Rooftop Rainwater Harvesting for Mombasa

Scenario Development with Image Classification and Water Resources Simulation

authored by

Robert O. Ojwang, Jörg Dietrich, Prajna Kasargodu Anebagilu, Matthias Beyer, Franz Rottensteiner

Abstract

Mombasa faces severe water scarcity problems. The existing supply is unable to satisfy the demand. This article demonstrates the combination of satellite image analysis and modelling as tools for the development of an urban rainwater harvesting policy. For developing a sustainable remedy policy, rooftop rainwater harvesting (RRWH) strategies were implemented into the water supply and demand model WEAP (Water Evaluation and Planning System). Roof areas were detected using supervised image classification. Future population growth, improved living standards, and climate change predictions until 2035 were combined with four management strategies. Image classification techniques were able to detect roof areas with acceptable accuracy. The simulated annual yield of RRWH ranged from 2.3 to 23 million cubic meters (MCM) depending on the extent of the roof area. Apart from potential RRWH, additional sources of water are required for full demand coverage.

Organisation(s)

Institute of Hydrology and Water Resources Management
Institute of Photogrammetry and GeoInformation (IPI)

External Organisation(s)

CoastWater Services Board (CWSB)
Federal Institute for Geosciences and Natural Resources (BGR)

Type

Article

Journal

Water (Switzerland)

Volume

9

No. of pages

19

ISSN

2073-4441

Publication date

20.05.2017

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Biochemistry, Geography, Planning and Development, Aquatic Science, Water Science and Technology

Sustainable Development Goals

SDG 6 - Clean Water and Sanitation, SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.3390/w9050359 (Access: Open)