G Capelli

Water criticality in the Colli Albani (Rome, Italy

The Colli Albani Hydrogeological Unity has a good regional water resource. The geological setting of the area has been defined reconstructing the morphology of roof of prevolcanic substratum and the geometry of the aquifers by the realization of cartographies made of several profiles to different scales. The project of hydrogeological surveying of wells, springs and discharge’s streams have been led to define the state of conservation of water resources. The results of this research have underlined a distributed and relevant drawdown of ground water table and of river capacity network. Specific studies, supported by cartographies elaborated by GIS, have been led to define all the parameters concerning the hydrogeological balance: precipitation, evapotranspiration, runoff, effective infiltration, withdrawals. The analysis of the hydrogeological balance, have led to a definition of specific rules for the management of water resources in order to recover the situations of over-exploitation. Key terms: Aquifer, Aquifer drawdown, Hydrogeological balance, Latium Italy, Alban Hills 1 Studio effettuato con il finanziamento dell’INGV – “Pericolosità associata alla risalita di fluidi endogeni nei Colli Albani” – Responsabile Prof. Renato Funiciello. Introduction The Colli Albani volcano has been the most important water resource of the city of Rome since Roman times. The volcanic succession, which overlies a clayey aquiclude of Pliocene age, can be considered as an individual aquifer, although the permeability associated with interbedded lavas and pyroclastic rocks is highly variable, both laterally and vertically. The area was rapidly urbanized during the second half of the 20 century, with the consequent proliferation of urban and industrial settlements, as well as intensive farming activities. FIG. 1:Volcanic and sedimentary structures and their relations (Modified after DE RITA et alii, 1988). LEGEND: 1) Product of the Albano activity; 2) Product of the Faete activity; 3) Product of the Tuscolano-Artemisio activity; 4) Marine and/or continental clay and sand deposits Pliocene-Quaternary; 5) Clayey arenaceous Miocene flysch; 6) Carbonate succession Mesozoic-Cenozoic; 7) Intrusive magmatic body; 8) Thermometamorphic facies. Capelli G., Mazza R., / Giornale di Geologia Applicata 1 (2005) 261 – 271 262 At present, water pumping in the area is intense and largely uncontrolled, leading to over-exploitation of the aquifer so that the groundwater table is lowered by several tens of meters and locally by up to 100 m. This finding suggests that water pumping is such as to deplete the local strategic reservoir, making it necessary to implement correct water management policies and practices. FIG. 2: Geological sketch map of the Colli Albani volcanic complex (DE RITA et alii, 1995). LEGEND: 1) Travertine; 2) Plio-Pleistocene sedimentary units; 3) Colli Albani final hydromagmatic phase products; 4) Colli Albani Faete phase products; 5) Colli Albani TuscolanoArtemisio phase products; 6) Lava flows; 7) Sabatinian hydromagmatic units; 8) Sabatinian air-fall deposits; 9) Sabatinian ignimbrites; 10) Tortonian flysch (pelitic.sandy facies); 11) Meso-Cenozoic pelagic carbonate units (Sabina facies); 12) Meso-Cenozoic carbonate platform units (Latium-Abruzzi facies); 13) Caldera rims; 14) Crater rims: a) Ariccia, b) Nemi, c) Albano, d) Giuturna, e) Valle Marciana, f) Pantano Secco, g) Prata Porci, h) Castiglione; 15) Hydrogeological cross-section (see FIG. 3). Capelli G., Mazza R., / Giornale di Geologia Applicata 1 (2005) 261 – 271 263

GIS-based hydrostratigraphic modeling of the city of Rome (Italy): analysis of the geometric relationships between a buried aquifer in the Tiber Valley and the confining hydrostratigraphic complexes

