Natural conditions of Japanese geography

According to the climate classification of Keben, Hokkaido belongs to temperate continental humid climate; Honshu, Shikoku and Kyushu have subtropical humid climate; Ryukyu Islands has a subtropical humid climate and a tropical rain forest climate. Due to the large latitude in Japan, the temperature difference between north and south is very significant. The continuous peaks run through the center of the Japanese archipelago, which makes the climate difference between the Pacific coast and the Sea of Japan very large. Because Japan is located on the east coast of the mid-latitude continent, Japan's climate is obviously influenced by the intersection of monsoon and ocean current. Japan is an island country with small annual temperature difference and abundant precipitation, which has obvious maritime climate characteristics. All of the above have led to significant differences in rainfall between Japan and the Korean Peninsula and North China at the same latitude.

Japan has distinct seasons all year round. From May to September, tropical air flows from the Pacific Ocean to Japan, and Kuroshio and pro-tide meet in the surrounding waters, bringing sultry and abundant summer to Japan. The "Meiyu" rainy season, which marks the beginning of summer, starts from south to north. This rainfall front is called "Meiyu Front". There are plum rains all over Japan except Hokkaido. Until July, the Pacific monsoon will occupy the warm and humid air flow over Japan, and the rainy season will end and summer will come. From midsummer to early autumn, there will be an intermittent rainy season called "autumn rain" in northern Japan and eastern Japan. Japan will also encounter multiple typhoons in summer and autumn. On average, ten typhoons approach Japan every year, and three or four of them will land, causing casualties and losses. At the end of June, 1 1, the cold air in Siberia gathered into a high pressure and tended to a low pressure in the northern Pacific Ocean. As a result, the cold wind blew from the west to Japan, and absorbed a lot of moisture when passing through the Sea of Japan, bringing severe cold and blizzard to "Ri Japan" facing the Sea of Japan. Especially in Hokuriku (Toyama Prefecture and Niigata Prefecture), the snow is deepest in the mountains. On the other side of the ridge, the snow was blocked by the ridge. Winter weather in eastern Japan is usually sunny and dry, but the temperature is still low. After winter is over, spring begins. Affected by the tropical continental air mass, high and low pressure alternately pass over Japan. In late March, cherry blossoms were in full bloom all over Japan, and people held annual flower viewing activities one after another.

Japan can be divided into five climatic zones, namely, Japan's marine climate zone, Pacific climate zone, central highland climate zone, Seto inland sea climate zone and Ryukyu Islands climate zone. The climate zone of the Sea of Japan includes the coastal areas of Hokkaido and Honshu Island. In winter, the northwest monsoon brings a lot of water vapor, which makes the coastal areas of the Sea of Japan often have a lot of snowfall in winter, and its snowfall is also the highest in the world. The Pacific climate zone includes Hokkaido, the Pacific coast of Honshu and most parts of Kyushu. In summer, due to the influence of plum rains and typhoons, there is more precipitation. In winter, the climate is drier. The central highland climate zone is a mountainous area in the central part of Honshu, which is relatively far from the ocean and has a high altitude, so the annual temperature is very high and the precipitation is less, which has strong continental climate characteristics. Setouchi-type climate zone refers to the coastal area of Seto Inland Sea, which is surrounded by mountains, the monsoon is blocked, and the annual precipitation is relatively small. Ryukyu Islands-type climate zone, including Okinawa Islands, is located at the southernmost tip of Japan, with high temperature and rainy all year round and distinctive maritime climate characteristics.

In order to adapt to the hot and humid climate in Japan, traditional Japanese residential buildings pay attention to ventilation in design, and often use sliding doors instead of fixed walls to promote indoor air circulation. And there is a certain space between the floor and the ground, so that moisture can pass under the house. However, with the development of economy, the number of traditional Japanese-style houses has been drastically reduced and replaced by western-style houses built of reinforced concrete. This kind of houses mostly adopt fixed walls and pay attention to air tightness. With the increasing number of high-rise buildings in cities, the heat island effect in metropolis and its suburbs has become increasingly prominent. The temperature in winter is warmer than before, and the high temperature and heat in summer is also a serious social problem. The sea around Japan has the Pacific Ocean in the east, the Philippine Sea in the south (Japan is regarded as a part of the Pacific Ocean), the East China Sea in the west, the Sea of Japan in the northwest and the Sea of Okhotsk in the northeast. The sea between Honshu and Shikoku is called Seto Inland Sea, which is dotted with many islands. The main Japanese straits are Tsutsugaru Strait between Hokkaido and Honshu, Guanmen Strait between Honshu and Kyushu, Zonggu Strait, Akashi Strait, Mingmen Strait and Ma Haixia. The larger bays are Tokyo Bay, Sanhe Bay and Osaka Bay.

