

Settling basins are among the essential units built to separate sediment suspended and within the inlet flow particles in water and wastewater treatment plants and irrigation canals. These basins' high efficiency requires proper design, creating a smooth and uniform flow along the basin, and reducing circulation zone as a factor in disrupting the sedimentation process. The present study investigates basin dimensions' effect on its flow pattern. Hence In the current study, the primary rectangular sedimentation basin was modelled three-dimensionally using Flow-3D software. This software takes advantage of two new advanced technique of VOF and FAVOR to model the free surface of the flow and the geometry, respectively. The dimensions of the basin were examined in two scenarios. In the first set-up, the length-to-width ratio was evaluated by increasing length and decreasing width simultaneously and the second part examined the length to depth ratio by decreasing depth and increasing width. In both situations, the volume and location of the inlet and outlet of the basin were constant and unchanged. The outcomes indicate that increasing the ratio of length-to-width and length to depth reduces the volume of the circulation zone significantly. The volume of these zones decreased from 53% for the L/W ratio of one (square basin) to 22% associated with the L/W ratio of eight. Likewise, the volume of these zones decreased by 38% as a result of increasing the L/d ratio from five to ten.

Analytical Model of Thermohaline Circulation in Land-Locked Basins: Analyzing the Impact of Friction on Circulation Reversal

Abstract The paper investigates switches of circulation orientation in inland basins, either at the surface or near the bottom. The study is based on an analytical 2D model used to simulate thermohaline circulation in lakes and inland seas. The model allows different density profiles varying in both horizontal and vertical directions. By assuming some simplifications (such as steady state, vanishing of an alongshore variability, and flat bottom), we are able to obtain an explicit expression of the circulation in the central transverse section of an elongated basin. Starting from three typical density profiles (bottom dense water, surface light water, and a combination of the two), the model reveals different circulation types (cyclonic and anticyclonic surface circulation, either prevailing along the whole vertical column or accompanied by an opposite circulation in the bottom layer). In addition, we analyze the impact of friction coefficients and basin dimensions on the switch from one circulation type to another. The simplified assumptions turn out not to be limiting, as other studies have shown that they do not change the main flow characteristics. More importantly, the results obtained are in keeping with empirical findings, numerical simulations, and physical experiments studied elsewhere.

Packing Dimensions of Basins Generated by Invariant Measures on a Sequence Space

Packing Dimensions of Basins Generated by Invariant Measures on a Sequence Space

Implications of geomorphometric parameters on the occurrence of landslides in the Kali Valley, Kumaun Himalaya, India

The Kumaun Himalaya registers frequent seismicity, neotectonic behaviour and incessant rainfall which accelerate hillslope processes governing landsliding phenomenon. Within the Kali Basin between Jauljibi and Garbyang, morphometric analysis of 45 fourth order sub-basins were carried out to prepare an erosion potential map of the region. The spatial distribution of 376 landslides including 158 debris slide and 97 rockfalls correlates well with the erosion map depicting 40% landslides in very high zone, 15% in high zone, 33% in moderate zone, 12% in low zone across the Kali Basin. The dominant parameters responsible for the erosion were evaluated using statistical methods such as Principal Component Analysis (PCA) and Agglomerative Hierarchal clustering (AHC). The comparison of PC1, PC2 and PC3 illustrates high erosion activity around the Main Central Thrust (MCT) and within the Vaikrita and Chipplakote formations which strongly reflect the function of basin dimension, bifurcation ratio, drainage density, relief and shape parameters for sub-basins exhibiting high proneness to flooding and typical surface runoff. The PCA results are consistent with AHC, where AHC clusters correspond with PCA factor loadings. Morphotectonic analysis using steepness index (Ksn) and valley floor width to height ratio (Vf) for the Kali and Dhauli rivers were integrated with landslide inventory that indicate the highest landslide density across the active Seraghat-Tintola Fault (STF) near Tawaghat and moderate to high density near topographic fronts of closely spaced active Lasku Fault (LF), Ghatibagar Kalika Fault (GKF) Rauntis Fault (RF) that outcrop within the Lesser Himalayan Sequences(LHS) exposed between Dharchula and Jauljibi.The study provides an understanding of quantitative geomorphometry as an useful approach to identify potentially active zones for slope failures and provide a guide to decision-makers in regional planning and mitigating the landslide hazard in the Kali valley which is developing hub for large scale infrastructural and tourist activities.

