ICSM : une stratégie pour la gestion des inondations dans des bassins versants en redéveloppement

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Stormwater treatment using permeable pavements

Permeable pavements are generally used in water-sensitive urban design as a component of a treatment train and as a source control measure for reducing stormwater flows and pollutant loads. In Australia, permeable pavement systems are an emerging technology and consequently there are few installations more than 10 years old. The performance of permeable pavements in terms of treatment of urban stormwater runoff from a number of typical, but different urban catchments is discussed. Water quality monitoring was carried out in the field to quantify the improvement that permeable pavement systems can make to runoff quality at a car park located at North Haven in Adelaide, South Australia, that utilise both conventional and permeable pavement systems. Extensive laboratory analysis using stormwater collected from four sites was carried out to assess the effectiveness of permeable pavement systems for reducing pollutant discharges. In general, the permeable pavement systems were found to improve stormwater quality when tested at a 5% significance level. The results show that, on average, permeable pavements were able to reduce nutrient concentrations (total nitrogen and total phosphorus), heavy metals (zinc, lead, copper, cadmium and nickel) and total suspended solids. The reductions in pollutant concentrations can be mainly attributed to mechanical filtration by various components of the permeable pavement system

Effect of elevated temperature on water meter accuracy: An investigative study using three positive displacement mechanical meters

Koech, RK ORCiD: 0000-0002-0563-6687In certain parts of Australia, summer temperatures can exceed 40 C. Domestic water meter performance under these extreme conditions is not well understood. The internationally adopted standard for pattern approval and verification (OIML R49-2 2006) does not require determination of the influence of both elevated water and ambient temperature on the error of measurement of the meter. A study was therefore undertaken to investigate these aspects using three positive displacement mechanical meters: two new 20mm nominal diameter (DN20) meters and one used 32mm nominal diameter (DN32) meter. A combination of temperature conditions was varied from 20 degreesC to 50 degreesC and the meter accuracy was determined. There was increased under-reading with the increase in water and ambient temperature. However, the measurement error largely remained within the limits of the maximum permissible error (MPE). It is concluded that, based on the results of this study, periodic elevated temperatures do not significantly affect the performance of domestic water meters and, therefore, do not adversely affect the water suppliers or consumers

Laboratory evaluation of dripper performance

Koech, RK ORCiD: 0000-0002-0563-6687The catch can method is traditionally used for evaluating performance of drip systems. Two variations of this method are commonly applied in laboratory testing of drippers: the sequential and the simultaneous method. This study compared uniformity and measurement uncertainty of the two methods,with the overall aim of improving irrigation water management. The simultaneous method was found to have a lower coefficient of variation(Cv) and measurement uncertainty, indicating that it is more accurate than the sequential method. In all the tests, however, the Cv was determined to be <5%, which is acceptable as per the current reference standard

Influence of clogging on the effective life of permeable pavements

This paper investigates the 'effective life' (or useful lifespan) of permeable pavement installations subject to sediment loadings. The broad aims of this study, which included both laboratory and field work components, were to improve understanding of the long-term pavement hydraulic conductivity, to assess the effective life of permeable pavements and to quantify the degree of sediment trapping and associated pollutant retention. Three types of permeable pavement were investigated. For each type the effects of pavement cleaning were also investigated. Over a simulated 35 years of sediment loading conducted in the laboratory, the results showed reductions of 59-75% in hydraulic conductivity with an average sediment retention of 94%. Suspended sediment concentrations measured at the outflow of the laboratory test beds did not show any significant difference between pavers that were subjected to cleaning and those that were not. For the field studies presented in this paper, hydraulic conductivities were very high in locations where permeable pavements are subjected to small to moderate sediment loads. At other locations with high coarse sediment and organic sediment loads, hydraulic conductivity tests indicated that clogging occurred at a rapid rate, particularly where runoff flowing onto the pavement was concentrated

Stormwater detention basin for improving road-runoff quality

Both wet and dry detention basins are commonly used for the treatment of road runoff. The basin investigated in this study was located on the eastern side of the southern expressway in Adelaide, Australia. Event mean pollutant concentrations (EMCs) and total pollutant loads were determined for the basin inflows and outflows. The water quality parameters tested included pH, conductivity, total suspended solids, total dissolved solids (TDS), total Kjeldahl nitrogen, total phosphorous, total hydrocarbons, cadmium, chromium, copper, lead, zinc and nickel. Six critical events were sampled in this manner during the course of the investigation. Total pollutant loads passing through as basin inflow were determined over the six monitored events. Comparison of basin inflow and outflow quality demonstrated that the average load reductions varied from as little as 18% for TDS up to 77% for total phosphorous and lead. While copper concentrations at the basin inflow were detected in four out of the six events, no detectable concentrations were found in the outflows. The average reductions for lead and zinc were more than 50% on more than 80% of occasions

Evaluation of Drip Irrigation Systems for Water Management in Orchards

Koech, RK ORCiD: 0000-0002-0563-6687This new volume in the Innovations and Challenges in Micro Irrigation series covers an array of technologies to estimate evapotranspiration and to evaluate parameters that are needed in the management of micro irrigation, with worldwide applicability to irrigation management in agriculture. Topics include recent evapotranspiration research, performance evaluation of filters and emitters, evaluation of fertigation and ground water with treated wastewater effluent, performance of pulse drip irrigated potato under organic agriculture practices in sandy soils, impact of polyethylene mulch on micro irrigated cabbage, and tree injection irrigation