"Opening Geumgang Sejong and Gongju Weirs... Environmental Improvement Including Appearance of Endangered Species"

Since 2017, Gates Opened... Ministry of Environment "Complete Opening Shows Effects"
Endangered Species Discovered... Aquatic Ecosystem Health Indicator 'Fish Health Index' ↑
Increase in Sediment Sand Ratio and Decrease in Organic Matter... Habitat Environment Improved

[Asia Economy Reporter Kim Bo-kyung] The Ministry of Environment announced on the 10th that the overall habitat environment of the Geum River ecosystem has significantly improved, with various endangered wild species appearing after the complete opening of the Sejong and Gongju weirs on the Geum River.

The Gongju Weir on the Geum River has been open since June 2017, and the Sejong Weir has been open since November of the same year. As of June this year, the Gongju Weir has been fully open for 778 days, and the Sejong Weir for 888 days.

After observing and analyzing the Sejong and Gongju weirs on the Geum River for three years, the Ministry of Environment stated that the possibility of restoring the natural state of the Geum River was confirmed as sandbanks and riparian spaces increased and diverse habitats were formed, with endangered species continuously discovered.

As the water flow accelerated, the proportion of sand in the sediment increased, and the organic matter content decreased, showing the effects of the opening.

The main monitoring results of the Sejong and Gongju weirs on the Geum River are as follows.

First, various riparian spaces such as sandbanks, mid-channel bars, and wetlands formed by the opening of the weirs were found to serve as habitats and resting places for various organisms, including endangered wild species.

At maximum opening, the sandbanks of the Sejong and Gongju weirs increased by 74 times the size of a soccer field (0.527㎢), and the riparian spaces increased by 115 times the size of a soccer field (0.819㎢).

It was confirmed that the endangered wild species, the second-class White-naped Crane, which breeds only on sandy and gravelly areas, widely inhabits the sections of the Sejong and Gongju weirs, including exposed sandbanks and mid-channel bars.

After the first-class endangered wild species, the White-spotted Char, was rediscovered downstream of the Sejong Weir last year, it was also found upstream of the Gongju Weir in the first half of this year. The Yellow-billed Egret (first-class endangered wild species), known to rarely appear only along the West Sea coast in summer, was also found downstream of the Sejong Weir.

The 'Fish Health Index,' which indicates the health of the aquatic ecosystem, also showed an increasing trend, which is believed to be due to the improvement of the river habitat.

The Fish Health Index rose from 35.6 before opening to 56.6 after opening at the Sejong Weir, and from 35.4 to 42.0 at the Gongju Weir. The Fish Health Index, calculated based on the fish species inhabiting the area, indicates better health as it approaches 100.

After the weirs were opened, the proportion of sand in the sediment increased, and the organic matter content showed a decreasing trend. When the sand proportion in the sediment increases and organic matter decreases, the sediment layer becomes cleaner, oxygen consumption decreases, and the habitat environment for aquatic organisms improves.

At the Gongju Weir, the sand proportion in the sediment increased by 1.5 times compared to before opening, and the organic matter content decreased to about half of the pre-opening level.

Kim Young-hoon, head of the Ministry of Environment's Investigation and Evaluation Team for the Restoration of the Four Major Rivers' Naturalness, said, "As a result of long-term observation of the Sejong and Gongju weirs on the Geum River, we confirmed several positive effects as water flow improved due to the opening of the weirs. We plan to do our best to ensure scientific and objective investigation and evaluation while expanding the opening of the weirs."

Detailed results of the observation and analysis of the Sejong and Gongju weirs on the Geum River can be found in the comprehensive report on weir opening and observation as of the first half of this year. This report will be available on the 'Weir Observation Comprehensive Information System' starting from the 11th.

The Ministry of Environment has been conducting weir opening and observation in 14 fields, including water quality and aquatic ecology, for the Four Major Rivers since June 2017. Observation results for 13 of the 16 weirs that have been opened so far are disclosed every half-year on the comprehensive information system.

This content was produced with the assistance of AI translation services.