What Causes Severe Rainfall in Kenya?

What Causes Severe Rainfall in Kenya?

Heavy rains and severe flooding have been hitting Kenya since March. They are among the most disastrous¹ rainstorms to hit the East African country in recent years.

At least 169 people have died from the heavy rains. At least 91 others are missing, the latest government estimates say.

On Monday, at least 48 people died after water blew through a blocked river tunnel under a railway line in southwestern Kenya.

The flooding has displaced more than 190,000 people and damaged roads and other structures.

Seasonal² weather patterns, climate change and other natural weather events all combine to create deadly rainstorms.

Long rainy season

Kenya and some other parts of eastern Africa have two main rainfall periods: the "long rains" season from March to May, and the "short rains" season from October to December.

The "long rains" season is when most of the country's average yearly rainfall happens.

In its forecast for this year's "long rains" season, the Kenya Meteorological Department predicted above-average rainfall in many parts of the country. It also warned of flooding, landslides³ and other harmful effects.

Last year's "short rains" season saw severe storms in many parts of the country. The meteorological department said Lamu, Mombasa and Garissa areas received nearly three times their long-term average rainfall.

Why is the rain so severe?

Kenya's rainfall frequency and intensity⁴ are affected⁵ by a natural climate system called the Indian Ocean Dipole.

The Indian Ocean Dipole makes the surface of the western Indian Ocean warmer and then colder than the eastern Indian Ocean. It causes heavy rainfall in areas west of the Indian Ocean, such as Kenya, and droughts in Indonesia and Australia.

Joyce Kimutai is a researcher at Imperial College London. She said that, in Kenya's case, the Indian Ocean Dipole and climate change are likely bringing more severe rainfall and flooding.

In a study in December last year, Kimutai and other scientists from World Weather Attribution found that human-caused climate change had made last year's "short rains" season in Kenya and other parts of eastern Africa up to two times more intense.

When will "long rains" end?

It has become more difficult to predict long-term weather in Kenya in recent years. The start and the length of dry and wet seasons have increasingly changed.

The Kenya Meteorological Department expects the "long rains" season to continue into June. In its latest weather report on Monday, the department said it expects heavy rain in six areas of the country. It also predicted flooding in low-lying areas and landslides in hilly areas.

Flooding in East Africa also has killed more than 150 people in neighboring Tanzania and Somalia. It has also affected hundreds of thousands of people in Ethiopia and Burundi.

Words in This Story

pattern - n. regular and repeated way in which something happens

forecast - n. statement about what you think is going to happen

frequency - n. the fact or condition of happening often

drought - n. a long period of time with little or no rain

1 disastrous   

adj.灾难性的，造成灾害的；极坏的，很糟的

参考例句：

• The heavy rainstorm caused a disastrous flood.暴雨成灾。
• Her investment had disastrous consequences.She lost everything she owned.她的投资结果很惨，血本无归。

2 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

3 landslides   

山崩( landslide的名词复数 )； （山坡、悬崖等的）崩塌； 滑坡； （竞选中）一方选票占压倒性多数

参考例句：

• Landslides have cut off many villages in remote areas. 滑坡使边远地区的许多村庄与外界隔绝。
• The storm caused landslides and flooding in Savona. 风暴致使萨沃纳发生塌方和洪灾。

4 intensity   

n.强烈，剧烈；强度；烈度

参考例句：

• I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
• The strike is growing in intensity.罢工日益加剧。

5 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。