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Sealed surfaces in urban areas change the water and energy balance resulting in decreased evapotranspiration and infiltration, magnified stormwater runoff, and sensible heat fluxes. Urban Green Infrastructures (UGI) are implemented to reverse such effects. This study examines the potential of a high-resolution grid-based model to show the impact of different degrees of urban land cover. The study area was divided into 52 cells and cells were categorized into four urban degrees of urbanization. Two scenarios were considered to represent the existing conditions of a study area in the Great Metropolitan Area of Costa Rica and the effects derived from the implementation of UGI. The software Surface Urban Energy and Water Balance Scheme (SUEWS) was employed to simulate both scenarios and compare them by using the Bowen ratio (β) as an indicator of changes in the energy balance. The results show a reduction of β associated with the spatial distribution of the cells with different degrees of urbanization, even in the cells where no changes were considered. Applying the SUEWS approach based on high-resolved land cover classes distribution enables a more detailed understanding of micro-climatic benefits of UGI in high-density urban areas and may result in additional insights for decision-making.
Rebecca Wiegels; Fernando Chapa; Jochen Hack. High resolution modeling of the impact of urbanization and green infrastructure on the water and energy balance. Urban Climate 2021, 39, 100961 .
AMA StyleRebecca Wiegels, Fernando Chapa, Jochen Hack. High resolution modeling of the impact of urbanization and green infrastructure on the water and energy balance. Urban Climate. 2021; 39 ():100961.
Chicago/Turabian StyleRebecca Wiegels; Fernando Chapa; Jochen Hack. 2021. "High resolution modeling of the impact of urbanization and green infrastructure on the water and energy balance." Urban Climate 39, no. : 100961.
Urban green infrastructure (UGI) provides multiple functions that combine ecological and social benefits. UGI is being increasingly promoted and implemented in the Global North. In other parts of the world, such as in the Global South, infrastructures for UGI implementation and promotion are sparse. The state of infrastructure development and informal settlements in the Global South present different constraints and demands that should be explicitly addressed. This study presents an approach to addressing the specific conditions and physical limitations of UGI development in urban areas of the Global South. A four-step methodology was developed to assess the implementation potential for retrofitted and multifunctional urban green infrastructure in public areas. This methodology consists of (1) an initial site analysis, (2) defining design criteria and general strategies, (3) exploring the different dimensions of multifunctionality as the basis for deriving spatial typologies, and (4) assessing spatial suitability for potential placements for UGI elements. The methodology was applied to a study area in the metropolitan region of San José, Costa Rica. The results indicate the potential to improve the hydrological (up to 34% of surface runoff reduction), ecological (an increase of green space by 2.2%, creation of 1500 m length of roadside greenery and two new habitat types), and social conditions (2200 m of road type upgrading) of the site through UGIs. This assessment of different multifunctionality dimensions can serve as a guide for future UGI promotion and implementation in urban areas of the Global South.
Tanja Fluhrer; Fernando Chapa; Jochen Hack. A Methodology for Assessing the Implementation Potential for Retrofitted and Multifunctional Urban Green Infrastructure in Public Areas of the Global South. Sustainability 2021, 13, 384 .
AMA StyleTanja Fluhrer, Fernando Chapa, Jochen Hack. A Methodology for Assessing the Implementation Potential for Retrofitted and Multifunctional Urban Green Infrastructure in Public Areas of the Global South. Sustainability. 2021; 13 (1):384.
Chicago/Turabian StyleTanja Fluhrer; Fernando Chapa; Jochen Hack. 2021. "A Methodology for Assessing the Implementation Potential for Retrofitted and Multifunctional Urban Green Infrastructure in Public Areas of the Global South." Sustainability 13, no. 1: 384.
