CHAPTER VIII

THE COASTAL DESERT

To the wayfarer from the bleak mountains the warm green valleys of the coastal desert of Peru seem like the climax of scenic beauty. The streams are intrenched from 2,000 to 4,000 feet, and the valley walls in some places drop 500 feet by sheer descents from one level to another. The cultivated fields on the valley floors look like sunken gardens and now and then one may catch the distant glint of sunlight on water. The broad white path that winds through vineyards and cotton-fields, follows the foot of a cliff, or fills the whole breadth of a gorge is the waste-strewn, half-dry channel of the river. In some places almost the whole floor is cultivated from one valley wall to the other. In other places the fields are restricted to narrow bands between the river and the impending cliffs of a narrow canyon. Where tributaries enter from the desert there may be huge banks of mud or broad triangular fans covered with raw, infertile earth. The picture is generally touched with color--a yellow, haze-covered horizon on the bare desert above, brown lava flows suspended on the brink of the valley, gray-brown cliffs, and greens ranging from the dull shade of algarrobo, olive and fig trees, to the bright shade of freshly irrigated alfalfa pastures.

After several months’ work on the cold highlands, where we rode almost daily into hailstorms or wearisome gales, we came at length to the border of the valley country. It will always seem to me that the weather and the sky conspired that afternoon to reward us for the months of toil that lay behind. And certainly there could be no happier place to receive the reward than on the brink of the lava plateau above Chuquibamba. There was promise of an extraordinary view in the growing beauty of the sky, and we hurried our tired beasts forward so that the valley below might also be included in the picture. The head of the Majes Valley is a vast hollow bordered by cliffs hundreds of feet high, and we reached the rim of it only a few minutes before sunset.

I remember that we halted beside a great wooden cross and that our guide, dismounting, walked up to the foot of it and kissed and embraced it after the custom of the mountain folk when they reach the head of a steep “cuesta.” Also that the trail seemed to drop off like a stairway, which indeed it was.[18] Everything else about me was completely overshadowed by snowy mountains, colored sky, and golden-yellow desert. One could almost forget the dark clouds that gather around the great mass of Coropuna and the bitter winds that creep down from its glaciers at night--it seemed so friendly and noble. Behind it lay bulky masses of rose-tinted clouds. We had admired their gay colors only a few minutes, when the sun dropped behind the crest of the Coast Range and the last of the sunlight played upon the sky. It fell with such marvelously swift changes of color upon the outermost zone of clouds as these were shifted with the wind that the eye had scarcely time to comprehend a tint before it was gone and one more beautiful still had taken its place. The reflected sunlight lay warm and soft upon the white peaks of Coropuna, and a little later the Alpine glow came out delicately clear.

When we turned from this brilliant scene to the deep valley, we found that it had already become so dark that its greens had turned to black, and the valley walls, now in deep shadow, had lost half their splendor. The color had not left the sky before the lights of Chuquibamba began to show, and candles twinkled from the doors of a group of huts close under the cliff. We were not long in starting the descent. Here at last were friendly habitations and happy people. I had worked for six weeks between 12,000 and 17,000 feet, constantly ill from mountain sickness, and it was with no regret that I at last left the plateau and got down to comfortable altitudes. It seemed good news when the guide told me that there were mosquitoes in the marshes of Camaná. Any low, hot land would have seemed like a health resort. I had been in the high country so long that, like the Bolivian mining engineer, I wanted to get down not only to sea level, but below it!

If the reader will examine Figs. 65 and 66, and the photographs that accompany them, he may gain an idea of the more important features of the coastal region. We have already described, in Chapters V and VII, the character of the plateau region and its people. Therefore, we need say little in this place of the part of the Maritime Cordillera that is included in the figure. Its unpopulated rim (see p. 54), the semi-nomadic herdsmen and shepherds from Chuquibamba that scour its pastures in the moist vales about Coropuna, and the gnarled and stunted trees at 13,000 feet (3,960 m.) which partly supply Chuquibamba with firewood, are its most important features. A few groups of huts just under the snowline are inhabited for only a part of the year. The delightful valleys are too near and tempting. Even a plateau Indian responds to the call of a dry valley, however he may shun the moist, warm valleys on the eastern border of the Cordillera.

