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Hikami KairoWatershed FIELD MUSEUM

氷上回廊

What is the Hikami Kairo?

Climate and global warming

A place where the winds meet, water is created, and wildlife comes and goes Around the central area of the Hikami Kairo, the snowfall has been decreasing year by year, and all types of changes occur.
How do we approach the unusual changes that sway the area’s rich natural environment and culture?

Mix of Seto Inland Sea side and the Sea of Japan side climates

The Seto Inland Sea coastal zone has what is referred to as a ‘Seto Inland Sea type climate’ that is warm with little rainfall. In contrast, the moist warm Tsushima current flows into the Sea of Japan, bringing heavy snowfall from the northwest winter monsoons. These two climates converge in Tamba City, Hyogo Prefecture, and the resulting temperature difference between morning and evening that creates the Tamba mist from autumn to winter provides the optimal conditions for delicious crops.

Blessings from ancient climate change

In the area around the Hikami Kairo, diverse wildlife has been coming and going in tune with the ancient rhythm of the climate fluctuating between cold glacial period and warm interglacial period, creating a rich natural environment. Our ancestors laid down firm roots in this area amidst the rich blessings, and now, over 25,000 years later, we can feel that richness in the satoyama that is full of life and the fruitful rice paddy landscapes.

But now, farmers have been noticing unusual changes around the Hikami Kairo in recent years, commenting that the snowfall has decreased considerably, that they are experiencing torrential rain (the appearance of cumulonimbus clouds) more frequently, and that they are seeing more and more Ikki-mizu (water that collects all at once when it rains and flows out). The farmers who have been tackling the regional climate and cultivating the earth for generations have age-old experience and intuition.
These are now being overthrown in modern climate change and creating instability in the rich harvest.

Concern about global warming is being actively discussed around the world, and the climate around the Hikami Kairo is gradually warming as well, producing a number of effects.

Unusual changes in the rich water

People in this region have passed on the saying that a light snowfall in winter means that the water will dry up in summer.
“Rain in summer is very important, but it flows away quickly. Snow in winter thoroughly soaks the mountains and keeps the area moist throughout the summer (so that the rivers do not dry up even in summer).” This embodies how people express the strong link between snow in winter and farming in summer.
However, if the snowfall continues to decrease due to warming, the water that has supported the richness of this area will experience unusual changes.

And this is not all.
For generations, the farmers have been developing a rich tapestry of knowledge about the area’s unique climate, for example about when the fog will disappear, when the number of clear days will start increasing, when the water will warm up, when the fog will become denser, when the insects will proliferate, when strong rice seedlings can be cultivated, and so on.
A change in climate means that all this traditional knowledge the farmers possess will suddenly lose its value and the rich harvest will be lost.

If global warming melts the ice on both the north and south poles

If the sea level rises 10 meters ? The plains downstream of the Kako River will become the sea floor.
If the sea level rises 50 meters ? The entire area from around Ono City to Takino-cho, Kato City will become inundated. In the Yura River area, the entire stretch from around Fukuchiyama City to Ichijima-cho, Tamba City will become the sea floor.
If the sea level rises 100 meters ? The seawater coming from the Seto Inland Sea up from the Kako River and the seawater coming from the Sea of Japan up from the Yura River will merge at the Miwakare in Iso, Hikami-cho, Tamba City, and the channel that divides the main island of Japan will appear. We have to prevent this from happening.

The Japanese islands if the sea level rises 100 meters

Disruption in the timing for growth in wildlife

Unusual weather has been disrupting the timing for growth of not only the crops in the fields, but also the vast wildlife living in the surrounding satoyama and virgin forests.
For example, there is danger of disruption in the timing for flowers to bloom and the timing for growth of the insects that carry the flower pollen. The frequent torrential rain in summer is causing entire plants to be torn from their roots and thrust out of their habitat and down the river, so that some species are disappearing. Also, recent investigations are starting to show that the vegetation that was previously protected by snow is being eaten by deer and is now on the verge of extinction.

If global warming proceeds rapidly, the balance of nature will certainly be disrupted. And yet, the forests and waterfront that are full of life actually have the potential to reduce the damage from global warming. Perhaps it will be the forests and waterfront brimming with wildlife that save us from the danger of global warming.