Low Impact Development Methods Research Articles

A fuzzy TOPSIS-based approach for prioritizing low-impact development methods in high-density residential areas.

The study successfully implemented six low-impact development (LID) methods to manage surface runoff in urban areas: green roof, infiltration trench, bio retention cell, rain barrel, green roof combined with infiltration trench, and rain barrel combined with bio-retention cell. Each method has unique benefits in mitigating surface runoff effects in urban environments. The following four indicators were used to evaluate the methods: runoff volume reduction, peak runoff flow rate reduction, economic sustainability, and social sustainability. The study, which lasted approximately 4 months, was conducted in an eastern Tehran metropolis residential area with a mix of old and new buildings. The SWMM model determined runoff volume and peak flow values, and a price analysis list determined the economic index. Local experts completed 25 questionnaires to evaluate the social index. Fuzzy TOPSIS multi-indicator decision criteria were used to prioritize LID methods, and the Rain barrel + Bio retention cell combined scenario emerged as the best option based on all four criteria. The method reduced peak runoff flow by 23.1-66.1% under rainfall with 10-year return periods. The green roof + infiltration trench method had the highest percentage reduction of 2,737 m3, while the infiltration trench had the lowest reduction of 273 m3.

Block-scale use of bioretention cells to restore the urban water balance: A case study in Tehran metropolis

Study regionA densely populated urban area located in the 13th municipality of Tehran metropolis, Iran. Study focusBioretention cell is one of the low-impact development methods that aims to restore the hydrological cycle in city areas before urban development. However, the bioretention cell's hydrological performance can vary in urban environments. As a result, this research investigated the effectiveness of a bioretention cell in reducing runoff and recharging groundwater in a densely populated metropolitan area located in eastern Tehran, Iran. Groundwater and surface water modeling were conducted separately. The SWMM model was used for surface water modeling, while a novel approach that utilized the SWMM groundwater module was implemented to assess the bioretention cell's impact on groundwater recharge quantitatively. New hydrological insights for the regionThe study found that implementing bioretention cells can significantly reduce total runoff volume, ranging from 75.6% to 60.7% for rainfall with a return period of 2–100 years. This reduction is due to increased infiltration from the bioretention cells, which can lead to a maximum monthly increase of 12.2–44.0 millimeters of groundwater table for the same rainfall events. The study highlights the effectiveness of retaining runoff through bioretention cells in mitigating flooding, restoring the hydrological cycle, and reviving aquifers in urban areas.

Profitability Analysis of Selected Low Impact Development Methods for Decentralised Rainwater Management: A Case Study from Lublin Region, Poland

Water scarcity affects at least 11% of the population and 17% of the territory of the European Union. Simultaneously in cities there is a problem of urban floods caused by violent and intense rainfalls. Decentralized drainage systems are designed to capture rainwater runoff at the place of precipitation and improve the hydrological conditions through the use of surface and subsurface infiltration, retention, and evapotranspiration techniques. The purpose of this paper was to evaluate the financial profitability of selected Low Impact Development (LID) methods for decentralized management of rainwater disposed from the roofs of two different buildings. In the presented conditions, the use of dual installations and infiltration tunnels turned out to be cost-effective solutions, whereas infiltration boxes were unprofitable for both buildings. The most unprofitable solution would become profitable if the investment costs were reduced by as much as 67% or if it was possible to generate 2.28 times more benefits. Although the research was carried out for specific conditions, the obtained results may be helpful in the implementation of similar investments. They are also a kind of contribution to the assessment of the cost-effectiveness of LID on a global scale due to the universality of the proposed research methodology.

Using AHP-PROMOTHEE for Selection of Best Low-Impact Development Designs for Urban Flood Mitigation

This work first studies the effects of several Low Impact development methods on urban flood control. The Analytic Hierarchy Process-Preference Ranking Organization Method for Enrichment Evaluation (AHP-PROMETHEE) combination method is then used to select the best design. A drainage system in Golestan town of Semnan under a 5-year return period is investigated as the case study. The LID methods are selected based on the region's conditions and facilities. Then Rain Barrel (RB), Permeable Pavement (PP), and Infiltration Trench (IT) were considered as LID methods. The RB, PP, IT, IT-PP, IT-RB, PP-RB, and IT-PP-RB are considered the best LID usage scenarios. Four analytical ranking criteria, implementation cost, hydraulic performance, environmental impact during implementation, and ease of implementation, are chosen for the ranking procedure. Also, the weight of these criteria was obtained using Analytic Hierarchy Process (AHP). Finally, after determining the weight criteria, the LID designs are ranked using the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) method. The results of hydraulic studies demonstrate the effectiveness of the PP-RB scenario with an average reduction of 90% of peak discharge and an average reduction of 80% of total flood volume. It is also observed that the weakest performance is related to the IT scenario, with an average decrease of 60% of peak flow and 47% of total flow volume. AHP-PROMETHEE analysis showed that the simultaneous use of RB and IT with a coverage percentage of 5% and a cost of $ 57,710 reduced the total volume by 51.54% and the peak discharge by 48.8% compared to the results of the current system. According to AHP-PROMETHEE, IT-RB-5 is the best project proposed among the 70 projects studied. This study showed that the AHP-PROMETHEE method is a practical method for choosing from several LID schemes for flood control.

