Application of GIS Techniques in Flood Extent Mapping and Management on Matebele Flood Plain in Shangombo District, Zambia

Morris Kambeu Manyika; Kabwe Mubanga

doi:10.53974/unza.jonas.7.1.1239

Morris Kambeu Manyika University of Zambia
Kabwe Mubanga

DOI: https://doi.org/10.53974/unza.jonas.7.1.1239

Keywords: Floods, GIS, flood extent mapping, Synthetic Aperture Radar, Land Use/Land Cover

Abstract

Floods are among the world’s most devastating hazards, negatively affecting ecological (provisional and regulatory services) and socioeconomic systems (loss of lives, property, and financial costs). Application of GIS techniques in flood mapping is increasingly becoming significant to establish extents and effects of floods. This study focused on establishing the spatial extents and trends in the flooding events on Matebele Plain in Shangombo District of Zambia using GIS techniques. Using stratified and simple random sampling, a descriptive research design was adopted to collect data through interviews with 173 respondents. Primary data was sourced using questionnaires on 160 respondents and interview guides on 13 key informants. Synthetic Aperture Radar (SAR) images in the C-band or C-SAR, integrated with supporting satellite data were used. Interview data was analyzed thematically with simple statistics, while satellite images were processed using ArcGIS 10.3 software and Sentinel Application Platform (SNAP). Results indicated that the maximum aerial coverage of floods was recorded in 2018, covering an area of 16,441 km2, representing 78% of the total area. A hypothetical analysis of the trends in time series using the Regression statistical analysis gave (p-0.001), with r2 of 70% indicating significant geospatial variations in the aerial coverage of floods from 2008 to 2018. A thematic analysis of the responses on effects of floods on land use activities gave a positive response rate of 97%. The general conclusion was that flooding on Matabele Plain has geospatial variations in extents. Further research on impacts of floods on specific land uses is highly recommended.

References

Arnesen, A. S., Silva, T. S. F., Hess, L. L., Novo, E. M. L. M., Rudorff, C. M., Chapman, B. D., & McDonald, K. C. (2013). Monitoring flood extent in the lower Amazon River floodplain using ALOS/PALSAR ScanSAR images. Remote Sensing of Environment, 130, 51–61. https://doi.org/10.1016/j.rse.2012.10.035.

Aronoff, (1995) Geographic Information Systems: A Management Perspective; WDL Publications Ottawa, Canada.

Chapman, J. B., and Canaan, W. D. 2001. Flood Maps are Key to Better Flood Damage Control. CE News, March 2001, 58–60.

Di Baldassarre, G., Schumann, G., Brandimarte, L. and Bates, P. (2011) Timely Low Resolution SAR Imagery to Support Floodplain Modelling: a Case Study Review. Surveys in Geophysics 32, 255–269 (2011). https://doi.org/10.1007/s10712-011-9111-9.

DMSG (2001), The Use of Earth Observing Satellites for Hazard Support; Assessments and Scenarios. Committee on Earth Observation Satellites Disaster Management Support Group, Final Report, NOAA, Dept. Commerce, USA.

Gibson (2000), Introductory Remote Sensing Principles and Concepts, Routledge, London.
Marshall, C. (1989). Designing qualitative research. Newbury Park, CA. Sage Publications.
Phiri, L. (2021), Residential flooding in Zambia from Remote Sensing and Geospatial Analysis perspective: A preliminary case study for Chawama Constituency floods in Lusaka City. Copperbelt University. Kitwe, Zambia.
Townsend, P. A., and Walsh, S. J. (1998). Modeling floodplain inundation using an integrated GIS with radar and optical remote sensing. Geomorphology, 21(3),295-312. https://doi.org/10.1016/S0169-555X(97)00069-X.

Wang, Y., Colby, J. D. and Mulcahy, K. A. (2002). An efficient method for mapping flood extent in a coastal floodplain using Landsat TM and DEM data. International Journal of Remote Sensing, 23(18), pp. 3681–3696. https://doi.org/10.1080/01431160110114484.

Zambia Vulnerability Assessment Committee (2009) Shangombo District Rapid Flood Impact Assessment Report. Zambia Vulnerability Assessment Committee, Lusaka. Zambia.

Zimba, H. (2017). Earth Observation-Based Assessment of Spatial and Temporal Trends in Inundation Extent in the Barotse Wetland, Western Zambia. University of Zambia. Lusaka. Zambia.