Green Infrastructure promotes the use of natural functions and processes as potential solutions to reduce negative effects derived from anthropocentric interventions such as urbanization. In cities of Latin America, for example, the need for more nature-based infrastructure is evident due to its degree of urbanization and degradation of ecosystems, as well as the alteration of the local water cycle. In this study, an experimental approach for the implementation of a prototype is presented. The prototype consists of a gray-hybrid element for first flush bio-treatment and runoff detention, adapted to the existing stormwater sewer. The experiment took place in a highly urbanized watershed located in the Metropolitan Area of Costa Rica. The characteristics of the existing infrastructure in the study area at different scales were mapped and compared using the Urban Water System Transition Framework. Subsequently, preferences related to spatial locations and technologies were identified from different local decision-makers. Those insights were adopted to identify a potential area for the implementation of the prototype. The experiment consisted of the adaptation of the local sewer to act as a temporal reservoir to reduce the effects derived from rapid generation of stormwater runoff. Unexpected events, not considered initially in the design, are reported in this study as a means to identify the necessary adaptations of the methodology. Our study shows from an experimental learning-experience that the relation between different actors advocating for such technologies influences the implementation and operation of non-conventional technologies. Furthermore, the willingness of residents to modify their urban environments was found to be associated to their own perceptions about security and vandalism occurring in green spaces. The implementation of the prototype showed that both the hydraulic performance is relevant for considering it as a success, as well as the dynamics of the adapted element with the existing urban conditions. In consequence, those aspects should be carefully considered as the design factors of engineering elements when they are related to complex socio-ecological urban systems.
Fernando Chapa; María Pérez; Jochen Hack. Experimenting Transition to Sustainable Urban Drainage Systems—Identifying Constraints and Unintended Processes in a Tropical Highly Urbanized Watershed. Water 2020, 12, 3554 .
AMA StyleFernando Chapa, María Pérez, Jochen Hack. Experimenting Transition to Sustainable Urban Drainage Systems—Identifying Constraints and Unintended Processes in a Tropical Highly Urbanized Watershed. Water. 2020; 12 (12):3554.
Chicago/Turabian StyleFernando Chapa; María Pérez; Jochen Hack. 2020. "Experimenting Transition to Sustainable Urban Drainage Systems—Identifying Constraints and Unintended Processes in a Tropical Highly Urbanized Watershed." Water 12, no. 12: 3554.
Green Stormwater Infrastructure (GSI), a sustainable engineering design approach for managing urban stormwater runoff, has long been recommended as an alternative to conventional conveyance-based stormwater management strategies to mitigate the adverse impact of sprawling urbanization. Hydrological and hydraulic simulations of small-scale GSI measures in densely urbanized micro watersheds require high-resolution spatial databases of urban land use, stormwater structures, and topography. This study presents a highly resolved Storm Water Management Model developed under considerable spatial data constraints. It evaluates the cumulative effect of the implementation of dispersed, retrofitted, small-scale GSI measures in a heavily urbanized micro watershed of Costa Rica. Our methodology includes a high-resolution digital elevation model based on Google Earth information, the accuracy of which was sufficient to determine flow patterns and slopes, as well as to approximate the underground stormwater structures. The model produced satisfactory results in event-based calibration and validation, which ensured the reliability of the data collection procedure. Simulating the implementation of GSI shows that dispersed, retrofitted, small-scale measures could significantly reduce impermeable surface runoff (peak runoff reduction up to 40%) during frequent, less intense storm events and delay peak surface runoff by 5–10 min. The presented approach can benefit stormwater practitioners and modelers conducting small scale hydrological simulation under spatial data constraint.
Sami Towsif Khan; Fernando Chapa; Jochen Hack. Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale. Land 2020, 9, 339 .
AMA StyleSami Towsif Khan, Fernando Chapa, Jochen Hack. Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale. Land. 2020; 9 (9):339.
Chicago/Turabian StyleSami Towsif Khan; Fernando Chapa; Jochen Hack. 2020. "Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale." Land 9, no. 9: 339.
Green Stormwater Infrastructure (GSI), a sustainable engineering design approach for managing urban stormwater runoff, has long been recommended as an alternative to conventional conveyance-based stormwater management strategies to mitigate the adverse impact of sprawling urbanization. Hydrological and hydraulic simulations of small-scale GSI measures in densely urbanized micro watersheds require high-resolution spatial databases of urban land use, stormwater structures, and topography. This study presents a highly resolved Storm Water Management Model developed under considerable spatial data constraints. It evaluates the cumulative effect of the implementation of dispersed, retrofitted, small-scale GSI measures in a heavily urbanized micro watershed of Costa Rica. Our methodology includes a high-resolution digital elevation model based on Google Earth information, whose accuracy was sufficient to determine flow patterns and slopes, as well as to approximate the subsurface stormwater structures. The model produced satisfactory results in event-based calibration and validation, which ensured the reliability of the data collection procedure. Simulating the implementation of GSI shows that dispersed, retrofitted, small-scale measures could significantly reduce impermeable surface runoff (peak runoff reduction up to 40%) during frequent, less intense storm events and delay peak surface runoff 5-10 minutes. The presented approach can benefit stormwater practitioners and modelers conducting small scale hydrological simulation under spatial data constraint.
