Water Conveyance Research Articles

Smart Mathematical Model for Chlorine Concentration Decay in Water Pipe Line Network

Water is the critical need of today world. Clean and drinking Water is made drinkable by water chlorination in repositories and water conveyance framework distribution system. To obstruct the bacterial growth a base measure of minimum amount of residual chlorine should remain in the water. It is a serious challenge for the checking point of view about residual chlorine to ensure the quality of water in the distribution system, as there are numerous factors which affect its concentration decay process. At the point when chlorine starts mixing with water it reacts with pipe wall and various other elements present in the water prompting to its concentration decay. This problem makes it necessary to investigate the behavior of chlorine decay pattern. In this paper we investigate that chlorine reducing with increment of the time period and various samples was collected from old age and newly built colony

Mobile flume for inverted semicircular Open channel

The discharge measurement is significant in wide engineering applications such as water conveyance, sewer system, irrigation, and drainage system. Many devices are designed to measure discharge in partially filled circular and semicircular channels. In this study new semicircular mobile flume depends on the concept of developing a contracted zone to have a control section was examined. The contraction was made by installing a vertical pipe with axial holes at the semicircular open channel to create critical flow. To evaluate the efficiency of this type of devices mathematical and experimental studies were presented. Specific energy, discharge, and Froude number equations were used to deduce the mathematical model. Experimental work was carried out in measuring the discharge values with known specific energy values. The experimental data was used to evaluate the mobile device to measure discharge. New equations for both discharge and discharge coefficient were presented. The verification leaded to have a discharge correction equation to calculate the discharge based on the contraction ratio and the measured water depth in the vertical pipe. Results of the comparison showed that the proposed model provided a reliable prediction of the discharge with high accuracy and maximum error up to 8.7%.

Statistical and Numerical Study of Chipping and Cracking in Segmental Lining

Some of the most frequent damages of concrete segments in shield tunnels are chipping and cracking, which are followed by degradation of lining system. In this paper, these types of damages are studied in four subway and two water conveyance tunnels. More than 2100 concrete rings are examined for chipping inspection and another 3000 for determination of the cracking. Statistical analysis of the research data showed that corners of the key and counter-key segments carry the highest number of chipping, while most of the cracking occur in the middle zones and shape of the segments and number of trust jacks affect the cracking pattern. Two kinds of numerical models are used to examine the underlying damages, which are based on geometrical characteristics of tunnel lining and boring machine besides operational mistakes. Findings of the numerical simulation revealed that installation of segmental lining with the least amount of erection tolerances results in low amount of chipping, this is while using key-segments with 12–17 degrees of insertion angle reduces total magnitude of damage due to tensile and compressive stresses. Furthermore, the deviation angle of TBM’s jack and segment’s axis should never be more than 5 degrees; otherwise even high-quality concrete segments wouldn’t remain undamaged. Employment of boring machines with articulated system is proposed in this case.

Geological hazards in tunnelling: the example of Gelas water conveyance tunnel, Iran

The characterization of geological hazards is of great importance in underground space and, in particular, tunnelling projects because it plays a crucial part in the selection of the tunnel route, the type and characteristics of excavation, and the technology adopted. It is also a fundamental stage in the design and construction of tunnelling-related structures. Tunnelling projects encounter various geological hazards, including those associated with the ground conditions, the groundwater level and the in situ stress regime. The aim of this study was to identify the probable hazards affecting the alignment of the Gelas water conveyance tunnel in Iran and the magnitude of risk in various sections along the tunnel route. Following a literature review of the geological hazards found in tunnelling projects with similar geological conditions, several potentially hazardous parameters were identified for assessment, including squeezing and groundwater inflow. The geotechnical characteristics of the rock masses were evaluated based on laboratory and field investigations to assess the geological hazards along the tunnel route. Seven sections along the tunnel route were selected to study the squeezing and water inflow hazards and their degree of occurrence using various previously reported techniques. Empirical, semi-empirical and theoretical–analytical methods were used to assess the squeezing potential. Analytical methods were applied to the prediction of groundwater inflow and then site groundwater rating and tunnel inflow classification methods were adopted to classify the route of the tunnel from the perspective of the groundwater inflow hazard. The results indicated that areas where faults and crush zones are located are highly susceptible to groundwater in-rush and squeezing.