Physical model test validation of dynamic similarity truncation method for an internal turret mooring system

The mooring system needs to be truncated in physical model test to adapt to the limited dimensions of offshore basins. Especially, the drag force and inertial force are required to be included in the dynamic mooring truncation methods, and the method should be verified by model test comparison. Here an effective dynamic truncation method is proposed based on slender rod theory and multi-objective cuckoo search optimization algorithm. The line tensions in time domain are transferred into frequency domain to implement the dynamic similarity. The proposed process can promote optimization efficiency in a great extent. In order to demonstrate the accuracy of the proposed method, a horizontal truncation is carried out to an internal turret moored FPSO working in 420 m water depth. The model test in deep-water basin is performed with static tests and irregular wave tests. It can be found that model test and numerical results show consistence on the static stiffness characteristics and dynamic response. The comparison verifies the reliability and accuracy of the proposed truncation method well.

Effect of Mulching and Permanent Planting Basin Dimensions on Maize (Zea mays L.) Production in a Sub-Humid Climate

In sub-humid regions, declining maize (Zea mays L.) yield is majorly attributed to unreliable rainfall and high evapotranspiration demand during critical growth stages. However, there are limited farm technologies for conserving soil water and increasing water use efficiency (WUE) in rainfed production systems amidst a changing climate. This study aimed at assessing the performance of different climate smart agriculture (CSA) practices, such as mulching and permanent planting basins (PPB), on maize growth, yield, water use efficiency and soil moisture storage. Field experiments involving mulches of 2 cm (M_2 cm), 4 cm (M_4 cm) and 6 cm (M_6 cm) thickness, permanent planting basins of 20 cm (PPB_20 cm) and 30 cm (PPB_30 cm) depths and the control/or conventional treatments were conducted for three maize growing seasons in the sub-humid climate of Western Uganda. Results indicate that maize biomass significantly increased under the tested CSA practices in the study area. Use of permanent planting basins relatively increased maize grain yield (11–66%) and water use efficiency (33–94%) compared to the conventional practice. Additionally, plots treated with mulch achieved an increase in grain yield (18–65%) and WUE (28–85%) relative to the control. Soil amendment with M_4 cm and M_6 cm significantly increased soil moisture storage compared to permanent planting basins and the conventional practice. Overall, the results highlight the positive impact of CSA practices on improving maize yield and water use efficiency in rainfed agriculture production systems which dominate the sub-humid regions.

A CFD-ML augmented alternative to residence time for clarification basin scaling and design

Particulate matter (PM), while not an emerging contaminant, remains the primary labile substrate for partitioning and transport of emerging and known chemicals and pathogens. As a common unit operation and also green infrastructure, clarification basins are widely implemented to sequester PM as well as PM-partitioned chemicals and pathogens. Despite ubiquitous application for urban drainage, stormwater clarification basin design and optimization lacks robust and efficient design guidance and tools. Current basin design and regulation primarily adopt residence time (RT) as presumptive guidance. This study examines the accuracy and generalizability of RT and nondimensional groups of basin geometric and dynamic similarity (Hazen, Reynolds, Schmidt numbers) to scale clarification basin performance (measured as PM separation and total PM separation). Published data and 160,000 computational fluid dynamics (CFD) simulations of basin PM separation over a wide range of basin configurations, loading conditions, and PM granulometry (particle size distribution [PSD], density) are examined. Based on the CFD database, a novel implementation of machine learning (ML) models: decision tree (DT), random forest (RF), artificial neural networks (ANN), and symbolic regression (SR) are developed and trained as surrogate models for basin PM separation predictions. Study results indicate that: (1) Models based solely on RT are not accurate or generalizable for basin PM separation, with significant differences between CFD and RT models primarily for RT < 200 hr, (2) RT models are agnostic to basin configurations and PM granulometrics and therefore do not reproduce total PM separation, (3) Trained ML models provide high predictive capability, with (R2) above 0.99 and prediction for total PM separation within ±15%. In particular, the SR model distilled from CFD simulations is entirely defined by only two compact algebraic equations (allowing use in a spreadsheet tool). The SR model has a physical basis and indicates PM separation is primarily a function of the Hazen number and basin horizontal and vertical aspect ratios, (4) With common presumptive guidance of 80% for PM separation, a Pareto frontier analysis indicates that the CFD-ML augmented SR model generates significant economic benefit for basin planning/design, and (5) CFD-ML models show that enlarging basin dimensions (increasing RT) to address impaired behavior can result in exponential cost increases, irrespective of land/infrastructure adjacency conflicts. CFD-ML applications can extend to intra-basin retrofits (permeable baffles) to upgrade impaired basins.

