According to 800zipcodes, Ethiopia is a state of East Africa. It borders to the North with Eritrea, to the East with Somalia and the Republic of Djibouti, to the South with Kenya, to the West with South Sudan.
The country, typically mountainous, can be briefly divided into three major morphological regions: the Ethiopian Highlands proper, the Danakil and the Galla-Somali Plateau. The base of the entire region is formed by eruptive and metamorphic pre-paleozoic crystalline rocks. This rocky substratum appears to be dominated by arenaceous and calcareous marine deposits dating back to the beginning of the secondary era and by vast expansions of very fluid lava materials, originating from Cretaceous cracks and fractures, which, modeling themselves on the pre-existing tabular surfaces of the Acrocoro Ethiopian, they reached a thickness of about 3000 meters. The discontinuity of the morphological horizons was subsequently accentuated by new telluric disturbances at the beginning of the tertiary era, which produced the sinking and huge pits that characterize East Africa.
The vast morphological unit of the Ethiopian massif, which is well suited to the name of ‘fortress’, rises in the western part, N and W of the great tectonic groove identified by the trench of the galla lakes, the Awash valley, the Inner Danakil and the Red Sea. The average height remains between 2000 and 2500 m, with numerous peaks reaching altitudes of over 4000. The plateau has two distinctly asymmetrical slopes. The western one appears carved by real canyons carved by the rivers which, originating from the eastern edge, descend towards the low Sudanese lands, with a tortuous course dictated above all by tectonics. Despite the lively work of erosion, the individual edges of the acrocoro are always leveled at the top and descend with tiered slopes. The eastern side instead looms with an accentuated slope over the ditches of the Danakil. This is a roughly triangular region, closed towards the sea by a series of coastal mountains, mostly volcanic and of recent origin, and surrounded for the rest by the rigid escarpments of the two plateaus; in the internal section it is characterized by the presence of large rocky lowlands or invaded by sands, which are nothing more than endorheic basins in which the waters that descend from the plateaus are lost, such as those of the Awash, the largest of the Ethiopian rivers flowing towards Ethiopia The Galla-Somali Plateau is in turn well differentiated from the two previous morphological units. Its watershed ridge to the North and NW, while exceeding 4000 m of altitude, is not as clear as the eastern one of the Ethiopian Acrocoro, as it descends towards less depressed lands, such as the bottom of the trench of the lakes, which in some places reaches 2000 m in height. The Somali plateau then slopes gently SE towards the Somali plain, hiding under a thick blanket of more recent land; river valleys have a predominantly NW-SE direction, Genale Doria) and Uebi Scebeli.
In relation to the geographical position, the Ethiopian region is dominated by a climate that can be defined as tropical, albeit with different gradations and shades, largely due to altimetric and orographic factors. Two thermo-rainy seasons alternate: one less hot from October to March, with little rainfall, and the other warmer from April to September, with more rainfall. If the extension of the territory in latitude explains an average decrease in rainfall going from the equator towards the tropics, other natural factors, such as the altitude and the arrangement of the relief, intervene to determine the profound regional differences, both thermal and anemometric and pluviometric. The proximity of the immense Asian continental mass must also be taken into account, so in winter Ethiopia finds itself under the influence of the anticyclone to the NE, while the cyclonic zone of central Africa expands to the SW. The resulting atmospheric circulation affects the plateau in the NE-SW direction, which is not very humid, and the scarce rains only sprinkle the coasts and the escarpment of the plateau. In the month of July the situation is reversed and the equatorial winds, hot and humid, coming from both the SE and the SW, discharge their waters on the higher areas. In this way, different situations are created between the plateau and the peripheral areas: in the former, the annual average exceeds 1000 mm everywhere, with values that on the central reliefs and in the western areas also reach 1800 mm, while towards the E and SE the quantities decrease to the minimum values of the central Danakil (50 mm) and of the foot of the Somali Plateau. As for rainfall, also for temperatures, altitude plays a predominant role; therefore, between the lowlands and the highland regions there are significant average differences, of 8-14 ° C. Local tradition divides the country in altimetric bands with particular thermal and pluviometric conditions (qollà, uoina degà, urec) which are reflected on biological, human and economic life
The hydrographic network, decidedly conditioned by the morphological structure, has a typical radial trend: the country, in fact, sends its waters to the Mediterranean (via the Nile), the Indian Ocean and the Red Sea. There are also, as noted, extensive endorheic areas. The rainfall regime found in most of Ethiopia and the absolute lack of glaciers and snowfields explain the prevalent torrential nature of the waterways; the morphology of the acrocorus then determines its uneven development. Except those of the endorheic area, no river runs entirely in Ethiopian territory: therefore, the massif is a great dispenser of water resources to the drought bordering areas, both Somali and Sudanese. Among the rivers that send their waters to the Nile, the main ones, from north to south, are the Gash, the Atbara and the Blue Nile, main axis of the Ethiopian hydrographic network. The most important rivers on the Indian Ocean side are the Juba and the Uebi Scebeli. Among the waterways of the endorheic area, the Omo (called Omo Bottego in honor of its explorer), which leads into Lake Turkana, and the Awash stand out. Ethiopia is also rich in lakes. Alongside those of the Fossa Galla (Zuai ; Langana; Awasa ; Abaya, formerly Margherita; Ciamò, formerly Ruspoli; Stefania or Chew Bahir), we must remember the Tana, whose origin is due to a lava dam at the head of the Blue Nile valley.