Tsaliet

File:Tinsehe waterfall 2.jpg]]

It is mostly a confined river, locally meandering in its narrow alluvial plain, with an average slope gradient of 25 metres per kilometre. With its tributaries, the river has cut deep gorges. Along the middle of its course, it occupies sandy pediments in Addeha.{{cite book |last1=Amanuel Zenebe |first1=and colleagues |title= The Giba, Tanqwa and Tsaliet rivers in the headwaters of the Tekezze basin. In: Geo-trekking in Ethiopia's Tropical Mountains - The Dogu'a Tembien District |date=2019 |publisher=SpringerNature |isbn=978-3-030-04954-6 |doi=10.1007/978-3-030-04955-3_14 |s2cid=199099067 }}

Runoff mostly happens in the form of high runoff discharge events that occur in a very short period (called flash floods). These are related to the steep topography, often little vegetation cover and intense convective rainfall. The peaks of such flash floods have often a 50 to 100 times larger discharge than the preceding baseflow.

The magnitude of floods in this river has however been decreased due to interventions in its upper catchment, particularly around the May Leiba reservoir. Physical conservation structures such as stone bunds{{cite journal |last1= Nyssen|first1= Jan|last2= Poesen|first2= Jean|last3= Gebremichael|first3= Desta|last4= Vancampenhout|first4= Karen|last5= d'Aes|first5= Margo|last6= Yihdego|first6= Gebremedhin|last7= Govers|first7= Gerard|last8= Leirs|first8= Herwig|last9= Moeyersons|first9= Jan|last10= Naudts|first10= Jozef|last11= Haregeweyn|first11= Nigussie|last12= Haile|first12= Mitiku|last13= Deckers|first13= Jozef|title= Interdisciplinary on-site evaluation of stone bunds to control soil erosion on cropland in Northern Ethiopia. |journal= Soil and Tillage Research |date=2007 |volume=94 |issue=1 |pages=151–163 |doi= 10.1016/j.still.2006.07.011|hdl= 1854/LU-378900|url= https://biblio.ugent.be/publication/378900|hdl-access= free}}{{cite journal |last1= Gebeyehu Taye and colleagues| title= Evolution of the effectiveness of stone bunds and trenches in reducing runoff and soil loss in the semi-arid Ethiopian highlands. |journal= Zeitschrift für Geomorphologie|date=2015 |volume=59 |issue=4 |pages=477–493 |doi= 10.1127/zfg/2015/0166| bibcode= 2015ZGm....59..477T }} and check dams intercept runoff.{{cite journal |last1= Nyssen|first1= J.|last2= Veyret-Picot|first2= M.|last3= Poesen|first3= J.|last4= Moeyersons|first4= J.|last5= Haile|first5= Mitiku|last6= Deckers|first6= J.|last7= Govers|first7= G.|title= The effectiveness of loose rock check dams for gully control in Tigray, Northern Ethiopia. |journal= Soil Use and Management |date=2004 |volume=20 |pages=55–64 |doi= 10.1111/j.1475-2743.2004.tb00337.x|s2cid= 98547102}}{{cite journal |last1= Etefa Guyassa and colleagues|title= Effects of check dams on runoff characteristics along gully reaches, the case of Northern Ethiopia. |journal= Journal of Hydrology |date=2017 |volume=545 |issue=1 |pages=299–309 |doi= 10.1016/j.jhydrol.2016.12.019|bibcode= 2017JHyd..545..299G |url= https://biblio.ugent.be/publication/8518957 |hdl= 1854/LU-8518957 |hdl-access= free }} On many steep slopes, exclosures have been established; the dense vegetation largely contributes to enhanced infiltration, less flooding and better baseflow.{{cite journal |last1= Descheemaeker|first1= K. and colleagues| title= Runoff on slopes with restoring vegetation: A case study from the Tigray highlands, Ethiopia. |journal= Journal of Hydrology |date=2006 |volume=331 |issue=1–2 |pages=219–241 |doi= 10.1016/j.still.2006.07.011|url= https://biblio.ugent.be/publication/378900|hdl= 1854/LU-378900 |hdl-access= free }} Examples are the Khunale exclosure and the Harehuwa exclosure.

File:Tsaliet in Addeha's irrigation scheme.jpg

File:Ruba Weyni irrigation.jpg irrigation scheme]]

Besides springs and reservoirs, irrigation is strongly dependent on the river's baseflow. Such irrigated agriculture is important in meeting the demands for food security and poverty reduction. Irrigated lands are established in the narrow alluvial plains along the river in:

• large lowland irrigation schemes with tropical fruits in Addeha
• spring-based irrigation in Ruba Weyni

The valley bottoms in the gorges of this river have been identified as transhumance destination zones. Transhumance takes place in the summer rainy season, when the lands near the villages are occupied by crops. Young shepherds will take the village cattle down to the gorge and overnight in small caves. The gorges are particularly attractive as a transhumance destination zone, because there is water and good growth of semi-natural vegetation.{{cite journal |title=Transhumance in the Tigray highlands (Ethiopia) |journal=Mountain Research and Development |date=2009 |volume=29 |issue=3 |pages=255–264 |doi=10.1659/mrd.00033 |last1=Nyssen |first1=Jan |last2=Descheemaeker |first2=Katrien |last3=Zenebe |first3=Amanuel |last4=Poesen |first4=Jean |last5=Deckers |first5=Jozef |last6=Haile |first6=Mitiku |doi-access=free |hdl=1854/LU-854326 |hdl-access=free }}

