Combined application of real-time control and green technologies to urban drainage systems

The increase in waterproof surfaces, a typical phenomenon of urbanization, on the one hand, reduces the volume of rainwater that naturally infiltrates the subsoil and, on the other, it determines the increase in speeds, flow rates, and outflow volume surface; at the same time, it causes a qualitative deterioration of the water. This study researched the optimal management of urban drainage systems via the combined application of real-time control and green technologies. A hydraulic model of the sewer system of the suburbs of Bologna (Italy) was set up using the Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) to evaluate the reduction in water volume and the masses of pollutants discharged in water bodies. The combined application of these technologies allows significantly reducing both the pollutants released into the receiving water bodies and the overflow volumes, while optimizing the operation of the treatment plants. Green technologies cause an average reduction equal to 45% in volume and 53% of total suspended solids (TSS) sent to the receiver. The modeled cases represent only some of the possible configurations achievable on urban drainage systems; the combined use of different solutions could lead to further improvements in the overall functioning of the drainage system

Water management in local development plans: the case of the old Fruit and Vegetable Market in Bologna

This paper describes the hydraulic simulation of an urban drainage system with SWMM 5.0 in order to evaluate the behavior of different solutions for the management of urban runoff. In particular have been analyzed different solutions for the flow peak reduction in the receiving water: retention basin, green roofs and infiltration tanks. The reuse of rainfall for irrigation has been analyzed in order to evaluate the reduction in the volume that flow into the sewer system. The simulations were performed adopting a long time rainfall series of 15 years recorded in Bologna (Italy)

A long-term hydrological modelling of an extensive green roof by means of SWMM

Green roofs provide multiple environmental and social benefits, among which the opportunity to control storm water runoff as they limit the rate of runoff after urbanization to the rate that would have occurred before urban development. The hydrological behaviour of a green roof is site specific, thus the local environmental parameters, the characteristics of the vegetation and the physical properties of its layers have to be considered in the evaluation of its performance. Furthermore, the hydrological performance of a green roof is influenced by the size of the plot (full-scale vs small scale), by the definition of “event”, and by the number of events included in the research. From this broader context this paper first provides a review of the scientific literature, with a focus on the hydrological behaviour of experimental full-scale installations and on hydrological modelling of green roof performance. Second, the study presents the results of a monitoring activity of a full-scale extensive green roof in Bologna (Italy). Continuous weather data and runoff were collected between January and December 2014, resulting in 69 storm events suitable for the study. Experimental data show that single event rainfall attenuation ranged from 6.4% to 100% with an annual average value of 51.9% which is consistent with other author's findings. Last, the study uses the field data to calibrate and validate a numerical model realized with the commercial software SWMM 5.1. The model was used to simulate the long-term hydrologic response, over one year, of the same full-scale extensive green roof and to compare it to an adjacent impervious roof of the same size. Modelling results confirm the role of green roofs in restoring the natural water regime by reducing the annual runoff volume. The comparison of the results between the experimental green roof monitoring and the SWMM simulation proved that the suggested model has good capabilities in simulating the hydrograph of stormwater runoff from green roofs along the year, as demonstrated by the quite high values of NSE and the low value of RSR in both the calibration and validation phase. Furthermore, the low difference (< 9%) in total retention between the 69 measured and simulated events confirms the suitability of the model for long term simulations. The proposed modelling approach demonstrates that SWMM can be used for assessing the performance of LID systems (Low Impact Development), and consequently for supporting local authorities or designers in the evaluation of the hydrological efficiency of green roofs

Experimental Infiltration Tests on Existing Permeable Pavement Surfaces

This study describes a field investigation that compares water infiltration rates of eight permeable parking lots located in Rimini City, Italy. In the experiment a single ring infiltrometer test was used to analyze the influence of the surface type, filling material, location in the parking stall, pavement age, and antecedent dry weather days on the infiltration capacity of the pavements. The results show that the permeability values are mostly affected by the position of the ring in the parking lot, filling material, and surface type rather than by the antecedent dry weather time and pavement age. The surface infiltration rate of the eight pavements ranges between a minimum of 123mm/h (site 6, permeable interlocking concrete paver, 2005) and a maximum of 20 137mm/h (site 4, concrete grid paver, 2005), exceeding the 97.2mm/h minimum design infiltration rate required by selected European authorities. The results also show that compaction decreases the infiltration rate. Therefore, the study could be useful in setting the standard test procedure to evaluate the performance of permeable pavements over time in the Mediterranean climate

