In a bid to address the devastating effects of the recent flooding in Mokwa, Niger State, Nigerian geospatial firm Geoinfotech Resources Ltd deployed cutting-edge drone and GIS technology to trace the root cause, assess the damage, and propose lasting solutions.
The field operation, carried out between June 12 and 14, was a multi-agency technical response aimed at bringing clarity to the incident that claimed lives, displaced residents, and destroyed properties in the Mokwa area.
A Rapid Response From Air and Ground
Geoinfotech’s team
- Mr. Temitope Makinde, Drone Pilot and GIS Expert, from Lagos
- Mr. Olugbenga Ebenezer B., Remote Sensing and GIS Analyst, from Abuja
- Mr. Michael, Company Videographer, from Lagos
took up the task and volunteered from its Lagos and Abuja offices. A day before the team arrived, the company’s DJI Matrice 4T drone was transported to Minna, the capital of Niger State, ahead of the main crew. On June 13, the team converged at Minna Airport:
The Lagos team arrived around 10:00 a.m., collected the drone equipment, and awaited the Abuja team’s arrival at 2:45 p.m. By 3:00 p.m., the full crew began the 4 hour 45 minute drive to Mokwa. Despite poor road conditions, they arrived safely at 7:45 p.m., appreciating their skilled driver for the successful journey.
Early Terrain Analysis and Planning
Upon lodging, Mr. Ebenezer immediately began GIS terrain analysis using satellite-based Digital Elevation Models (DEMs) and ArcGIS Pro. His findings revealed that Mokwa lies within a shallow valley, and just north of the town flows a river drainage channel—a likely contributor to the flood event.
Further verification came from UNOSAT flood extent data, which captured satellite imagery of Mokwa during the flooding. This analysis helped the team delineate an initial 600-hectare zone for the drone survey.
Drone Mission: Mapping the Disaster
On the morning of June 13, the team moved to the flood-affected area for ground verification and damage assessment. However, real-time inspection revealed the actual impact zone to be around 345 hectares, prompting Mr. Makinde to adjust the drone flight plan accordingly.
Using the DJI Matrice 4T, the team programmed a mission with appropriate front and side overlaps, covering the area at 200 meters altitude. The flight spanned 47 minutes across three battery cycles. Each battery delivered 18 minutes of flight time, and the mission was executed in three batches.
During pre-flight checks, the team was approached by officials from the National Emergency Management Agency (NEMA). They confirmed that the incident was a flash flood, caused by water overflow from a local irrigation dam, and encouraged the team’s effort, stressing the need for cooperation with state authorities.
Community Voices and Eyewitness Accounts
After the aerial survey, the team conducted community interviews, particularly with victims of the flood.
Questioning the flood victims:
- Source of the flood
- Height of the flood
- Time of the flood
- Direction of the water
In conclusion, according to locals, no visible waterway previously passed through the affected area.
However, two days of heavy rainfall prior to the event, caused water to accumulate at the base of the railway track, located 5 to 6 meters high to the north of Mokwa. On the morning of May 29–30, more rainfall led to a catastrophic overflow, breaching the railway base and releasing torrents of water into the community. The flood lasted for two hours, beginning around 6:00 a.m., with water starting to recede by 4:00 p.m. the same day. Locals reported flood water heights of up to 4 meters, confirming the flash flood’s intensity.
The team also noted that the clay-loamy soil of the area hindered water infiltration, causing rapid accumulation and discharge during heavy rains.
Technical Findings from Drone and GIS Analysis
The drone captured high-resolution orthophotos and elevation data used to create a Digital Terrain Model (DTM) of Mokwa. GIS processing showed that:
- Flood-impacted elevations ranged between 154–159 meters,
- While the source elevation of the flood was between 170–179 meters.
- The terrain had a gentle slope, barely visible to the naked eye, causing water to flow undetected until it overwhelmed the area.
The team generated hillshades, contours, flow direction, flow accumulation, and drainage channels, confirming that the floodwaters followed a natural watercourse toward the south of Mokwa, eventually draining into the River Niger.
The flood simulation reinforced the topographic findings and helped assess the true extent of the flood—approximately 150 meters wide, affecting 381 buildings. Analysis further revealed that many homes were unknowingly built along historic water pathways.
Conclusion and Proposed Solutions: From Data to Action
The devastating flood that struck Mokwa in the early hours of 6:00 a.m. on May 29, 2024, was a flash flood triggered by the overflow and eventual collapse of a local irrigation dam, following days of heavy rainfall. The accumulated water broke through the base of a 5–6 meter-high railway embankment, unleashing a surge of water that reached a height of up to 4 meters. Geoinfotech Ltd’s investigation revealed that the floodwaters extended approximately 150 meters in width, severely impacting residential areas and damaging 381 buildings in its path.
Based on the findings, Geoinfotech, alongside a consulting engineer, recommended the following immediate and long-term solutions:
- Construct a drainage from the local dam to River-Niger to prevent accumulation of water on one side
- Comprehensive town planning to guide future development.
- Engagement of certified professionals in infrastructure design and risk assessment.
- Installation of early-warning systems to alert residents ahead of potential flooding.
- Improved local awareness and reporting channels to aid disaster preparedness.
- Construction of a proper drainage system to manage water flow and reduce runoff velocity before it enters the community.
A Call for Geospatial-Led Disaster Resilience
Geoinfotech’s operation in Mokwa demonstrates the power of drones and geospatial technologies in disaster response, providing government bodies, communities, and planners with real-time evidence to make informed decisions.
As climate change increases the frequency and severity of flash floods across Nigeria, experts are calling for greater integration of geospatial intelligence in national disaster management strategies.
Geoinfotech’s work in Mokwa stands as a model of how local technology and talent can help communities adapt and protect lives in the face of environmental challenges.
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