The territory covered by the vegetation map extends for about 1845 hectares and includes the entire area of the Parco del Monte di Portofino (about 1143 hectares) and the so-called “corridor area” (about 702 hectares), which develops adjacent to and along the inland boundary of the park. On one side, its boundary coincides with the coast fine from Camogli to Santa Margherita Ligure and, on the other, with a line that starts from Camogli and, excluding the major residential conglomerations, runs inland until it reaches the coast line near Santa Margherita Ligure. The geolithological substrate largely consists of the Conglomerate di Portofino and Calcari del Monte Antola; sometimes in association with various types of detritic cover. consequently the geo-morphological structure is quite varied, with a prevalence of bleak, craggy formations and frequent rock outcrops, with different degrees of instability and erodibility. The highest conglomerate peak (610 117 a.s.1.) is that of Monte di Portofino, where remnants of a semaforo vecchio (a former lighthouse) are present. Going South East and partly on the same line, there are the peaks of Monte delle Bocche (506 in) and Monte Pollone (488 tn), which are of lower altitude, but still conglomerate.
Towards the North, there are the calcareous peaks of Portofino Vetta (428 m), of Monte di Ruta (417 tn) and finally, beyond the Valico di Ruta, in the “corridor” area, there are the peaks of Monte Esoli (441 m), of Monte Chiapparolo (477 m) and of Monte Ampola (578 m), which lie along the Northern boundary of this area. Practically all slopes are very steep and the transition from the bottom of the valley and the coastline to the slopes is generally quite sudden; so that, for example the line joining the Peak of Monte di Portofino and the nearest point on the coastline at the Cala dell’Oro (about 1.05 km in a horizontal direction), has an inclination of more than 30′ and therefore has an average gradient of about 59%. From these peaks and from the principal crest lines connecting these peaks, various valley lines branch out in different directions, and at different depths. At times these valleys are enclosed between steep slopes and secondary crest lines, ridges, rock outcrops and prominent blocks, that partly jut out over the sea. Besides those crest lines passing through the above mentioned peaks, there are relevant secondary ones that descend, in a fan-like fashion, from Monte di Portofino towards San Fruttoso; towards Punta Torretta; towards Monte Tocco, Semaforo Nuovo and beyond as far as Punta Chiappa; towards San Rocco and beyond until Camogli. Because of the steep slopes, the drainage basins are poorly developed. There are only few watercourses of some importance, all of torrential nature, though there are also permanent springs, largely used to teed the aqueducts. Among the main water courses Rio Gentile should be mentioned.
It is the principle drainage channel of the catchment basin that lies between Monte di Portofino and the crest lines that run from Monte di Portofino towards Camogli, on one side, and towards Monte di Ruta, Valico di Ruta and towards Monte Esoli and from Monte Esoli towards Camogli, on the other. Shorter streams, such as Fosso dei Bruchi, Valletta di Bricco, Vallone Cala dell’Oro, Vallone Fontanini, Fosso San Fruttuoso, Valle Ruffinale, Valle Vescini, can be found on the coastward side, when going towards South and proceeding to the Eastern limit. From here when going northwest along the part facing inland, we can find drainage basins with larger streams, such as Fosso dell’Acqua Viva, Torrente dell’Acqua Morta, Fosso Magistrato, Fosso San Siro, Torrente Bana. For an outline of the general climatic conditions one can rely on the data provided by the meteorological stations within (Semaforo Nuovo, 427 m Punta Chiappa, 5 m) and outside (Chiavari, 5 m) the studied area (GENTILE A. and VAGGE, 1992). More precise data, for local situations can be derived from hypothetical average temperatures, based on the variations related to altitude gradients.
Thus, for example, besides the ombrothermic diagrams which relate to the three above mentioned meteorological sites, others can be compiled that relate (GENTILE A., 1993 and 199.5) to sites at different altitudes, which also pertain to specific vegetation. On the basis of these meteorological data of ombrothermic graphs and of values of classical climatic indiceswhich derive from them, such as the aridity index of De Martonne (varying from 36 to 50), Langs pluviofactor (varying from 6 / to 82), and Emberger’s pluviothermic index (310, for Chiavari), the territory falls within the Mediterranean humid and perhumid macroclimate, with temperate winters. Having said this, however, it should be emphasised that, also on the basis of presumed altitudinal temperature variations, it would not be possible to delineate a mesoclimatic zonation sufficiently accurate to distinguish between the multiple habitats, where the microenvironmental status is determined by particular physiographic conditions (for example, exposition, acclivity, gullies and ravines, natural half-shade or shade etc.) with consequent marked microclimatic variations. Thanks to Parco di Portofino.
Portofino, a World apart.