Water consumptions in public schools

Water consumption per user in non-residential buildings is still a very complicated issue for engineers and designers in the process of analyzing water demand and water management. It is easier to design for residential units than for public buildings, as you never know exactly how many users will access the building daily, you can just estimate the number. Our goal is not to set certain and fixed numbers, as they probably will never exist, but to analyze the data we gathered through time and to try to get to an approximation of water usage in public schools connected to building occupants. This research integrates quantitative data of water consumption through water metering and historical data about users in buildings. Six hundred buildings have been monitored over a period of 5 years (2005 e 2010).We focused on consumptions for 3 types of schools: Nurseries (0-3 years old children), Kindergartens (3-6 years) and Elementary Schools (6-11 years). Finally we studied how they are linked to building occupants on a daily consumption rate. The results are that the rational basic demand for water is estimated as 48 liters per pre-school student per day and 18 liters per elementary school student per day. Moreover younger children use more water on a daily basis than elementary school students, as they need more services, such as laundries and kitchens, whereas older students consume water mainly in restrooms

Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

The operating conditions of urban drainage networks during storm events depend on the hydraulic conveying capacity of conduits and also on downstream boundary conditions. This is particularly true in coastal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration), but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of climate variables. The case study is a portion of the drainage system of Rimini (Italy), implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system identified the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables' values has lead to the definition of charts representing the combined degree of risk "rainfall-sea level" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year rainfall-sea level time series has demonstrated the reliability of the analysis

Real time monitoring of water quality in an agricultural area with salinity problems

Agriculture is a highly water-demanding sector. Developed in recent years, the precision farming approach allows to optimize irrigation without compromising crops productivity. WSN networks are a key element of this approach because they allow to monitor continuously large number of parameters providing the possibility of a real-time intervention on field management practices. The WSN networks can be used to measure traditional parameters such as precipitation, soil moisture, or irradiation and others such as the quality of irrigation water and groundwater. The qualitative monitoring of these parameters is essential when the cultivation is carried out under complex conditions such as those represented by soils with salinization problem. This work fits this context by presenting the results of the first 13 months of an experimental campaign aimed at the measurement of soil, water (quality of irrigation and drainage water of the fields) and groundwater parameters by a WSN system. This paper analyzes results of this activity and provides practical suggestions to ensure a more efficient system

Ophthalmological emergencies and the SARSCoV-2 outbreak

Since the end of 2019, an outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), originating in the Chinese city of Wuhan has spread rapidly worldwide causing thousands of deaths. Coronavirus disease (COVID-19) is supported by SARS-CoV-2 and represents the causative agent of a potentially fatal disease that is of great global public health concern. Italy has been the first European country recording an elevated number of infected forcing the Italian Government to call for total lockdown. The lockdown had the aim to limit the spread of infection through social distancing. The purpose of this study is to analyze how the pandemic has affected the patient’s accesses to the Ophthalmological Emergency Department of a tertiary referral center in central-northern Italy, during the lockdown period. The charts of all patients that came to the Emergency Department during the lockdown period (March 10 –May 4, 2020) have been retrospectively collected and compared with those in the same period of 2019 and the period from 15 January– 9 March 2020. A significant reduction of visits during the lockdown has been observed, compared with those of pre-lockdown period (reduction of 65.4%) and with those of the same period of 2019 (reduction of 74.3%). Particularly, during the lockdown, minor and not urgency visits decreased whereas the undeferrable urgency ones increased. These pieces of evidence could be explained by the fear of patients to be infected; but also revealed patients misuse of emergency services