Flash floods and landslides cause destruction and fatalities at the peak of seasonal rainfall

• Exceptionally heavy rains, widespread flash floods, and landslides characterize the peak of the short rains over parts of East Africa. Last week’s rains have resulted in fatalities, destruction of property, and significant crop damage and infrastructure in parts of Djibouti, Ethiopia, Kenya, Uganda, and Tanzania.

• Overall, above-average rainfall since the start of the season in October has been beneficial for crop development and conditions of rangeland and water resources across much of the worst drought-affected areas of the eastern Horn. Meanwhile, the harvesting and drying of long-rains crops over parts of the western and northern sector of the horn have been largely constrained by ongoing extended seasonal rains.

• The current well above-average seasonal rains are attributed to the current very strong, positive Indian Ocean Dipole (IOD). Though starting to weaken slightly, the IOD is forecast to remain at record strength into December.

• The short-term rainfall outlook for November into mid-December indicates an increased likelihood for continued heavy rainfall and an elevated risk of flash floods over much of Kenya, the Lake Victoria basin, and western and southern areas of the region including parts of the East African coastal strip. The current rainfall season is expected to be one of the wettest in record since the 1980s in most parts of the region.

The October through November seasonal rainfall performance was generally characterized by exceptionally heavy rainfall in October and late November, punctuated by dry spells in early- to mid-November across much of East Africa. Recent widespread torrential rainfall has resulted in severe flash floods and landslides which have caused human fatalities, destruction of property, and significant crop damage and infrastructure, especially over the western Pokot county of Kenya where 132 people have been confirmed dead and 17,000 displaced following the landslides. Flash floods in Djibouti have also caused almost 10 human fatalities and significant destruction of property and infrastructure. Other areas currently adversely affected by ongoing floods include parts of northeastern Uganda, central, southern, and southeastern Kenya, and northeastern Tanzania. Central and northern areas of Ethiopia have also experienced localized landslides and exceptionally heavy and widespread unseasonal rains that jeopardized ongoing harvesting of major crops.

Overall, most parts of the eastern Horn, Kenya, Uganda, Burundi, and eastern Tanzania received between 100 to 300 mm or more beyond typical rainfall amounts during this period (Figure 1). This represents between 200 and 400 percent of average cumulative rainfall in most areas. However, parts of eastern DRC, western Rwanda, and southwestern Uganda experienced cumulative rainfall deficits between 50 and 200 mm. The rest of region received near-average rainfall amounts.

In spite of the recent second wave of floods and landslides, much of the region has significantly benefited from the ongoing above-average rainfall, with well above normal cropping and rangeland conditions and replenishment of surface and ground water resources. As such, crop and livestock production are generally expected to be above-average, though agricultural production may be reduced in areas that were severely flooded or have been affected by locusts. Rift Valley Fever (RVF) remains a potential threat to livestock production under current environmental conditions over the eastern Horn and parts of vulnerable pastoral and agropastoral zones with exceptional vegetation and surface water conditions. As measured by the Normalized Difference Vegetation Index (NDVI), significantly above-average vegetation conditions are prevalent over Sudan, southeastern South Sudan, eastern and southern Ethiopia, central and parts of southern Somalia, Kenya, northeastern Uganda, and eastern Tanzania (Figure 2). Rwanda, Burundi, and eastern DRC have been obscured by persistent cloud coverage, though this is suggestive of continued rains and likely improvement in vegetation conditions. The rest of region is experiencing near-average vegetation conditions, with the exception of central Tanzania and parts of northern Ethiopia and northeastern Somalia, which are presently experiencing below-average vegetation conditions.

Mid-season field reports from multiple sources – confirmed by FEWS NET WRSI crop simulation models – are also indicative of favorable cropping conditions ranging from vegetative to reproductive stages across parts of the eastern Horn, especially the agropastoral regions of eastern and central Kenya, southern Somalia, and northeastern Tanzania. However, some reports indicate localized areas of staggered crop planting in parts of southeastern Kenya, with some crops at early vegetative phase. Recent abnormal heavy rains in mid-November to early December have helped ease the widespread infestation of Fall Armyworm (FAW) in these cropping areas. However, extreme soil saturation (over 200 percent of average rainfall amounts), flash floods, and landslides, together with the threat of desert locust infestation (eastern and northeastern Ethiopia, Hawd Somalia, and Yemen) are likely to adversely impact crop and rangeland production. Much of the region dependent on the short rains is expected to have well above-average yield prospects. Meanwhile, the long rains and Meher seasonal crop harvesting and drying are presently being constrained by persistently heavy and extended seasonal rains. The short-term rainfall outlook is for sustained moderate to heavy rains in Ethiopia and southeastern South Sudan. Meanwhile, Sudan is forecast to remain generally sunny and dry allowing for harvesting and drying activities.

