Luca G Lanza

University of Genoa | UNIGE · Dipartimento di Ingegneria civile, chimica e ambientale (DICCA)

The airflow velocity pattern generated by a widely used non-catching precipitation gauge (the Thies laser precipitation monitor or LPM) when immersed in a wind field is investigated using computational fluid dynamics (CFD). The simulation numerically solves the unsteady Reynolds-averaged Navier–Stokes (URANS) equations and the setup is validated ag...

Dynamic calibration was performed in the laboratory on two catching-type drop counter rain gauges manufactured as high-sensitivity and fast response instruments by Ogawa Seiki Co., Ltd. (Japan) and the Chilbolton Rutherford Appleton Laboratory (UK). Adjustment procedures were developed to meet the recommendations of the World Meteorological Organiz...

The supply of various non-potable water usages based on the harvesting and management of rainwater in urban areas allows to save high-quality water resources for strictly potable use and to limit the squandering of precious freshwater resources. A rainwater harvesting system included in a reconversion project of a former military area located in th...

The measurement accuracy of an electroacoustic precipitation sensor, the Vaisala WXT520, is investigated to quantify the associated wind-induced bias. The device is widely used as a noncatching tool for measuring the integral features of liquid precipitation, specifically rainfall amount and intensity. A numerical simulation using computational flu...

The wind‐induced bias of catching‐type precipitation measurement instruments is quantified using Computational Fluid Dynamics with embedded liquid (raindrops) and solid (snowflakes) particle tracking. The performance of six common commercial gauges having different outer geometry is compared under a range of Precipitation Intensity (PI) and wind sp...

The wind‐induced bias of rainfall measurements obtained from non‐catching instruments is addressed in this work with reference to the Laser Precipitation Monitor (LPM) optical disdrometer manufactured by Thies CLIMA. A numerical simulation approach is adopted to quantify the expected bias, involving three different models with increasing complexity...

The University of Genova (Italy) maintains a historical meteorological station that has provided daily rainfall measurements over a quasi-bicentennial period since 1833. The daily rainfall series is analyzed here to assess the impact of long-term precipitation trends on the performance of a rainwater harvesting system. The collected rainwater is us...

A procedure to adjust rainfall intensity (RI) measurements to account for the wind-induced measurement bias of traditional catching-type gauges is proposed and demonstrated with an application to a suitable case study. The objective is to demonstrate that adjustment curves derived from numerical simulations and disdrometer measurements allow for a...

In situ weather sensors aiming at the measurement of liquid atmospheric precipitation (rainfall) experienced limited conceptual innovation in recent decades, except for the data recording and transmission components [...]

A procedure to adjust rainfall intensity (RI) measurements to account for the wind-induced measurement bias of traditional catching-type gauges is proposed and demonstrated with application to a suitable case study. The objective is to demonstrate that adjustment curves derived from numerical simulation and disdrometer measurements allows for a-pos...

The need for high-resolution and low maintenance weather stations is the major factor behind the increasing adoption of Non-Catching Gauges (NCGs) by national weather services and research institutions. Data from such instruments are used for several applications and in numerous research fields, where instrumental biases can have a strong impact. F...

Precipitation is among the most important meteorological variables for, e.g., meteorological, hydrological, water management and climate studies. In recent years, non-catching precipitation gauges are increasingly adopted in meteorological networks. Despite such growing diffusion, calibration procedures and associated uncertainty budget are not yet...

2 WMO Lead Centre "B. Castelli" on Precipitation Intensity, Italy Adjustments of the wind-induced bias of conventional catching type rain gauges derive from collection efficiency (CE) curves that can be obtained either from field experiments or from numerical simulation (Lanza and Cauteruccio, 2021). The use of numerical simulation allows to overco...

RainWater Harvesting (RWH) and the use of the collected rainwater for the irrigation of urban green areas allow saving potable water resources with respect to a traditional supply from the urban water distribution system. The potential for RWH and reuse depends on the urban surfaces made available for rainwater collection, the associated runoff coe...

