Climate change is globally causing more intense meteorological phenomena. Our cities experience increased rainfall intensity, more intense heat waves, and prolonged droughts providing economic, social, health and environmental challenges. Combined with population growth and rapid urbanization, the increasing impact of climate change will make our cities more and more vulnerable, especially to urban flooding. In order to adapt our urban water systems to these challenges, the adoption of newly emerging water management strategies is required. The complexity and scale of this challenge calls for the integration of knowledge from different disciplines and collaborative approaches. The water sensitive cities principles provide guidance for developing new techniques, strategies, policies, and tools to improve the livability, sustainability, and resilience of cities. In this study, the DAnCE4Water modeling approach promoting the development of water sensitive cities was applied to Parma, an Italian town that has faced serious water issues in the last few years. The city, indeed, had to face the consequences of flooding several times, caused by the inadequacy of both the network of open channels and the sewerage network due to the urban expansion and climate change of the last 30 years. Through the model, the efficiency of decentralized technologies, such as green roofs and porous pavement, and their integration with the existing centralized combined sewer system was assessed under a range of urban development scenarios. The obtained results show that the adoption of an integrated approach, including soft engineering hydraulic strategies, consisting in the use of natural and sustainable solutions, can increase resilience to urban flooding. Further, the study shows that there is a critical need for strategic investment in solutions that will deliver long-term sustainable outcomes.

The evaluation of sediment yield by water erosion taking into consideration the possible impact of climate change is the object of this work, concerning the use of the Modified Universal Soil Loss Equation (MUSLE) in an Italian case study. This empirical model was implemented in a Geographical Information System, taking into account Alpine hydrology and geomorphological and climate parameters, which are crucial in the analysis of the intensity and variability of sediment yield production processes. The case study is the Guerna Creek basin, a small-sized mountain watershed placed in Lombardy, in the South-Central Alps (Northern Italy). In recent decades it has been hit at the same time by floods and erosive phenomena, showing its hydraulic-hydrological weakness. Three future climate change scenarios from 2041 to 2060, around the middle of this century, were built according to CORDEX data referring to three different Representative Concentration Pathways (RCP 2.6, RCP 4.5, RCP 8.5). The findings showed that in the future climate, the sediment yield at the basin scale might change by 24–44% for a single heavy storm in the middle of the current century.

Urban green spaces, including green roofs (GRs), are vital infrastructure for climate resilience, retaining water in city landscapes and supporting ecohydrological processes. Quantifying the hydrologic performance of GRs in the urban environment for future climate scenarios is the original contribution of this research developed within the URCA! project. For this purpose, a continuous modelling approach is undertaken to evaluate the hydrological performance of GRs expressed by means of the runoff volume and peak flow reduction at the event scale for long data series (at least 20 years). To investigate the prediction of GRs performance in future climates, a simple methodological approach is proposed, using monthly projection factors for the definition of future rainfall and temperature time series, and transferring the system parametrization of the current model to the future one. The proposed approach is tested for experimental GR sites in Genoa and Rende, located in Northern and Southern Italy, respectively. Referring to both the Genoa and Rende experimental sites, simulation results are analysed to demonstrate how the GR performance varies with respect to rainfall event characteristics, including total depth, maximum rainfall intensity and ADWP for current and future scenarios.

The climate change of the last half century is globally causing an increasingly in violent meteorological phenomena. Cities are experiencing the pressures of these phenomena and they are facing many challenges - economic, social, health and environmental.Over the coming decades the population growth and the rapid urbanization will bring to a tumultuous growth of the cities that will become more and more vulnerable, especially to flood hazards.In order to make our urban water systems more effective to these challenges new water management strategies must be developed. The complexity of this challenge calls for the integration of knowledge from different disciplines and collaborative approaches.The concept of Water Sensitive Cities is one of the starting points for developing new techniques, strategies, policies, and tools to ensure a better liveability, sustainability, and resilience of the cities.In this study, the DAnCE4Water model to promote the development of Water Sensitive Cities, was applied to Parma, an Italian town that faced serious water issues in the last years. Through the model the efficiency of new decentralized technologies, as green roofs and porous pavement, and their integration with the existing centralized technologies (sewerage), was estimated.The first phase of the study concerned the analysis of the current state of the sewerage network and the relative critical issues. Flow rates and the amount of surface runoff were calculated using the SWMM modelling software.In the second phase three hypothetical different scenarios were created by adopting different intervention strategies. The first scenario was created by using green roofs for a percentage of existing buildings in the urban area equal to 30%; the second scenario was created by adopting the porous pavement technology. For the third scenario, a possible urban development was simulated, with its consequent population, without adopting any flood risk mitigation strategy. A hydraulic study was carried out for each scenario highlighting the differences in terms of runoff formation and percentage of infiltration.The integrated approach enables a city to test its current water management practices and policy, it helps cities to identify their short and long term goals to enhance water sensitivity, it gives a quantification of benefits and costs and it provides an estimate,  still in the design phase, of the effectiveness of possible strategies under different scenarios like climate changes, changes in the societal needs and urban changes by modelling the complex dynamics between societal system, urban environment and the urban water system.

