Performance Of Drainage Systems Research Articles

A tool for detecting and diagnosing faults in the drainage systems of existing buildings

A building drainage system is an essential facility for building construction. The faulty performance of drainage equipment invalidates the entire system and threatens people’s health. A comprehensive tool for diagnosing the drainage systems of existing buildings, based on an empirical approach and levelling methodology was validated by studying 53 building drainage systems. Drainage system faults or problems were explicitly detected for facilitating decision-making regarding retrofitting. This paper proposes a comprehensive strategy and diagnostic tool that involves using a personal computer and mobile device application to diagnose faults in existing buildings. The proposed diagnostic tool can enable applying building information modelling in managing the performance and infection risk of building drainage systems.

PENGARUH REVITALISASI SUNGAI TERHADAP KINERJA SISTEM DRAINASE KALI PEPE HILIR KOTA SURAKARTA

<p><em>Flood in Surakarta mostly due to overflowing rivers that flow through the region of Surakarta. The river is part of the urban drainage system. Department of Public Works (DPU) as the local government agency is responsible for the drainage management in Surakarta. One of form of implementation of the river management as part of drainage system is river revitalization program of Pepe River downstream which performed by the DPU. Despite Pepe River downstream revitalization program has been implemented in a variety of activities, the event of flooding due to overflowing Pepe River downstream still occur. Where as the flood is one of the performance indicators of urban drainage system. Thus, from that background it can be defined in research formulation problems, that is how the influence of the river revitalization performed by the DPU Surakarta against Pepe River downstream performance as part of urban drainage system in Surakarta. </em></p><p><em>This research uses quantitative descriptive analysis supported by several analytical techniques including descriptive narrative analysis to identify the characteristics of the revitalization of Pepe River downstream and paired simple t-test analysis to identify the changes of drainage system performance. Next, the relations from the results of both analysis will be identified using explanatory descriptive analysis. Based on the analysis results, it shows that the characteristics of the revitalization of Pepe River downstream is categorized in moderate intensity, because it only includes physical and social activities. Although there are improved changes in the drainage system performance. On the river section I, there are less significant changes with the number of the biggest changes ison the indicator of gabions, that is 11. On the river section II, the drainage system performance changes are significant with the number of the biggest changes is on the indicator of sedimentation, that is 38. In river section III, there are less significant changes with the number of the biggest change is on the indicator of garbage accumulation, with a score of 21.Therefore, it can be argued that the river revitalization program performed by the DPU Surakarta affects the Pepe River downstream performance as the primary drainage channel in the drainage system in Surakarta. The influence can be seen from the reversion of river functions as a drainage channel which is marked by changes in Pepe River downstream drainage system performance from before the river revitalization performed and after the revitalization performed, which is improved.</em></p><p><em> </em></p><p><strong><em>Keywords</em></strong><em>: river revitalization, catchment area, drainage system performence</em></p><p> </p>

Analyzing subsurface drain network performance in an agricultural monitoring site with a three-dimensional hydrological model

Summary Effectiveness of a subsurface drainage system decreases with time, leading to a need to restore the drainage efficiency by installing new drain pipes in problem areas. The drainage performance of the resulting system varies spatially and complicates runoff and nutrient load generation within the fields. We presented a method to estimate the drainage performance of a heterogeneous subsurface drainage system by simulating the area with the three-dimensional hydrological FLUSH model. A GIS analysis was used to delineate the surface runoff contributing area in the field. We applied the method to reproduce the water balance and to investigate the effectiveness of a subsurface drainage network of a clayey field located in southern Finland. The subsurface drainage system was originally installed in the area in 1971 and the drainage efficiency was improved in 1995 and 2005 by installing new drains. FLUSH was calibrated against total runoff and drain discharge data from 2010 to 2011 and validated against total runoff in 2012. The model supported quantification of runoff fractions via the three installed drainage networks. Model realisations were produced to investigate the extent of the runoff contributing areas and the effect of the drainage parameters on subsurface drain discharge. The analysis showed that better model performance was achieved when the efficiency of the oldest drainage network (installed in 1971) was decreased. Our analysis method can reveal the drainage system performance but not the reason for the deterioration of the drainage performance. Tillage layer runoff from the field was originally computed by subtracting drain discharge from the total runoff. The drains installed in 1995 bypass the measurement system, which renders the tillage layer runoff calculation procedure invalid after 1995. Therefore, this article suggests use of a local correction coefficient based on the simulations for further research utilizing data from the study area.