A preliminary hydrostratigraphic model of the city of Rome (Italy) was completed through the analysis of geological and hydrogeological data, and by using geographic information system (GIS)-based operations. The complex lithostratigraphic setting of a local Quaternary volcano-sedimentary multilayer was simplified into hydrostratigraphic complexes considering textural properties of terrains and hydraulic conductivity values. The Tiber River Valley, in the middle of the urban area, was analyzed separately from the surrounding areas. GIS tools were used in a multiple-step procedure to reconstruct the geometry of bounding surfaces of the main hydrostratigraphic complexes. Particular care was given to the characterization of a confined gravelly aquifer lying at the base of the upper Pleistocene–Holocene alluvium that fills the Tiber Valley. Updated isobaths and thickness maps of this layer were produced. Three-dimensional reconstruction identifies areas of potential recharge between the alluvium aquifer and the surrounding hydrostratigraphic complexes. In the central sector of the city, the gravel deposits are laterally confined by a thick aquitard corresponding to the Pliocene clayey bedrock of the city; in contrast, a potential recharge area can be hypothesized in the northern areas, where the upper Pleistocene–Holocene valley cross cuts the Paleotiber Graben, filled with older and highly permeable gravels and clays.RésuméUn premier modèle hydrostratigraphique de la Ville de Rome (Italie) a été finalisé grâce à l’analyse des données géologiques et hydrogéologiques et à la mise en oeuvre d’applications basées sur un système d’information géographique (SIG). La configuration lithostratigraphique complexe d’un multi-couche volcano-sédimentaire local d’âge quaternaire a été schématisée en des complexes hydrostratigraphiques définis par les propriétés texturales des terrains et les valeurs de la conductivité hydraulique. La Vallée du Fleuve Tibre, au cœur de l’aire urbaine, a été analysée à part des zones environnantes. Les outils du SIG ont été mis en œuvre en suivant une démarche multi-phasée, destinée à reconstituer la géométrie des surfaces délimitant les principaux complexes hydrostratigraphiques. Un soin particulier a été apporté à la caractérisation de l’aquifère graveleux captif présent à la base des alluvions du Pléistocène–Holocène supérieur qui comblent la vallée du Tibre. Les isobathes actualisées et les cartes d’épaisseur de cette couche ont été établies. La reconstitution en 3D identifie des secteurs de recharge potentielle entre l’aquifère alluvial et les complexes hydrostratigraphiques environnants. Dans le secteur central de la ville, les dépôts graveleux sont confinés latéralement par un aquitard épais correspondant au substratum argileux pliocène de la ville ; par contraste, une zone de recharge potentielle peut être supposée dans les quartiers nord où une vallée confluente Pléistocène–Holocène supérieur recoupe le Graben du Paléo-Tibre, comblé par des graviers et des sables plus anciens et fortement perméables.ResumenSe completó un modelo hidroestratigráfica preliminar de la ciudad de Roma (Italia) a través del análisis de datos geológicos e hidrogeológicos, y por el uso de operaciones basadas en un sistema de información geográfica (SIG). La compleja configuración litoestratigráfica de una multicapa local volcano – sedimentario del Cuaternario se simplificó en complejos hidroestratigráficos considerando las propiedades texturales de los terrenos y los valores de conductividad hidráulica. El valle del Río Tiber, en el medio del área urbana, fue analizado separadamente de las áreas circundantes. Herramientas SIG fueron usadas en un procedimiento múltiples pasos para reconstruir la geometría de las superficies circundantes de los principales complejos hidroestratigráficos. Se prestó particular cuidado a la caracterización del acuífero gravoso confinado que yace en la base del aluvio Pleistoceno superior–Holoceno que rellena el valle