Historical data is limited, but it appears that Congo River’s annual high water season at Kisangani results in major inundations every 15 to 18 years. Large parts of the city are flooded.
Kisangani’s location on the equator, at the bend in the Congo River, makes it vulnerable to catastrophic floods when high rainfall coincides over both the northern and southern tributaries of the Congo River’s eastern basins. In these high rainfall years, flood waters mount through October and into November at the end of the northern rainy season. The water crests in late December as rains peak south of the equator.
Exceptional floods were recorded in Kisangani in 1962 and again in 1979.
The 1997 floods were particularly bad. High water crested in late December at the highest levels in 35 years. Over 70 people were reported drowned or swept off by the river and tens of thousands left homeless. More than 1200 cases of cholera were reported over the New Year, with hundreds of deaths. Flooding coincided with other challenges to the city and its population. Fighting between the forces of ex-dictator, Mobutu, and the advancing rebels loyal to Laurent Kabila had devastated the city earlier in the year leaving the city ill prepared for the natural disaster and thus contributing to the heightened death toll.
This year, 2015, flood waters returned, with levels reportedly higher than in 2003, but not approaching the 1997 records. In November and December heavy rains fell over Congo’s southern basins, including the TL2, but the worst was avoided thanks to an early onset of the dry season in the north with water level of the northern tributaries dropping before the heavy southern rains. So far, we have heard of no deaths from drowning or confirmation of death from Cholera.
Kisangani will flood again. And new patterns may emerge as global climates change. The city will require, along with dykes, basic information on the regional rainfall patterns, information that is not now in hand. Collection of meteorological data, and notably rainfall for Central Africa, was considered important several decades ago, but now has plunged to levels similar to the early 20th century.
Operational rain gauges per year in Central Africa. Published in Congo Basin rainfall climatology: Can we believe the climate models?
At the recently concluded Climate Change Conference, COP 21, in Paris, the least-developed nations called on developed countries to help their poorer neighbors to adapt to climate disasters. Priorities include, among other things, early drought warnings for farmers and development of dykes or other measures to protect sensitive environments during torrential rains. It is questionable, however, what can be done with the collapse of record keeping in Central Africa; the case from DRCongo, with more than 50% of the Congo Basin, is the most dire.
Central African precipitation recording stations. World Meteorological Organization, World Weather Watch Regional Basic Climatological Network.
A congolese, Tosi Mpanu Mpanu, leads the COP 21 movement of the least-developed nations. Tosi could do worse than to start with a commitment by his own country to reestablish credible meteorological record keeping.
Thanks to John Hart for this post and thanks to Michel Mopanga for the photos.