Evaluation of DRAINMOD for Potato Crop under Cold Conditions in the Canadian Prairies

<abstract> <b><sc>Abstract.</sc></b> Subsurface drainage is used for removing excess water in poorly drained agricultural lands. The performance of subsurface drainage systems varies depending on the soil, crop, and climatic factors. Field evaluation of drainage systems under different field conditions can be costly and time-consuming, necessitating the use of computer models for the design and the evaluation of long-term performance. DRAINMOD is a widely used model for simulating shallow groundwater hydrology in poorly or artificially drained farmlands. The objective of this study was to evaluate DRAINMOD for simulating the hydrology and potato (Solanum tuberosum) crop yield under cold climatic conditions. Data were obtained from a field study that was conducted during 2010 to 2012 in southern Manitoba in a fine sandy loam soil. DRAINMOD calibration and validation were done using data from subsurface-drained plots with drain spacing of 15 m and average drain depth of 1.06 m. Daily subsurface drainage flow, weather parameters, irrigation rate, and water table depth were measured onsite. Subsurface drainage and water table depth were the main variables that were evaluated with DRAINMOD simulations. In general, DRAINMOD predictions of subsurface drainage flow and water table depth were in good agreement with observed values on a daily basis. Statistical parameters showed that DRAINMOD predictions of daily water table depth were more accurate than model predictions of daily drainage flow. The Nash-Sutcliffe modeling efficiency values were in the range of 0.69 to 0.76 for drainage flow and 0.57 to 0.94 for water table depth. The mean absolute error was between 70 and 134 mm for water table depth predictions and between 0.42 and 0.44 mm for drainage flow predictions. The root mean square error was 0.77 to 1.14 mm for drainage flow and 83 to 147 mm for water table depth. DRAINMOD overpredicted potato yield by up to 1%. Based on the results, it is concluded that DRAINMOD predictions of the shallow groundwater hydrology under cold climate were satisfactory.

Performance of Subsurface Tube Drainage System in Saline Soils: A Case Study

In order to improve the saline and water logged soils caused due to groundwater table rise, installation of subsurface drainage system is considered as one of the best remedies. However, the design of the drainage system has to be accurate so that the field performance results conform to the designed results. In this investigation, the field performance of subsurface tube drainage system installed at the study area was evaluated. The performance was evaluated on the basis of comparison of the designed value of water table drop as 30 cm after 2 days of drainage and predicted and field measured hydraulic heads for a consecutive drainage period of 14 days. The investigation revealed that the actual drop of water table after 2 days of drainage was 25 cm, about 17 % less than the designed value of 30 cm after 2 days of drainage. The comparison of hydraulic heads predicted by Van Schilfgaarde equation of unsteady drainage with the field-measured hydraulic heads showed that the deviation of predicted hydraulic heads varied within a range of ±8 % indicating high acceptability of Van Schlifgaarde equation for designing subsurface drainage system in saline and water logged soils resembling to that of the study area.

Stochastic Multiobjective Optimization Model for Urban Drainage Network Rehabilitation

AbstractFlooding in urban areas has become increasingly common in recent decades, as a result of increased urbanization, decreased infiltration rates, and climate change. Hydraulic rehabilitation plans can be developed and implemented to maintain suitable urban drainage system performance. Determining the effective plans, however, requires the involvement of rainfall uncertainties in the modeling and using special tools. In this study, statistical copula functions are established to determine joint probability distribution of rainfall variables considering their dependence structure. The most credible distribution is then used through the Monte Carlo simulation (MCS) to investigate rainfall uncertainties. A multiobjective optimization model is also developed and, after validation, is linked to the EPA-SWMM model for evaluating urban drainage rehabilitation scenarios. The copula-based multiobjective optimization model represents a range of cost-effective rehabilitation plans in terms of overflow improvemen...

A generalised Dynamic Overflow Risk Assessment (DORA) for Real Time Control of urban drainage systems

An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored in the drainage network, (ii) the expected runoff volume (calculated by radar-based nowcast models) and – most important – (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows for a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible function which allows for the prioritisation of the discharge points according to their sensitivity and intended use. DORA was tested on a hypothetical example inspired by the main catchment in the city of Aarhus (Denmark). An analysis of DORA’s performance over a range of events with different return periods, using a simple conceptual model, is presented. Compared to a traditional local control approach, DORA contributed to reduce CSO volumes from the most sensitive points while reducing total CSO volumes discharged from the catchment. Additionally, the results show that the inclusion of forecasts and their uncertainty contributed to further improving the performance of drainage systems. The results of this paper will contribute to the wider usage of global RTC methods in the management of urban drainage networks.

