Okcheon Reservoir shrinks 89% as drought grips southern Korea

The worst of the extreme heat has subsided, but a prolonged lack of rainfall continues to cause severe drought across southern Korea. Water levels at major dams and reservoirs have fallen rapidly, exposing their beds.

A cumulative 601.6 millimeters (23.7 inches) of rain fell nationwide over the six months from Feb. 4 to Aug. 3, equivalent to 80.1 percent of the seasonal average of 755 millimeters, the Ministry of the Interior and Safety and the Korea Meteorological Administration (KMA) said Sunday.

Busan, South Gyeongsang and Ulsan received just 555.6 millimeters of rain during the same period, 61.4 percent of the seasonal average of 895.1 millimeters.

As of Aug. 3, drought conditions had developed in 50 cities and counties nationwide due to below-average rainfall. The southern parts of North Gyeongsang and South Gyeongsang were experiencing “normal drought” conditions at the caution level, the third-highest of the four-tier system. Busan, Gimhae in South Gyeongsang and Ulju County in Ulsan were experiencing severe drought, the second-highest level.

Conditions at agricultural reservoirs are even more serious. The nationwide average reservoir storage rate stood at just 53.2 percent as of Aug. 3.

Securing water for farming has become especially urgent in southern regions, where storage rates are far below seasonal averages because of the rainfall shortage. South Gyeongsang had the lowest rate, at 39.6 percent, followed by North Jeolla at 44.6 percent, Jeju at 48.5 percent, South Jeolla at 48.6 percent and North Gyeongsang at 52.4 percent. The government has been using river water to replenish reservoirs, particularly in southern regions, and has also deployed water trucks to supply farms directly.

Among the country’s dams, Unmun Dam in North Gyeongsang is under the highest drought warning of very severe, while Miryang Dam in South Gyeongsang and Seomjin River Dam in North Jeolla are at severe, the second-highest level. Water from the Nakdong and Geumho rivers is being used as an alternative supply for areas served by Unmun Dam.

The loss of water resources caused by the drought is clearly visible in satellite images.

An analysis of satellite imagery from last year and this year by satellite startup TelePIX found that the water surface area of Okcheon Reservoir in Changnyeong, South Gyeongsang, had fallen 88.8 percent, from 0.129 square kilometers (32 acres) on July 29 last year to 0.014 square kilometers on Aug. 1 this year.

The images show that most of the reservoir bed was exposed in the span of just one year, with water remaining only near the intake.

“Southern regions received only about half their average rainfall this summer, causing reservoir storage rates and soil moisture levels to fall significantly as drought conditions worsened across the region,” said Kim Hye-ri, a senior researcher at TelePIX.

“Storage rates at Daegok Dam [in Ulsan] and Okcheon Reservoir have fallen to around 10 percent, making preparations for water shortages necessary,” Kim said.

The drought is expected to persist for the time being, as the KMA forecasts below-average rainfall in August and September.

The extreme heat has also caused a succession of casualties. Two people died of heat-related illnesses in Seoul alone on Friday, which marked Ipchu, the traditional beginning of autumn. A man in his 50s exhibited unusual behavior on a street in Jungnang District, Eastern Seoul, at around 6 p.m. A woman in her 80s lost consciousness at her home in Gangnam District, Southern Seoul. Both were taken to hospitals but died.

The temperature in Seoul reached 38 degrees Celsius (100.4 degrees Fahrenheit) that day, the highest recorded on Ipchu since weather observations began in 1907. On Saturday, 131 people nationwide suffered heat-related illnesses, two of whom died.

The extreme heat, which even approached 40 degrees, has eased somewhat over the weekend. Seoul’s daily low fell to 24.5 degrees on Sunday, ending a streak of 17 consecutive tropical nights, defined as nights when the temperature does not fall below 25 degrees.

Temperatures of around 35 degrees are nevertheless expected to persist under clear skies for the time being. Daytime highs in Seoul are forecast to remain between 34 and 35 degrees through the middle of the week.

“Apparent temperatures will rise above 33 degrees in most parts of the country and above 35 degrees in some inland areas, prolonging the heat wave and tropical nights,” a KMA official said.

BY KIM MIN-WOOK, CHON KWON-PIL [kim.hayoon1@joongang.co.kr]