Everis Aeroespacial y Defensa S.L.U. (ES)
EO Clinic support requested by: Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) Ethiopia Office
Requesting activity: Strengthening Drought Resilience in Arid and Semi-Arid Lands (SDR-ASAL)
Requesting activity type: Technical Assistance (TA)
EO Clinic relevant Thematic Groups: TG1 (Agriculture), TG2 (Climate Change), TG8 (Transport), TG9 (Urban), TG10 (Water Resources Management), TG11 (Non-EO Information and Analytics)
Work Order number: EOC0012
Work Order status: Completed
Work Order start: 2020 Sep 25
Work Order end: 2021 Jan 15
Over 7 million people live in the Afar and Somali Regions in Ethiopia. Most of them are pastoralists and agro-pastoralists who depend on semi-mobile livestock for their livelihoods. Currently their economic and social systems are under pressure due to population growth and the impact of climate change (increasing frequency and severity of droughts and floods). GIZ has a programme in place, called the Strengthening drought resilience (SDR) programme to help facing this situation. Furthermore, GIZ in collaboration with the Ethiopian Ministry of Agriculture, Livestock and Natural Resources, has developed the “Strengthening Drought Resilience in Arid and Semi-Arid lands” (SDR-ASAL) program. The objective of this programme is to develop a holistic approach for land rehabilitation in this area. One of the main aspects of SDR-ASAL is to rehabilitate degraded water catchments and pasture areas in dry valleys. In this initiative, state and non-state actors together with pastoral and agro-pastoral communities have created the conceptual foundations for the rehabilitation and use of dry valleys and their productive use. Some measures that can be developed are for example simple dry-stone and the construction of weirs to reduce the speed of runoff water and to retain eroded soil in the river channel. The objective is to build water spreading weirs/cascades in suitable locations (dry valleys) to control flash floods from the highlands and direct some of the precious water to low-lying plains where it can be stored in the soil. This will allow reintroducing agricultural practices. In addition, groundwater aquifers can be fed rather than letting the water rush through the valley unused. This technique was developed in the 1990s and tested very successfully in various countries in western Africa. It is now introduced in the Ethiopian lowlands starting 2014 and ever since has been further adjusted to the local conditions. There is a huge potential in the Ethiopian lowlands to improve rural development and the livelihood systems by this type of rehabilitation of degraded watersheds.
The overall purpose of the present EO Clinic activation is to support GIZ Ethiopia and its partners in the site selection process (site identification and delineation) for future weir construction project activities using EO data, i.e. to conduct a site suitability analysis.
“In order to identify the most suitable project sites dry valleys for their project, GIZ Ethiopia created a catalogue of site selection criteria called “Cascade Suitability Matrix – GIZ SDR”. This catalogue includes physical, biological and social location factors that are combined to identify most suitable areas for project implementation. Examples are physical aspects (sufficient stones and sand available for construction, closest permanent water point, road access), biological aspects (predominant soil type, signs of cultivation), social aspects (proximity of marketplace, presence and maintenance of enclosures, proximity of the next hamlet/village, number of hamlets/villages in this area).
In the absence of data on dry streambeds, it is expected that the Contractor develops a limited AoI within the AFAR region by performing a hydrological analysis on an available DEM to identify likely stream beds. The AoI should exclude permanent streams (i.e. streams of the greatest Strahler value). The Contractor shall perform the above analysis and present/discuss the result, a suitable AoI consisting of a buffer region around likely dry stream beds to the stakeholders prior to the main site suitability analysis. The buffer shall be chosen keeping in mind the distances mentioned in the Cascade Suitability Matrix.
It is acknowledged that not all factors defined in the Cascade Suitability Matrix (physical, biological and social) can be mapped with EO. The Contractor shall identify which factors can be characterised from space, and select satellite imagery with resolutions suitable for the detection of the features described in the matrix (e.g. villages). No general minimum mapping unit or resolution are defined, as these will depend on the solution provided by the Contractor.
Based on EO information, a scoring matrix shall be completed. The data will be used to identify most promising/suitable new project sites for the effective and sustainable rehabilitation and use of degraded land in dry valleys of the Ethiopian lowlands. The most suitable sites will be evaluated for future projects.