The relations of [65] , representing the Camaná-Vitor region, are typical of southern Peru, with one exception. In a few valleys the streams are so small that but little water is ever found beyond the foot of the mountains, as at Moquegua. In the Chili Valley is Arequipa (8,000 feet), right at the foot of the big cones of the Maritime Cordillera (see Fig. [6]). The green valley floor narrows rapidly and cultivation disappears but a few miles below the town. Outside the big valleys cultivation is limited to the best spots along the foot of the Coast Range, where tiny streams or small springs derive water from the zone of clouds and fogs on the seaward slopes of the Coast Range. Here and there are olive groves, a vegetable garden, or a narrow alfalfa meadow, watered by uncertain springs that issue below the hollows of the bordering mountains.
| Fig. 67—Irrigated and irrigable land in the Ica Valley of the coastal desert of Peru. | Fig. 68—The projected canal to convey water from the Atlantic slope to the Pacific slope of the Maritime Cordillera.[19] |
In central and northern Peru the coastal region has aspects quite different from those about Camaná. At some places, for example north of Cerro Azul, the main spurs of the Cordillera extend down to the shore. There is neither a low Coast Range nor a broad desert pampa. In such places flat land is found only on the alluvial fans and deltas. Lima and Callao are typical. [66] , compiled from Adams’s reports on the water resources of the coastal region of Peru, shows this distinctive feature of the central region. Beyond Salaverry extends the northern region, where nearly all the irrigated land is found some distance back from the shore. The farther north we go the more marked is this feature, because the coastal belt widens. Catacaos is several miles from the sea, and Piura is an interior place. At the extreme north, where the rains begin, as at Tumbez, the cultivated land once more extends to the coast.