Il contributo della idro-geomorfologia nella valutazione delle piene in Campania

2010 - 2011Italy and, in particular, the Campania region, has been exposed to Hydraulic Risk since long ago. In hydraulic risk analysis the definition of maximum flood discharge with a specific return time (T) is crucial and, to this aim, the VAPI- Campania procedure (1995) was adopted in the Campania region. The VAPI method is based on a geo-morphoclimatic model, identifying 7 climatic homogenous areas with respect to the rainfall probability density function and 3 classes of permeability for the rainfall-runoff transformation model. At the XXX National Congress on the Hydraulic and Hydraulic Engineering (IDRA 2006), the hydrological working group of Salerno University (Rossi and Villani (2006)), pointed out guidelines for up-dating the VAPI-Campania and, in particular the role of: orographic barriers in the evaluation of intensity and persistence of the extreme rainfalls; and the individuation of hydro-geomorphotypes for the rainfall-runoff modeling at the catchments and sub-catchments scales. In this framework, the present thesis gives a contribution to a hydro-geomorphological approach to achieve the two guidelines mentioned above. This research focuses first on the automatic individuation and objective delimitation of the orographic barriers in order to upgrade the heuristic delimitation (expert judgment) used in the simplified model of orographically induced rainfall of Rossi et al. (2005). The proposed procedure is based on the basic concepts of the hierarchic orometry (hierarchical mountain geomorphometry), prominence and parent relationships, to delineate the 'orographic mountain' in various spatial scale (hierarchical- multiscale approach). Also, the procedure defines the 'morphologic mountains' and its components (ridge, plain and hillslope) using slope, altitude, relief ratio and exposition with respect to the dominant perturbation fronts and its moving direction. The second topic of research deals with the individuation of the hydrogeomorphotypes. To this aim, the prototypal work of Guida et al. (2007), was taken into account as a guideline in the identification of the hydrogeomorphotypes and the decisional scheme of Scherrer and Naef (2003), here modify, allowed the identification of the three dominant runoff mechanisms on the Campania region. In particular, the prototypal procedure of Guida has been here objectified and automatized, defining the 9 elementary landscape forms (Troch et al., 2002), characterized in terms of sub-surface flow and soil moisture storage, under an objectbased GIS environment. The procedure here presented allowed identification on the hydro-geomorphological map, and of the runoff mechanisms: Hortonian overland flow for excess of saturation, subsurface flow, and deep percolation. In order to test the procedure some hydro-geomorphological analysis have been carried out based on data from two instrumented experimental catchments and on rainfall data from the Regional Functional Center of the Campania Civil Protection Sector. The results allowed to calculate the hydrologic index named Runoff Index, which improves the evaluation of the runoff coefficient (Cf) for un-gauged basins. Other analyses were performed on further 4 catchments with similar hydrologic and geologic behavior in order to extended the procedure to the whole Campania region. Also, conceptual discussions on the implementation of the Runoff Index in the rainfall-runoff transformation operated with a largely used hydrologic software, HECHMS, was made, in order to evaluate the feasibility of the procedure proposed in the present research and improve the RI in hydraulic risk evaluation at a regional scale. [edited by author]X n.s

Hydro-Geomorphologic-Based Water Budget at Event Time-Scale in A Mediterranean Headwater Catchment (Southern Italy)

The Ciciriello catchment is a 3 km2 drainage sub-basin of the Bussento river basin, located in the southern part of the Campania Region (Southern Italy). Since 2012, this catchment has been studied using an interdisciplinary approach—geomorphological, hydrogeological, and hydrological— and a hydro-chemical monitoring system. Following previous research, the aim of this paper is to calibrate, on this catchment, the hydrologic parameters for a water budget at event time-scales using the HEC-HMS model, adopting object-based hydro-geomorphological class features. Firstly, lumped modeling was performed to calibrate the hydrologic parameters from 20 observed hydrographs at the downstream monitoring station of the Ciciriello catchment. Then, physical-based rainfall–runoff modeling was conducted using three different procedures: (1) applying the recession coefficients to each outlet with a newly defined hydro-geomorphologic index (HGmI); (2) assessing the storage coefficient for each sub-basin as a weighted mean of HGmI; and (3) using the storage coefficient associated with the largest HGmI in the sub-basin. The adopted procedures were tested using diverse goodness-of-fit indices, resulting in good performance when the object-based hydro-geomorphotypes were used for the parameter calibration. The adopted procedure can thus contribute to improvements in rainfall–runoff and water budget modeling in similar ungauged catchments in Mediterranean, hilly, and forested landscapes

Using hydro-chemograph analyses to reveal runoff generation processes in a Mediterranean catchment