Though ranking high among the relevant environmental variables (due to the well-known significant interactions with the everyday human life and economic activities), atmospheric precipitation is not yet measured operationally with neither the degree of accuracy that would meet the most demanding applications nor any rigorous standardization framewo...

This chapter describes and discusses the available catching and non-catching rainfall measurement instruments (rain gauges) and their main characteristics. Standard calibration methods are reported for catching-type gauges. Optimal correction algorithms for the interpretation of tipping-bucket rain gauge records are presented, together with correct...

A high accuracy of in situ liquid and solid precipitation measurements, though understated in most research studies and technical applications, is imperative to substantiate both scientific achievements and decision-making. However, both operational and dedicated scientific measurements are still currently performed with a much lower accuracy than...

This chapter describes the measuring principles and technological solutions available for in-situ measurements of liquid (rain) and solid (snow) atmospheric precipitation. They can be classified into catching and non-catching precipitation gauges. Instruments belonging to the first family are generally based on gravity-related measuring principles...

Accurate snowfall measurements are necessary for meteorology, hydrology, and climate research. Typical uses include creating and calibrating gridded precipitation products, the verification of model simulations, driving hydrologic models, input into aircraft deicing processes, and estimating streamflow runoff in the spring. These applications are s...

A physical full-scale experimental set-up was designed and implemented in the wind tunnel to reproduce and capture the trajectories of falling water drops when approaching the collector of catching type precipitation gauges, reproducing rainfall measurements in windy conditions. The experiment allowed to collect, for the first time, a large data se...

Wind tunnel (WT) experiments were conducted to reproduce the wind-induced deviation of rain drop trajectories when approaching the collector of catching type gauges. Three typical outer shapes of the instrument body (cylindrical, inverted conical and “chimney” shapes) were tested using full-scale models. The airflow pattern upstream of and above th...

Wind tunnel (WT) experiments were conducted to reproduce the wind-induced deviation of rain drop trajectories when approaching the collector of catching type gauges. Three typical outer shapes of the instrument body (cylindrical, inverted conical and “chimney” shapes) were tested using full-scale models. The airflow pattern upstream of and above th...

Abstract Non‐catching type gauges are the emerging class of in situ precipitation measurement instruments. For these instruments, rigorous testing and calibration are more challenging than for traditional gauges. Hydrometeors characteristics like particle size, shape, fall velocity and density must be reproduced in a controlled environment to provi...

Numerical studies of the wind-induced bias of precipitation measurements assume that turbulence is generated by the interaction of the airflow with the gauge body, while steady and uniform free-stream conditions are imposed. However, wind is turbulent in nature due to the roughness of the site and the presence of obstacles, while precipitation gaug...

The hotplate precipitation gauge operates by means of a thermodynamic principle. It is composed by a small size disk with two thin aluminium heated plates on the upper and lower faces. Each plate has three concentric rings to prevent the hydrometeors from sliding off in strong wind. As for the more widely used tipping-bucket and weighing gauges, me...

Despite the numerous contributions available in the literature about the wind-induced bias of rainfall intensity measurements, adjustments based on collection efficiency curves are rarely applied operationally to rain records obtained from catching-type rain gauges. The many influencing variables involved and the variability of the results of field...

Adjustments for the wind-induced undercatch of snowfall measurements use transfer functions to account for the expected reduction of the collection efficiency with increasing the wind speed for a particular catching-type gauge. Based on field experiments or numerical simulation, collection efficiency curves as a function of wind speed also involve...

Self‐similar and fractal patterns and processes are very common in nature, and water has often a key role in their genesis or dynamics over relevant timescales. They are easily the result of searching for efficient solutions to occupy most of the available volume, connect the most locations on a surface, saving or dissipating energy, etc. After rec...

In operational conditions wind is the main environmental source of measurement biases for catching-type precipitation gauges. The gauge geometry induces a deformation of the surrounding airflow pattern, which is generally characterized by relevant updraft zones in front of the collector and above it. This effect deviates the trajectories of the lig...

