Leonardo Alfonso

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Verified

Leonardo verified their affiliation via an institutional email.

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• MSc, PhD
• Professor (Associate) at IHE Delft Institute for Water Education

Off‐stream reservoirs are artificial water storage structures that increase the flood risk of an area. In some places, related risk reduction plans are based on a risk classification of these structures, which follows local water resource management regulations. These classification methods typically follow deterministic qualitative guidelines that...

This research focuses on hydrodynamic modeling of flash floods in arid regions, specifically simulating a historical Wadi flash flood event in Tunisia using Delft3D FM. The study involved calibrating the model by adjusting infiltration and roughness parameters, leading to accurate simulation results. Validation using social media data demonstrated...

Flood risk management faces challenging decisions to balance between reducing disastrous flood consequences and different societal goals such as development. The inherent complexity and limited data often lead to significant uncertainties in decision‐making, potentially resulting in suboptimal resource allocation. Consequently, there may be value i...

Water distribution network (WDN) models are a common decision support tool for understanding the behavior and performance of WDNs, aiding in the planning and management of WDN systems. The increasing availability of real-time data has recently promoted the exploration of Data Assimilation (DA) techniques to improve these models. However, flow, pres...

The water reuse facilities of industrial parks face the challenge of managing a growing variety of wastewater sources as their inlet water. Typically, this clustering outcome is designed by engineers with extensive expertise. This paper presents an innovative application of unsupervised learning methods to classify inlet water in Chinese water reus...

Water distribution network (WDN) models are a common decision support tool for understanding the behavior and performance of WDNs, aiding in the planning and management of WDN systems. The increasing availability of real-time data has recently promoted the exploration of Data Assimilation (DA) techniques to improve these models. However, flow, pres...

Ensuring a reliable water supply in the face of changing conditions and growing demand is a critical global challenge. Water distribution networks (WDNs) are essential infrastructure, but traditional modeling methods based on historical data often struggle to adapt in real-time and integrate new information. In order to lower model errors in WDN mo...

The Routledge Handbook of Geospatial Technologies and Society provides a relevant and comprehensive reference point for research and practice in this dynamic field. It offers detailed explanations of geospatial technologies and provides critical reviews and appraisals of their application in society within international and multi-disciplinary conte...

Hydroinformatics was established 30 years ago as a novel discipline in which computer modelling of water was combined with developments of Informational and Computational Technologies for purposes of introducing new and different approaches to water engineering, management, and decision support. The late Professor Michael B. Abbott is widely recogn...

The presence of leaks in water distribution networks (WDN) is a problem of global concern that causes significant annual losses of treated water. Most efforts to solve this problem concentrate on the development of methods to help locate leaks in the least possible time. However, the decision to repair leaks is not always trivial because of their u...

The proliferation of Citizen Science initiatives has increased the expectations of practitioners who need data for design, analysis, management and research in environmental applications. Many Citizen Science experiences have reported tangible societal benefits related to improved governance of natural resources due to the involvement of citizens a...

Accurate and precise rainfall records are crucial for hydrological applications and water resources management. The accuracy and continuity of ground-based time series rely on the density and distribution of rain gauges over territories. In the context of a decline of rain gauge distribution, how to optimize and design optimal networks is still an...

Precipitation is a main input to many hydrological applications, such as water management, flood forecasting and hydrological modelling. The goodness of the rainfall field estimation can thus affect their performances. Despite radar-based and satellite-based measurements have nowadays become very common and accurate, rain gauges monitoring stations...

Floods are the natural hazards that are causing the most deaths worldwide. Flood early warning systems are one of the most cost-efficient methods to reduce death rates, triggering decisions about evacuation of exposed population. Although previous studies have investigated the effect of human behaviours on evacuation processes, studies analysing a...

Water distribution networks (WDNs) need to guarantee that water is delivered with adequate quality. This paper compares the performance of 12 multiobjective procedures to limit water quality deterioration in a WDN through the optimal operation of valves. The first objective (ObF1) is to minimize the water age, chosen as a surrogate parameter of qua...

In this work a comparative study was carried out, in which different methods were used in the literature that seek to evaluate the number of stations and the quality of the information generated by the hydrometric network of a watershed, using Information Theory concepts. The underlying idea is the so-called optimal network whose function, accordin...

This paper compares the performance of 12 multiobjective procedures to limit water quality deterioration in a WDN through the optimal operation of valves. The first objective is to minimize the water age, chosen as a surrogate parameter of quality deterioration, and the second objective is to minimize the number of valve closures. The optimization...

This chapter aims to describe the latest innovative approaches for integrating heterogeneous observations from static social sensors within hydrological and hydrodynamic modelling to improve flood prediction. The distinctive characteristic of such sensors, with respect to the traditional ones, is their varying lifespan and space-time coverage as we...