Complex Fluctuation of Power Price in Dual-Channel and Multienergy Supply Chain Based on Sticky Expectation

According to the current power supply focused reform in China, a dual-channel and multienergy supply chain model is constructed. The supply chain has a new energy enterprise, a traditional energy enterprise, and the State Grid that is the retailer. New energy company and traditional energy company sell electricity to the State Grid at wholesale prices, and at the same time they enter the market to retail power products. Multiequilibriums and their practical significance are discussed. The complex dynamic is investigated using a bifurcation diagram, Lyapunov exponent, parameter basin, and fractal dimension. In this multilayer supply chain network, the price adjustment of the State Grid will make the entire supply chain face greater volatility risks, and dual-channel suppliers, that is, new energy and traditional energy companies are also involved in this volatility. Further, considering the sticky information, the sticky expectation of electricity price is built for studying the lagging electricity price. The dynamic characteristics of the sticky model are investigated, and new phenomena are discovered: 3-orbit bifurcation and mutation appear with fractals. This means that prices continue to swing and oscillate on three tracks. Through comparison of the fractal dimension, an important conclusion is discovered: the purpose of sticky expectations for electricity prices is to stabilize price fluctuations, but sticky expectations make the market more complicated. The article provides a strategic reference for exploring the power market in China.

Packing dimensions of basins generated by distributions on a finite alphabet

We consider a space of infinite signals composed of letters from a finite alphabet. Each signal generates a sequence of empirical measures on the alphabet and the limit set corresponding to this sequence. The space of signals is partitioned into narrow basins consisting of signals with identical limit sets for the sequence of empirical measures and for each narrow basin its packing dimension is computed. Furthermore, we compute packing dimensions for two other types of basins defined in terms of limit behaviour of the empirical measures.

Multi-objective optimization of stepped spillway and stilling basin dimensions

Abstract In the present paper, an optimization procedure is proposed for stepped spillway design dimensions, which leads to maximum energy dissipation rate and minimum construction cost, considering independently the chute cost and stilling basin cost. Three independent objective functions are thus simultaneously satisfied. The procedure involves four main tools: the multi-objective particle swarm optimization method (MOPSO) to find Pareto solutions in one run, the K-means clustering algorithm to reduce the size of the obtained non-dominated solutions, the pseudo-weight vector approach (PWV) to facilitate the decision making and to select some adequate solutions, and finally, CFD simulations to analyze the retained optimal solutions. The suitability of the proposed procedure is tested through an example of application. As results, a set of 20 solutions with different satisfaction levels is found and compared to existing solutions. A multi-objective optimization problem may have many different solutions; the originality of the present work lies in the proposed procedure, which explores several possible solutions and reduces their number to give help to the decision making. Furthermore, an approximate expression of spillway total cost is also derived as a function of flow energy dissipation rate.

Morphometric analysis of basins located in the piedmont of central western Argentina

Morphometric characteristics are quantitative indicators of basin elements, which influence the magnitude and variability of hydrological processes. The main objective of this work is to determine morphometric parameters related to the geometry, relief and drainage network of 34 sub-basins located in the WEST of Mendoza capital city (Argentina), between parallels 32° 55’ and 32° 58’ S and meridians 68° 53’ and 69° 05’ W. This information will allow understanding and characterize the hydrological processes in the eastern slope of the Precordillera, Piedmont and Mogotes low hills range. Based on previous cartography, a base map was made, where basins were delimited, riverbed and level curves were digitized and the dimensions of basins and hypsometric bands were subsequently determined. In this way, the basic information was obtained from the calculation of the shape indexes, hypsometric curve, height and mean slope, network parameters and Horton’s laws. A Geographical Information System (GIS) has been used for the delineation and calculation of the morphometric parameters of the basins, using free software GvSIG.

Packing dimensions of basins in the space of sequences

We consider a space of infinite signals composed of finite-alphabet letters. Each signal generates a sequence of empirical measures on the alphabet and a limit set corresponding to this sequence. The space of signals is partitioned into narrow basins consisting of signals with identical limit sets for the empirical measures, and the packing dimension is computed for each narrow basin.

A Hydrodynamic Study of Water Flushing Parameters to Improve the Water Quality Inside Marinas and Lagoons

This research describes how integration of engineering and environmental aspects into the planning with extensive use of numerical hydrodynamics models by using MIKE 21 software. A parametric study for different parameters which affect the residence time hence the water quality in lagoons, marinas, harbors and coastal basins was carried out to establish guidelines to improvement methods for water flushing of marinas and lagoons. Finite element conceptual computer models are applied to simulate and investigate the most important factors dominate the resident time and water exchange rate like tidal inlets characteristics (number-location-width), the shape of water body, basin dimensions and tidal variations. The boundary condition, water level variations used in simulations are collected based on the conditions of fishery ports and lagoons along Egyptian coastal line in Mediterranean and red sea. This study conducted a wide range of numerical simulation (more than 50 HD models) with different geometry and boundary conditions. The results showed that the square shape of water surface area is more efficient for small water body areas. While, as the area required increased, the rectangular water surface efficiency become closer. The inlet width and its location should be determined wisely to achieve the optimization for the usage of project. Finally, the results showed that as the level variations values increased, the maximum flood current velocities at the entrance increased. In addition, the flow spreading quality increased with higher water level values over the all water surface area regardless the water depth.