Geology

From the higher to the lower locations, the following geological formations are present:^[1]

• Lower basalt
• Amba Aradam Formation
• Agula Shale^[2]
• Mekelle Dolerite^[3]
• Antalo Limestone
• Quaternary alluvium and freshwater tufa^[4]

Geomorphology and soils

The main geomorphic units, with corresponding soil types are:^[5]

• Hagere Selam Highlands, along the central basalt and sandstone ridge
  • Associated soil types
    • shallow soils with high stone contents (Skeletic Cambisol, Leptic Cambisol, Skeletic Regosol)
    • moderately deep dark stony clays with good natural fertility (Vertic Cambisol)
    • deep, dark cracking clays, temporarily waterlogged during the wet season (Pellic Vertisol)
  • Inclusions
    • Rock outcrops and very shallow soils (Lithic Leptosol)
    • Rock outcrops and very shallow soils on limestone (Calcaric Leptosol)
    • Deep dark cracking clays with very good natural fertility, waterlogged during the wet season (Chromic Vertisol, Pellic Vertisol)
    • Shallow stony dark loams on calcaric material (Calcaric Regosol, Calcaric Cambisol)
    • Brown loamy soils on basalt with good natural fertility (Luvisol)
• Gently rolling Antalo Limestone plateau, holding cliffs and valley bottoms on limestone
  • Associated soil types
    • shallow stony soils with a dark surface horizon overlying calcaric material (Calcaric Leptosol)
    • moderately deep dark stony clays with good natural fertility (Vertic Cambisol)
    • deep, dark cracking clays on calcaric material (Calcaric Vertisol, Calcic Vertisol)

• • Inclusions
    • Rock outcrops and very shallow soils (Lithic Leptosol)
    • Shallow very stony loamy soil on limestone (Skeletic Calcaric Cambisol)
    • Deep dark cracking clays with very good natural fertility, waterlogged during the wet season (Chromic Vertisol, Pellic Vertisol)
    • Brown to dark sands and silt loams on alluvium (Vertic Fluvisol, Eutric Fluvisol, Haplic Fluvisol)

Common soil types in Hech'i are Vertisol, Vertic Cambisol, Cumulic Regosol, Calcaric Regosol and Phaeozem.^[6] and, northeast of May Leiba Reservoir, “red-black” Skeletic Cambisol–Pellic Vertisol catenas on basalt and Calcaric Regosol–Colluvic Calcaric Cambisol–Calcaric Vertisol catenas on limestone.^[7]

Climate and hydrology

Vegetation and exclosures

The tabia holds several exclosures, areas that are set aside for regreening.^[14] Wood harvesting and livestock range are not allowed there. Besides effects on biodiversity,^[15][16][17] water infiltration, protection from flooding, sediment deposition,^[18] carbon sequestration,^[19] people commonly have economic benefits from these exclosures through grass harvesting, beekeeping and other non-timber forest products.^[20] The local inhabitants also consider it as “land set aside for future generations”.^[21] In this tabia, some exclosures are managed by the EthioTrees project. They have as an additional benefit that the villagers receive carbon credits for the sequestered CO₂,^[22] as part of a carbon offset programme.^[23] The revenues are then reinvested in the villages, according to the priorities of the communities;^[24] it may be for an additional class in the village school, a water pond, or conservation in the exclosures. The following exclosures are managed by the Ethiotrees project in the tabia:^[25]

• Gemgema, near the village of Tsigaba (95.47 ha)
• May Be'ati, near the homonymous village (45.42 ha)

Settlements

The tabia centre Halah holds a few administrative offices, a primary school, and some small shops. The largest settlement, actually a small town, is Ala'isa, where a market is organized on Thursdays. There is also a health post and several small restaurants and shops.^[11] There are a few more primary schools across the tabia. The main other populated places are:^[10]

History

The history of the tabia is strongly confounded with the history of Tembien.

One particularity is that, during warfare, a major access to Dogu'a Tembien is through the slopes east of Ala'isa town. The Derg army was defeated here by TPLF during a major battle of the 1980s civil war.

Religion and churches

Most inhabitants are Orthodox Christians. The following churches are located in the tabia:

Inda Siwa, the local beer houses

In the main villages, there are traditional beer houses (Inda Siwa), often in unique settings, where people socialise. Well known in the tabia are^[11]

• Tsadkan Kiros at Addi Qolqwal
• Letay Assefa at Halah
• Kiros Abadi at Ala'isa
• Birhan Haddush at Ala'isa

Legends and myths

The lapiez or surface karst at Inda Meru’e near Hechi is commonly interpreted as a petrified group of people on their way back from a marriage party and who had omitted to greet the church. There is also, near Hech’i a huge cubic rock, named Ilias’ rock which would have been rolled there for sake of church building.^[27]

Touristic attractions

• Viewpoints on Imba Ra'isot, Guyeha Ridge and Meri'a Ziban

Geotouristic sites

The high variability of geological formations and the rugged topography invite for geological and geographic tourism or "geotourism".^[32] Geosites in the tabia include:

Birdwatching

Birdwatching (for the species, see the main Dogu'a Tembien page) can be done particularly in exclosures and forests. The following bird-watching sites have been inventoried^[33] in the tabia and mapped. :^[10]

• Iyesus church forest
• Mika'el church forest in Ala’isa
• May Be'ati church forest

Trekking routes

Trekking routes have been established in this tabia.^[34] The tracks are not marked on the ground but can be followed using downloaded .GPX files.^[35]

• Trek 12, from Rubaksa, along several geosites to Hechi and Addi Qolqwal
• Trek 13, from Mizane Birhan through Tsigaba and May Be'ati to Addi Qolqwal and Meri'a Ziban on the main road
• Trek 14, along the ridges on the highest places in the tabia
• Trek 26, from Ala'isa to the Ekli Imba peak in Arebay