Antonia Longobardi

Relating soil moisture and air temperature to evapotranspiration fluxes during inter-storm periods at a Mediterranean experimental site

The assessment of the water losses by actual evapotranspiration plays a very important role in water resources management, especially in particular environments suffering soil water stresses and water shortages. The rationales of this study are the scarcity of experimental data, the difficulties in the measurement of direct and continuous evapotranspiration fluxes, and the switching between controls by climate and soil water availability. The temporal patterns of observed soil moisture and air temperature of over three years at an experimental site in southern Italy have been analyzed to investigate the relation between them and the actual evapotranspiration volume, estimated using the soil water budget method. To this end, an event-based empirical analysis has been performed, exploring the relation between the mentioned variables. One of the major findings of the explorative phase is the qualitative and quantitative identification of the switching between climate and soil water balance as the controls over actual evapotranspiration at the experimental site. This threshold process has then been modelled at the event and sub-event scale, establishing simple empirical equations to predict actual evapotranspiration losses as a function of soil water content. Multilevel-recorded data also allowed the investigation of the importance of soil depth.

Trend Analysis of Annual and Seasonal Air Temperature Time Series in Southern Italy

Meteorological variables trend analysis, on different spatial and temporal scales, has been of great concern during the past century because of the attention paid from the scientific community to global climate change. According to some recent studies, the southern areas of Italy are suffering strengthening drought conditions. The aim of this study is to analyse temperature time series, detecting potential trends and assessing their significance and magnitude. For this purpose about 62 gauged stations, mainly located within the Campania region, Southern Italy, have been analysed for the period 1924–1999. Statistical analysis of the database highlight that: (i) trend appears predominantly positive, both at the annual and seasonal scale (ii) at the annual scale positive trends are significant for 34 % of total stations, (iii) significant positive and negative trend average magnitude appear rather severe, ranging from −1.5 °C/decade to +0.85 °C/decade respectively.

At which time step do we need to monitor the stream hydro-chemistry properties for low flow characterization?

The low flow regime features are frequently described in terms of global indices and, among these, the most relevant are the baseflow index and the flow duration curve. Low flow indices have to be computed from observed streamflow data, but monitoring campaigns are time and cost consuming activities. The aim of the present study is then to identify the impact of the monitoring time step resolution, with particular reference to the low flow regime. To the scope, the hydro-chemographical dataset recorded, during a two year monitoring campaign, at the T. Ciciriello experimental catchment, a 3km2 watershed located in the Cilento, European and Global Geopark (Southern Italy), have been analyzed. Water depth (D), discharge (Q), electrical conductivity (EC) and rainfall time series are available. Assuming the daily time scale as the baseline, a fictitious monitoring experiment has been performed, sampling the observed daily time series at different multiple-day time steps. Main global statistic are computed for the different fictitious series and compared to the daily series. The baseflow patterns, filtered with the use of a mass balance method, appear statistically similar and the differences in terms of low flow indices fall within a 10% range.

Hydrological Modelling For River BasinManagement In A Highly Hydro-geologicalConditioned Environment

Water resources management represents a present key issue in hydrology, and hydrological models generating streamflow time series are useful tools in this field. It is possible to refer, in the extreme, to lumped or fully distributed approaches, but when river basins with particular features have to be modeled it is possible to take advantage of a semi-distributed formulation. In this study we propose a semi-distributed conceptually based modeling approach, supported by field measurements collected within several seasonal campaigns, that has been set up for the Bussento river basin, located in southern Italy, characterized by soils and rocks with highly different hydraulic permeability and above all a highly hydro-geological conditioning. The proposed approach, which joins together all hydraulic, hydrological and geological data, is able to reproduce the river discharge mean characteristic.