A User-Friendly Software Package to Develop Storm Water Management Model (SWMM) Inputs and Suggest Low Impact Development Scenarios

Increases in imperviousness due to urbanization and industrialization increases stormwater runoff and nonpoint source pollution. Approaches reducing these hydrological impacts include low impact development (LID) methods. Various methods have been developed and applied to date, and an evaluation of stormwater runoff and a reduction of non-point source pollution has been conducted. The Storm Water Management Model (SWMM) is capable of simulating various LID approaches, although selecting and implementing a suitable method for a specific target area, when considering the cost of various low impact development approaches, requires significant time and effort. A software program called Storm Water Management Model–low impact development design program (SWMM-ING), that can be optimally applied to deal with the cost of low impact development methods, was developed in this study. For SWMM-ING, an optimization process was conducted for low impact development, which can reduce stormwater runoff by 10%, suspended solid by 15%, and total phosphorus by 15%. The spatial arrangement and the area of the permeable pavement, bioretention cells, infiltration trenches, and green roofs were determined. Because SWMM-ING has a user-friendly graphical interface, and the optimization process of the low impact development approach is simple and straightforward, it has the advantage of not requiring specialized knowledge.

Modeling and investigating the effect of the LID methods on collection network of urban runoff using the SWMM model (case study: Shahrekord City)

In recent decades, the accumulation of residential regions has increased due to the expansion of urbanization. This has led to an increase in the impermeable areas and, thus, increasing surface runoff in the cities. Therefore, it is necessary to control surface runoff using Low Impact Development (LID) methods in cities. In this research, using the hydraulic-hydrological SWMM model, the collection network of surface runoff of Shahrekord city was simulated in 2, 5, and 10 years return periods. The calibration of the model was performed in two rainfall events. Afterward, validation was performed using sensitivity analysis with calibrated values, which NSE, RMSE, and% BIAS indices showed good simulation accuracy. After this stage, three methods of the green roof, permeable pavement, and rain barrels were located in 14 selected sub-catchments of Shahrekord. The results of these methods on the volume and peak runoff of selected sub-catchment showed that green roof, permeable pavement, and rain barrels, respectively, reduce the volume and discharge peak runoff by 46, 21, and 25%, on average. Moreover, increasing the rainfall period would increase the effectiveness of using these methods. Also, the results of investigating the value of the discharge and volume of runoff within the drainage canals, the capacity of the canals, and downstream of selected sub-catchment, indicated the reduction of these values due to the application of LID methods. As a result, it was concluded that the effect of using a green roof was greater than the others.

Life cycle cost savings analysis on traditional drainage systems from low impact development strategies

Areas that are covered with natural vegetation have been converted into asphalt, concrete, or roofed structures and have increased surface impermeability and decreased natural drainage capability. Conventional drainage systems were built to mimic natural drainage patterns to prevent the occurrence of waterlogging in developed sites. These drainage systems consist of two major components: 1) a stormwater conduit system, and 2) a runoff storage system. Runoff storage systems contain retention basins and drywells that are used to store and percolate runoff, whereas conduit systems are combination of catch basins and conduit pipes used to collect and transport runoff. The construction of these drainage systems is costly and may cause significant environmental disturbance. In this study, low impact development (LID) methods that consist of extensive green roofs (GRs) and permeable interlocking concrete pavements (PICPs) are applied in real-world construction projects. Construction project documents were reviewed, and related cost information was gathered through the accepted bidding proposals and interviews of specialty contractors in the metropolitan area of Phoenix, Arizona. Results indicate that the application of both LID methods to existing projects can save an average of 27.2% in life cycle costs (LCC) for a 50-year service life and 18.7% in LCC for a 25-year service life on the proposed drainage system, respectively.

Can antecedent moisture conditions modulate the increase in flood risk due to climate change in urban catchments?

Climate change coupled with the current trend in rapid urbanization is increasing the risk of flooding that can cause loss of life and damage to property. Adapting to climate change impacts and flood mitigation has become a life critical factor as well as a severe challenge. Green infrastructure and low impact development methods are common approaches that are increasingly used to address stormwater management in developed environments. The analysis and results of this study show that AMC/IC does impact flood response even in urban developed catchments and that it can significantly impact flood responses during storm events. We show that considering AMC/ICs coupled with changes in seasonal rainfall patterns that are projected for warmer climates in the future can modulate some of the increases in flood risk due to climate change.The prevailing thought is that Antecedent Moisture Conditions (AMCs) have little to no relevance in urban hydrology, particularly in relation to climate change. However, current trends in use of stormwater management methods that depend on local storage and infiltration is increasingly making AMC or Initial Conditions (IC) a factor in urban flooding. Despite this trend there is little available literature that discuss the aspect of AMC/IC that can have an implication on urban flood management. Here, we move towards filling this gap in current literature related to impacts of AMCs in flooding of developed areas by focusing on how possible changes in seasonal rainfall patterns in a warming climate might impact AMC and starting conditions in stormwater Best Management Practices (SWBMPs), and how those changed initial conditions impact flood risk in developed areas. Using a comprehensive hydrologic/hydraulic model of an urban/developed catchment and continuous simulation, we demonstrate the importance of accurately accounting for initial conditions in flood assessments. We consider average summer temperatures based on approximately 70 years of historic data to select warm and cold years. We compare the model results between the warm and cold years as a proxy to look at trends related to a future warming climate.

