Describe the natural geographical environment of Dongying, with concise and accurate content.

Dongying City is located in the Yellow River Delta in northern Shandong Province. The Yellow River, the mother river of the Chinese nation, flows into the Bohai Sea in Dongying City. The geographical location of Dongying City is 36 55' ~ 3810' north latitude and18 07' ~110' east longitude. It borders Bohai Sea in the east and north, Binzhou City in the west, Zibo City and Weifang City in the south. The maximum longitudinal distance from north to south is123km, and the maximum lateral distance from east to west is 74km, with a total area of 7923km2.

Geological Dongying City is located at the eastern end of Jiyang Depression in North China Depression. The strata include Archaean Taishan Group, Paleozoic Cambrian, Ordovician, Carboniferous and Permian, Mesozoic Jurassic and Cretaceous, Cenozoic Tertiary and Quaternary. Proterozoic, Upper Ordovician, Silurian, Devonian, Lower Carboniferous and Mesozoic Triassic are missing. From north to south, the depressions and bulges mainly include Chengzikou bulge (east end), Chezhen sag (east), Yihezhuang bulge (east), Zhanhua sag (east), Chenjiazhuang bulge, Dongying sag (east half) and Guangrao bulge (part).

The landform inclines from southwest to northeast along the direction of the Yellow River. The highest elevation in the southwest is 28 meters (Dagu elevation, the same below), and the lowest elevation in the northeast is 1 meter, and the natural ratio is reduced to1/8000 ~112000. The highest altitude in the west is 1 1m, and the lowest altitude in the east is 1m, and the natural proportion is reduced to 1/7000. The Yellow River crosses the border, which is high near the river and low far away. The natural ratio of the river behind the river drops to 1/7000, and the floodplain is 2 ~ 4m higher than the river behind the river, forming a "suspended river on the ground". There are five types of micro-landforms in the city: ancient floodplain highlands, accounting for 4. 15% of the total area of the city, mainly distributed in the upper reaches of the Yellow River breach; Floodplain highlands, accounting for 3.58% of the city's total area, are mainly distributed between the Yellow River channel and the levee; Slightly inclined flat land, accounting for 54.54% of the city's total area, is a transitional zone between hills and depressions; Shallow depressions, accounting for 10.68% of the city's total area, are mainly distributed between the ancient floodplain highlands south of Xiaoqing River and the slightly inclined flat land between the gentle hills north of Xiaoqing River and the low-lying areas of the old Yellow River. Beach land accounts for 27.05% of the city's total area, which is distributed in a strip parallel to the coastline. (Shi Yan)

Climate Dongying City is located in the mid-latitude, backed by the sea, influenced by Eurasia and the western Pacific Ocean, and belongs to the continental monsoon climate of warm temperate zone. Its basic climate is characterized by Leng Xia heat in winter and distinct seasons. It is dry and windy in spring, and the temperature in early spring is changeable, often accompanied by spring cold, and it recovers quickly in late spring, often accompanied by spring drought; In summer, it is hot and rainy, hot and humid, and sometimes it is attacked by typhoons; In autumn, the temperature drops, the rain drops sharply, and the sky is crisp; In winter, the weather is dry and cold, the cold wind blows frequently, the north wind and northwest wind blow more, and the rain and snow are scarce. The main meteorological disasters are frost, dry hot wind, gale, hail, drought, waterlogging and storm surge. There is no obvious climate difference between north and south in China. The annual average temperature is 12.8℃, the frost-free period is 206 days, and the accumulated temperature ≥ 10℃ is about 4300℃, which can meet the needs of crops in two years and three seasons. The average annual precipitation is 555.9 mm, mostly concentrated in summer, accounting for 65% of the annual precipitation. The annual precipitation changes greatly, which is prone to drought and flood disasters.

In 20 10 year, the annual average temperature of the whole city is 13. 1℃, which is slightly 0.3℃ higher than normal. The annual precipitation is 548. 1mm, slightly less than normal 1%. Sunshine hours are 23 15.2 hours, less than normal 13%. The general climatic characteristics are as follows: the temperature in winter is slightly higher than normal, the temperature is low in stages, the temperature changes frequently, and the precipitation is basically the same as that in normal years; The temperature is slightly lower in spring, with uneven distribution of cold and warm, and the low temperature lasts for a long time. The precipitation is the same as normal, but there is a big difference between north and south. In summer, the temperature is high, the number of high temperature days is frequent, the precipitation is abundant but the spatial and temporal distribution is extremely uneven, drought or flood occurs in some periods, and thunderstorms, hail and other weather occur from time to time; The temperature in autumn is slightly higher than normal, and the precipitation is less than normal. There is basically no precipitation from the end of 10 to the end of10; At the end of the year (65438+February), the temperature was slightly higher and the precipitation was less. (Xin Zhihong)

