4. The Agro-Nolano is the subject of our study. It is situated between Mount Somma, the calcareous hills of Cancello and the Avella mountains and includes the territory of Nola and Acerra. This area is easily accessible and suitable for human settlement. It has been densely populated since ancient times as can be witnessed by the numerous presences of tombstones and historical findings.
5. The Agro-Nolano is a flat and slightly mountainous area. The climate is mild and strictly mediterranean with hot, sultry summers and rains in the autumn-winter seasons
6. This area originated from the filling of early deep paleomorphologic follows. At the beginning of the quaternary era (1,5-2 million years ago) it was still a seabed. Then it was trasformed by materials coming from the nearby vulcanic areas and by colluviums which exogenous agents had cut from the mountain surrounding the plain.
7. For this reason most surface layers of the ground are sandy-clayey, not very firm and are mixed with ash and lapilla. This makes the layers pervious and fertile More in-depth the first layer is of vulcanic origin and successively the clayey layers which aresometimes on tuffaceous banks
8.
9. Stratigraphy shows some impermeable layers (clay and sand) which are alternated with pervious layers of tuff and sea clay These act as basis and cover of the layers The water table is found at different deptha: its level is higher in the areas contiguous to the hills
10. The heighth of the first water level found from the surface changes according to the different seasons, to the springs which feed them and to quantities of water drawn out The first water level is more exposed to pollution
11. Over the last ten years the water table has become lower due to excessive exploitation, so it is necessary to use the deeper one