Reduction the impact of running system of sprinkling machine on the soil

Carried out researches have allowed to establish the optimum plan for the installation of sprinklers for sprinkling machine "Kuban-LK1M" (Cascade) and "CASCADE" in accordance with the applicable running systems and parameters of water conveyance pipeline, load-bearing capacity of the soil and the application rate.

Mechanical properties and loading response of prestressed concrete cylinder pipes under internal water pressure

Prestressed concrete cylinder pipes (PCCPs) are widely used in large-scale water conveyance projects. It is important to study the mechanical properties and loading response of PCCPs to ensure trouble-free operation. There were insufficient test data pertaining to the deformation of the concrete cores (including the inner and the outer concrete core), the prestressing wire, the mortar coating, especially the steel cylinder. In this paper, a full-scale test was performed on a PCCP under internal water pressure through fiber Bragg grating (FBG) sensing technology. The test results showed that the state of PCCPs would reach three limit-states successively. Firstly, the strains of the concrete cores, the prestressing wire, the steel cylinder and the mortar coating increased linearly with the growth of the internal water pressure. The cracks in the concrete cores indicated the beginning of the serviceability limit-state. The corresponding pressure is 1.8 MPa. The growth of the internal water pressure primarily affected the steel cylinder and the prestressing wire during the continuous period. When the steel cylinder yielded at the pressure of 2.25 MPa, the pipe reached its elastic limit-state. At last, the strength of the pipe decreased obviously as the cracks propagated throughout the concrete cores. The pipe would come to the strength limit-state until the prestressing wire yielded. The test results found that the internal water pressure relieved final prestress of the inner concrete core was different from that of the outer concrete core in the embedded-cylinder pipe (ECP). It was also proved that FBG sensing technology could be the continuous monitoring system for the condition assessment of PCCPs. In particular, the test results demonstrated that the appropriate quality of materials and proper operation guaranteed trouble-free operation of PCCPs. The objective of this research is to provide experimental references for the application of PCCPs and push back safety assessment of this type of large-diameter pipes.

Modelling the hydrologic effects of vegetation growth on the long-term trajectory of a reclamation watershed

Reclamation watersheds that integrate fen peatlands into the design require the inclusion of uplands that are capable of supporting forest development while concurrently supplying sufficient groundwater recharge to downgradient wetland ecosystems. This necessitates selecting materials with suitable soil hydraulic properties and identifying the appropriate thickness and layering to fulfill the dual function of uplands as water storage, and water conveyance features. Currently, these systems incorporate tailings sand - a mine waste material - overlain by a cover soil of fine forest-floor material. The developmental pathway of these uplands is currently unknown, and it is unclear whether these landforms will provide enough groundwater recharge once a climax vegetation community establishes. Therefore, this research attempts to estimate the maximum density of vegetation, and associated water balance fluxes of a constructed upland integrated into a peatland watershed. The numerical modelling software HYDRUS-1D simulated soil moisture dynamics using a 65-year meteorological record, and a plant water stress algorithm was used to estimate the maximum sustainable leaf area index that the upland could support. Based on the thickness of the cover soil, the upland could support an average leaf area index of 1.2. Under this vegetation density, average annual groundwater recharge was 83 mm, and predominantly supplied by snowmelt (64%). Given this quantity of recharge, the model indicates that the upland will continue to provide enough groundwater to offset the anticipated water deficit in the downgradient fen ecosystem. However, by altering the design of the upland, specifically the spatial arrangement and thickness of cover soil, the same recharge could be supplied while also allowing for a higher average vegetation density. Such a design could allow for the creation of watersheds with a higher proportion of peatland.