Flood risk management is one of priorities set by the European Union to protect population and assets. In a very recent report of the European Environment Agency dealing with urban adaptation to climate change (EEA, 2020), extreme weather events (heatwaves, heavy precipitation, flooding and droughts) are expected to cause the most pronounced impacts in European cities, besides vector‑borne diseases. Italian regions are taclking flood risk management also by setting regulations on the runoff production in urban areas.According to a recent regulation approved by Regione Lombardia municipalities are requested to prepare the Hydraulic Risk Management Plan, including measures to ensure compliance with the principle of the ‘hydraulic’ and ‘hydrological’ invariance for the urban area, in which runoff volumes generated by an intense meteoric event must remain unchanged or at least must be limited. The idea arises from the need to manage the rainwater drainage in urban contexts, where the existing sewerage system has been designed based on an inadequate return time period.The planning activity requires a modelling framework accounting for both the open channel network (mainly addressing irrigation demand) and the sewer pipe network. While separate hydraulic models might help the management provided by separate authorities, an integrated model is ensuring a complete representation of the system hydrodynamics. This type of model is characterized by a much more complex structure which requires greater data accuracy for the construction and calibration of the model in order to obtain realistic results.Some critical issues are being presented for Brescia, a town located in Northern Italy, at the foothills of the Alps.  Potential flood risk is linked to the dense historical irrigation and drainage channels network that cross the urban area from north to south and the old city centre. Critical areas are those hosting the post-war urban development where the waterways have been uncovered and covered in a chaotic and uncontrolled way, in some cases even under houses and other buildings.

Key Points: Affordable sensors allow continuous monitoring of soil moisture and hydrological performance in rain gardens. Using sensors for predictive maintenance lowers expenses and increases the longevity of rain gardens. Rain gardens (RG) are essential for sustainable stormwater management, but their effectiveness relies on consistent maintenance, which is both critical and costly. This study explores the use of low-cost electronic sensors to monitor biofilter conditions and enable predictive maintenance, reducing manual inspections and improving operational efficiency.The experiment involved 15 laboratory-scale columns, replicating the typical structure of rain gardens, with stratified layers: a ponding zone, fine sand filter, coarse sand with mulch transition layer and a gravel drainage layer. The columns were divided into three groups to simulate different conditions: a control group (C) representing optimal performance, a group with preferential flow paths (P) simulating surface erosion, and one with surface clogging (S) due to sediment accumulation. Each column had five sensors to monitor soil moisture and temperature: two Chameleon Soil Water Sensors, two temperature probes, and one Truebner SMT 100 sensors. Data were collected in real time and transmitted to a cloud-based system. To evaluate the columns, simulated rainfall events, reflecting varying intensities and antecedent dry periods based on Melbourne’s historical weather patterns, were applied. The SMT sensor effectively tracked volumetric water content (VWC), identifying peaks from simulated rainfall events and showing variability across different antecedent dry days (ADD). However, Chameleon sensors exhibited performance degradation over time due to soil drying, root growth, and temperature variations. Inflow, outflow, and infiltration rates were measured to assess hydrological behavior, but these data alone were insufficient to differentiate healthy from malfunctioning systems. Consequently, indices were developed to differentiate the hydraulic performance of each group. Parameters such as peak time, peak span, and delay time were identified as notable in diagnosing operational states. For instance, the clogging group exhibited delayed response times and retained less water. In contrast, preferential flow columns displayed immediate responses to rainfall. Post-experimentation, the columns were disassembled to analyze physical changes in soil stratigraphy and assess root development, providing additional insights into the impact of hydraulic malfunctions on overall system health. In conclusion, this research underscores the potential of integrating low-cost sensor technologies into the management of rain gardens. Real-time monitoring not only enhances the reliability and longevity of these systems but also reduces operational costs, contributing to the broader goal of fostering resilient and sustainable urban environments. Future research should refine sensor applications and expand testing under diverse environmental conditions.