The following is a country-by-country update on recent seasonal progress to date:

• In Somalia, October through November seasonal rainfall performance has been well above average and has resulted in significantly improved rangeland resources in most parts of Somalia. Despite the recent decline in Juba and Shabelle river levels, a high risk of flash floods persists due to heavy rainfall forecast over the eastern Ethiopian highlands. The recent severe floods in October and anticipated continued flooding are likely to continue adversely impacting the southern riverine agricultural areas of the upper and lower Shabelle and Juba. Currently, the worst-affected area is Belet Weyne where nearly 200,000 people were displaced. The key sorghum-growing areas of Bay/Bakool are currently experiencing favorable cropping conditions with crops in reproductive stages and average to well above-average yield prospects. The short-term rainfall outlook shows an increased likelihood of the seasonal rains subsiding over much of Somalia, except in northern and coastal regions where continued rainfall is forecast into early December.
• In Ethiopia, extended seasonal rains and desert locusts are likely to adversely impact the Meher harvest. According to the latest national and FAO reports, the worst-affected areas are in the Afar, Amhara, Oromia, Somali, and Tigray regions. According to the Regional Bureau of Agriculture, desert locusts are estimated to have damaged approximately 75,000 hectares of both crop and rangeland thus far. Meanwhile, well above-average rainfall in October resulted in flooding in riverine areas, human displacements, and damage of household assets and infrastructure. Overall, cumulative seasonal rainfall performance has been largely beneficial to vegetation and surface water conditions and is likely to positively and significantly impact livestock production and productivity in the medium term. Rains are forecast to continue in coming weeks over eastern and central Ethiopia, with the development of tropical cyclones forecasted off the northern Somalia coast.
• In Kenya, the second wave of widespread well-above average rainfall at the peak of the rainy season has resulted in severe flash floods and landslides which have caused human fatalities and damage to property and infrastructure over northwestern, central, southern, and southeastern counties. The worst-affected area was west Pokot County, where at an estimated 132 people were killed, and more than 17,000 people were displaced according to government authorities.  Rescue and relief response were constrained by persistent rains and impassable roads. Overall, the current short rains have affected an estimated 300,000 people countrywide, according to the latest KRCS and UNOCHA reports. Meanwhile, the current seasonal rains have been largely beneficial for most of the cropping areas and pastoral counties dependent on the short rains in the northern, eastern, and parts of southern regions. Further heavy rainfall is forecast in the country, with increased risks of continued flooding in the coming weeks.
• In Sudan, the extended seasonal rains are forecast to subside and give way to sunny and dry conditions in the coming weeks. This is expected to promote the harvest and crop drying activities which were limited by rainfall. Following above average June through October seasonal rains, crop and livestock production remain favorable with average to well above average cropping and vegetation prospects,
• In South Sudan, southeastern areas of the country continued to experience above average rainfall through November. These rains have resulted in significantly better-than-average cropping and vegetation conditions in this region. Similarly, in much of the country better-than-normal cropping conditions are expected, due to the good October to November seasonal rains. Although, according to latest field and official Government reports, heavy rainfall and flooding resulted in loss of more than 70,000MT in parts of Bahr el Ghazal and rendered roads impassable for past weeks in Yirol town. However, the seasonal rains are forecast to cease in coming weeks, marking the start of sunny and dry conditions in the country, apart from the southeastern region of Kapoeta.
• In Uganda, cropping conditions over much of northern, southern, and eastern regions of Uganda are currently very good. Much of the early planted maize, beans, and other pulses are currently available in the eastern, central, northwestern regions. Meanwhile, crops in the southwest are currently in advanced reproductive stages and in better-than-average conditions. These crops are likely to be harvested later in December.
•  In Rwanda and Burundi, season A rains intensified in November and despite the mixed rainfall performance at the onset of the season in October there are significant improvements in vegetation and cropping conditions. Rwanda received near-average amounts, with Burundi experiencing above average rainfall. Most crops are currently in vegetative to reproductive stages and in favourable condition. Moderate to heavy rainfall, with elevated risk of flooding is expected in the coming weeks.
• In Tanzania, the Mt. Kilimanjaro and most eastern coastal regions of the country were extremely wet from October through November. Some localized areas receiving between 400 to 600 percent of normal rainfall during this period.  There are unconfirmed reports of flooding in these areas; however, most cropping and vegetation conditions are exceptionally favorable. More seasonal rains are forecast in coming weeks, as tropical rainfall systems are expected to shift southwards into Tanzania.
• In Djibouti, several days of heavy rains in late November resulted in flash floods, with nearly 10 people killed and damage to property and infrastructure. More rains likely in coming weeks, as neighboring Red Sea and northern Somalia coastal regions, remain active with frequent moderate to heavy rains.
• In DRC, international and local media report indicate many people have been killed floods and landslides, caused the on-going persistent torrential rains in Kinshasa, DRC. However, parts of eastern DRC bordering Rwanda and Burundi have below average rainfall cumulative rainfall, since the start of the October seasonal rains. Heavy to very heavy rains are forecast to continue in the country.
• In Yemen, sunny and dry conditions prevailed over much of the country, apart from the western coastal and highland areas. Vegetation conditions are generally significantly better-than-normal in the western sector of country, in response to recent rains. The rest of the country has near-normal vegetation. Little to no rainfall expected in the country in coming weeks, although there is an increased likelihood for light to moderate rains over western coastal strip.

FORECAST

The two-week rainfall outlook through mid-December indicates an increased likelihood for continued moderate to localized very heavy seasonal rains over much of East Africa. There is continued heightened risk of flooding over Kenya, Lake Victoria basin and its environs and parts of the flood prone areas of Tanzania, Rwanda and Burundi. Forecast development of tropical cyclones this week over western Indian Ocean, is likely to be disruptive and result in further rainfall over East Africa coastal areas, especially northeastern Somalia, eastern Ethiopia, much of Kenya and Tanzania, as indicated in Figure 3. October to mid-December period has been one of the wettest on historical record, as shown in Figure 4. Areas in deep to dark shades of blue are expected to be wetter than the El-Nino influenced short-rains of 1997 and 2006.