Impact of a Changing Environment on Drainage System Performance

Pavement of the surfaces, along with a possible climate change induced increase of rainfall intensities, is one of key factors accountable for (increased) flooding in urban areas. Consequently higher runoffs have an impact on sewer system performance in terms of higher risk of flooding and decrease of storm water treatment performance. This paper presents a sensitivity analysis to compare impact of increased rainfall intensities and pavement of urban areas. It can be seen that both impacts result in a similar figure. Hence it is important to look into both aspects when trying to predict future performance of combined sewer systems.

Climate Change Impacts on the Built Environment in Nigeria

The populations, infrastructure and ecology of cities are at risk from the impacts of climate change which affect urban ventilation and cooling, urban drainage and flood risk and water resources. Built areas exert considerable influence over their local climate and environment, and urban populations are already facing a range of weather-related risks such as heat waves, water pollution and flooding. Although climate change is expected to compound these problems, building designers and spatial planners are responding through improved building design and layout of cities. There is also a need for weather data for testing future performance of urban drainage and water supply systems. Urban forestry and associated programmes are expected to play leading roles in the built environment too. This paper x-rayed significant climate change impacts expected to shape the future character and functioning of urban systems, in Nigeria, people’s attitude to the change, the findings have serious implications for how hazards are managed. The paper also highlighted strategies for managing and preventing climate change on built environment. The importance of public awareness through effective hazard education was also suggested.

Performance assessment of separate and combined sewer systems in metropolitan areas in southern China

To assess the performance of urban drainage systems in metropolitan areas in southern China, 12 urban drainage systems, including nine separate sewer systems (SSSs) and three combined sewer systems (CSSs) were monitored from 2008 to 2012 in Shanghai and Hefei. Illicit connection rates of SSS were determined. The results indicate that serious illicit connections exist for most SSSs. Annual volume balance for two SSSs with serious illicit connection was assessed with a hydraulic model to determine the dry weather overflow volume. Although interception facilities have been implemented in SSSs, for some systems with serious illicit connections, a considerable volume of dry weather overflow still existed. Combined with monitoring of dry/wet weather flow quality, the pollutant load caused by wet/dry weather overflow was quantified. The results revealed that there was no obvious advantage of having SSSs over CSSs in terms of pollutant control. The serious pollution caused by illicit connections and insufficient management occurs in many cities in China. The performance assessment of separate and CSSs in Shanghai and Hefei provides important lessons and practical experience that can be applied to the construction and management of urban drainage system in China as well as other developing countries.

Air water flows in building drainage systems

This paper investigates the mechanisms of two-phase flows that occur in commercial and industrial roof drainage systems. Both traditional gravity-fed and siphonic roof drainage systems are examined.Air entrainment plays a fundamental role in the performance of siphonic roof drainage systems. In particular, air entrainment has a significant effect on:maximum system flowrate capacity;pipe friction losses;operational system pressures;operational gutter water depths; andability of the system to prime.However, experimental results presented here demonstrate that the reduction in system capacity is not directly proportional to the increase in air content. One possible explanation for this is that water and air will be affected differently by sub-atmospheric pressures. The effect air entrainment has on roof drainage performance is investigated. The ways in which air is introduced into the system are identified and the effects of different air/water ratios are quantified. Finally methods for reducing air entrainment are described.

Potential and limitations of modern equipment for real time control of urban wastewater systems

Real Time Control (RTC) has become an accepted technique for improving the performance of Urban Drainage Systems (UDS) due to its flexibility and sustainability. Numerous implementations of RTC have been reported during the last decades. At the same time, guideline documents and state-of-the-art reports have been published. Whereas the general aspects and challenges of planning and installation of RTC systems are well covered, there is a lack of information about the adequate equipment for RTC of UDS. After identifying and briefly discussing the basic components of RTC systems for UDS, this paper describes the specific components in detail. This comprises the introduction of available technologies for sensors, actuators, controllers and telemetry systems in the context of RTC and the discussion of their potential and limitations. Lessons learned from the field operational experiences and future trends and challenges are identified.

