Human aspects of water management at impoverished settlements. The case of Doornkop, Soweto

Since 1996, the South African government has undertaken a considerable project to fulfil the proclaimed right of citizens to access sufficient water and sanitation (Government of South Africa, 1996) through traditional water management and water governance. However, democracy has not yet provided significant improvements to informal dwellers. Doornkop (Soweto) is a clear example of a community fighting for its rights to access clean water and adequate wastewater sanitation systems. Beyond traditional water management and social and environmental water governance, an ethical view of managing water policies through principles of “human dignity” and “human equality” has arisen in order to provide basic water services. Equal opportunities to manage water are provided, analysing the impact of the principles of the United Nations Educational, Scientific and Cultural Organisation (UNESCO) upon South African informal communities through the implementation of human water governance. The objectives of the study ascertain if those two principles are relevant to improve the community’s living conditions as well as to positively affect the “Principles of water governance” and the “Water principles”. With this aim, a case study was set up at Doornkop (Soweto), in which 416 informal dwellers among a relocated group, a tenure group and a squatter group were tested through the Smart PLS method. Results showed that water services can be highly improved through human water management, a model that can be applied to other underdeveloped areas in the world

Simulation of the hydraulic performance of highway filter drains through laboratory models and stormwater management tools

Road drainage is one of the most relevant assets in transport infrastructure due to its inherent influence on traffic management and road safety. Highway filter drains (HFDs), also known as ?French Drains?, are the main drainage system currently in use in the UK, throughout 7000 km of its strategic road network. Despite being a widespread technique across the whole country, little research has been completed on their design considerations and their subsequent impact on their hydraulic performance, representing a gap in the field. Laboratory experiments have been proven to be a reliable indicator for the simulation of the hydraulic performance of stormwater best management practices (BMPs). In addition to this, stormwater management tools (SMT) have been preferentially chosen as a design tool for BMPs by practitioners from all over the world. In this context, this research aims to investigate the hydraulic performance of HFDs by comparing the results from laboratory simulation and two widely used SMT such as the US EPA?s stormwater management model (SWMM) and MicroDrainage®. Statistical analyses were applied to a series of rainfall scenarios simulated, showing a high level of accuracy between the results obtained in laboratory and using SMT as indicated by the high and low values of the Nash-Sutcliffe and R2 coefficients and root-mean-square error (RMSE) reached, which validated the usefulness of SMT to determine the hydraulic performance of HFDs.The laboratory research was part of a wider research project funded by the company Carnell Group Services Ltd. Daniel Jato-Espino’s research internship at Coventry University and its participation in the research that led to this article was jointly funded by the CAWR, Coventry University, and the Spanish Ministry of Economy and Competitiveness through the research projects RHIVU (Ref. BIA2012-32463) and SUPRIS-SUReS (Ref. BIA2015-65240-C2-1-R MINECO/FEDER, UE), financed by the Spanish Ministry of Economy and Competitiveness with funds from the State General Budget (PGE) and the European Regional Development Fund (ERDF). A further acknowledgement to XP Solutions for providing a licence to use MicroDrainage®

Laboratory analysis of the infiltration capacity of interlocking concrete block pavements in car parks

Interlocking Concrete Block Pavements (ICBPs) have been widely used in car parks to reduce runoff. Researches have demonstrated that clogging is the most influential factor in the reduction of the infiltration capacity of this type of permeable pavement. Nevertheless, there is no laboratory study of the infiltration performance of ICBPs that combines clogging levels with variables related with the topography of car parks such as runoff surface length (RSL) and surface slope (SS). This paper studies the infiltration behaviour of ICBP during their operational life in a car park using an improved version of the Cantabrian Fixed (CF) Infiltrometer. This laboratory device simulates direct rainfall and runoff from adjacent impervious areas over an ICBPs surface of 0.25m2 for different slopes (0, 3, 5, 7 and 10%) and three scenarios of clogging (surface newly built, surface clogged and surface clogged with maintenance). This paper presents the results of the tests and a statistical analysis based on three regression models (corresponding to each clogging scenario) depending on the RSL and SS variables. All models passed a confidence level of 95%, presenting high R2 values and showing that RSL is a more influential variable than the SS for all clogging scenarios

Efficient Urban Runoff Quantity and Quality Modelling Using SWMM Model and Field Data in an Urban Watershed of Tehran Metropolis

This study aims to calibrate and validate the EPA Storm Water Management Model from field measurements of rainfall and runoff, in order to simulate the rainfall-runoff process in an urban watershed of Tehran metropolis, Iran. During and after three significant storm events, the flow rates, total suspended solids (TSS), total phosphorus (TP), and total Kjeldahl nitrogen (TKN) concentrations were measured at the outlet of the catchment, and were used in the model calibration and validation process. The performance of the SWMM model was evaluated based on the statistical criteria, as well as graphical techniques. In this study, a local sensitivity analysis was carried out to identify the key model parameters, show that “the percentage of impervious surface in each subwatershed had the most effect on the model output”. Based on the analysis of the results, SWMM model calibration and validation can be judged as satisfactory, and the goodness-of-fit indices for simulating runoff quality and quantity are placed in acceptable ranges. The adjustment obtained for the variations in the measured and simulated flow rates, pollutograph concentrations, total pollutant load, peak concentration, and the event mean concentration (EMC) confirms the considerable predictive capability of the SWMM model when it is well calibrated by using field measurements

