Strong Rains and Flooding in Korea Over the Summer

Weather...  A favourite topic of conversation of Canadians.


With temperatures in Busan predicted to remain below twenty degrees for the next few days (and temperatures in Canada reaching below zero degrees in Winnipeg last night), I'm reminiscing about my summer.  But summer weather is not always all that rosy.  Actually, this summer, the weather was outright nasty in Korea.

First of all, there was the heat.  In July, temperatures rose above 35 degrees in southern areas of the country, and above 32 degrees in Seoul.  High temperatures occurred in August and in September as well.  However, temperatures were relatively normal this year.  It seemed to me that Korea was much hotter last September than this September.

More serious was the large quantities of rainfall that Korea received during the last summer.  Already in June, rainfall levels were 1.8 times higher than typical levels experienced in previous years.  In Seoul, June rainfall levels were 3 times higher than historical levels!  Things did not improve in July.  Heavy July rains caused damage to homes, farms, and road infrastructure.  Floods and landslides occurred, and people were killed.  On one July afternoon, 100 MILLIMETERS PER HOUR of rain fell on Seoul!!!  More rain fell in August, but not as much as in July.

Rain in Korea is sometimes caused by a monsoon phenomenon, related to the monsoon that brings rain to southern Asia.  Typhoons also bring a lot of rain when they pass over Korea.  I was not in Korea during the summer, and so did not see the intense rain.  I did, however, experience the passage of a typhoon in Korea last autumn.  That was a pretty intense experience, and I honestly don't feel a strong need to repeat it.  The typhoon's rains were very strong, soaking pedestrians in spite of their umbrellas.  100 millimeters of rain per hour is A LOT of falling water!

Busan during a typhoon.

Pedestrians trying to stay dry in a typhoon.

North Korea was strongly affected by rains last summer as well.  In particular, rain in July caused significant damage to farms in North Korea, so much so that representatives of international organizations like UNICEF and the World Food Program visited the country to assess the damage.  The damage was so severe that the South Korean Red Cross and the government of South Korea sent emergency food aid to North Korea.

In South Korea, the worst of the damage was caused by landslides.  One landslide occurred near Chuncheon city (춘천시), a small city in the north-eastern province of Gangwon (강원도).  Thirteen people died in this landslide, including ten students from a university in Seoul who were doing volunteer work out there.  Also, in Seoul, a landslide occurred on Umyeon mountain (우면산), a small mountain located within the city, south of the Han river.  Soil and water flowed down the mountain into a residential neighbourhood, destroying apartments and burying people.  Officials were also concerned that other people could be injured by land mines after this landslide, as it is known that land mines were placed on Umyeon mountain during the Korea war.

All this flooding prompted public calls for a re-assessment of the capacity of the drainage infrastructure throughout Korea.  In addition, the landslide at Umyeon mountain became a major political issue.  I saw a Korean news broadcast during which it was discussed at length, and a committee was struck to investigate its causes.  In mid-September, the committee published a report in which they argued that the landslide was caused by blocked drainage infrastructure on Umyeon mountain.

Rain drainage in Korea is an important matter.  When I first came here, I was struck by how mountainous the country is.  Mountains are present even within the city limits of Seoul and Busan, and residential areas of both of these cities are built in the valleys between the mountains, with some neighbourhoods located directly beside the mountains.

Apartment buildings at the foot of Inwang mountain, in Seoul.

Apartment buildings beside Baekyang mountain, in Busan.

Building these neighbourhoods and apartment buildings so close to mountains has required a significant transformation of the mountain landscape.  These neighbourhoods have largely been built on terraces that have been dug into the mountains.

A wall at the border of a terrace and a mountain.

But streams run down many of the mountains, and it is important to ensure that mountain runoff does not cause damage to the inhabited terraces below.  For this reason, drainage and erosion control infrastructures have been installed on the mountains and on the perimeter of the terraces.  It seems sensical to me that, if this drainage infrastructure fails, flood waters and landslides could damage the terraces below the mountain.

Geumjeong mountain in Busan.  The path of a stream can be seen on the mountain.

Beomeo temple, in Busan. The path of a stream can be seen on the mountain above the temple.

A small drainage trench on Geumjeong mountain.

A drainage trench beside a path on Geumjeong mountain, in Busan.

A concrete drainage trench on Baekyang mountain, in Busan.

A concrete drainage trench in a park, on the slope of Baekyang mountain.

Drainage infrastructure above the perimeter wall of a terrace, on Baekyang mountain.

Interestingly, Koreans have been terracing the landscape of their country for quite a long time.  Rice agriculture requires a lot of water, and for this reason, many farms are constructed on terraces.

Abandoned agricultural terraces, on Baekyang mountain.

A vegetable garden on a terrace, on Baekyang mountain.

So rainy was the summer in Korea that in mid-August, one of the country's major newspapers celebrated the return of blue summer skies.  But by late August, signs of the coming autumn were already visible.