Sponge city construction in China: policy and implementation experiences

Abstract To deal with the three universal urban water problems – namely storm floods, water pollution and water shortage – China has implemented a comprehensive solution: the Sponge City Construction Project. Sponge cities aim to reduce runoff and pollution, and also to restore downstream ecologies. They combine low impact development methods with grey infrastructures, large-scale flood control projects and rehabilitation. This paper describes Chinese experiences of construction and financing for implementation of sponge cities, which could provide references to other countries for building sustainable, climate-resilient cities and urban water management systems. It illustrates the objectives and methods of the sponge city design and demonstrates the differences in configuration and funding structures in cities of different climates and economic conditions. The total construction area involved in the pilot cities covers 449 km2. The configurations are distinct due to different economic conditions, climates and land forms: a humid district inclines to drainage-efficient approaches and pollution control devices, while a semi-humid district prefers green infrastructures and rainwater reuse facilities. The Chinese government plays an important role in the funding of sponge cities: Chinese central government provided CNY (¥)20.7 billion for the construction of 16 cities during 2015–2017, while the rest came from local governments and non-governmental investors.

Análise dos Desenvolvimentos Urbanos de Baixo Impacto e Convencional

This study shows the use of Conventional and LID methods in a microbasin, proving that through urban planning it is possible to create hydrologically functional landscapes, with a behavior similar to the natural one. The comparative analysis of the urban planning methods was performed in an urban microbasin on the Campus of the Federal University of Sao Carlos, in the Monjolinho River basin, in the municipality of Sao Carlos/SP. Hydrological, urbanistic and environmental aspects were evaluated to compare three scenarios: pre-development, existing conventional development and low impact development (LID). Parameters were selected to allow evaluating the proposed scenarios. The results show a landscaping and esthetic gain in the low impact development project, with the creation of 24% plant cover area, increase of areas rendered permeable by reducing 17% of the impervious areas (roads, parking lots and sidewalks) compared to conventional urbanization. As to the hydrological aspects, a reduction of 21% peak flow and 26.9% post-development volume are achieved compared to the conventional one, using LID techniques without the benefit of integrated maangement practices (IMPs). Using IMPs the infitration of rain water keeps the conditions as close as possible to natural conditions

Modeling the Effects of Low Impact Development on Runoff and Pollutant Loads from an Apartment Complex

The effects of low impact development (LID) techniques, such as green roofs and porous pavements, on the runoff and pollutant load from an apartment complex were simulated using the Site Evaluation Tool (SET). The study site was the Olympic Village, a preexisting apartment complex in Seoul, South Korea, which has a high percentage of impervious surfaces (approximately 72% of the total area). Using the SET, the effects of replacing parking lots, sidewalks and driveways (37.5% of the total area) having porous pavements and rooftops (14.5% of the total area) with green roofs were simulated. The simulation results indicated that LID techniques reduced the surface runoff, and peak flow and pollutant load, and increased the evapotranspiration and soil infiltration of precipitation. Per unit area, the green roofs were better than the porous pavements at reducing the surface runoff and pollutant loads, while the porous pavements were better than green roofs at enhancing the infiltration to soil. This study showed that LID methods can be useful for urban stormwater management and that the SET is a useful tool for evaluating the effects of LID on urban hydrology and pollutant loads from various land covers.

The epidemiology of injuries in Atlanta day-care centers

The severity and frequency of short-duration, but damaging, urban area floods have increased in recent years across the world. Alteration to the urban micro-climate due to global climate change impacts may also exacerbate the situation in future. Sustainable urban stormwater management using low impact development (LID) techniques, along with conventional urban stormwater management systems, can be implemented to mitigate climate-change-induced flood impacts. In this study, the effectiveness of LIDs in the mitigation of urban flood are analyzed to identify their limitations. Further research on the success of these techniques in urban flood mitigation planning is also recommended. The results revealed that LIDs can be an efficient method for mitigating urban flood impacts. Most of the LID methods developed so far, however, are found to be effective only for small flood peaks. They also often fail due to non-optimization of the site-specific and time-varying climatic conditions. Major challenges include identification of the best LID practices for the region of interest, efficiency improvements in technical areas, and site-specific optimization of LID parameters. Improvements in these areas will allow better mitigation of climate-change-induced urban floods in a cost-effective manner and will also assist in the achievement of sustainable development goals for cities.