del Tiber. Se produjeron Isobatas actualizadas y mapas de espesores de esta capa. La reconstrucción 3D identifica áreas de recarga potencial entre el acuífero aluvial y los complejos hidroestratigráficos circundantes. En el sector central de la ciudad, los depósitos de gravas están lateralmente confinados por un acuitardo espeso correspondiente a la base arcillosa del Plioceno de la ciudad; en contraste, se puede introducir la hipótesis de un área potencial de recarga en las áreas del norte, donde el cruce del valle Pleistoceno superior–Holoceno corta el graben Paleotiber, rellenado con viejas y altamente permeables gravas y arenas.摘要意大利罗马城的一个初步水文地层模型通过地质与水文地质数据的分析已完成,并且利用了基于运算的地理信息系统(GIS)。考虑到地形的结构特性和渗透系数,当地的第四系火山多层沉积的复杂地层设置在水文地层综合体中被简化。Tiber河谷位于市区中心,与周围地区分开分析。GIS工具用于多步骤重建主要水文地层综合体的边界面的几何形状。特别注意到了布满整个河谷的位于更新世—全新世冲积层基底之上的承压砾石含水层。该层的更新的等深线和厚度图已完成。3D重建标识冲积含水层和周围水文地层综合体之间的潜在补给区。在城市的中心区,砾石沉积侧向被厚层弱透水层封闭,其与城市的上新世粘土基岩一致;相反地,潜在补给区可以假定为北边的区域,其上更新世—全新世河谷横切Paleotiber 地堑,充填了更老的和高渗透性的砾石和砂。RiassuntoUn modello preliminare della città di Roma (Italy) e’ stato completato attraverso l’analisi di dati geologici ed idrogeologici, ed attraverso l’uso di operazioni basate su sistemi informativi geografici (GIS). Il complesso assetto litostratigrafico del multistrato vulcano-sedimentario del Quaternario è stato semplificato in complessi idrostratigrafici considerando le proprietà tessiturali dei terreni e i valori di conducibilità idraulica. La Valle del fiume Tevere, posta nel mezzo dell’area urbana, è stata analizzata separatamente. Funzionalità GIS sono state utilizzate in una procedura articolata per ricostruire la geometria delle superfici di tetto dei principali complessi idrostratigrafici. Particolare cura è stata data alla caratterizzazione di un acquifero ghiaioso che si trova alla base delle alluvioni pleistoceniche–oloceniche che riempiono la Valle del Tevere. Sono state realizzate nuove mappe delle isobate e dello spessore di questo strato. Tramite una ricostruzione 3D sono state identificate le aree di potenziale ricarica tra l’acquifero alluvionale e i circostanti complessi idrostratigrafici. Nel settore centrale della città i depositi ghiaiosi sono confinati lateralmente da uno spesso aquiclude che corrisponde al bedrock argilloso della città; al contrario, un’area di potenziale ricarica può essere ipotizzata più a nord, laddove la valle pleistocenica–olocenica è incisa nel graben del Paleotevere, riempito da ghiaie e argille più antiche e ad alta permeabilità.ResumoConcluiu-se um modelo hidroestratigráfico preliminar da cidade de Roma (Itália) através da análise de dados geológicos e hidrogeológicos, efetuado com base em operações que utilizam sistemas de informação geográfica (SIG). Para o efeito, a complexa configuração litoestratigráfica multicamada do Quaternário vulcano-sedimentar foi simplificada em complexos hidroestratigráficos, considerando as propriedades texturais dos terrenos e os seus valores de condutividade hidráulica. O Vale do Rio Tibre, no meio da área urbana, foi analisado separadamente das áreas circundantes. Utilizaram-se ferramentas SIG para um procedimento de reconstrução sucessivo da geometria dos limites dos principais complexos hidroestratigráficos. Foi tido um especial cuidado na caraterização de um aquífero confinado de cascalho sob a base do aluvião Plistocénico superior–Holocénico que preenche o Vale do Tibre. Foram produzidos mapas de isobatimétricas e de espessura desta camada. A reconstrução 3D identifica áreas de recarga potencial do aquífero entre o aquífero aluvionar e os complexos hidroestratigráficos envolventes. No setor central da cidade, os depósitos de cascalho são confinados lateralmente por um espesso aquitardo correspondente ao soco argiloso Pliocénico da cidade; em contraste, pode ser considerada como hipótese uma área potencial de recarga nas áreas a norte, onde o vale Plistocénico superior–Holocénico corta o Graben de Paleotiber, preenchido com cascalhos e areias mais antigos, altamente permeáveis.