Novel modulated flow, self configuring, siphonic roof drainage system

Siphonic roof drainage systems are an efficient method of removing rainwater rapidly from roofs. Siphonic roof drainage systems are designed to run full-bore, resulting in sub-atmospheric system pressures, higher driving heads and higher system flow velocities. Hence, siphonic roof drainage systems normally require far fewer downpipes, and the depressurised conditions also mean that much of the collection pipework can be routed at high level, thus reducing the extent of any underground pipework. But, they work properly at only one roof run-off rate and therefore suffer from sizing and operational problems that limit their performance. Climate change is creating situations where normal ranges of rainfall intensity are being frequently exceeded, and this may have an impact on the performance of siphonic roof drainage systems. A multiple parallel pipe siphonic roof drainage system appears to offer benefits and avoids sizing problems associated with current siphonic roof drainage systems. A movable cap covering the inlet to a small bank of parallel pipes has the potential to avoid noise associated with making and breaking siphonic action through flow modulation. Laboratory scale tests demonstrate the basic feasibility of the multiple parallel pipe system and indicate that handover of flow between pipes occurs smoothly and that the flow modulation cap functions reliably. This technology includes moving parts and smaller diameters (19 mm ID) than are currently accepted (32 mm ID) in the British Standards and product development will be required. Practical application: Original research detailing an innovative development of a multi-pipe siphonic roof drainage system. This provides a wide design flow rate range and flow modulation caps reduce noise significantly by avoiding priming failure. Potentially extends the technique to a smaller building size than with current siphonic systems and offers climate change resilience potential.

Simulation of Horizontal and Vertical Drainage Systems to Combat Waterlogging Problems along the Rohri Canal in Khairpur District, Pakistan

AbstractContinuous seepage from earthen canals creates a serious water-management problem in Pakistan. Efficient water management through a properly designed drainage system is therefore indispensable and imperative not only for the control of waterlogging, but also to provide a favorable environment for crop root development that ultimately enhances crop growth and increases yield potential. This paper discusses the effectiveness of different remedial measures adopted to intercept seepage from the Rohri canal and control the rising water table on 1,000 ha of agricultural land near the Gambat railway station in the district of Khairpur in the Sindh Province of Pakistan. A three-dimensional (3D) finite-element model for groundwater flow and solute transport (FEMGWST), developed at Universiti Putra Malaysia, has been used to evaluate the performance of horizontal and vertical drainage systems, operating either independently or simultaneously, for different flow levels in the Rohri canal. Simulation results ...

Empirical approach to main drain system design and solid transportation performance in buildings

Water-saving facilities were constructed in response to the sustainability and global issues all over the world. However, the performance of drainage systems must be ensured as the volume of flush water is reduced. Otherwise, it might cause sanitary problems to indoor environments and interrupt building functions. According to the methodology of investigation and observation, this paper categorized parameters that dominate the solid transportation performance of main drains. An empirical experiment was executed to clarify the quantitative influence of these parameters. A calculation model for estimating the boundary condition of main drain design is conducted. Furthermore, an estimation interface is validated and proposed as an assessment tool for practical application. Practical implication: This paper offers an evaluation tool by statistic methodology to ensure solid transportation performance. An estimating model and regulation proposal of solid transportation in main drains of buildings that can guide the designer and engineer to confirm the performance of drainage system is validated and proved to be practicable. Furthermore, this research conducted an estimation interface to validate the solid transportation performance, which can offer an assessment tool for practical application. The results can contribute to building code guidelines and lead to new technical development of building drainage systems.

An integrated urban drainage system model for assessing renovation scheme

Due to sustained economic growth in China over the last three decades, urbanization has been on a rapidly expanding track. In recent years, regional industrial relocations were also accelerated across the country from the east coast to the west inland. These changes have led to a large-scale redesign of urban infrastructures, including the drainage system. To help the reconstructed infrastructures towards a better sustainability, a tool is required for assessing the efficiency and environmental performance of different renovation schemes. This paper developed an integrated dynamic modeling tool, which consisted of three models for describing the sewer, the wastewater treatment plant (WWTP) and the receiving water body respectively. Three auxiliary modules were also incorporated to conceptualize the model, calibrate the simulations, and analyze the results. The developed integrated modeling tool was applied to a case study in Shenzhen City, which is one of the most dynamic cities and facing considerable challenges for environmental degradation. The renovation scheme proposed to improve the environmental performance of Shenzhen City's urban drainage system was modeled and evaluated. The simulation results supplied some suggestions for the further improvement of the renovation scheme.

