Describe Dongying’s natural geographical environment in a short and precise manner.
The introduction to Dongying.com is very clear.
Dongying City is located in the Yellow River Delta area 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′～38°10′ north latitude and 118°07′～119°10′ east longitude. It borders the Bohai Sea to the east and north, Binzhou City to the west, and Zibo City and Weifang City to the south. The maximum longitudinal distance from north to south is 123 kilometers, and the maximum horizontal distance from east to west is 74 kilometers, with a total area of 7923 square kilometers.
Geology Dongying City is located at the eastern end of Jiyang Depression in the North China Depression. The strata from old to new include the Archaean Taishan Rock Group, the Paleozoic Cambrian, Ordovician, Carboniferous and Permian, Mesozoic Jurassic, Cretaceous, Cenozoic Tertiary and Quaternary systems; missing Proterozoic, Paleozoic Upper Ordovician, Silurian, Devonian, Lower Paleocarbon and Mesozoic Triassic. The depressions and bulges from north to south mainly include: Chengzikou bulge (east end), Chezhen sag (east), Yihezhuang bulge (east), Zhanhua sag (east), Chenjiazhuang bulge, Dongying sag (Eastern half), Guangrao salient (part), etc.
Landform: The terrain slopes from southwest to northeast along the direction of the Yellow River. The highest elevation in the southwest is 28 meters (Dago elevation, the same below), the lowest elevation in the northeast is 1 meter, and the natural ratio drops to 1/8000 to 1/12000; the highest elevation in the west is 11 meters, and the lowest elevation in the east is 1 meter, and the natural ratio Reduced to 1/7000. The Yellow River passes through the border. In the direction away from the river, the height near the river is high and the distance away from the river is low. The natural ratio behind the river is reduced to 1/7000. The river bottom is 2 to 4 meters higher than the land behind the river, forming a "hanging river on the ground." There are 5 types of micro landforms in the city: ancient river beach highlands, accounting for 4.15% of the city's total area, mainly distributed in the upper reaches of the Yellow River breach fan; river beach highlands, accounting for 3.58% of the city's total area, mainly distributed between the Yellow River channel and the levee; Sloping flat land, accounting for 54.54% of the city's total area, is the transition zone between hills and depressions; shallow flat land, accounting for 10.68% of the city's total area, is mainly distributed between the ancient river beach highlands to the south of Xiaoqing River, and to the north of Xiaoqing River. Among the slightly sloping flat land, between the gentle hills and in the low-lying areas of the old Yellow River; beach land, accounting for 27.05% of the city's total area, is distributed in a strip parallel to the coastline. (Historical Statement)
Climate Dongying City is located in mid-latitudes, with its back to the land and the sea. It is affected by the Eurasian continent and the western Pacific. It has a warm temperate continental monsoon climate, and its basic climate characteristics are cold winters. Summer is hot and the four seasons are distinct. Spring is dry and windy, and early spring is unstable, with late-spring cold often occurring. Late spring warms up quickly, and spring drought often occurs. Summer is hot and rainy, with high temperatures and humidity, and is sometimes invaded by typhoons. In autumn, the temperature drops, the rain drops sharply, and the sky is high. The air is refreshing; in winter, the weather is dry and cold, with frequent cold winds, mostly northerly and northwesterly winds, and little rain or snow. The main meteorological disasters include frost, hot and dry winds, strong winds, hail, drought, waterlogging, storm surges, etc. There is no obvious climate difference between the north and south of the territory. The annual average temperature is 12.8℃, the frost-free period is 206 days, and the accumulated temperature of ≥10℃ is about 4300℃, which can meet the three crops of crops in two years. The average annual precipitation is 555.9 mm, mostly concentrated in summer, accounting for 65% of the annual precipitation. Interannual precipitation changes greatly, easily causing droughts and floods.
In 2010, the city's annual average temperature was 13.1°C, slightly 0.3°C higher than normal; annual precipitation was 548.1 mm, slightly 1% lower than normal; and the number of sunshine hours was 2315.2 hours, 13% lower than normal. The general climate characteristics are: winter temperatures are normally slightly higher, with periodic low temperatures and frequent alternations of cold and warm, and precipitation is basically the same as normal; spring temperatures are normally slightly lower, with uneven distribution of cold and warm temperatures and long low temperatures, and precipitation is the same as normal but There is a large difference in precipitation between the north and the south; the temperature in summer is relatively high, high temperature days occur more frequently, the precipitation is abundant but the spatial and temporal distribution is extremely uneven, drought or rainstorms occur in some periods, and thunderstorms, hail and other weather events occur from time to time; the temperature in autumn is slightly normal. High, the precipitation is less than normal, and there is basically no precipitation from late October to the end of November; at the end of the year (December), the temperature is slightly higher than normal, and the precipitation is less. (Xinzhihong)
Soil The city’s soil is divided into five categories: cinnamon soil, sandy ginger black soil, fluvo-aquic soil, saline soil and paddy soil. Brown soil is mainly distributed in the area south of Xiaoqing River, accounting for about 4% of the city's soil area. It is a high-yield and stable production area of grain, cotton and vegetables in the city. Shajiang black soil is mainly distributed in the low-lying areas of Xiaoqing Henan brown soil area, accounting for 0.6% of the city's total soil area. This soil is suitable for growing shallow-rooted crops such as wheat, corn, and sorghum, and is a soil type with great potential in agriculture. Fluvo-aquic soil accounts for 59% of the city's soil area and is the city's main cultivated soil. It has been improved by cultivation and is suitable for growing wheat, corn, cotton and other crops. The salt soil is distributed in strips offshore, accounting for 36% of the city's total soil area. The natural vegetation includes reeds, yellow cabbage, thatch, mugwort, etc., and is mainly used for water and animal husbandry (plantation) development. Paddy soil is mainly distributed in the old rice areas of Lijin and Kenli, accounting for 0.2% of the total soil area. After more than 20 years of hydroponic maturation, it has initially acquired the characteristics of young paddy soil.
