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Population growth has led to the intensification of average daily traffic (ADT), highlighting vehicles as one of the major sources of heavy metal (HM) pollution in cities. The objective of this paper is to conduct a spatial analysis of the HM pollution associated with road-deposited sediments (RDSs), based on the ADT observed in the main roads of a Latin American megacity (Bogotá, Colombia). The following risk indices were considered: Geoaccumulation Index (Igeo), Integrated Pollution Index (IPI), Ecological Risk Index (ERI), Comprehensive Potential Ecological Risk Index (CERI), Hazard Index (HI), and Carcinogenic Risk Index (CRI). The findings confirm that a size fraction < 250 μm is the most suitable for studying the risk of HMs in the RDS from the indices considered. The best HMs indicative of the relationship with ADT are Ni, Cu, and Pb. The Pb is the HM of most attention, and Cr gains positions for its toxicity level during the evaluation of ecological, non-carcinogenic, and carcinogenic risks, respectively. Finally, the linear regression models developed between ADT and each of the risk indices considered have a better fit (R2 > 0.910) compared to the linear regression models developed between ADT and HM concentrations (R2 > 0.322). [ABSTRACT FROM AUTHOR]

Rainwater Harvesting (RWH) is the practice of capturing and storing stormwater for later use. In addition to being an alternative source of water for non-potable applications, RWH is also used to effectively reduce stormwater runoff volumes and pollutant loads dropped into sewage systems. RWH is typically carried out by placing a variety of Sustainable Urban Drainage Systems (SUDS) in different locations of the urban landscape. However, because of the staggering number of potential combinations of SUDS typologies and spatial configurations that can be used, identifying a strategy that optimally selects and allocates SUDS to maximize the benefits of RWH is a complex endeavor. One of the challenges that emerges during the optimal design and location of these systems is incorporating the inherent uncertainty of the rainfall. In this paper, we develop a flexible computational framework that couples a Geographic Information System (GIS) with a two-stage stochastic mixed integer linear program (TS-MILP) to select and locate SUDS in order to minimize the use of potable water for irrigation and reduce the water runoff at a minimum cost. This framework incorporates an iterative participatory approach to engage stakeholders in the decision-making process. We tested the proposed methodology on a case study for the central campus at Universidad de Los Andes (Bogotá, Colombia). Our results showed that the expected value of the total runoff volume and the consumption of potable water can be reduced up to 67% and 50%, respectively. • A flexible computational framework to select and allocate SUDS was developed. • The objectives are minimizing the use of potable water for irrigation and reducing the water runoff at a minimum cost. • A Geographic Information System (GIS) is coupled with a two-stage stochastic mixed integer linear program (TS-MILP). • The proposed methods can be easily adapted to incorporate a wide variety of stakeholder requirements or preferences. • An iterative participatory approach is used to include stakeholders in the decision-making process. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyze the changes that have been produced in the temperature, humidity, precipitation, and edaphic parameters due to the presence of vertical gardens in the wetland "La Vaca" in Bogotá (Colombia). There are some conflicts in this wetland regarding the uses of the land due to the illegal urbanization settlements in flood-prone zones; to which a loss of the natural space of the wetland and the effects of climate warming is added. For this reason, vertical gardens are presented as an alternative for the solution to the aforementioned problems, since their implementation can act as a control barrier to possible floods considering their properties of water retention and temperature control. This work also sets its sight on knowing what changes have been produced in the environmental variables mentioned before with the presence of vertical gardens, and also on studying its temporal and spatial variability in the environment of the study area. The investigation begins with the installation of three vertical gardens with floating vegetation systems, installation of drip irrigation, and organic fertilizer built from the invasive vegetation of the wetlands. Subsequently, in the absence of vertical gardens, control areas are proposed for comparison with climatic and edaphic measurements. Finally, different statistical analyzes are performed, such as the comparison of means with parametric and non-parametric tests, among others, to determine spatial differences, and the changes that have been produced in time series. Vertical gardens are an alternative of "green growth" that make it possible to restore green areas and Riparian Buffer Zones in wetlands, using the resources of the environment to reduce costs in possible floods and the effects that are generated by climate change. [ABSTRACT FROM AUTHOR]