Aquatic weed classification, environmental effects and the management technologies for its effective control in Kerala, India

Abstract: Aquatic weeds, the unabated plants completing life cycle in water, are a serious menace to the environment. Dense colonies of aquatic weeds are observed in the southern regions of Kerala which mainly includes Ernakulam, Kottayam, Idukki and Alappuzha districts. The noxious aquatic weeds invade inland water masses, estuaries inshore regions of seas and are now abandoned. The rapid and excessive growth of aquatic weeds in varied and wide environmental condition limits the sustained performance of many drainage and irrigation system, reducing the productivity of agricultural land. Aquatic weeds are classified into emergent, floating and submerged weeds according to the various habitats. Many species are found in Kerala which were originally introduced into botanical gardens. The major aquatic weeds found in Kerala include Salvinia spp., Eichhornia crassipes, Pistia stratiotes, Alternanthera spp., Azolla, common duckweed, and Hydrilla verticillata. Reduction or elimination of aquatic weeds is possible through well planned management strategies which includes preventive and control (biological, physical, chemical, eco-physiological) measures. A successful weed control program depends on the resources available, the weeds present and the ability to carry out effective control methods. Operational research and /or pilot projects have to be initiated in the problematic areas on long term basis, using technical recommendations derived from research experiments. Keywords: aquatic weeds, classification, effects, management technology DOI: 10.3965/j.ijabe.20120501.010 Citation: Jayan P R, Nithya Sathyanathan. Aquatic weed classification, environmental effects and the management technologies for its effective control in Kerala, India. Int J Agric & Biol Eng, 2012; 5(1): 76

Enhanced efficiency of pluvial flood risk estimation in urban areas using spatial–temporal rainfall simulations

AbstractUrban areas are concentrations of flood risk because of the density of development and because they tend to be constructed in low‐lying areas. They may be subject to flooding from rivers or the sea but are also vulnerable to the effects of intense direct rainfall, which can overwhelm urban drainage systems, and cause complex and often localised patterns of pluvial flooding. The risk from pluvial flooding is particularly difficult to assess because it is sensitive to the spatial–temporal characteristics of rainfall, local run‐off and surface flow processes, the performance of urban drainage systems, and the exact location of buildings. Sampling the variability or uncertainty in all of these processes in order to generate accurate flood risk estimates quickly becomes computationally prohibitive, especially for large urban areas. In this paper, we evaluate alternative approaches for making use of high‐resolution spatial–temporal rainfall simulations in urban flood risk analysis. Flood depths are computed with a coupled sewer and surface flood model, and flood damage is estimated using standard depth‐damage criteria. Efficient sampling of rainfall events and judicious use of response surfaces that relate rainfall event properties to flood volumes and damages are evaluated and shown to reduce the computational expense of risk analysis by more than 70%. The risk analysis methodology is successfully demonstrated for two contrasting urban locations in the UK.

Effect of Drainage Parameters Change on Amount of Drain Discharge in Subsurface Drainage Systems

One of the most important factors for appropriate performance of subsurface drainage systems is having adequate discharge for drains. For this purpose, knowledge about effect of drainage parameters change on drain discharge is essential in subsurface drainage systems. In this article, using change all of the drainage parameters by EnDrain software, changes of drains discharge has been investigated in subsurface drainage systems. The most amount of change in drain discharge for one percent increase or decrease in each of drainage parameters was owned by depth of water level in drain below soil surface equal to 3.0%. Also about maximum and minimum of obtained drain discharge for drainage parameters change has been discussed.

Hydraulic Impacts on Urban Drainage Systems due to Changes in Rainfall Caused by Climatic Change

Changes in climate were a growing concern during the last decade and will be even greater in the coming years. When investigating the impact from changes in the climate on urban drainage systems, two challenges are (1) what type of input rainfall data to use and (2) what parameters to use to measure the impacts. The overall objective of this study is to investigate the hydraulic performance of urban drainage systems related to changes in rainfall, and through these hydraulic parameters describe the impact of climate change. Input rainfall data represent today’s climate and three future time periods (2011–2040, 2041–2070, and 2071–2100). The hydraulic parameters used were water levels in nodes (e.g., as the number of floods, and frequency and duration of floods) and pipe flow ratio. For the study area, the number of flooded nodes and the geographical distribution of floods will increase in the future, as will both the flooding frequency and the duration of floods.