Historic drought influences outmigration dynamics of juvenile fall and spring-run Chinook Salmon

Riverine ecosystems around the world have undergone extensive anthropogenic alterations, often to the detriment of native aquatic biodiversity. Migratory fishes are particularly vulnerable to habitat fragmentation and degradation. For example, Chinook Salmon populations in the Sacramento River, CA have been declining for nearly a century. Its Mediterranean climate, position in a landscape dominated by urban and agricultural land use, and the presence of an inland delta that serves as the hub of California’s vast water conveyance system, makes this a particularly perilous region for migrating juvenile salmon. This study used acoustic telemetry to investigate survival and routing of juvenile fall and spring-run Chinook Salmon through their riverine and estuarine migratory phases during the historic California drought of 2012–2016. Survival to the ocean in this river system is already lower relative to Chinook Salmon populations in North American. Survival to the Pacific Ocean ranged from 0.0–9.1% over the course of this three-year study. Use of four migratory routes through the Delta was variable, both within and between years. We documented extensive use and relatively high survival in Steamboat Slough (up to 41.5% routing through and up to 39.8% survival), part of the Sacramento River’s distributary network. Migration through this pathway precludes juvenile salmon from encountering junctions leading to low survival routes. Results from this modeling effort provide valuable information and highlight opportunities for directing management actions to benefit these ecologically and economically valuable runs of Chinook Salmon.

The social-ecological system driving effective invasive plant management: two case studies of non-native Phragmites

Globally, the management of invasive plants is motivated by a desire to improve ecosystem services (e.g., recreation, flood mitigation, soil fertility for agriculture, aesthetics) and critical habitat for imperiled species. To reduce invader populations and impacts, it is important to document the social and ecological basis (i.e., the social-ecological system) for the management that has been employed and areas where a greater level of coordination among stakeholder groups (managers, scientists, legislators, resource users) could improve efforts. We present a conceptual model that builds on current thinking for how best to connect these four stakeholder groups—to foster stronger citizen lobbying for impacted resources, science-based governance, legislator-driven noxious weed laws and funding for management and science, knowledge co-production by scientists and managers, and co-management by managers and resource users. In light of our model, we present two case studies based in Nebraska and Utah, U.S.A. involving a common North American wetland invader, Phragmites australis (non-native common reed). In Nebraska, potential lawsuits stemming from water conveyance was strong motivation for funding management. In Utah, duck hunters and other resource users initially instigated management. Progress toward the successful management of Phragmites has been the result of manager-scientist partnerships addressing a knowing-doing gap among practitioners, the complexities of management mosaics, as well as overcoming economic and logistical constraints. Our model demonstrates how legislative initiatives can fund new research and bolster on-going management, while organically building strong partnerships among scientists, managers, and resource users that are key for successfully managing invasive species.

Presentation and validation of induction irrigation as an efficient and profitable method

Abstract The scarcity of water resources along with population growth and low precipitation exert stresses on the agricultural sectors of arid regions. The evapotranspiration losses due to water use in the warm months of the year are high for walnut production, for example, which is one of the main Iranian agricultural exports. Also, the water losses occurring in flood irrigation, surface storage, and water conveyance, and the high costs of drip irrigation increase the need for efficient irrigation methods. This study proposes induction irrigation as a novel method for preventing evapotranspiration losses, increasing water-use efficiency, and raising agricultural profitability. Induction irrigation relies on recharge and extraction wells to inject treated sewage and withdraw groundwater, respectively, and create a saturated zone in the plants' root area. This paper demonstrates that induction irrigation applied to walnut orchards would lower costs and water losses, avoid surface pollution, and increase agricultural profitability.

Fluid-Structure Interaction Response of a Water Conveyance System with a Surge Chamber during Water Hammer

Fluid–structure interaction (FSI) is a frequent and unstable inherent phenomenon in water conveyance systems. Especially in a system with a surge chamber, valve closing and the subsequent water level oscillation in the surge chamber are the excitation source of the hydraulic transient process. Water-hammer-induced FSI has not been considered in preceding research, and the results without FSI justify further investigations. In this study, an FSI eight-equation model is presented to capture its influence. Both the elbow pipe and surge chamber are treated as boundary conditions, and solved using the finite volume method (FVM). After verifying the feasibility of using FVM to solve FSI, friction, Poisson, and junction couplings are discussed in detail to separately reveal the influence of a surge chamber, tow elbows, and a valve on FSI. Results indicated that the major mechanisms of coupling are junction coupling and Poisson coupling. The former occurs in the surge chamber and elbows. Meanwhile, a stronger pressure pulsation is produced at the valve, resulting in a more complex FSI response in the water conveyance system. Poisson coupling and junction coupling are the main factors contributing to a large amount of local transilience emerging on the dynamic pressure curves. Moreover, frictional coupling leads to the lower amplitudes of transilience. These results indicate that the transilience is induced by the water hammer–structure interaction and plays important roles in the orifice optimization in the surge chamber.