Japan has the sixth longest coastline in the world. Japan's coastline is tortuous, influenced by the terrain, and the coastline of each region has distinct characteristics. The coastline along the Sea of Japan is relatively straight and short. The coast of Sanluhai in Iwate Prefecture and the coast of Nagasaki Prefecture belong to Luoshui Bay with complicated twists and turns, which are suitable for the development of aquaculture and are also famous tourist attractions. Seto inland sea coastal counties with many islands are also counties with long coastline in Japan.

In the Pacific Ocean of Japan, a warm current called Kuroshio flows from south to northeast, and its tributary, the Tsushima Current, flows into the Sea of Japan between the Korean Peninsula and Japan through the Ma Haixia. Another cold current called pro-tide flows from the North Pacific to the south. A hi-tide tributary named Limanliu flows into the Sea of Japan via tatar strait. Two currents meet in the northeast, bringing abundant plankton, making the northeast rich in fish resources and becoming one of the three major fishing grounds in the world. However, overfishing of fishery resources has led to a decline in catches in some areas of Japan. In addition, sewage discharge from coastal industrial cities led to red tides in some sea areas of Japan. Due to the narrow and mountainous terrain in Japan, the rivers in Japan are generally short in length, with large drop and small basin area. Japan is a region with more precipitation in the world. In summer, rainfall tends to be concentrated in a short period of time, which makes rivers in Japan flood from time to time and brings certain disasters. The average annual precipitation in Japan is about1.700mm, and the average annual precipitation per capita is about 5,200m3, which is lower than the world average of 23,000m3. In addition, most rivers in Japan are relatively short, and precipitation will soon flow into the sea, which is difficult to use. Therefore, although there is a lot of precipitation in Japan, the per capita available water resources are low. In areas with dry climate and less precipitation, such as the coast of Seto Inland Sea, residents even need to build water storage tanks to store water in dry season.

According to the Statistical Yearbook 2007 of the Statistics Bureau and the Statistical Institute of the Ministry of Internal Affairs and Communications of Japan, the longest river in Japan is Shinagawa, which is 367 kilometers long. Xinnongchuan originated in the south of Wujiaxinyue at the junction of saitama, Yamanashi Prefecture and Nagano Prefecture, and flowed into the Sea of Japan in Niigata. The river with the widest drainage area in Japan is Yinchuan, with a drainage area of 16840 square kilometers. The mainstream of Yinchuan originated in the mountainous area at the junction of Gunma County and Niigata County. Into the Pacific Ocean between Kunzi City in Chiba Prefecture and Shenqi City in Ibaraki Prefecture. Its basin area accounts for most of the Kanto Plain. In addition to these two rivers, other major rivers in Japan include Ishikawa and Tianyanchuan in Hokkaido. Northbound Sichuan, Awujing Sichuan, and the top of Northeast Sichuan; Arakawa in Kanto; Muchuan in central China; 40,000 rivers in the four countries; Tsukikawa in Kyushu, etc.

There are not many lakes in Japan. According to the information of the River Bureau of Japan's Ministry of Land, Infrastructure, Transport and Tourism, the largest lake in Japan is Lake Biwa in Shiga Prefecture, with an area of 670.3 square kilometers. Lake Biwa is a structural lake with a long history and diverse ecosystems, and it is also an important water source in Kansai region. The deepest lake is Tianze Lake in Akita Prefecture, with a maximum water depth of 423.4 meters. The lake with the highest altitude is Zhongchan Temple Lake in Tochigi Prefecture, with an altitude of 1.269 meters. Due to the frequent volcanic activities in Japan, there are many craters and fault lakes in Japan, such as Quxielu Lake, Shikoku Lake, Toyako Lake and Shihada Lake. There are some lakes in coastal areas, such as Balang Lake, Xiapu Lake, Binming Lake and Zhonghai Lake. In order to realize power generation and river development, Japan has also built many reservoirs, such as Heibu Reservoir and Deshan Reservoir.