Water quality deterioration in water distribution networks can be associated with high water residence time in the network. To this end, some previous studies have proposed optimization procedures for valve management. However, these studies generally come up with operational configurations assuming deterministic user demand patterns that may never...

Decision-making processes for integrated wastewater management plans require the support of cost accounting and management techniques. This is particularly challenging in the Kidron-Wadi an-Nar basin, whose river is currently an open sewer and plans need to account for water stress, complex topography and socio-political differences. For these reas...

Decision-making processes for integrated wastewater management plans require the support of cost accounting and management techniques. This is particularly challenging in the Kidron-Wadi an-Nar basin, whose river is currently an open sewer and plans need to account for water stress, complex topography and socio-political differences. For these reas...

The introduction of new information and communication technologies enables communities to share information and self-organize in the response to disasters. Crowd-sourcing approaches enable professional authorities to capture information from the ground in real-time. However, there is a gap between the professional and community-driven response: loc...

Diverse hydrologic and hydraulic models of varying complexities have been proposed in the past few decades to accurately predict the water levels and discharges along rivers. Among them, the hydrologic routing models are widely used because of their simplicity, minimal data, and computational requirements. Due to their simplified assumptions, howev...

This paper comparatively assesses the performance of five data assimilation techniques for three parameter Muskingum routing with a spatially lumped or distributed model structure. The assimilation techniques used include direct insertion (DI), nudging scheme (NS), Kalman filter (KF), ensemble Kalman filter (EnKF) and asynchronous ensemble Kalman f...

This paper reviews recent hydrological risk assessment, communication and early warning systems and proposes a framework to reformulate the classic view of Early Warning and Monitoring Systems towards a participatory one. The new framework is developed for flood risks (from multiple flood hazards), using examples from selected Nordic and other Euro...

To improve hydrological predictions, real-time measurements derived from traditional physical sensors are integrated within mathematic models. Recently, traditional sensors are being complemented with crowdsourced data (social sensors). Although measurements from social sensors can be low cost and more spatially distributed, other factors like spat...

Waternomics is a European Union-funded research project aspiring to develop and introduce Information and Communication Technology (ICT) as an enabling technology to manage water as a resource, increase end-user conservation awareness, affect behavioural changes and avoid water losses through leak detection. Existing leakage detection methods are g...

Trihalomethanes (TTHMs) are water disinfection by-products whose consumption via drinking water may eventually be harmful for human health, as they could have carcinogenic effects, also for the exposure to them via non-ingestion routes [1]. In the present work the possibility to reduce the vulnerability of the population exposed to TTHMs by the opt...

Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors' location. In this study, a methodology for the optimal placement of wastewater monitoring sensor...

This study investigated the distribution and fractionation of metals (Mn, Ni, Pb, Cr, Cu, Zn, As, Cd, Hg and Sn) in surface sediments of Tema Harbour (Greater Accra, Ghana) as well as its ecological implications. Significant differences in sediment concentrations of Mn, Ni, Cr, Cu, Zn, As and Sn were observed across the Tema Harbour. Geochemical in...

Sensors and sensor networks play an important role in decision-making related to water quality, operational streamflow forecasting, flood early warning systems, and other areas. In this paper we review a number of existing applications and analyse a variety of evaluation and design procedures for sensor networks with respect to various criteria. Mo...

Efficient management of a sewer system includes the control of the conveyed wastewater quality to adequately operate treatment plants and protect the receiving water bodies. Moreover, these systems are vulnerable to either accidental spills or intentional unauthorized discharges. To properly manage them, a limited number of sensors could be placed...

Monitoring stations have been used for decades to properly measure hydrological variables and better predict floods. To this end, methods to incorporate these observations into mathematical water models have also been developed. Besides, in recent years, the continued technological advances, in combination with the growing inclusion of citizens in...

The Colombian Ministry of Environment, Housing and Territorial Development issued the Policy for Integrated Water Resources Management in 2010, with the formulation of Basin Management Plans (POMCA) as a key component. The main purpose of these plans is to support land use planning and sustainable management of renewable natural resources. Since th...

The aim of this study is to assess the influence of sensor locations and varying observation accuracy on the assimilation of distributed streamflow observations, also taking into account different structures of semi-distributed hydrological models. An ensemble Kalman filter is used to update a semi-distributed hydrological model as a response to me...

Sensors and sensor networks play an important role in decision-making related to water quality, operational streamflow forecasting, flood early warning systems and other areas. Although there is a variety of evaluation and design procedures for sensor networks, most of the existing approaches focus on maximising the observability and information co...

Flood mapping is a common flood hazard mitigation measure. Advanced methods and tools including flood inundation models are generally used to estimate potential flood extent maps. However, these tools are affected by uncertainty. Although the adoption of Probabilistic Flood Maps (PFM) to visualise uncertainty is of interest, it is still not clear h...