Assessing baseflow index vulnerability to variation in dry spell length for a range of catchment and climate properties

2496 Copyright

Historical Reconstruction of Erosive Storms Driving Damaging Hydrological Events in the Bonea Basin, Southern Italy

This chapter presents an assessment of annual cumulative erosive storms driving Multiple Damaging Hydrological Events (MDHE) such as floods, landslides and accelerated slope erosion events. This was done in a Mediterranean area where difficulties arise in the reconstruction of the relation between storm erosivity, due to the lack of long detailed and homogeneous recorded time series. This gap has been filled in by merging historical precipitation data from European datasets (Pauling A, Luterbacher J, Casty C, Wanner H, Climate Dynam 26:387–405, 2006) with written proxy documents in which damaging hydrological events were recorded. The research was focused on the Bonea river basin, located in Southern Italy, where a large number of hydrological disasters has occurred (and documented) during the period 1700–2000. For this purpose, a parsimonious approach was used to develop a model named CESAM (Cumulative Erosive Storm Anomalies per Annum) from a previous erosivity anomalies equation and evaluated against erosivity data compatible with the RUSLE scheme. The historical climatology of the Bonea basin has shown pronounced interannual and interdecadal variations dependent on multi-decadal scale erosivity, reflecting the mixed population of thermo-convective and cyclonic rainstorms with large positive-and-high anomalies.

Water Resources Assessment for Karst Aquifer Conditioned River Basins: Conceptual Balance Model Results and Comparison with Experimental Environmental Tracers Evidences

Water resources management, more and more limited and poor in quality, represents a present key issue in hydrology. The development of a community is highly related to the management of the water resources available for the community itself and there is a need, for this reason, to rationalize the existing resources, to plan water resources use, to preserve water quality and, on the other hand, to prevent flood risk. The importance of decision support systems tools, such as hydrological models, generating streamflow time series which are statistically equivalent to the observed streamflow time series, is even more important considering the combination of multiple and complex issues concurring in the definition and optimization of water resources management practices. When river basins with particular features have to be modelled, both traditionally conceptually based models and more recent sophisticated distributed models appear to give not very reliable results. In those cases it is possible to take advantage of a semi-distributed formulation, where every sub-catchment is modelled to account for its features and informations coming from all the sub-catchments are related to each other in order to improve the system description. In this study, starting from the application of a catchment scale modelling tool, we propose a semi-distributed conceptually based framework, able to describe the sub-catchment scale systems hydrological response. The modelling approach is supported by field measurements collected within several seasonal campaigns, that has been set up for the Bussento river basin, located in Southern Italy, well known to hydrogeology and geomorphology scientists for its karst features, characterized by soils and rocks with highly different hydraulic permeability and above all an highly hydrogeological conditioning. The groundwater circulation is very complex, as it will be later discussed, and groundwater inflows from the outside of the hydrological watershed and groundwater outflows toward surrounding drainage systems frequently occur. With the aim to enhance the knowledge of the interaction between the groundwater and surface water and acknowledged the substantial help given by natural isotope tracers experiments to solve hydrological complex systems circulations problems, radon-in water concentrations have also been collected, in a limited number of cross sections, along the upper Bussento river reach.

Smart Stormwater Management in Urban Areas by Roofs Greening

By 2050 the world population will grow to about 9 billion contributing to deep changes in urban areas structure. This would increase the effect of water deficiency and along with projected climate changes the impact of urban floodings, urban heat islands or drought. Smart cities could be key part of the solution contributing to improve the quality life of citizen in urban areas with the adoption of smart, intelligent technologies and infrastructure for energy, water, mobility, buildings, and government. The concept of smart water refers to the ability to provide and manage this primary resource in quantitative and qualitative terms in order to satisfy the future needs of population. The green roof (GR) is a technique belonging to the sectors of smart energy and smart water. It could provide several benefits: sound and thermal insulation of the buildings, mitigation of the urban heat island effects, reduction of air pollution, additionally, GR induces important hydraulic advantages acting as an effective tool for reducing flood risk in urban area with runoff reduction, attenuation and delay of the peak flow. In this paper, the retention capacity of two green roof test beds located in the campus of University of Salerno has been investigated. The analysis has referred to measures of runoff and rainfall conducted in 2017 during the months of February and March. The two roofs substantially differ in the composition of the water storage layer made up of expanded clay in GR1 and of commercial drainage panels in GR2. The retention capacity of the two test beds has been compared. The results confirm that both green roofs, although to a different extent, are effective for the reduction of total runoff volume of rainwater falling on their area.