The water‐energy nexus in the Middle East: Infrastructure, development, and conflict

AbstractWater and energy are closely linked in the Middle East and North Africa (MENA) through coupled networks of infrastructure. This review explores the water‐energy nexus of infrastructure to explicate different patterns of development and de‐development in the MENA. First, the review highlights why states, donors, and firms have long built large‐scale coupled water‐energy infrastructures to provide urban services, expand irrigated agriculture, and foster development. Yet, too often the adverse social and environmental impacts from the construction of dams, water conveyance structures, groundwater mining, and desalination plants have been overlooked. We then examine the water‐energy nexus through infrastructure for the most important users of water and energy in the MENA region: urban populations and the agricultural sector. Third, the review illustrates that while investments in water and energy infrastructure generated significant gains in human development for much for of the region, the post‐2011 wars reversed many of these development gains in conflict‐affected countries through the destruction and deterioration of water‐energy infrastructures. The unprecedented displacement of populations within and across borders has also created new challenges for host communities, where infrastructures for providing water and energy services were already overstretched. The review further highlights the growing role of humanitarian assistance in providing water and energy services to refugees, internally displaced populations, and host communities. Overall, this review examines how the nexus of water and energy infrastructure shapes human security, livelihoods, and political economies in the MENA region.This article is categorized under: Human Water > Water Governance Engineering Water > Planning Water

Predicting seepage from unlined earthen channels using the finite element method and multi variable nonlinear regression

Seepage losses from unlined channels are a major contributor to water loss in the agricultural sector. Quantification of seepage losses can improve water conveyance efficiency and provide solutions to water scarcity. In this study, a numerical simulation method is applied to investigate the factors that affect seepage from earthen channels. SEEP/W software was used to generate finite element method (FEM) solutions of the seepage flow equations. 246 numerical models, including different sections of trapezoidal, rectangular, and triangular earthen channels were studied using FEM. Numerical results are compared to available observation data from Zayandeh-Rud irrigation channels in Iran. Non-linear regression equations for the four empirical seepage equations are obtained from the SPSS statistical software. The results show that nonlinear multivariate regression relationships provide a suitable match for estimating seepage discharge. The accuracy of the suggested nonlinear regression equation in terms of R2 and RE are 0.928 and -2.42 %, respectively. Comparison of the seepage discharge with the empirical relationships showed that the empirical relationships have excessive error.

TBM penetration rate prediction based on the long short-term memory neural network

Tunnel boring machines (TBMs) are widely used in tunnel engineering because of their safety and efficiency. The TBM penetration rate (PR) is crucial, as its real-time prediction can reflect the adaptation of a TBM under current geological conditions and assist the adjustment of operating parameters. In this study, deep learning technology is applied to TBM performance prediction, and a PR prediction model based on a long short-term memory (LSTM) neuron network is proposed. To verify the performance of the proposed model, the machine parameters, rock mass parameters, and geological survey data from the water conveyance tunnel of the Hangzhou Second Water Source project were collected to form a dataset. Furthermore, 2313 excavation cycles were randomly composed of training datasets to train the LSTM-based model, and 257 excavation cycles were used as a testing dataset to test the performance. The root mean square error and the mean absolute error of the proposed model are 4.733 and 3.204, respectively. Compared with Recurrent neuron network (RNN) based model and traditional time-series prediction model autoregressive integrated moving average with explanation variables (ARIMAX), the overall performance on proposed model is better. Moreover, in the rapidly increasing period of the PR, the error of the LSTM-based model prediction curve is significantly smaller than those of the other two models. The prediction results indicate that the LSTM-based model proposed herein is relatively accurate, thereby providing guidance for the excavation process of TBMs and offering practical application value.

