Investigating the feasibility of using precipitation measurements from weather RaDAR to estimate potential recharge in regional aquifers: the Majella massif case study in Central Italy

Abstract

Rain gauge spatial sparsity and temporal discontinuity of data represent one of the major issues for reliable recharge estimations. In the past decades, the use of ground-based microwave weather RaDAR has dramatically improved quantitative rainfall estimation by providing spatially continuous estimates of rainfall over an area of more than 400 km2 every 10 minutes. Furthermore, weather RaDAR data have also proved relatively reliable in mountainous areas. These paramount features of RaDAR-derived precipitation data could improve the estimation of potential recharge of aquifers, which rely on geospatializations (e.g., Thiessen polygons) of rainfall data collected by a sparse rain gauge network which often shows lacking at high altitude (i.e., recharge areas), introducing additional uncertainty in the inflow volumes. Weather RaDAR rainfall estimation is also affected by various sources of error, which can be reduced by proper post-processing; however, uncertainties remain, especially for surface rain rate estimations. Despite the currently necessary complex numerical processing, the purpose of the study is to evaluate the use of the weather RaDAR data as an alternative or in addition to meteorological data. Based on the above considerations, the feasibility of using RaDAR-based precipitation data to estimate aquifer potential recharge and calculate a detailed water budget in the areas characterized by high elevations, such as the Majella massif in the central Apennines, has been evaluated. To address this objective, the water budget has been calculated in the 2017-2018 period using both RaDAR-based precipitation data and rain gauge data, as well as adopting different methods (i.e., Turc and Thornthwaite). Although intrinsically uncertain, the RaDAR-based precipitation data provided solid results, pointed out by comparing it with water budget obtained by rain gauge data, and especially with experimental literature data. This interdisciplinary work may pave the way for continuous monitoring of aquifer potential recharge at extremely high temporal and spatial resolution.

Estimating a Reliable Water Budget at a Basin Scale: A Comparison between the Geostatistical and Traditional Methods (Foro River Basin, Central Italy)

“…After calculating the amount of water returning to the atmosphere, the outflow was calculated according to Equation (9). In order to quantify runoff and infiltration, Potential Infiltration Coefficients (I R ) derived from the most complete geological map of the study area [30] were considered.…”

“…However, the quantification of available water resources connected to the direct rainfall recharge, as in river basins [7], is often affected by the problem of the spatial representativeness of the data (i.e., rainfall and temperature) collected in sparse weather stations across areas that are hundreds to thousands of square kilometers, and which are usually recorded as time series and then interpolated to obtain a spatial distribution [8]. As a matter of fact, the distribution of weather data is often not optimal according to both a spatial and an altimetric point of view [9].…”

Guidelines for sustainable management of groundwater inflows and geothermal heat in tunnels

“…They found contrasting trends with increasing water table at some points, and decreasing at some others, even in a small area of about 500 km 2 . Di Curzio et al (2022) evaluated the use of the weather RaDAR data as an alternative or to integrate traditionally gathered meteorological data to estimate aquifer potential recharge in the Majella massif (Italy). Finally Nicolini et al (2022) investigated, using the tracer masse balance method, the Fiume-Vento karstic complex (Italy) characterised by sulfuric acid speleogenesis type in order to understand groundwater circulation and dilution phenomena.…”

Comparing Rain Gauge and Weather RaDAR Data in the Estimation of the Pluviometric Inflow from the Apennine Ridge to the Adriatic Coast (Abruzzo Region, Central Italy)

“…Despite all the above-mentioned critical factors, weather-radar-derived rainfall datasets are valuable with respect to rain gauge networks because they can potentially reduce the uncertainty about precipitation inflow volumes due to their higher spatial-temporal resolution. Weather radars are currently networked and generally used for weather surveillance, hydrological, and meteorological purposes with a special emphasis on data assimilation [18], in support of civil protection activities [19], as well as to better define the water budget in regional aquifers [20] or in wide catchments [21].…”