The Tsaliet Group, an older sequence of metamorphic rock is named after the Tsaliet River.{{cite book |last1=Sembroni |first1=A. |last2=Molin |first2=P. |last3=Dramis |first3=F. |title=Regional geology of the Dogu'a Tembien massif. In: Geo-trekking in Ethiopia's Tropical Mountains — The Dogu'a Tembien District |date=2019 |publisher=SpringerNature |isbn=978-3-030-04954-6 |url=https://www.springer.com/gp/book/9783030049546}} Based on crystallisation ages of its rocks in Eritrea and Ethiopia, it is estimated that the igneous activity occurred between ~850 and 740 million years ago. The Tsaliet Group has recorded the arc volcanism and the formation of crust that later formed part of the Arabian-Nubian Shield.{{Citation |last=Abbate |first=Ernesto |title=Geology of Ethiopia: A Review and Geomorphological Perspectives |date=2015 |url=https://doi.org/10.1007/978-94-017-8026-1_2 |work=Landscapes and Landforms of Ethiopia |pages=33–64 |editor-last=Billi |editor-first=Paolo |access-date=2023-10-13 |series=World Geomorphological Landscapes |place=Dordrecht |publisher=Springer Netherlands |language=en |doi=10.1007/978-94-017-8026-1_2 |isbn=978-94-017-8026-1 |last2=Bruni |first2=Piero |last3=Sagri |first3=Mario}} The Group consists of partially metamorphosed volcanic and sedimentary rocks (impure marble, slate, calcareous siltstone, sericite-chlorite schist, greywacke, and tuff), with a minimum thickness between 1500 and 2500 metres.Tefera, M., Chernet, T., Haro, W., 1996. Geological Map of Ethiopia (1:2,000,000). Ethiopian Institute of Geological Survey. Addis Ababa, Ethiopia

File:Tsaliet River near Addeha.jpg

From upstream to downstream, the following lithological units occur in the catchment.

• Phonolite plugs
• Upper basalt
• Interbedded lacustrine deposits
• Lower basalt
• Amba Aradam Formation

File:Tinsehe waterfall.jpg bank]]

• Antalo Limestone
• Quaternary freshwater tufa{{cite journal |last1=Moeyersons |first1=J. and colleagues |title=Age and backfill/overfill stratigraphy of two tufa dams, Tigray Highlands, Ethiopia: Evidence for Late Pleistocene and Holocene wet conditions. |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=2006 |volume=230 |issue=1–2 |pages=162–178 |bibcode=2006PPP...230..165M |doi=10.1016/j.palaeo.2005.07.013 }}
• Adigrat Sandstone
• Edaga Arbi Glacials
• Tsaliet metamorphic rock

Logically, in the uppermost stretches of the river, only the pebbles and boulders of the upper lithological units will be present in the river bed, whereas more downstream one may find a more comprehensive mix of all lithologies crossed by the river.

File:Tsaliet down from Dabba Selama.jpg

During its course, this river passes through two woredas and constitutes their boundary over some six kilometres. On the various parts:

• Dogu’a Tembien to the southeast
• Kola Tembien to the northwest

Trekking routes have been established across and along this river.{{cite book |title=Description of trekking routes in Dogu'a Tembien. In: Geo-trekking in Ethiopia's Tropical Mountains - The Dogu'a Tembien District |date=2019 |publisher=SpringerNature |isbn=978-3-030-04954-6 |url=https://www.springer.com/gp/book/9783030049546}} The tracks are not marked on the ground but can be followed using downloaded .GPX files.{{cite web|url=https://www.openstreetmap.org/traces/tag/nyssen-jacob-frankl |title=Public GPS Traces tagged with nyssen-jacob-frankl |publisher=OpenStreetMap |date=2018-12-27 |accessdate=2022-05-05}}

• Trek 3 follows the river course
• Trek 21 runs at half height on the flanks of the Tsaliet gorge in Haddinnet
• Treks 23 and 26 round the upper catchment

In the rainy season, flash floods may occur and it is advised not to follow the river bed. At times it may be impossible to cross the river in the rainy season.{{cite book |chapter=Logistics for the Trekker in a Rural Mountain District of Northern Ethiopia|date=2019 |publisher=Springer-Nature |pages=537–556 |doi=10.1007/978-3-030-04955-3_37 |title=Geo-trekking in Ethiopia's Tropical Mountains |series=GeoGuide |last1=Nyssen |first1=Jan |isbn=978-3-030-04954-6 |s2cid=199198251 }}

• List of Ethiopian rivers

{{reflist}}

Category:Rivers of Ethiopia

Category:Dogu'a Tembien

Category:Tigray Region

Category:Nile basin