Globally, the risks from extreme weather are significant and increasing, mainly because larger numbers of people and their assets are being exposed to floods. To cope with such events a now-casting service would be worth to validate weather alerts and to give civil protection offices timely information on the precipitation. In this work, rain-monit...

This paper describes the results obtained by the application of an innovative environmental monitoring technique able to estimate rainfall intensity in real time by processing the attenuation of microwave satellite link signal measured by low cost sensors. The satellite that has been used during our work, Turksat 42° E, belongs to the plethora of s...

Transfer functions are generally used to adjust for the wind-induced undercatch of solid precipitation measurements. These functions are derived based on the variation of the collection efficiency with wind speed for a particular type of gauge, either using field experiments or based on numerical simulation. Most studies use the wind speed alone, w...

This work presents the performance of an innovative environmental monitoring system-Smart Rainfall System (SRS)-that estimates rainfall in real-time by means of the analysis of the attenuation of satellite signals (DVB-S in the microwave Ku band). SRS consists in a set of peripheral microwave sensors placed on the field of interest, and connected t...

Globally, the risks from extreme weather are significant and increasing, mainly because larger numbers of people and their assets are being exposed to floods. To cope with such events a now-casting service would be worth to validate weather alerts and to give civil protection offices timely information on the precipitation. In this work, rain-monit...

Despite the apparent simplicity, it is notoriously difficult to measure rainfall accurately because of the challenging environment within which it is measured. Systematic bias caused by wind is inherent in rainfall measurement and introduces an inconvenient unknown into hydrological science that is generally ignored. This paper examines the role of...

The mechanical assembly of a tipping-bucket rain gauge is often calibrated as a stand-alone instrument. However, the measurement accuracy depends on the associated data-logger as well, especially in case the rainfall intensity is derived from the measurement. This paper reports the calibration of a set comprising the tipping-bucket rain gauge assem...

Launched in 2011 within the European Metrology Research Programme (EMRP) of EURAMET, the joint research project "MeteoMet" – Metrology for Meteorology – is the largest EMRP consortium: National Metrology Institutes, Universities, meteorological and climate agencies, Research Institutes, collaborators and manufacturers are working together, developi...

The airflow surrounding any catching-type rain gauge when impacted by wind is deformed by the presence of the gauge body, resulting in the acceleration of wind above the orifice of the gauge, which deflects raindrops and snowflakes away from the collector (the wind-induced undercatch). The method of mounting a gauge with the collector at or below t...

The Solid Precipitation Intercomparison Experiment (SPICE) was conducted as an internationally coordinated project, initiated and guided by the Commission for Instruments and Methods of Observation (CIMO) of the World Meteorological Organization (WMO). The SPICE field experiments took place between 2013 and 2015, with a preparatory stage during the...

An innovative environmental monitoring system - Smart Rainfall System (SRS) - that estimates rainfall in real-time by means of the analysis of the attenuation of satellite signals (DVB-S in the microwave Ku band) is presented. Such a system consists in a set of peripheral microwave sensors placed on the field of interest, and connected to a central...

Eight rainfall events recorded from May to September 2013 at Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the rainfall intensity (RI) from tipping-bucket rain gauges (TBRGs). We assumed a drop-counter catching-type gauge as a working reference and compared r...

A number of rain events recorded from May to September 2013 at the Hong Kong International Airport (HKIA) have been selected to investigate the performance of post-processing algorithms used to calculate the Rainfall Intensity (RI) from Tipping-Bucket Rain Gauges (TBRGs). We assumed a drop counter catching-type gauge as a working reference and comp...

Pluvial flooding in urban areas may derive from the limited or temporarily reduced efficiency of surface drainage, even when the underlying storm sewers are properly designed. This study focuses on the impact of uncertainties in the operational condition of the surface drainage system on pluvial flood hazard. The flood propagation model FLURB-2D is...