Characterising the geomorphological and physicochemical effects of water injection dredging on estuarine systems

Dredging is a globally important aquatic system management activity, used for navigation improvement, contamination removal, aggregate production and/or flood risk mitigation. Despite widespread application, understanding of the environmental effects of some dredging types remains limited. Field campaigns in 2016 and 2017 in the River Parrett estuary, UK, therefore investigated the geomorphic and physicochemical effects of Water Injection Dredging (WID), a poorly studied hydrodynamic dredging technology. WID, applied to restore channel capacity for the maintenance of flood water conveyance in the tidal River Parrett, influenced surface elevations but not grain-size characteristics of dredged bed sediments. Topographic alterations due to the 2016 WID operation were short-lived, lasting less than 10 months, although benefits of the 2017 WID operation, in terms of volumetric change, outlasted the ≈12-month study period. Dredging had a significant impact on water physicochemistry (pH, dissolved oxygen, total suspended solids and turbidity) when comparing pre- and during-dredging conditions within the dredge reach, although time-series analysis found dredging effects were comparable in magnitude to tidal effects for some parameters. WID is typically targeted at the thalweg and not the banks, rendering the geomorphic signature of the method different to those of other, often more invasive dredging technologies (e.g. mechanical dredging methods). Further, thalweg not bankside dredging may have potential positive ecological implications, particularly where the majority of biomass is located within the channel margins, as in the tidal River Parrett. Collectively, data suggest WID can be an effective method for sediment dispersal within tidal systems although regular application may be required to maintain cross sectional areas, particularly where management precedes periods of low flows and/or high rates of sediment accumulation. In future, more work is required to better understand both the physical and ecological implications of WID as a flood risk management tool in estuaries and rivers.

Research on water inrush and mud inrush from water-rich fault fracture zone of deep tunnel in mountainous area

Taking the potential risk of water and mud inrush in the construction of a water conveyance tunnel of a hydropower station as the engineering background, based on the field investigation and data collection, the whole process of tunnel construction is simulated and analyzed by using 3D finite element Midas. The results show that because the tunnel passes through the strong water rich fault fracture zone, the filling material in the fault fracture zone has obvious stress concentration under the coupling action of high stress, high pressure seepage and construction disturbance, and the displacement of the filling material has increased significantly. After the fault fracture zone is exposed, the seepage speed has increased significantly, indicating that water and mud inrush disaster has occurred here. It is suggested that when the tunnel passes through complex water-rich fault, monitoring and early warning and excavation support measures should be strengthened to prevent water and mud inrush accidents. The research results have a certain guiding role for the safe construction of the tunnel project.

Agricultural water use accounting provides path for surface water use solutions

Agricultural water demands can conflict with habitat needs in many North Coast watersheds. Understanding different water use patterns can help reduce conflict over limited supplies. We measured on-farm crop water use and conducted grower interviews to estimate the agricultural water demand in the upper Russian River and Navarro River watersheds. Annual agricultural water demand was less than 11% in the Russian River, and 2% in Navarro River, of the total annual discharge in each watershed. However, because demands are concentrated in the dry season when instream flows are at a minimum, these relatively small amounts can represent a significant constraint to stream habitat conditions. We have shared our study results in broad basin and community water resource planning efforts, including flow management of the Russian and Navarro rivers and implementation of the Sustainable Groundwater Management Act in the Ukiah Basin. Findings and recommendations from this study have influenced on-the-ground solutions to meet water demand in these watersheds, including construction of off-stream wintertime storage capacity to replace summertime stream diversions, and use of a municipal recycled water conveyance system as a replacement for summer diversions.