Soil Urban soils are divided into five categories: cinnamon soil, Jiang Sha black soil, fluvo-aquic soil, saline soil and paddy soil. Cinnamon soil is mainly distributed in the south of Xiaoqing River, accounting for about 4% of the city's soil area, which is the high and stable yield area of grain, cotton and vegetables in the city. Black soil in Jiang Sha is mainly distributed in the low-lying areas of cinnamon soil area in the south of Xiaoqing River, accounting for 0.6% of the total soil area in the city. This kind of soil is suitable for planting shallow-rooted crops such as wheat, corn and sorghum, and it is a potential soil type in agriculture. Tidal soil accounts for 59% of the city's soil area and is the main cultivated soil in the city. After cultivation and improvement, it is suitable for planting crops such as wheat, corn and cotton. Saline soil is distributed in the offshore zone, accounting for 36% of the total soil area in the city. Natural vegetation includes reed, yellow beard, thatch and wormwood, which are mainly used for water conservancy development and animal husbandry (planting). Paddy soil is mainly distributed in Lijin and Kenli old rice areas, accounting for 0.2% of the total soil area. After more than 20 years of hydroponics, it has initially possessed the characteristics of young paddy soil.

The Dongying section of the Yellow River starts from Binzhou boundary, runs through Dongying City from southwest to northeast, and flows into Bohai Sea in the northeast of Kenli County, with a total length of138km. The runoff of the Yellow River varies greatly from year to year, with uneven distribution and large sediment concentration during the year. According to the measured data of Lijin Hydrological Station 1950 ~ 200 1 year, the average annual runoff of the Yellow River is 33.26 billion cubic meters, with the maximum of 97.3 1 100 million cubic meters (1964) and the minimum of10.8 billion cubic meters (/kloc). Maximum discharge10400 m3/s (1July, 958), minimum discharge and main flow interruption; The average annual sediment discharge is 836 million tons, with the maximum of 265,438+tons (1.958) and the minimum of1.500 million tons (1.997).

Since the 1990s, the annual runoff of the Yellow River has decreased and the flow has been cut off frequently. After 1999, the yellow river water resources commission strengthened the management of water transfer along the yellow river, and the phenomenon of water cut-off slowed down, and continuous flow was realized from 2000 to 20 10. In 20 10, the inflow of water from Lijin Station of the Yellow River was 20.08 billion cubic meters, 37.3% less than the historical average, and the inflow of sand was 654.38+69 million tons, 78.6% less than the historical average.

Besides the Yellow River, there are 30 backbone water systems in the city. Taking the Yellow River as the dividing line, the south of the Yellow River belongs to the Huaihe River Basin, including Xiaoqing River and its tributaries Zi River, Yang River, Nihezi River and Preparation River, tributaries Xiaohezi, Wujiadagou, Guangpu River and Wuganpai, Guangli River and its tributaries, Dongying River, Laoguangpu River, Wuliuhe River and Pai, Yongfeng River and its tributaries Sanpaigou, Weihe River and Xiaodao River. The north of the Yellow River belongs to the Haihe River Basin, with Chaohe and its tributaries Chuguan River, Taiping River, Maxin River, Lizhan River and Caoqiaogou, and the east main stream has Caoqiaogou, Tiao River, Shenxian River and its tributaries Dong Xinwei River 10 rivers.

The coastline of Dongying City in the sea area starts from Shunjianggoukou in the north and reaches Zimaigoukou in the south, with a total length of 4 12.67 km, accounting for about 1/9 of the coastline of Shandong Province. The beach area from "0" meters to the coastline is 10 19000 hectares. The shallow sea area within the negative 10 meter isobath is 4800 square kilometers. The coastal seabed is relatively flat, with shallow seabed muddy silt accounting for 77.8% and sandy silt accounting for 22.2%. The transparency of seawater is 32 ~ 55cm. The temperature and salinity of seawater are greatly influenced by continental climate and runoff of the Yellow River. In winter, there are two months of ice age along the coast, and the range of sea water flowing ice is 0 ~ 5 nautical miles, and the salinity is about 35 ‰; In spring, the seawater temperature is 12℃ ~ 20℃ and the salinity is 22 ‰ ~ 3 1 ‰. In summer, the seawater temperature is 24℃ ~ 28℃ and the salinity is 2 1 ‰ ~ 30 ‰. There is a low temperature and low salt water tongue near the Yellow River estuary all the year round. Dongying sea area is semi-enclosed, and most sections along the coast are irregular semidiurnal tides twice a day. The daily high and low tide range is generally 0.2 ~ 2m, and the high tide mostly occurs in March ~ April and July ~165438+1October, with the highest tide level exceeding 5m. Storm surge disasters are prone to occur, and there are 7 storm surge disasters with a height of more than 3.5 meters in a hundred years. Under the influence of the Yellow River and other rivers, the coastal waters are low in salinity, high in oxygen content, rich in organic matter and rich in bait, which is suitable for many kinds of fish and shrimp to find bait, reproduce and migrate.