The use of windshields to reduce the impact of wind on snow measurements is common. This paper investigates the catching performance of shielded and unshielded gauges using numerical simulations. In Part II, we investigate the role of the gauge and windshield aero-dynamics, as well as the varying flow field due to the turbulence generated by the ga...

The aero-dynamic response of snow gauges when exposed to the wind is responsible for a significant reduction of their collection performance. The modifications induced by the gauge and the wind shield onto the space/time patterns of the undisturbed airflow deviate the snowflakes trajectories. In Part I we investigate the disturbed air velocity fiel...

The most widely used device to measure rainfall is the tipping bucket rain gauge (TBR), although there is no standard design. The precision and accuracy of TBR measurements vary, and calibration procedures are dependent upon the organisation or institution operating a network. Consequently, rainfall datasets may be heterogeneous and not easily comp...

The liquid precipitation at the ground level is measured by means of different techniques and technologies for areal and point-scale quantification of rainfall intensity RI (mm/h) and the resulting total precipitation amount h (mm). Point-scale precipitation gauges fall in two main categories: catching type gauges, which collect the liquid equivale...

The monitoring of hydro-meteorological variables for operational and research purposes requires accurate measurements. The reliability of such measurements varies depending on the need to meet different requirements in several sectors, including aviation, agriculture, civil protection, entertainment and weather forecast. In the case of rain gauges,...

Recent studies have used numerical models to estimate the collection efficiency of solid precipitation gauges when exposed to the wind, in both shielded and unshielded configurations. The models used computational fluid dynamics (CFD) simulations of the airflow pattern generated by the aerodynamic response to the gauge/shield geometry. These are us...

The accurate measurement of snowfall is important in various fields of study such as climate variability, transportation, and water resources. A major concern is that snowfall measurements are difficult and can result in significant errors. For example, collection efficiency of most gauge-shield configurations generally decreases with increasing wi...

La presente invenzione si riferisce ad un metodo per effettuare il potenziamento (bilanciamento, taratura dinamica e correzione in tempo reale) di un pluviometro a vaschette basculanti che viene realizzato mediante la sola rilevazione dei tempi di ribaltamento delle vaschette stesse e ad un dispositivo che realizza tale potenziamento.

A small size laboratory test-bed was created at the University of Genoa in order to evaluate the drainage capacity of permeable pavements by monitoring inflow, runoff and subsurface outflow. The laboratory test programme was designed to investigate the influence of rainfall intensity and pavement slope on the hydrologic response of permeable paveme...

The present invention relates to a method for the determination of the precipitation intensity from a moving vehicle/boat, and system for the space-time characterization of a precipitation field on wide territory areas. More specifically, the invention concerns a method, which allows obtaining precipitation intensity real values from data collected...

The contribution of any single uncertainty factor in the resulting performance of infield rain gauge measurements still has to be comprehensively assessed due to the high number of real world error sources involved, such as the intrinsic variability of rainfall intensity (RI), wind effects, wetting losses, the ambient temperature, etc. In recent ye...

The aerodynamic response of solid precipitation gauges when exposed to the wind is responsible for a significant reduction of their catching performance. This effect is known as the " exposure problem " and consists in the modification of the space/time patterns of the undisturbed airflow operated by the gauge itself or the employed wind shield, ca...

Tecnica di correzione dinamica in tempo reale delle intensità di pioggia misurate da pluviometri a pesata basata sull’ipotesi di funzionamento in termini di sistema dinamico lineare di 1° ordine, determinazione della relativa costante di tempo tramite semplici prove di laboratorio, e ricostruzione del segnale di pioggia reale.

Device for checking the calibration of catching instruments measuring rainfall intensity, which comprises a plurality of containers having a predetermined internal volume, the volume of at least two of said containers being different from each other, said containers being intended to contain respective amounts of a liquid, wherein each container is...

Green roofs are increasingly used as sustainable urban drainage systems due to their retention and detention capacity; however, the impact of green roofs in term of water quality is still a debated issue among researchers. A monitoring programme was carried out at the University of Genoa on a full-scale experimental site to assess the quality of st...

