| dc.description.abstract | Floods are the most catastrophic and dangerous disasters that usually inhibit the development of countries at a sustainable rate, and these include a strong rainfall that affects urban areas where Rainfall directed from high elevations to lowlands results in strong floods that destroy lives and property in urban areas of Kigali city. Kigali has an altitude of 1400-2000 m, resulting in a steep slope, and the urban area has grown, with more floods destroying infrastructure and damaging businesses. Geospatial techniques were used to come up with maps for flood management. Despite the fact that there is a persistent problem of flooding in Kigali that has resulted in the destruction of infrastructure, damaged crops, and restricted movement, there’s no existing formal flood management system to mitigate these recurring problems. The study aimed at analyzing the successive urban flooding of Kigali City resulting from heavy rainfall that causes strong storm water to be directed into urban areas and, hence, determining the location of the drainage in Kigali that can mitigate flood risks through analysis using geospatial techniques.
The first method used was to make statistics that show how rainfall in Kigali has been increasing from 2000 to 2018. The results show that from 2017 to 2018, a strong rainfall in urban areas brought more floods. The second method, DEM, is used to generate slope, flows of water and watershed, and the change in elevation (contours), where the comparison between wetland places and cadastral survey data from 2018 results in showing a number of parcels in risk areas where 165,223,152 km2 is a wetland with 56,244 residential plots in a risk area. Thirdly, the overlay between the slope, rainfall, wetland, and topographic maps of Kigali shows 5 areas where flood risk is high and where flood management should focus in order to slow down floods by using drainages that can follow a vertical interval of 100 meters. As the altitude of Kigali is between 1400-2000 m, a vertical interval of 100 m in elevation is quite significant, implying that five areas for drainage must be built while causing no disruption to existing infrastructure. Because rainfall in Kigali ranged between 462 and 1193 mm from 2000 to 2018, the city should be able to save a lot of water by utilizing drainages that can direct floods into artificial lakes that can be used for various activities such as fishing culture or to distribute water for water conservation. This study found that 22% of the settlement areas were affected by floods on the cadastral data in Kigali, which caused plot values to decrease and slowed down agriculture projects.
This study recommended that they change the design of household reservoirs for rainwater as a flood control measure by creating drainage at 100-meter vertical intervals in the five areas identified in our research. This would help reduce the amount of storm water flow directed into urban areas | en_US |