Laboratory Assessment of the Infiltration Capacity Reduction in Clogged Porous Mixture Surfaces

Permeable pavements have been used widely across the world to manage urban stormwater. The hydrological behaviour of permeable surfaces is a complex process affected by many factors, such as rainfall intensity, rainfall duration, pavement geometrical conditions, and clogging level of the permeable surface, amongst others. This laboratory study was carried out to assess the influence of clogging level and rainfall intensity on the infiltration capacity of porous mixture surfaces used in Permeable Pavement Systems (PPS). Porous Concrete (PC) and Porous Asphalt (PA) mixtures with different air void contents (15%, 20%, and 25%) were subject to different clogging scenarios by using varying sediment loads (0, 500, and 1000 g/m2). Permeability experiments were carried out for each clogging scenario through a new rainfall simulator specially developed, tailored, and calibrated for the laboratory simulation of a wide range of rainfall events. Permeability measurements were taken under all different scenarios as a result of the combination of the different rainfall events (50, 100, and 150 mm/h) simulated over the specimens of porous mixtures and the sediment loads applied to them. The results showed that the PC mixtures tested perform better than the PA ones in terms of infiltration capacity, showing less potential for clogging and being more easily cleaned by the wash-off produced by the simulated rainfall events

An Experimental and Numerical Approach to Multifunctional Urban Surfaces through Blue Roofs

Uncontrolled urban growth causes a number of problems associated with land use, stormwater management and energy generation. Sustainable Urban Drainage Systems (SUDS) are positioned as an alternative to traditional constructive solutions, contributing towards the generation of multifunctional urban spaces for efficient stormwater management and energy consumption reduction. Nevertheless, this combined goal calls for a deeper understanding of the heat transfer processes that govern the temperature performance in SUDS in order to be further validated as infrastructure to house renewable energy elements. This study intends to determine the thermal properties of two types of blue roofs under extreme conditions of performance (wet and dry), depicting the operation features of their layers and comparing their performances based on the materials used. With this aim, a hybrid experimental methodology, combining laboratory and numerical modelling, was designed using standardized equipment (ISO 8990:1994 and ASTM C1363-05), improving previous methods proposed in the study of the thermal properties of SUDS. The section with expanded clay improved the hydraulic capacity by 4.8%. The section without expanded clay increased its thermal transmittance value by 64.9% under wet conditions. It was also found that the presence of water increased the equivalent thermal conductivity in both sections by 60%

Barrera para depósito de partículas

Barrera para depósito de partículas, para proteger vías de comunicaciones, propiciando la acumulación de nieve o arena en la zona de la barrera sobre la que azota el viento, barlovento, o en zona posterior, sin llegar a la vía; compuesta por una pluralidad de pantallas que combinan una geomalla y una red de cable, hallándose sujetas a postes anclados en el terreno.Solicitud: 200901283 (21.05.2009)Nº Pub. de Solicitud: ES2350990A1 (28.01.2011)Nº de Patente: ES2350990B1 (22.09.2011

The long-term hydrological performance of Permeable Pavement Systems in Northern Spain:An approach to the "end-of-life" concept

Porous mixtures and Interlocking Concrete Block Pavements (ICBP) are the most widely used surfaces in Permeable Pavement Systems (PPS). Despite the fact that there are many studies based on the hydrological performance of PPS, there are few long-term studies that identify the end of life of PPS regarding their hydrological performance. A field study has been developed over 10 years in the experimental car park “Las Llamas” in the city of Santander, Northern Spain. Permeability was measured in 37 car park bays (nine Polymer-Modified Porous Concrete, nine Porous Asphalt, and 17 ICBP of two different designs). Tests were conducted under the Spanish Standard NLT-327/00 for the porous-mixture surfaces and the ASTM methods C1701/C1701M-17a and C1781/C1781M-15 for porous mixtures and ICBP, respectively. No maintenance was carried out in this car park since it was opened to traffic in 2008, allowing for the assessment and identification of the hydrological failure of each surface. The research showed that after 10 years of operation without maintenance, the bays constructed using porous mixtures were completely clogged, reaching the end of their operational life after nine years. However, ICBP maintained high infiltration rates, showing better resilience to sediment clogging. Further research is needed to confirm the evolution of ICBP surfaces

Descriptive Analysis of the Performance of a Vegetated Swale through Long-Term Hydrological Monitoring: A Case Study from Coventry, UK

Vegetated swales are a popular sustainable drainage system (SuDS) used in a wide range of environments from urban areas and transport infrastructure, to rural environments, sub-urban and natural catchments. Despite the fact that vegetated swales, also known as grassed swales, have received scientific attention over recent years, especially from a hydrological perspective, there is a need for further research in the field, with long-term monitoring. In addition, vegetated swales introduce further difficulties, such as the biological growth occurring in their surface layer, as well as the biological evolution taking place in them. New developments, such as the implementation of thermal devices within the cross-section of green SuDS for energy saving purposes, require a better understanding of the long-term performance of the surface temperature of swales. This research aims to contribute to a better understanding of these knowledge gaps through a descriptive analysis of a vegetated swale in Ryton, Coventry, UK, under a Cfb Köppen climatic classification and a mixed rural and peri-urban scenario. Precipitation and temperature patterns associated with seasonality effects were identified. Furthermore, a level of biological evolution was described due to the lack of periodical and planned maintenance activities, reporting the presence of both plant species and pollinators. Only one event of flooding was identified during the three hydrological years monitored in this research study, showing a robust performance