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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
The treatment methods used for the treatment train can be grouped into two categories: infiltration practices and detention. Infiltration practices can be further divided into three classes: swales and filter strips, percolation trenches, and infiltration basins. Swales and filter strips use vegetation such as grasses to minimize the amount of directly connected impervious area, which also reduces the runoff velocity and allows the water an extended amount of time to infiltrate the soil. A swale is a shallow trench seen along streets and highways, and a filter strip is a strip of land across that stormwater, from an impervious area, sheet flows before entering drainage. The vegetation acts as a filter, removing approximately 80% of the contaminants during runoff [Whalen and Callum, 1988].
Stormwaters: Management
Published in Yeqiao Wang, Fresh Water and Watersheds, 2020
John C. Clausen, Michael E. Dietz
Vegetated swales can be used as an alternative to conventional curb and gutter conveyance systems (Figure 23.5). Modern swales, also termed “bioswales,”[4] are designed differently from the older ditches that were just meant to convey runoff. Modern swales are engineered to provide storage and infiltration of stormwater, but they also will convey runoff from larger events to reduce flooding potential. However, pollutant removal is generally low in swales (Table 23.2). Vegetated swales are similar to vegetated filter strips, but they are designed to convey stormwater as well. They may retain high percentages of suspended solids, N, and P, but the retention rates are variable (Table 23.2).
Urban water infrastructure
Published in Jiri Marsalek, Blanca Jiménez-Cisneros, Mohammad Karamouz, Per-Arne Malmquist, Joel Goldenfum, Bernard Chocat, Urban Water Cycle Processes and Interactions, 2014
Jiri Marsalek, Blanca Jiménez-Cisneros, Mohammad Karamouz, Per-Arne Malmquist, Joel Goldenfum, Bernard Chocat
Biofiltration by grass filters and swales serves to reduce runoff volume by infiltration and to enhance runoff quality by such processes as settling, filtration, adsorption and bio-uptake. Swales are commonly applied in the upstream reaches of drainage areas to control runoff flows and enhance runoff quality. Vegetated filter strips are feasible in low-density developments with small contributing areas with diffuse runoff, suitable soils (good sorption), and lower groundwater tables. Swales are shallow grassed channels functioning in a similar way as vegetated biofilters and are best suited for small areas with permeable soils and low groundwater tables (Schueler, 1987).
Optimal size, type and location of low impact developments (LIDs) for urban stormwater control
Published in Urban Water Journal, 2021
Khashayar Saniei, Jafar Yazdi, Mohammad Reza MajdzadehTabatabei
Different types of LIDs are used to control flooding and reduce pollutant loads in various catchments. In this study, based on local conditions, four different types of LIDs including swale, bioretention, permeable pavement and detention pond were used. Swales are shallow and vegetated open channels that are used to reduce runoff speed, purify stormwater and increase water conductivity. In this study, swales are assumed to be replaced by traditional drainage channels along the streets. Moreover, bioretentions are good choices for air lands that exist in the catchment. Permeable pavements were assumed for sidewalk areas and street surfaces. They infiltrate the surface runoff into the bottom layers and eliminate some contaminants. Detention ponds are also considered in some places of the catchment, based on the local feasibility studies, conducted by the Tehran municipality (TETO 2016).
Variations of infiltration capacity with flow hydraulic parameters in permeable stormwater channels
Published in ISH Journal of Hydraulic Engineering, 2022
Badronnisa Yusuf, Ahmed Mohammed Sami Al-Janabi, Abdul Halim Ghazali, Ibrahiem Al-Ani
The trapezoidal cross section is usually preferred for swales because it offers ample capacity with a minimum depth and ease of construction, however, the recommended range values of base width, side slope and longitudinal slope are 0.5 to 3 m, 2 to 4, and 0.1% to 0.5%, respectively (DID 2012). The study, therefore, was conducted using trapezoidal cross-section models with the range of values considered.
Making Practices in Pursuit of Ecological Ethos: Learnings from Three Ecovillages in Australia
Published in International Journal of Human–Computer Interaction, 2023
Participants try to grow as much food as possible to minimise their environmental footprint in all ecovillages. We can witness people’s interaction with the local environment in edible gardens. For example, the garden in EV2 is located on a slope. P10 designs the swale along the contour to slow rain flow and stop minerals from draining away. Instead of the traditional method of digging dams to store water, the swale is a more efficient way to capture water and prevent it from evaporating. He also installed a swivel pipe to control the water level of the swale when it rains heavily. They aim to create a forest majoring in food plants that build topsoil. The by-product is that the forest feeds residents. EV2 was a cow paddock before 2008. There is now a forest here after 13 years of planting because it is being restored as an ecosystem. In his view, the strategy of sustainability is syntropic farming, planting nuts and fruits of deep roots, long-lived trees. Trees like avocados, nuts, and olive trees can live hundreds of years. P10 comments that syntropic farming is an example that provides high-value nutrition, and produces more topsoil and biomass with little labour: I became fascinated with growing food and the link between food and mental health and well-being. And the more I studied that, and the more I realized that mainstream production of the city is releasing carbon and destroying the atmosphere. They require a forest. Trees sequester carbon. Something a pin dropped to me that this was a holistic solution. It turns out that truly healthy food, what truly healthy food with low food miles, is not just good for us. It’s good for the planet. So the goal is to produce topsoil. We want to get a forest majoring in food plants. So the by-product is that the forest feeds us. If the goal is to grow food, you will knock down a forest to put in a row of quick cash crops to get money and food quickly. But that drives an ecosystem back into entropy. Decay and break down. A forest is syntropic. Every day. What’s in front of us? Here we have more biomass, more oxygen, more topsoil, no labour. (Figure 8) P10 also introduces the ram pump he made in the garden. Ram pump or hydraulic ram can often be seen in remote and off-the-grid contexts. It can pump water just using water kinetic energy without any outside power. In other words, it uses water to pump water. P10 believes the ram pump he uses can run for more than 50 years without service. The water comes down with velocity and drives the ram pump. Half the water comes out, used for irrigation, while the other half is driven up higher than the source, where they store it in a tank. In his opinion, it is a perfect example of sustainable technology, which is simple, long-lasting, and not about planned obsolescence (Figure 9).