River: The Dongying section of the Yellow River starts from the Binzhou border, runs through the entire territory of Dongying City from southwest to northeast, and flows into the Bohai Sea in the northeast of Kenli County, with a total length of 138 kilometers. The runoff of the Yellow River varies greatly between years, is unevenly distributed within the year, and contains large amounts of sediment.
According to the measured data of Lijin Hydrological Station from 1950 to 2001, the average annual runoff of the Yellow River is 33.26 billion cubic meters, with a maximum of 97.31 billion cubic meters (1964) and a minimum of 1.88 billion cubic meters (1997); the maximum flow is 10,400 cubic meters per second ( July 1958), the minimum flow is a dry river; the average annual sediment load is 836 million tons, with a maximum of 2.1 billion tons (1958) and a minimum of 15 million tons (1997).
Since the 1990s, the annual runoff of the Yellow River has decreased, with frequent outflows. After 1999, the Yellow River Water Conservancy Commission intensified the management of water diversion in areas along the Yellow River, and the flow interruption phenomenon slowed down, achieving continuous flow from 2000 to 2010. In 2010, the water inflow to Lijin Station of the Yellow River was 20.08 billion cubic meters, 37.3% less than the historical average, and the sand inflow was 169 million tons, 78.6% less than the historical average.
Except for the Yellow River, the city has 30 backbone drainage rivers. Taking the Yellow River as the dividing line, the south of the Yellow River belongs to the Huaihe River Basin, including the Xiaoqing River and its tributaries Zihe, Yanghe, Nihezi, and Zhuihe Rivers, the Branchmai River and its tributaries Xiaohezi, Wujiadagou, Guangpu River, and Wuganpai River. , Guangli River and its tributaries overflow river, Dongying River, Laoguangpu River, Wuliuganhepai, Liuganpai, Yongfeng River and its tributaries Sanpaigou, Zhangzhen River and Xiaodao River 20 rivers; north of the Yellow River Belonging to the Haihe River Basin, there are 10 rivers including the Chaohe River and its tributaries Chuguan River, Taiping River, Masin River, Zhanli River, Caoqiaogou, Caoqiaogou East Mainstream, Tiaohe River, Shenxiangou and its tributary Xinweidong River.
Sea area: The coastline of Dongying City starts from the mouth of Shunjianggou River in the north and ends at the mouth of Zimaigou River in the south, with a total length of 412.67 kilometers, accounting for about 1/9 of the coastline of Shandong Province. The area of tidal flats from "0" meters to the shoreline is 101,900 hectares. The shallow sea area within the minus 10-meter isobath is 4,800 square kilometers. The seabed along the coast is relatively flat, with muddy silt accounting for 77.8% of the shallow seabed and 22.2% sandy silt. The transparency of sea water is 32 to 55 centimeters. Seawater temperature and salinity are greatly affected by continental climate and Yellow River runoff. There is a two-month glacial period along the coast in winter. The range of seawater ice drift is 0 to 5 nautical miles, and the salinity is about 35‰. In spring, the seawater temperature is 12℃~20℃, and the salinity is mostly 22‰~31‰; in summer, the seawater temperature is 24‰. The temperature is ℃ ~ 28 ℃, and the salinity is 21‰ ~ 30‰; there are tongues of low temperature and low salt water near the mouth of the Yellow River all year round. The Dongying sea area is semi-enclosed. The tides on most shore sections are irregular semidiurnal tides, which occur twice a day. The daily high and low tide difference is generally 0.2 to 2 meters. Spring tides mostly occur from March to April and July to November. In July, the highest tide level exceeds 5 meters. It is prone to storm surge disasters. In the past century, there have been 7 storm surge disasters with tide levels higher than 3.5 meters. Under the influence of the Yellow River and other rivers, the offshore sea has low salinity, high oxygen content, rich organic matter, and rich bait, which is suitable for feeding, breeding, and migration of various fish and shrimps.