The greater part of the coastal region is occupied by the desert. Its outer border is the low, dry, gentle, eastward-facing slope of the Coast Range. Its inner border is the foot of the steep descent that marks the edge of the lava plateau. This descent is a fairly well-marked line, here and there broken by a venturesome lava flow that extends far out from the main plateau. Within these definite borders the desert extends continuously northwestward for hundreds of miles along the coast of Peru from far beyond the Chilean frontier almost to the border of Ecuador. It is broken up by deep transverse valleys and canyons into so-called “pampas,” each of which has a separate name; thus west of Arequipa between the Vitor and Majes valleys are the “Pampa de Vitor” and the “Pampa de Sihuas,” and south of the Vitor is the “Pampa de Islay.”

The pampa surfaces are inclined in general toward the sea. They were built up to their present level chiefly by mountain streams before the present deep valleys were cut, that is to say, when the land was more than a half-mile lower. Some of their material is wind-blown and on the walls of the valleys are alternating belts of wind-blown and water-laid strata from one hundred to four hundred feet thick as if in past ages long dry and long wet periods had succeeded each other. The wind has blown sand and dust from the desert down into the valleys, but its chief work has been to drive the lighter desert waste up partly into the mountains and along their margins, partly so high as to carry it into the realm of the lofty terrestrial winds, whence it falls upon surfaces far distant from the fields of origin. There are left behind the heavier sand which the wind rolls along on the surfaces and builds into crescentic dunes called médanos, and the pebbles that it can sandpaper but cannot remove bodily. Thus there are belts of dunes, belts of irregular sand drifts, and belts of true desert “pavement” (a residual mantle of faceted pebbles and irregular stones).

Yet another feature of the desert pampa are the “dry” valleys that join the through-flowing streams at irregular intervals, as shown in the accompanying regional diagram. If one follow a dry valley to its head he will find there a set of broad and shallow tributaries. Sand drifts may clog them and appear to indicate that water no longer flows through them. They are often referred to by unscientific travelers as evidences of a recent change of climate. I had once the unusual opportunity (in the mountains of Chile) of seeing freshly fallen snow melted rapidly and thus turned suddenly into the streams. In 1911 this happened also at San Pedro de Atacama, northern Chile, right in the desert at 8,000 feet (2,440 m.) elevation, and in both places the dry, sand-choked valleys were cleaned out and definite channels reëstablished. From a large number of facts like these we know that the dry valleys represent the work of the infrequent rains. No desert is absolutely rainless, although until recently it was the fashion to say so. Naturally the wind, which works incessantly, partly offsets the work of the water. Yet the wind can make but little impression upon the general outlines of the dry valleys. They remain under the dominance of the irregular rains. These come sometimes at intervals of three or four years, again at intervals of ten to fifteen years, and some parts of the desert have probably been rainless for a hundred years. Some specific cases are discussed in the chapter on Climate.

The large valleys of the desert zone have been cut by snow-fed streams and then partly filled again so that deep waste lies on their floors and abuts with remarkable sharpness against the bordering cliffs (Fig. 155). Extensive flats are thus available for easy cultivation, and the through-flowing streams furnish abundant water to the irrigating canals. The alluvial floor begins almost at the foot of the steep western slope of the lava plateau, but it is there stony and coarse--hence Chuquibamba, or plain of stones (chuqui = stone; bamba = plain). Farther down and about half-way between Chuquibamba and Aplao (Camaná Quadrangle) it is partly covered with fresh mud and sand flows from the bordering valley walls and the stream is intrenched two hundred feet. A few miles above Aplao the stream emerges from its narrow gorge and thenceforth flows on the surface of the alluvium right to the sea. Narrow places occur between Cantas and Aplao, where there is a projection of old and hard quartzitic rock, and again above Camaná, where the stream cuts straight across the granite axis of the Coast Range. Elsewhere the rock is either a softer sandstone or still unindurated sands and gravels, as at the top of the desert series of strata that are exposed on the valley wall. The changing width of the valley is thus a reflection of the changing hardness of the rock.

