Japanese who thought about prevention of desertification by human wisdom from ancient times

Before going to the Sahara Desert in Algeria, geographer Iwao Kobori vaguely thought that everything was a sandy desert, but when he actually visited, the sandy desert was one-fifth or six minutes. The impression was that it was a desert of rocks. Therefore, I came to insist that it is appropriate to write “desert” （沙漠）as “desert”（砂漠） in the sense that there is little water.　「沙」 means scarce water in Chinese character.

Since the “First Desertification Prevention Conference” was held in Nairobi, Kenya in 1977, I was sick of how much I had achieved that goal, and rather than thinking about high-tech technology and desalination of seawater, Mr. Kobori said. , He came to think that a technology like Qanat, which can be dealt with even in developing countries, would be more effective for desertification. He decided to get the answer by visiting the deserts of Algeria.

Qanats are called “karez” in Afghanistan and Xinjiang Uygur Autonomous Region of China, “foggara” in Algeria, and “faraj” in Oman, and their depth and total length vary from country to country. Qanats exist in Spain, Southern Italy, Palermo, Sicily, and Romania, all believed to have originated in Iran, but Iran, Afghanistan, and China are used on a large scale.

There is also a small qanat called “Mambo” in Suzuka City, Mie Prefecture, Japan, but Mr. Kobori states that this was not introduced from Iran, but was born from the wisdom of life unique to Japan.

Born in Iran during the Achaemenid era, the qanats were created to promote agriculture and expand settlements. A qanat begins a vertical well dug at the foot of the mountain which has abundant water, supplying water to far lands by using long side hole wells. Irrigation with qanats is popular in Iran, but there are currently 30,000 and 50,000 qanats in Iran. There are various theories as to when the qanat began, but it has been confirmed that it existed at least in the 700s BC. During the Achaemenid era, qanats spread throughout Iran. Persepolis was also watered by this qanat. Local governors and generals of the Achaemenid dynasty also focused on building qanats to promote agriculture and lay their own economic base.

Qanats are a valuable source of water in arid desert areas such as Iran. Seen from a distance, the swelling soil wells are lined up in the desert, as if the lunar craters were stretched out. During this period, the wastelands and deserts were thought to be inhabited by the evil gods Ahriman and the devil, and it was considered good to bring green farmland by irrigation. Water and green were symbols of heaven for the desert people. Therefore, the Achaemenid kings also focused on opening irrigation canals and striving to secure food.

There are concerns about the progress of desertification due to global warming. As desertification progresses, agricultural land will decrease, causing food problems. In addition, the decrease in green space leads to an increase in greenhouse gases, creating a vicious cycle that causes further warming. The international community should follow Mr. Kobori’s observations and seriously consider the wisdom of the ancients.