Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology
Abstract
:1. Introduction
- To systematically harness open-access remotely-sensed and readily available geospatial data to improve catchment-scale flood modelling.
- To explore the use of freely available aerial photos for flood model validation in vegetation-dominant regions in comparison to synthetic aperture radar (SAR).
- To quantify the magnitude and impact of the devastating 2012 flood in Nigeria.
Study Area
2. Materials and Methods
2.1. Methodological Framework
2.2. Datasets
2.2.1. River Discharge and Flood Frequency Estimates
2.2.2. Modified Shuttle Radar Topography Mission (SRTM) DEM
2.2.3. River Bathymetry
2.2.4. Moderate Resolution Imaging Spectroradiometer (MODIS) Water Product (MWP)
2.2.5. Synthetic Aperture Radar (SAR)
2.2.6. Ice, Cloud, and Land Elevation Satellite (ICESat)/Geoscience Laser Altimeter System (GLAS) spot height
2.2.7. Manning’s Roughness
2.2.8. Aerial Photos
2.2.9. Data for Flood Impact Evaluation
2.3. Caesar-Lisflood (CL) Hydrodynamic Model Description and Setup
2.4. Model Calibration and Validation
3. Results and Discussion
3.1. Integration of Open-Access Remote Sensing and Geospatial Data for Catchment-Scale Flood Modelling
3.2. Flood Model Re-Validation in Vegetation-Dominant Region Using Freely Available Aerial Photos and SAR
3.3. Quantifying the Magnitude and Impact of the 2012 Flood in Nigeria
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Dates [YYYY-MM-DD] | Images and Availability | Baro (m3/s) | Return Period (1-in-year) | Umaisha (m3/s) | Return Period (1-in-year) | |||
---|---|---|---|---|---|---|---|---|
TSX | MDS | R2 | CSKD | |||||
2012-09-03 | × | √ | √ | × | 5187 | 2 | 12,303 | 2 |
2012-09-25 | √ | √ | × | × | 8533 | 50 | 20,328 | 100 |
2012-10-09 | × | √ | √ | × | 6969 | 5 | 17,378 | 50 |
2012-10-11 | × | √ | √ | × | 6696 | 5 | 16,771 | 20 |
2012-10-12 | × | √ | √ | × | 6504 | 5 | 16,520 | 20 |
2012-11-06 | × | √ | √ | √ | 3270 | 2 | 7955 | 2 |
Spatial Data | Data Source | Sub-Domains | ||
---|---|---|---|---|
Lokoja | Onitsha | Niger Delta | ||
MODIS Water Product | Nigro [45]; NASA [58] | √ | √ | × |
SAR: TerraSAR-X | ICSD | √ | × | × |
SAR: Radarsat-2 | Ekeu-wei [39]; SPDC | × | × | √ |
SAR: Cosmo-SkyMed | Ekeu-wei [39]; SPDC | × | × | √ |
Aerial photos | Ekeu-wei [39]; SPDC | × | × | √ |
River Bathymetry | Royal Haskoning; Digital Horizon | √ | √ | × |
ICESat | O’Loughlin et al., [42] | √ | √ | √ |
Modified SRTM DEM | O’Loughlin et al. [40], Sampson et al. [41] | √ | √ | √ |
Performance | Overall | Lokoja | Onitsha | Niger Delta |
---|---|---|---|---|
F | 0.235 | 0.729 | 0.534 | 0.095 |
Bias | 4.245 | 1.183 | 1.140 | 9.661 |
% Flood Capture | 99.972 | 92.012 | 74.545 | 92.186 |
Performance | Overall | Lokoja | Onitsha | Niger Delta |
---|---|---|---|---|
F | 0.273 | 0.808 | 0.529 | 0.187 |
Bias | 2.511 | 0.918 | 1.132 | 3.432 |
% Flood Capture | 75.308 | 85.679 | 73.802 | 69.946 |
Points of Focus | Data Points (n = 287) | Hits | Miss | % Accuracy |
---|---|---|---|---|
A | Aerial photo and model flooded | 196 | 91 | 69 |
B | Aerial photo and SAR flooded | 37 | 250 | 13 |
C | Aerial photo, model and SAR flooded | 43 | 244 | 15 |
D | The aerial photo only flooded | 62 | - | - |
Flood | Area (km2) | Population | Built-up (km2) | Roads (km) |
---|---|---|---|---|
2012 Model | 425.8 | 32,703 | 12.648 | 34.573 |
1-in-100 year Modelled | 427.2 | 32,867 | 12.834 | 32.987 |
2012 Observed (Satellite) | 440.2 | 34,391 | 12.326 | 37.287 |
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Ekeu-wei, I.T.; Blackburn, G.A. Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology. ISPRS Int. J. Geo-Inf. 2020, 9, 512. https://doi.org/10.3390/ijgi9090512
Ekeu-wei IT, Blackburn GA. Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology. ISPRS International Journal of Geo-Information. 2020; 9(9):512. https://doi.org/10.3390/ijgi9090512
Chicago/Turabian StyleEkeu-wei, Iguniwari Thomas, and George Alan Blackburn. 2020. "Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology" ISPRS International Journal of Geo-Information 9, no. 9: 512. https://doi.org/10.3390/ijgi9090512
APA StyleEkeu-wei, I. T., & Blackburn, G. A. (2020). Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology. ISPRS International Journal of Geo-Information, 9(9), 512. https://doi.org/10.3390/ijgi9090512