Evaluation of Agriculture Development Projects status in Lake Tana Sub-basin applying Remote Sensing Technique

Abstract

This study aims at the evaluation of water resources use in Lake Tana sub-basin based on the status of eight development projects that are planned to be executed in this region. Remote sensing and satellite imaging have been used in addition to their product applications. This is vital due to its hydrological significance and direct impact on Egyptian water resources. The Normalized Difference Vegetation Index (NDVI) has been calculated, for the year 2017, to recognize the agriculture land use and land cover. Then, by integration with the potential agriculture projects basic data, such as water consumption and crop pattern, water resources use in the basin was evaluated and quantified. The analysis performed in this study showed the following: the Koga project was the only implemented project from the proposed eight irrigation and drainage projects; the Megech and SouthWest (SW) Tana projects are still under construction. The density of the vegetation cover varies yearly from 75% to 100% in the Gumera project, whereas it did not exceed 40% in the NorthEast and NorthWest Tana projects. It varies from 15% to 100% in the Megech, Ribb, SouthWest Tana, and Gilgel Abbay projects. Projects' calculated NDVI coverages reflect the behavior of the local community in cultivation depending on rainfall (green water), or by direct extraction from rivers as supplementary irrigation (Blue Water). This behavior may be based on their own interests and uses, not based on planning or investment, except for the Koga project. The water consumption from those projects is estimated at about 933 million m 3 /year.

Groundwater Modeling to Assess Climate Change Impacts and Sustainability in the Tana Basin, Upper Blue Nile, Ethiopia

“…As we reduce the withdrawals by 50%, about 0.63 km 3 /yr of water could be allocated in the late-century period (2081-2100) from hydropower to agricultural needs. If a critical circumstance arises (e.g., CSIRO-Mk3 RCPs 4.5 or 8.5), this could feed a significant portion of projected agricultural water requirements of 0.93 km 3 in the area [64]. This scenario would, however, compromise direct withdrawal (W), accounting for the hydropower requirements of the Tana Beles project, leading towards a more manageable problem.…”