Disclaimer: This is just the start of a diary article, details about mapping objectives, progress and obstacles/questions will follow

Description of the area

The Ndomba Sector (Collectivé de Ndomba) is the easternmost sector of the Kabeya-Kamuanga Territory. While the eastern and southern borders of the sector are as well the borders of the territory (which have already been mapped for years), the western border of the sector is the River Lubi.

Roads and paths

This sector is still very remote, despite of the fact that the big City of Mbuji-Mayi and the highway Route National 1 (RN1) are close by in the south-east and south. The main reason for the remoteness is that a number of meandering rivers hinder or limit the asccess from almost all directions. The main access road from the south and from Mbuji-Mayi has been the one which leaves RN1 at 6° 06 28.3 N / 23° 26 03`` E just west of the village of Tschibombo - only 20 kilometers west of Mbuji-Mayi. This road follows the border of the watersheds of the river Mulenda (east) and of the rivers Lubi and Kagangayi (west). This way the crossing of rivers and streams is avoided for most of the distance.

I have been an active OSM mapper (and contributor to some HOT task mapping projects in different countries ) since 2013, mainly mapping based on satellite imagery. My main focus has been on Ethiopia, North Korea and DR Kongo.

At the moment (from March 2025 on) I try to map waterways and watersheds of the Ethiopian tributaries of the Blue Nile (called አባይ = ābayi/Abbay/Abbai in Amharic). A lot of theses waterways and the areas around them have been very poorly mapped yet. I have started with the river which is called Rahad (نهر الرهد) in Arabic and Shinfa (ሽንፋ ወንዝ) in Amharic.

The rivers in the Ethiopian highlands are of crucial importance for the cultivation of the land and the settlement structure - in a way which is unusual and often uknown for European people: The settlements are usually on top of the mountains (using the rain at the main water source) between the rivers, not at the rivers. A lot of the rivers and their ravines are blocking travelling and transport, not supporting it.

River Shinfa (ሽንፋ ወንዝ / نهر الرهد)

Relation of the main course of the river

Detailed Mapping Finished based on Esri Imagery
Downstream
River Shinfa - right tributary A
* about 10m wide at confluence, clear/dark water, meandering (SI = 1.84)
* so far mapped length 7.60 Km - E to W
* from 12°03’21.0’‘N 36°37’51.5’’ E to 12°03’54.6’‘N 36°35’39.0’’ E
* height: 1225 m to 1080 m (19.08 ‰ botton slope)

River Shinfa Section 1
* up to 30 m wide, ravines, light brown water, twisting (SI= 1.436)
* length 7.18 Km - SE to NW
* from 12°03’54.6’‘N 36°35’39.0’’ E to 12°05’33.5’‘N 36°33’28.1’’ E
* height: 1080m to 1000 m (11.14 ‰ botton slope)

River Shinfa - right tributary B
* 35m wide and more at confluence, light brown water, twisting (SI = 1.504)
* so far mapped length 21.39 Km - NE to SW
* from 12°08’39.8’‘N 36°40’37.9’’ E to 12°05’33.5’‘N 36°33’28.1’’ E
* height: 1200 m to 1000 m (9.35 ‰ botton slope)

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