The Shinano River is the longest in Japan; the river flows through most of the prefectures of Nagano and Niigata. It originates from the foot of the Komu Shindake Mountains in Honshu, known as the Japanese Alps; it flows northward to the northeast and flows into the Sea of Japan in Niigata City, with a total length of 367 kilometers (228 miles).
The river has many tributaries upstream and downstream flow through the Niigata Plain to form deltas and swamps. Due to the floods in spring, a spillway was built in 1923. The Shinano River has long been Japan's inland waterway, and Niigata, at the mouth of the river, is one of its many ports.
Since the "Manyoshu" in ancient times, many poems have described this iver. In modern times, many songs also describe the well-known river that induces homesickness in Japanese. The following post will introduce more facts about the physical geographic features of the Shinano River.
Size and Description of Shinano River
The Shinano River is the longest in Japan, and its drainage area is the third largest in Japan at 11,900 square kilometers. It is called the "Shinano River System" as a whole. Still, the section is called "Chikumagawa" in Nagano Prefecture, and the rest is called "Shinano" after passing through Shisui County, Nagano Prefecture, and entering Niigata Prefecture. The watershed covers almost the entire Shin-Etsu region (Nagano and Niigata). There is also the Nakazu River, a small tributary from Nolan Lake in Gunma Prefecture, so the entire Shinano River basin covers Nagano, Niigata, and Gunma. The Chikuma River is upstream of the Shinano River and the mainstream of the entire Shinano River system.
Length and Area Of the Shinano River
The length of the part called the Chikuma River is 214 kilometers, and the part of the Shinano River is 153 kilometers, and the total length is 367 kilometers. The area of the Shinano basin is 11,900 square kilometers, which is as wide as the area of Niigata prefecture. The number of river branches of the Shinano River is second in Japan.
|Total Length||367 km|
|Basin Area||11,900 sq km|
|Average Discharge||503 cubic m/s|
The upper reaches of the Shinano River have the most typical inland climate; the southern part has apparent characteristics of the Tokai climate. At the same time, the Hokuriku region influences the northern part, and the climatic conditions are complex. Due to the complex terrain, the annual precipitation in the Shinano River basin is also very different. The following year's precipitation from November to February accounts for 40%-50% of the annual precipitation, mostly due to snowfall. There is often heavy precipitation followed by the rainy season from June to July.
The Shinano River is flood-prone, which is caused by concentrated rainstorms during the snowmelt period and the Meiyu period. The main causes of disasters upstream are flood disasters during the typhoon period. The floods in the middle and lower reaches of the Shinano River generally occur in the snowmelt period from March to April and the heavy rain period from July to October. Floods in the heavy rain period mainly occur in the early Meiyu period, the early autumn rain period, and the season of concentrated rainfall, such as typhoons and thunderstorms.
The Shinano River is not only rich in water sources but has been an important waterway for transporting food and daily necessities since ancient times. Today, there are more than 100 hydropower stations in the upstream and various tributaries; the Shin-Takasegawa Hydropower Station ranks first in the country. The downstream has the advantages of comprehensively utilizing shipping, irrigation, and industrial water. There are many lagoons near the estuary; Niigata Port is the largest port along the Sea of Japan.