The EC-FP7 WeSenseIt project proposes to develop a Citizen Observatory of wate r, aiming at enhancing environmental monitoring and forecasting with the help of citizens equipped with low-cost sensors and personal devices such as smartphones and smart umbrellas. At this point, the following question arises: how can citizens, who are part of a citize...

In 2010 and 2011 Colombia was hit by severe floods. After this situation, Colombian government and river basin authorities started developing plans and preparing actions for adaptation to climate change. Together with Dutch institutes a demonstration study and capacity building program was executed in 2013–2014. A systematic analysis of future extr...

Waternomics is a European Union-funded research project aspiring to develop and introduce Information and Communication Technology (ICT) as an enabling technology to manage water as a resource, increase end-user conservation awareness, affect behavioural changes and avoid water losses through leak detection. Existing leakage detection methods are g...

One of the most crucial steps in flow frequency studies is the definition of Homogenous Regions (HRs), i.e. areas with similar hydrological behavior. This is essential in ungauged catchments, as HR allows information to be transferred from a neighboring river basin. This study proposes a new, entropy-based approach to define HRs, in which regions a...

The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based con...

Experiences of citizen-based reporting of rainfall events using lab-generated videos

This chapter discusses how innovation impacts water management, water services and water-dependent sectors as well as water-related employment opportunities in quantitative and qualitative terms.

Floods are one of the most frequent and disruptive natural hazards that affect man. Annually, significant flood damage is documented worldwide. Flood mapping is a common preimpact flood hazard mitigation measure, for which advanced methods and tools (such as flood inundation models) are used to estimate potential flood extent maps that are used in...

Accurate flood predictions are essential to reduce the risk and damages over large urbanized areas. To improve prediction capabilities, hydrological measurements derived by traditional physical sensors are integrated in real-time within mathematic models. Recently, traditional sensors are complemented with low-cost social sensors. However, measurem...

A core problem associated with the water quality monitoring in the sewer system is the optimal placement of a limited number of monitoring sites. A methodology is provided for optimally design water quality monitoring stations in sewer networks. The methodology is based on information theory, formulated as a multi-objective optimization problem and...

Monitoring stations have been used for decades to properly measure hydrological variables and better predict floods. To this end, methods to incorporate such observations into mathematical water models have also being developed, including data assimilation. Besides, in recent years, the continued technological improvement has stimulated the spread...

Monitoring stations have been used for decades to properly measure hydrological variables and better predict floods. To this end, methods to incorporate such observations into mathematical water models have also being developed, including data assimilation. Besides, in recent years, the continued technological improvement has stimulated the spread...

Lack of data is one of the most common problems in water management. Although technologies to produce data with enough spatial and temporal resolution and acceptable quality and quantity are available, they are only affordable by a few countries in the world. In parallel, we are experiencing an exciting technological moment. There will soon be one...

Early warning systems have been used in the last decades to provide accurate flood forecast and reduce flood risk in urbanized areas. In order to reduce the intrinsic model uncertainty and improve the flood forecasting accuracy, different data assimilation techniques have been proposed to update model states and output as response of real-time obse...

El presente artículo tiene como fin el de transmitir a la comunidad científica latinoamericana algunas de las lecciones aprendidas más valiosas obtenidas durante sus tres años de ejecución por un consorcio de once instituciones establecidas en Holanda, Italia, Suiza, Inglaterra y Eslovenia. El documento está parcialmente basado en el resumen de pol...

Effects of Uncertain Control in Transport of Water in a River-Wetland System of the Low Magdalena River, Colombia. L. Alfonso and M. Tefferi Abstract During the 2010 and 2011, extreme flooding events affected the low Magdalena River catchment, Colombia, with devastating consequences. This triggered the urgency of adjusting the new river basing plan...

Pressure determination in water distribution systems (WDS) is important because it generally drives the operational actions for leakage and failure management, backwater intrusion and demand control. This determination would ideally be done through pressure monitoring at every junction in the distribution system. However, due to limited resources,...

The Cauca River is the drinking water source for 1.3 million inhabitants of the city of Cali, Colombia. Although the river discharge is sufficient to handle the water demand of the city all year long, significant water pollution events cause frequent disruption to the Puerto Mallarino Treatment Plant (PMTP) and the water supply service, with substa...

The reliable evaluation of the flood forecasting is a crucial problem for assessing flood risk and consequent damages. Different hydrological models (distributed, semi-distributed or lumped) have been proposed in order to deal with this issue. The choice of the proper model structure has been investigated by many authors and it is one of the main s...

Accurate real-time forecasting of river water level is an important issue that has to be addressed in order to prevent and mitigate water-related risk. To this end, data assimilation methods have been used to improve the forecasts ability of water model merging observations coming from stations and model simulations. As a consequence of the increas...