Sami Towsif Khan; Fernando Chapa; Jochen Hack. Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale. 2020, 1 .
AMA StyleSami Towsif Khan, Fernando Chapa, Jochen Hack. Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale. . 2020; ():1.
Chicago/Turabian StyleSami Towsif Khan; Fernando Chapa; Jochen Hack. 2020. "Highly Resolved Rainfall-Runoff Simulation of Retrofitted Green Stormwater Infrastructure at the Micro-Watershed Scale." , no. : 1.
The increasing demand for water in urban areas of developing countries has been given more importance to rainwater harvesting techniques in the last decades. However, there is still a lack of general approaches to show and compare the potential to benefit effectively from direct roof runoff at different locations. Past studies mainly focused on specific design conditions, making it difficult to interpret and upscale their results in zones with similar conditions. This research explores the influence of rainfall characteristics and design parameters: storage tank size, catchment area, and daily water demand on rainwater harvesting systems designed for water supply. Sixteen locations in Ecuador with varying hydroclimatic characteristics were selected to evaluate our methodology. A mass balance method using satellite records of the Tropical Rainfall Measuring Mission was employed to estimate optimal dimensions based on the reliability of the system. Our results suggest that locations with similar annual rainfall and seasonality have similar performances of rainwater harvesting systems. Based on that premise, regional approaches can be formulated. They can be employed as a tool to support decision-makers promoting policies related to rainwater harvesting at local and regional scales.
Fernando Chapa; Manuel Krauss; Jochen Hack. A multi-parameter method to quantify the potential of roof rainwater harvesting at regional levels in areas with limited rainfall data. Resources, Conservation and Recycling 2020, 161, 104959 .
AMA StyleFernando Chapa, Manuel Krauss, Jochen Hack. A multi-parameter method to quantify the potential of roof rainwater harvesting at regional levels in areas with limited rainfall data. Resources, Conservation and Recycling. 2020; 161 ():104959.
Chicago/Turabian StyleFernando Chapa; Manuel Krauss; Jochen Hack. 2020. "A multi-parameter method to quantify the potential of roof rainwater harvesting at regional levels in areas with limited rainfall data." Resources, Conservation and Recycling 161, no. : 104959.
Urbanization nowadays results in the most dynamic and drastic changes in land use/land cover, with a significant impact on the environment. A detailed analysis and assessment of this process is necessary to take informed actions to reduce its impact on the environment and human well-being. In most parts of the world, detailed information on the composition, structure, extent, and temporal changes of urban areas is lacking. The purpose of this study is to present a methodology to produce high-resolution land use/land cover maps by the use of free software and satellite imagery. These maps can help to understand dynamic urbanizations processes to plan, design, and coordinate sustainable urban development plans, especially in areas with limited resources and advancing environmental degradation. A series of high-resolution true color images provided by Google Earth Pro were used to do initial classifications with the Semi-Automatic Classification Plug-in in QGIS. Afterwards, a new methodology to improve the classification by the elimination of shadows and clouds, and a reduction of misclassifications through superimposition was applied. The classification was carried out for three urban areas in León, Nicaragua, with different degrees of urbanization for the years 2009, 2015, and 2018. Finally, the accuracy of the classification was analyzed using randomly defined validation polygons. The results are three sets of high-resolution land use/land cover maps of the initial and the improved classification, showing the detailed structures and temporal dynamics of urbanization. The average accuracy of classification reaches 74%, but up to 85% for the best classification. The results clearly identify advancing urbanization, the loss of vegetation and riparian zones, and threats to urban ecosystems. In general, the level of detail and simplicity of our methodology is a valuable tool to support sustainable urban management, although its application is not limited to these areas and can also be employed to track changes over time, providing therefore, relevant information to a wide range of decision-makers.
Fernando Chapa; Srividya Hariharan; Jochen Hack. A New Approach to High-Resolution Urban Land Use Classification Using Open Access Software and True Color Satellite Images. Sustainability 2019, 11, 5266 .
AMA StyleFernando Chapa, Srividya Hariharan, Jochen Hack. A New Approach to High-Resolution Urban Land Use Classification Using Open Access Software and True Color Satellite Images. Sustainability. 2019; 11 (19):5266.
Chicago/Turabian StyleFernando Chapa; Srividya Hariharan; Jochen Hack. 2019. "A New Approach to High-Resolution Urban Land Use Classification Using Open Access Software and True Color Satellite Images." Sustainability 11, no. 19: 5266.