Abstract:
The management of water resources in the study area is a complex issue due to limited data,
rapid population growth, dryness and complex physiographic environment. Rainwater harvesting
systems (RWH) are a prominent solution to deal with water scarcity by conserving available
water resources and the energy needed to deliver water to the water supply systems. The impact
of climate change on water resources can be reduced by rainwater harvest is essential to
sustainable water management. The identification of suitable sites for RWH is an important step
to maximize the water availability, land productivity, and groundwater conservation in semi -arid
areas. This study aims to select the optimum sites for different indigenous RWH systems in
Gondar Zuria district using Geographic Information Systems (GIS), Remote Sensing (RS) and
Multi-criteria Analysis (MCA). The selection criterion in this study is based on biophysical
factors as well as socio-economic parameters. These criteria were identified based on literature
review and by participating local experts in evaluating the importance of each criterion. The
consistency ratio between the experts‘ opinions was evaluated using the pair wise comparison
method and a final weight was computed for each criterion. Four RWH systems namely,
Terraces, Check-dams, Farm ponds and Spate irrigation are selected. Each RWH system is
analyzed separately and the suitability map has been done. The Weighted Linear Combination
(WLC) technique was applied in combination of the Boolean technique to generate the final
suitability maps for RWH systems in Gondar Zuria district. The results of the suitability maps
indicated that a sufficient area of moderate and high suitability is existed in the study area for the
RWH systems, particularly very low suitability, low suitability, moderate suitability, high
suitability and very high suitability are 188.24km
2
(14%),649.62km
2
(48%),227.64km
2
(17%),277.05km
2
(20%) and 16.46km
2
(1%) respectively. Finally, the results of the sensitivity
analysis revealed that developing the suitability maps for potential RWH using relative weights
and AHP excel model over analysis are more accurate. Furthermore, it is noticeable from the
sensitivity analysis that the rainfall layer is the most sensitive layer among others and
inaccuracies in this layer can lead to errors in the identification of the RWH suitable sites.
Key words: - Rainwater harvesting, GIS, RS, Gondar Zuria woreda, Water scarcity