The paper deals with the hydro-chemical analysis performed in order to reveal processes, sources, paths and timing of the runoff generation in an experimental catchment representative of the hilly, terrigenous and forested watershed in the Mediterranean humid eco-region of southern Italy. The analysis is based on the data recorded at the outlet of the catchment during 2013–2014. A mixing law procedure was applied on discharge (Q) and electrical conductivity (EC) data, by using the Q–EC end members previously collected at selected groundwater, sub-surficial and surficial stations. In this way, we found four bound curves delimiting fields in a Q–EC plot, each with hydro-chemograph value ranges. At annual time scale, the analysis revealed a seasonal behaviour of the hydrological response, different for the wet period, when the aquifer is recharging, and the dry periods, when the aquifer is discharging, despite frequent summer rain showers. At event time scale, the catchment seems to show the behaviour of a typical hydro-geomorphic threshold system. We interpreted this behaviour as due to a progressive addition of water from distinctive components (i.e. deep aquifer, riparian corridor, hillslope and hollow), each with originally different mechanisms of runoff production (i.e. groundwater, groundwater ridging, saturation excess, infiltration excess and soil pipe exfiltration) and response time. During the event, the contributing areas enlarge upward the riparian corridors and the zero-order basins, where the aforementioned components become superposed and the mechanisms interact more and more. We hypothesize that the threshold values between different states of the system are defined by the intersections of the boundary curves on the Q– EC plot. Different patterns in the Q–EC hysteretic cycles are prevalently related to the pre-event soil saturation and groundwater contributions to stormflow and recharge mechanisms. Copyright © 2016 John Wiley & Sons, Ltd

Space-time Distribution of Radon-222 from Groundwater-Streamflow-Atmosphere Interactions in the Karst Systems of the Campania Region (Southern Italy)

Karst systems provide 25% of the drinking water resources to the world‘s population and sustain aquatic life in most fluvial eco-systems. In contrast, the singular process of aquifer recharge, the particular mechanism of subterranean pathway and the complex interactions between surface and groundwater make these systems highly variable in space-time hydrological behaviour and vulnerable to contamination and pollution. In order to provide a useful approach to integrate traditional approach at the above problem resolution, this chapter describes the findings from Radon-222 activity concentration monitoring data from stream-flow and in-stream springs measurement in typical Mediterranean karst landscapes. The study areas which concern are located in the protected area of the Campania region (Southern Italy), primarily in the Cilento and Vallo di Diano National Park- European Geopark and Regional Park of Picentini Mnt and surrounding. In these protected areas, the management of the relevant water resources requires adequate groundwater assessment by performing hydro-geomorphological and hydrological modelling supporting planning tasks in water protection for domestic drinking use, riverine wildlife preservation and water quality maintenance in application of the European Water Framework Directive (EWFD)

Digital orographic map of peninsular and insular Italy

This paper describes method and contents of the digital orographic map of peninsular and insular Italy, comprising the islands of Elba, Sicily and Sardinia at 1:1,250,000 scale. The map was obtained using a modification of a previous proposal to define mountain orders, starting from the SRTM-NASA digital elevation model (90×90 m cell). The method, comparable to the well known drainage network ordering system, uses the topographic concepts of key contour, key saddle, summit point, prominence, and others. It was implemented in a step-by-step GIS-based procedure in order to automatically identify, delimit and order mountains and hills. The procedure permits the derivation of the parent relationship between orographic entities and organizes the ordered mountains in an orographic hierarchy. The orographic mapping system is able to produce an orographic dataset from DEM's, organize orographic geodatabases and manage mapping tools in many research fields. The map here presented is particularly useful to support interdisciplinary studies in tectonic geomorphology, topo-climatology, regional hydrology and landscape ecology at national scale

An Integrated Approach to Sub-SurfaceWater Pathways for the Sustainable Development of the Architectural Landscape of Agro-Urban Areas

This paper presents the results of multidisciplinary research which addresses the issue of sustainability within the design of urban agricultural landscapes through the joint solution of architecture and hydro-geomorphology for the management, accessibility and use of urban agricultural landscapes. If the traditional separation between urban and productive land has now been overcome by the inclusion of agricultural areas within the cities, what is still under discussion is how to make its planning sustainable, especially in densely urbanized contexts. This research was developed with a methodology able to combine different types of data in order to satisfy needs relating to the availability of water for land supply and to make this landscape—both rural and urban—accessible to the city. Historical traces, interpretative insights, and hydro-geomorphological reading models of the territory were analysed. Their interweaving has made it possible to develop a prototype of a water and landscape infrastructure that combines a system for subsurface water, cycle–pedestrian paths and small-scale architecture features around the water tanks. The research has been tested in the city of Pozzuoli (NA) in Southern Italy, within the Monteruscello neighbourhood. The result led to a design solution of an integrated system which contributes to implementing the green transition within cities

An Integrated Approach to Sub-Surface Water Pathways for the Sustainable Development of the Architectural Landscape of Agro-Urban Areas

This paper presents the results of multidisciplinary research which addresses the issue of sustainability within the design of urban agricultural landscapes through the joint solution of architecture and hydro-geomorphology for the management, accessibility and use of urban agricultural landscapes. If the traditional separation between urban and productive land has now been overcome by the inclusion of agricultural areas within the cities, what is still under discussion is how to make its planning sustainable, especially in densely urbanized contexts. This research was developed with a methodology able to combine different types of data in order to satisfy needs relating to the availability of water for land supply and to make this landscape—both rural and urban—accessible to the city. Historical traces, interpretative insights, and hydro-geomorphological reading models of the territory were analysed. Their interweaving has made it possible to develop a prototype of a water and landscape infrastructure that combines a system for subsurface water, cycle–pedestrian paths and small-scale architecture features around the water tanks. The research has been tested in the city of Pozzuoli (NA) in Southern Italy, within the Monteruscello neighbourhood. The result led to a design solution of an integrated system which contributes to implementing the green transition within cities