According to GETZIPCODES, Angola includes a part of the great South African plateau and a part of the Longo basin. The plateau, consisting mainly of schists and granites, largely covered by a blanket of red laterite and, in eastern Angola, by arenaceous sedimentations, probably Triassic, and by Pleistocene and recent alluvial and eluvial deposits, lowers slowly towards the east, rising instead in the center up to 2620 m. (M. Moco). To the west it ends with a raised edge, which takes various names (Serra de Chela, Serra de Numpaca, Serra de Hanha, Serra de Canganza, etc.) and descends more or less rapidly on a hilly coast. Recent eruptive rocks, mainly basalt, form a series of hills, almost bare of vegetation, between Benguella and Mossamedes. River erosion has affected the plateau wide and deep valleys, dividing it; and in some parts he shaped it in such a way as to give it the appearance of a mountainous region.
The raised edge of the plateau reaches its greatest heights in the central part, and is almost everywhere parallel to the coast. This is partly low and sandy, partly high, with good natural harbors (Bahia dos Tigres, Porto Alexandre, Loanda, Lobito, etc.), some of which are protected by sandy peninsulas, which the coastal currents have formed by accumulating the contributions solids discharged into the ocean from the main rivers (Cuanza, Cunene).
Cretaceous limestone and Neogenic soils with marine facies emerge in the coastal strip.
Going inland from the sea, there are therefore three areas in Angola: the coastal one, that of the greenhouses, and that of the plateau proper. This morphology is common to all of southern Africa.
The climate varies according to latitude and altitude. There are two seasons, the dry from June to September, the humid from October to the end of May; this is also the time of floods and hurricanes. On the coast, the climate is clearly tropical, there are never cold winters, the average annual temperature is 20 °; the region also feels the benefit of the cold Benguella current, which runs from the Cape of Good Hope to the Gulf of Guinea, and sometimes of the sea breeze that reaches the coastal cities and villages between the plateaus and the sea; but the dominant wind is that of the land, which carries the marshy miasmas of the marshes which are formed especially during the rainy season. On the highlands, the climate is temperate and frost is not uncommon during the winter. During the hot season, which corresponds to that of the rains, the maximum temperatures do not exceed 26 ° in the shade; in the night the temperature often drops to 5 °. The rainfall regime differs according to the regions. Precipitation decreases from N. to S., and with it the swamp fevers decrease. The areas adjacent to the Cunene river can be considered as dry and resemble the “veld” of southern Africa. From W to E. the rains, scarce above the coast, become more abundant proceeding inland, up to 1800 mm. annual. The plateaus in the dry season are healthy; once malaria and sleeping sickness have disappeared, the climate is excellent for Europeans, except for sudden changes in temperature between day and night. In the deep valleys elephantiasis is widespread among the natives.
On the great plateau of Benguella and Moxico, almost in the center of the region, the numerous rivers that radiate in every direction originate; they mostly belong to four large hydrographic basins: Congo, Cuanza, Cunene and Zambezi. The Congo, in its last lower stretch, marks for 160 km. the N. border of Angola; the largest steamers can go up it as far as Matadi. The Cuango, the Kwilu and the Cassai belong to the Congo basin, with their numerous tributaries, which all originate from the highlands north of the 11th parallel. Long stretches of border run along the Cuango and Cassai. The Cuanza basin is entirely included in the colony’s territory; the main river (950 km. long) has its sources in the plateau of Bihé, reaches the Atlantic just at S. di Loanda, and is accessible to small steams up to Dondo (150 km. route); the most important farms of the colony have settled on its banks. The Cunene, 1200 km long, crosses most of the healthy uplands of Benguella and Mossamedes; the mouth of the river, in S. della Bahia dos Tigres, is almost always blocked by sand banks. In the upper course the Cunene is abundant in water and in the rainy season it forms a vast lake at the confluence with its tributary Caculovar, near Humba; for 300 km. of its lower stretch marks part of the southern border of Angola. The Cubango, which originates in the Bihé plateau, runs towards the SE, belongs to the Zambezi basin. navigable in some places by indigenous boats; its major tributary is the Cuito; gets lost in the vast temporary swamps of Makarikari. Of the course of the Zambezi, Angola includes a stretch up to the Sapuna cataracts, and the two large right tributaries, the Cuando and the Lungue Bungo, which, like other tributaries of the Zambezi itself, cross in their lower course immense sandy plains where they form vast swamps. In the Atlantic, independent of the basins mentioned, rivers of relatively limited course flow: the Loje, which flows at 3 km. north of Ambriz; the Cuvo, which reaches the bay of Benguella Velha; the Catumbela, which flows into the Lobito bay, etc. The territory of Cabinda is crossed by the river Sciloango for about 120 km. These rivers, which pour directly into the Atlantic, slow down their course by entering the sandy coastal area and, if on the one hand they contribute to forming malarial areas.