There is a wide range of products between Chuquibamba at 10,000 feet (3,050 m.) at the head of the valley and Camaná near the valley mouth. At the higher levels fruit will not grow--only alfalfa, potatoes, and barley. A thousand feet below Chuquibamba fruit trees appear. Then follows a barren stretch where there are mud flows and where the river is intrenched. Below this there is a wonderful change in climate and products. The elevation falls off 4,000 feet and the first cultivated patches below the middle unfavorable section are covered with grape vines. Here at 3,000 feet (900 m.) elevation above the sea begin the famous vineyards of the Majes Valley, which support a wine industry that dates back to the sixteenth century. Some of the huge buried earthenware jars for curing the wine at Hacienda Cantas were made in the reign of Philip II.

The people of Aplao and Camaná are among the most hospitable and energetic in Peru, as if these qualities were but the reflection of the bounty of nature. Nowhere could I see evidences of crowding or of the degeneracy or poverty that is so often associated with desert people. Water is always plentiful; sometimes indeed too plentiful, for floods and changes in the bed of the river are responsible for the loss of a good deal of land. This abundance of water means that both the small and the large landowners receive enough. There are none of the troublesome official regulations, as in the poorer valleys with their inevitable favoritism or downright graft. Yet even here the valley is not fully occupied; at many places more land could be put under cultivation. The Belaunde brothers at Cantas have illustrated this in their new cotton plantation, where clearings and new canals have turned into cultivated fields tracts long covered with brush.

The Majes Valley sorely lacks an adequate port. Its cotton, sugar, and wine must now be shipped to Camaná and thence to Mollendo, either by a small bi-weekly boat, or by pack-train over the coast trail to Quilca, where ocean steamers call. This is so roundabout a way that the planters of the mid-valley section and the farmers of the valley head now export their products over the desert trail from Cantas to Vitor on the Mollendo-Arequipa railroad, whence they can be sent either to the cotton mills or the stores of Arequipa, the chief distributing market of southern Peru, or to the ocean port.

The foreshore at Camaná is low and marshy where the salt water covers the outer edge of the delta. In the hollow between two headlands a broad alluvial plain has been formed, through which the shallow river now discharges. Hence the natural indentation has been filled up and the river shoaled. To these disadvantages must be added a third, the shoaling of the sea bottom, which compels ships to anchor far off shore. Such shoals are so rare on this dry and almost riverless coast as to be a menace to navigation. The steamer _Tucapelle_, like all west-coast boats, was sailing close to the unlighted shore on a very dark night in April, 1911, when the usual fog came on. She struck the reef just off Camaná. Half of her passengers perished in trying to get through the tremendous surf that broke over the bar. The most practicable scheme for the development of the port would seem to be a floating dock and tower anchored out of reach of the surf, and connected by cable with a railway on shore. Harbor works would be extraordinarily expensive. The valley can support only a modest project.

The relations of Fig. 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.

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. Fig. 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.

These three regions contain all the fertile coastal valleys of Peru. The larger ones are impressive--with cities, railways, ports, and land in a high state of cultivation. But they are after all only a few hundred square miles in extent. They contain less than a quarter of the people. The whole Pacific slope from the crest of the Cordillera has about 15,000 square miles (38,850 sq. km.), and of this only three per cent is irrigated valley land, as shown in Fig. 66. Moreover, only a small additional amount may be irrigated, perhaps one half of one per cent. Even this amount may be added not only by a better use of the water but also by the diversion of streams and lakes from the Atlantic to the Pacific. Figs. 67 and 68 represent such a project, in which it is proposed to carry the water of Lake Choclococha through a canal and tunnel under the continental divide and so to the head of the Ica Valley. A little irrigation can be and is carried on by the use of well water, but this will never be an important source because of the great depth to the ground water, and the fact that it, too, depends ultimately upon the limited rains.

The inequality of opportunity in the various valleys of the coastal region depends in large part also upon inequality of river discharge. This is dependent chiefly upon the sources of the streams, whether in snowy peaks of the main Cordillera with fairly constant run-off, or in the western spurs where summer rains bring periodic high water. A third type has high water during the time of greatest snow melting, combined with summer rains, and to this class belongs the Majes Valley with its sources in the snow-cap of Coropuna. The other two types are illustrated by the accompanying diagrams for Puira and Chira, the former intermittent in flow, the latter fairly constant.[20]