Since 2007, the University of Genoa has been carrying out a monitoring programme to investigate the hydrologic response of green roofs in the Mediterranean climate by installing a green roof experimental site. In order to assess the influence of green roofs on the storm water runoff quality, water chemistry data have been included in the monitoring...

The available calibration experiences about rain intensity gauges relying on the weighing measuring principle are based on laboratory tests performed under constant reference flow rate conditions. Although the Weighing Gauges (WG) do provide better performance than more traditional Tipping Bucket Rain Gauges (TBR) under constant reference flow rate...

Short interval snowfall, drizzle and light rainfall events can be hard to measure with precipitation gauges due to sampling limitations, wind effects, and noise. The noise observed in the data sampling can often be greater than the detectable signal from a real precipitation event. In addition wind effects can induce differential air pressure on th...

Contextually to the ongoing Solid Precipitation InterComparison Experiment (SPICE), the WMO experimental initiative concerning solid precipitation measurement instruments, the Lead Centre "B.Castelli" on Precipitation Intensity has recently conducted laboratory investigations to test the performance of the automatic weighing type (WG) gauges under...

The OTT Pluvio2 weighing type (WG) and the GEONOR T-200 vibrating-wire type (VWG) precipitation gauges were selected to compose the reference monitoring system of the WMO Solid Precipitation InterComparison Experiment field sites. It has been largely demonstrated in past laboratory activities how the weighing type gauges do provide more accurate pe...

Stormwater runoff discharges from the urban environment have been identified as one of the major causes of quality deterioration in receiving water bodies. The pollutant load associated with stormwater runoff from urbanised areas conveys a heterogeneous mixture of constituents including particulate matter (PM), organic and inorganic compounds, nutr...

A drop counter catching-type gauge and a tipping-bucket rain intensity gauge are compared in this paper in order to investigate the performance of suitable correction algorithms. Comparison in the field is performed at the resolution of 1min by assuming the drop counter as a working reference at low to medium rainfall rates. The observed deviations...

Domestic Rainwater Harvesting (DRWH) is recognized as one of the widely accepted solutions to save potable water in buildings and has seen increasing popularity in Europe due to the improved reliability and understanding of system design and realization issues. In this paper, the performance of DRWH systems is examined in order to support their opt...

The analysis of counting and catching errors of both catching and non-catching types of rain intensity gauges was recently possible over a wide variety of measuring principles and instrument design solutions, based on the work performed during the recent Field Intercomparison of Rainfall Intensity Gauges promoted by World Meteorological Organizatio...

In recent years the WMO Commission for Instruments and Methods of Observation (CIMO) fostered noticeable advancements in the accuracy of precipitation measurement issue by providing recommendations on the standardization of equipment and exposure, instrument calibration and data correction as a consequence of various comparative campaigns involving...

Measurement accuracy requirements for rainfall intensity gauges under operational use are becoming tighter after the recent Field Intercomparison of Rainfall Intensity Gauges promoted by WMO (the World Meteorological Organisation) demonstrated the achievable accuracy of a number of commercially available instruments (Vuerich et al., 2009). Various...

Flooding events in urban areas occur quite frequently as a consequence of rain events of lower intensity than the design one, even in case of correct network dimensioning. Inlets are in those cases the critical nodes, and efficient drainage is only ensured when care is taken on their appropriate design and positioning within the drainage area. The...

The analysis of counting and catching errors of both catching and non-catching types of rain intensity (RI) gauges was possible for the first time over a wide variety of measuring principles and instrument design solutions based on the recent Field Intercomparison of Rainfall Intensity Gauges promoted by WMO, the World Meteorological Organisation....

In order to investigate the hydrologic response of a green roof system within the urban environment, a monitoring campaign is carried out at the green roof site of the University of Genova (Italy). Experimental data confirm that the green roof is able to significantly mitigate the generation of runoff with median values of retained volume and peak...