Although Information Theory concepts have been successfully applied in hydrology and other fields to quantify the amount of information contained in singular variables and shared by multiple variables, the valuation of these quantities is sensible to different parameters. In particular, the bin size of histograms and the Pearson correlation coeffic...

This research presents the preliminary results of an ongoing research that further explores the results obtained during the decision-making game " Do probabilistic forecasts lead to better decisions? " , which Ramos et al (2012) conducted at the EGU General Assembly 2012 in the city of Vienna. In that game, several cases of flood forecasts with and...

Recent research in ensemble and probabilistic hydro-meteorological forecasting have studied what probabilistic information is required by decision makers and how it can be most effectively visualised. This work analyses if decision making in flood early warning is also influenced by the way the decision question is posed. For this purpose, the deci...

Information-theory provides, among others, conceptual methods to quantify the amount of information contained in single random variables and methods to quantify the amount of information contained and shared among two or more variables. Although these concepts have been successfully applied in hydrology and other fields, the evaluation of these qua...

An accurate definition of river geometry is essential to implement one-dimensional (1D) hydraulic models and, in particular, appropriate spacing between cross-sections is key for capturing a river’s hydraulic behaviour. This work explores the potential of an entropy-based approach, as a complementary method to existing guidelines, to determine the...

用基于知识的方法制定一种风险预防文化. Translation: Kun Yan.

KULTURisk Método para el desarrollo de una cultura de prevención del riesgo No. 3 Diciembre 2013 Introducción El famoso dicho de Benjamín Franklin " Una onza de prevención vale más que una libra de curación " es un dicho común en varios lenguajes. Sin embargo, la experiencia común muestra que tal mensaje no se aplica totalmente cuando se trata de a...

Final Policy Briefs of the EC-FP7 KULTURisk project (2011-2014)

Miscalibration of radar determines a systematic error (i.e., bias) that is observed in radar estimates of rainfall. Although a rain gauge can provide a pointwise rainfall measurement, weather radar can cover an extended area. To compare the two measurements, it is necessary to individuate the weather radar measurements at the same location as the r...

In recent years water-related risks are increasing worldwide. In particular, floods have been one of the most damaging natural disasters in Europe, in terms of economic losses. Non-structural measures such as flood risk mapping are generally used to reduce the impact of flood in important area. The increasing data availability makes it possible to...

The role of decision-makers is to take the outputs from hydrological and hydraulic analyses and, in some extent, use them as inputs to make decisions that are related to planning, design and operation of water systems. However, the use of these technical analyses is frequently limited, since there are other non-hydrological issues that must be cons...

The acquisition of good hydrologic information is an important issue in water management since it is the basis of decisions concerning the allocation of water resources to different users. However, sufficient data are often not available to describe the behaviour of such systems, especially in developing countries, where monitoring networks are ina...

In recent years an increasing number of flood-related fatalities has highlighted the necessity of improving flood risk management to reduce human and economic losses. In this framework, monitoring of flood-prone areas is a key factor for building a resilient environment. In this paper a method for designing a floodplain monitoring network is presen...

Because the collection of data in water systems is important for making informed decisions, monitoring networks are designed and installed in such systems. Traditionally, the design of hydrometric monitoring networks has been concentrated on measuring streamflow/precipitation at particular key (gauged) sites so that streamflow/precipitation can be...

The fast developments in mobile phone technologies are creating new opportunities for water and environment operation and management, particularly in relation to the involvement of communities. However, at the same time, this fast development is generating series of experiments that have had major drawbacks that limit their application to real case...

The design of stabilization ponds for the treatment of wastewater is traditionally based on empirical guidelines. Even more the hydraulic design is normally over simplify. However, the performance of a pond will highly depend on the proper hydraulic design. This paper present an approach that combines the traditional empirical design with the use o...

This paper presents experiences with development of mobile phone demonstrator applications in the water domain in different application areas such as water distribution, hydrological data collection, flood management and water quality information dissemination. A brief overview of technologies for developing mobile phone applications is presented,...

To support the decision making processes of flood risk management and long term floodplain planning, a significant issue is the availability of data to build appropriate and reliable models. Often the required data for model building, calibration and validation are not sufficient or available. A unique opportunity is offered nowadays by the globall...

A method for siting water level monitors based on information theory measurements is presented. The first measurement is joint entropy, which evaluates the amount of information content that a monitoring set is able to collect, and the second measurement is total correlation, which evaluates the level of dependency or redundancy among monitors in t...

Water systems management depends on monitoring data that adequately describes the hydrological processes of interest for such systems. An information theory-based method for siting the monitors is developed, with the objective of locating a limited set of monitors that maximizes the joint information content of water level measurements based on Sha...