Groundwater of Rome

ABSTRACT This paper describes the contents of the new Hydrogeological Map of the City of Rome (1:50,000 scale). The map extends to the entire municipality (1285 km2) and is based on both the most recent scientific studies on the groundwater field and new survey activities carried out in order to fill the data gaps in several areas of the examined territory. The map is the result of a combination of different urban groundwater expertise and Geographic Information System (GIS)-based mapping performed using the most recent available data and has been produced with the intention of furnishing the City of Rome with the most recent and updated information regarding groundwater.

Studi idrogeologici in ambito urbano: gli esempi del VI e XI Municipio della Città di Roma

The purpose of this project was to define the hydrogeological scheme of the Tiber delta by means of the reconstruction of the sedimentary bodies to identify aquifers and aquiclude. The hydrogeological complexes of delta are overlain on plio-pleistocenic deposits from which depend the morphology and geometry, affecting recharge and flow distributions and the relationships with the neighbouring hydrogeological units. For the hydrological investigations 120 wells have been considered to observe the water level, and electrical conductivity, temperature and ph were detected in the sites. Beside, given the presence of surface hydrology, channels and water-scooping machine systems, in a network of points a detailed topographic survey, and a physico-chemical study of the waters, was carried out. The objective of the fieldwork was to map the properties of the groundwater (and non groundwater): the resulting thematic maps, water-table contours map, electrical conductivity contours map, temperature contours map, can be interpreted to observe the level of groundwater-surface and the salinity of the waters, that can be inferred from the electrical conductivity. The results show a saline intrusion and a widespread contamination of the Tiber delta, that represents a very high risk to water management. A consistent and rigorous groundwater protection policy is needed to assess the groundwater vulnerability. Key terms: hydrogeology, hydrology, Tiber Delta, saline intrusion, physico-chemical of the groundwater, water management. Termini chiave: idrogeologia, idrologia, Delta del Fiume Tevere, intrusione salina, chimico-fisica dell’acqua sotterranea, gestione della risorsa idrica.

Le risorse idriche nei travertini della Piana di Tivoli-Guidonia. La modellazione numerica come strumento di gestione degli acquiferi

La piana di Tivoli-Guidonia e un bacino subsidente collocato nel Lazio a ridosso dell’Appennino Centrale, a Nord del Complesso Vulcanico dei Colli Albani. Il bacino e limitato a Nord dai rilievi dei Monti Cornicolani, ad Est dai Monti Lucretili, a Sud dal Fiume Aniene e ad Ovest da rilievi costituiti prevalentemente da terreni marini pliocenici. Fin dall’inizio della subsidenza, datata attorno ai 115.000 anni, sviluppatasi per mezzo di un sistema di faglie ad andamento circa Nord-Sud, e iniziata un’intensa attivita idrotermale nell’area, che ha determinato l’accumulo di un importante e continuo deposito di travertino di spessore massimo oltre agli 80 metri. Il flusso idrotermale, ancora oggi attivo, si manifesta attraverso diverse emergenze di acque sulfuree (con temperature di circa 23°C e conducibilita elettrica di circa 3000 μS/cm) localizzate in corrispondenza di punti di risalita dei fluidi endogeni circolanti nel substrato carbonatico confinato (Capelli et al., 1987). Fin dall’epoca romana il travertino (“Lapis Tiburtinus”), ampiamente sfruttato per rivestire la maggior parte dei monumenti dell’Urbe, era stato coltivato esclusivamente nei suoi strati superficiali per la modesta soggiacenza delle acque sotterranee. A partire dal secondo dopoguerra, l’avvento di pompe idrauliche sempre piu potenti ha permesso di abbassare la falda acquifera e di approfondire la coltivazione. Attualmente, in seguito all’espansione della vicina Citta di Roma a spese delle periferie, la presenza antropica e le attivita estrattive e termali nella piana di Tivoli-Guidonia coesistono in un delicato equilibrio. Per fornire un utile strumento di gestione della risorsa idrica in questo contesto, partendo dai numerosi studi condotti negli ultimi 10 anni sulla geologia e sull’idrogeologia locale, e grazie al monitoraggio in continuo dei principali parametri delle acque di falda, e stato realizzato un modello numerico in stato stazionario del sistema idrogeologico della piana delle Acque Albule utilizzando i codici MODFLOW-2005 (Harbaugh, 2005) e UCODE-2005 (Poeter et al., 2005). Il modello, allo stato attuale, permette di valutare possibili effetti sulla superficie piezometrica a seguito del variare delle condizioni sia naturali che antropiche.

Quantitative Hydrogeology of Volcanic Lakes: Examples from the Central Italy Volcanic Lake District

Volcanic lakes are surface expressions of the hydrogeology of volcanic complexes. Hydrogeological analysis of volcanic complexes is important both in terms of management of the water resource and from the point of view of associated geothermal and volcanic processes. In particular volcanic lakes are the site of possible mixing between superficial fluids (water) and endogenous fluids (gas and/or magma). The Tyrrhenian volcanic domain hosts several volcanic lakes, which, depending on their origin, can be classed as crater lakes or caldera lakes. The presence of large cities (like Rome), and intense industrial and agricultural activities have significantly modified the “natural” equilibrium and groundwater resources have been significantly depleted during the last 20–30 years. In many areas the situation has turned “critical”, involving both the lowering of groundwater and lake levels. In this chapter, we present the results of quantitative hydrogeological analysis of two volcanic lakes in the surroundings of the densely urbanized hinterland of Roma capital city (Italy): the Bracciano caldera lake basin (Sabatini volcanic complex) and the Albano crater lake basin (Colli Albani volcano). The groundwater flow systems have been analyzed and the hydrogeological water balances defined. A focus has been put on the areas with larger aquifer depletion. The methodologies applied to the lake water balances include GIS analyses supported by geostatistics.