Application of novel data mining algorithms in prediction of discharge and end depth in trapezoidal sections

Flow measurement in irrigation and drainage networks and water conveyance channels have particular importance. Direct methods of flow measurement are costly, time-consuming and are generally associated with losses of energy in flow. In this study, estimation of discharge and end depth of free overfall flows in trapezoidal channels section were investigated. For this purpose, data-driven techniques including dynamic evolving neural-fuzzy inference system (DENFIS), multivariate adaptive regression spline (MARS) and M5 model tree (M5Tree) were developed. 189 laboratory data experiments, six different scenarios based on geometric variables including side slope (m), bed width (B), bed slope (S0), and hydraulic variables including critical depth (Yc), critical slope (Sc) and end depth (YE) or discharge (Q) were applied. The model’s performance was evaluated thorough several statistical indicators and graphical presentations. The accuracy of all three models were apparent in estimation of the discharge and the end depth for most of the scenarios. The results showed that the DENFIS model for the input combination of all variables (Yc, YE, B, S0, m, Sc) with the maximum values of R2 and Nash-Sutcliffe efficiency coefficient (NSE) that were equal to 0.976 and 0.975, respectively, and the minimum values of RMSE, MAE, PBIAS and RSR, that were equal to 0.0015, 0.0989, −1.5906, and 0.1574, respectively, showed the highest estimation accuracy. Regarding the end depth estimation, DENFIS model for the input combination including the variables Yc, Q, Sc, m, B with the highest values of R2 and NSE equal to 0.993 and 0.992 respectively, and the lowest values of RMSE, MAE, PBIAS and RSR equal to 0.0028, 0.1628, 0.7383 and 0.0883, respectively, had a better performance compared to other MARS and M5Tree. The results of this study suggest DENFIS as a suitable and powerful model for estimation of discharge in irrigation and drainage networks.

Evaluation of TBM disc cutter wear issue in hard rock tunneling; a case study

The research project in this study is a part of a 36 kilometer tunnel with 6.32 m in diameter for conveyance of water from the western of Zagros to the Uromia Lake that is under construction through hard rock by using of two tunnel boring machines. Lithology of the tunnel alignment including of granite, granodiorite, hornfels, schist, limestone, dolomite, shale, slate and phyllite. The wear of cutting tools is one of the main challenges of the studied tunnel, which impact significant cost and serious delays on schedule. Wear can be defined as the continuous and unwanted loss and removal of material from the surface of a solid object, as e result of mechanical actions, such as contact and relative motion between two objects. Abrasive wear and impact wear are one of the most important type of wear occurs on the TBM disc cutters. In this paper field actual cutter wear data belong to 9.5 Km of the bored tunnel, geotechnical properties and laboratory information are used to study the wear phenomena. Field data show that abnormal wear of disc cutters with 51 percent is more than normal wear. Also the study of disc cutter consumption rate in relation the geological characteristics and TBM parameters show that the Cerchar abrasivity index (CAI) and uniaxial compressive strength (UCS) are in agreement with disc cutter consumption rate. The obtained results indicate that thrust, torque and penetration rate have a relatively good relation with disc cutter consumption rate. It was not found any relation between rock mass quality index, geological strength index and disc cutter wear rate. In general the relative cutter life in the studied tunnel is in accordance with the relation proposed after Bruland (1998).

Assessing effectiveness of thermal treatment and mixing with coarse-grained particles in stabilization of marly soils

Marly soils can show problematic behaviors such as swelling and dispersion when subjected to water. It can cause problems for various civil constructions, including building foundations, water conveyance canals, highways, and airport runways; so appropriate measurements should be taken to stabilize these soils. In this study, two stabilization methods, including thermal treatment and mixing with coarse-grained particles, were utilized to limit swelling of marly soil samples collected from around the Sonqor city and also to improve their strength properties. The results of experimental tests showed that thermal treatment in high temperatures (after 100 °C) led to a decrease and an increase in liquid and plastic limits, respectively, and subsequently plasticity index decreased. However, after 475 °C, the Atterberg limits were almost unchanged. Also, it was found that with increasing heating levels, the swelling potential of the soil samples decreases as free swelling index values of the samples changed from 13.9% (high swelling potential) at 100 °C to 0.89% (low swelling potential) at 500 °C. Based on the experiments, it was observed that by adding 30% of coarse particles to the marly soil samples, engineering properties such as maximum dry density (γdmax), California bearing ratio, and unconfined compressive strength have been improved up to 10%, 59%, and 30%, respectively. Therefore, the stabilized marly soils could be considered as appropriate construction materials.