Evaluating groundwater resource of an urban alluvial area through the development of a numerical model

AbstractAs established in the European Water Framework Directive, the development of groundwater numerical models is fundamental for adopting water management plans aimed at preserving the water resource and reducing environmental risks. In this paper, authors present a methodology for the estimation of groundwater resource of an alluvial valley, in an urban area characterized by a complex hydrostratigraphic setting and scarcity of hydrogeological data; the study area is the urban and sub-urban area of Rome (Italy). A previous, elaborated hydrostratigraphic model set the base for the development of 3D, steady state, sub-basin scale numerical model, implemented by the finite-difference code MODFLOW 2000®; the water system components were derived by elaboration of available data. The alluvial aquifer of the Tiber River Valley, which runs in the middle of the City in a NNW–SE direction, has been analyzed in detail, since it is covered by a densely populated area hosting most of Rome’s historical heritage, and it is characterized by low quality geotechnical parameters. Results suggest that in areas with high hydrostratigraphic complexity and scarcity of hydrogeological data, a sub-basin scale, and steady-state numerical model can be very helpful to verify the conceptual model and reduce the uncertainty on the water budget components. The proposed steady-state model constitutes the base for future applications of transient state and local scale models, required for sustainable water management.

Memorial to Prof. Paolo Bono 1940–2012

Professor Paolo Bono passed away in February, 2012 before he was able to see this special issue of Environmental Earth Sciences come to fruition. He was integrally involved in planning and implementing the Geokarst Hazards Conference due to his long-term interest in and investment in the karst of Vietnam. Paolo will be missed and there follows a memorial to him prepared by his colleagues at the University of Rome ‘‘La Sapienza’’ and Professor Hai Tran, organizer of the conference. Paolo was born in Kalimnos, Greece, March 15, 1940. He served as an Associate Professor of Hydrogeology beginning in the 1980s at the University of Rome ‘‘La Sapienza’’, teaching students of Geological Sciences and Environmental Sciences. He retired at the end of 2010. Since the 1970s his researches were related to Regional Quantitative Hydrogeology in regards to resource occurrence, hydrostructure boundary conditions and assessment of renewable groundwater resources in Italy. At the same time he was active in national and international multidisciplinary projects promoted by the National Research Council (CNR). In the 1980s he performed hydrological and hydrogeological investigations and taught training courses within the framework of a cooperative program between the governments of Italy and Lesotho. Since the 1990s he devoted his research to environmental pollution, with particular reference to hydrochemistry and water isotope data ranging from rain to spring water. During the last 10 years, he was involved in international projects for the evaluation of groundwater resources in the Galapagos Islands, Socotra Island and in Vietnam, under the umbrella of the Italian Ministry of Foreign Affairs and of UNESCO. Paolo was a member of the Scientific Council of the ‘‘Research Center for Quaternary and Environmental Evolution’’ of the CNR, of the Karst Commission of the International Association of Hydrogeologists (IAH) and of the Scientific Committee of CISDAM (Interdisciplinary Center of Studies on Mediterranean Environments). He served for many years on the Editorial Board of Geologica Romana, Journal of the Earth Science Department of La Sapienza University, and, of course, on the Editorial Board of Environmental Earth Sciences (formerly Environmental Geology). Results of his research activity have been published in national and international journals, conference proceedings and official reports. Particular recognition is due to the highquality hydrogeological maps he contributed to the field, including the Hydrogeological Scheme of Central Italy, 1986. Today this is still the basic hydrogeological map used in Central Italy for scientific and technical purposes. In addition to the above biographical sketch, which briefly and incompletely describes the official activity of the scientist, we want to add our modest description of the man, colleague and researcher, that Paolo was during his long tenure at La Sapienza University. Paolo was a strong, tenacious, tireless man, who dedicated his life to hydrogeology, through research and J. W. LaMoreaux P.E. LaMoreaux & Associates, Inc., Tuscaloosa, AL, USA