Geological Landforms
Qingdao is a costal and hilly city, its terrain descends from east to west, uplifts along south and north and sinks in the middle.The mountain area accounts for approximately 15.5% of the city’s total area and the hilly area 2.1%, flatland 37.7% and depression area 21.7%. The city’s coast is formed by three basic types: the hilly rocky coast dotted with headlands and bays, mountainous harbor argillaceous silt coast and bedrock gravel coast. And there are underwater shoal, modern underwater delta and marine-erosion plain at the bottom of the shallow sea.
The geotectonic location of Qingdao belongs to the secondary tectonic unit of the New Huaxia Uplift Belt- the northeast edge of Jiaonan uplift area and the south middle part of Jiaolai depression area. The whole Paleozoic strata and part of mid Mesozoic strata are absent in this area, but volcanic rock of the Cretaceous are well developed and exposed widely in the city. Magmatic rocks mainly include Jiaonan-period Yuejishan Mountain type gneissose granite in the Proterozoic era, late Yanshanian Aishan Mountain type granodiorite in the Mesozoic era and granite in Laoshan Mountain area. The entire downtown area lies on such granite enabling a stable natural foundation for construction on it. The geological structure of this region is mainly governed by the fault structure. The fault block uplift is relatively stable in its entirety and the rise in general is not big in this region since the tertiary period.
The Mountains
The city has three major mountain ridges. Laoshan Mountain is located at the southeast part of the city; it is steep and extends westward and northward to the downtown area with the peak reaching 1,132.7 m above sea level. Daze Mountain stands in the north with its peak at 736.7 m above sea level and all the mountains of Pingdu and part of the mountains in Laixi belong to Daze Mountain. The Jiaonan mountain group composed of Dazhu Mountain (peak at 486.4 m above sea level), Xiaozhu Mountain (peak at 724.9 m above sea level), Tiejue Mountain (peak at 595.1m above sea level) and other mountains are located in the southern part of the city. The hill ridge in downtown consists of Fushan Mountain (peak at 384 m above sea level), Taiping hill (peak at 150 m above sea level), Qingdao Hill (peak at 128.5m above sea level), Xinhao Hill (peak at 99 m above sea level), Fulong Hill (peak at 86m above sea level) and Zhushui Hill (peak at 80.6 m above sea level), etc.
The Rivers
Overview: Qingdao has 224 rivers of different sizes that are all of monsoon region rain source type and most of them are small rivers that originate from mountains and run into the sea with their own estuaries. There are 33 relatively large rivers with over 100 square kilometers basin area. And the city has three main water systems, i.e. Dagu River, North Jiaolai River and the coastal rivers.
The Dagu River water system includes the main stream of Dagu River and its tributaries like Xiaogu River, Wugu River, Liuhao River and South Jiaolai River. Originating from Fu Mountain of Zhaoyuan City, Dagu River is the largest river of Qingdao; it flows southward into Qingdao crossing Laixi, Pingdu, Jimo, Jiaozhou and Chengyang before emptying into the sea at Nanmatou Village of Jiaozhou. The river is 179.9 km long with its basin area of 6,131.3 km2 (including 1,500 km2 basin of South Jiaolai River) and it is the largest water system at Jiaodong Peninsula. The annual average runoff volume of Dagu River is 661 million m3. Before 1970’s, the river had a clear seasonal feature: water level rising quickly in summer due to flood and having water all year round; but afterwards, except the flood season, the middle and lower reaches of the river dry up.
North Jiaolai River water system includes the North Jiaolai River and its tributaries and the main tributaries within the boundary of Qingdao are Ze River, Dragon King River, Xian River and White Sand River with a total basin area of 1,914 km2. Originating from the northern slope of the watershed of Yaojia Village of Pingdu City, North Jiaolai River flows northward along the border of Pingdu City and Changyi City and leaves Qingdao at Damiaojia Village, Xinhe Town of Pingdu City before emptying into Laizhou Bay. The main stream of the river is 100 km long with a basin area of 3,978.6 km2. And the annual average runoff volume of the river is 253 million m3 and the mean annual sediment content is 0.24 kg/ m3.
The Coastal Rivers System refers to the rivers that flow into the sea with their own estuaries. The major rivers include White Sand River, Moshui River, Wanggezhuang River, White Horse River, Jili River, Zhoutuan River and Yang River.
The Sea area and tides
Coastline and bays: The total sea area of Qingdao is about 12,200 km2, in which the sea area within the territorial sea baseline is 8,405 km2. The total length of the coastline (including the coastline of its islands) is 816.98 km, including 710.9 km mainland coastline which represents more than 1/4 of the coastline of Shandong Province. The coastline is winding with capes and bays alternatively distributed. The bays with an area of more than 0.5 km2 are scattered from north to south including Dingzi Bay, Kaolao Bay, Yanshui Bay (also called Hengmen Bay), Laoshan Bay (also called North Bay), Xiaodao Bay, Wanggezhuang Bay, Qingshan Bay, Yaodao Bay, Taiqing Palace Mouth, Liuqinghe Bay, Laoshan Mouth, Shazikou Bay, Maidao Bay, Fushan Bay, Taiping Bay, Huiquan Bay, Qianhai Bay (also called Zhanqiao Bay), Jiaozhou Bay, Tangdao Bay, Lingshan Bay, Ligen Bay, Guzhen Mouth, Zhaitang Bay, Dongjiakou Bay, Muguandao Bay, etc. And there’re 49 bays within Jiaozhou Bay, including Haixi Bay (including Xiaocha Bay, Xuejiadao Bay), Huangdaoqian Bay, Hongdao Bay, Nugu Mouth, Cangkou Bay, etc.
Islands: There were originally 70 islands in Qingdao. In 1987, Zhaitang Front Island and Zhaitang Back Island were connected by an artificial embankment into one Zhaitang Island and Qianliyan Isle was included into the jurisdiction of Haiyang. In 2006, three islands not officially reported (Shidao Reef, Daqiao Island and Xiaoqiao Island) were confirmed through satellite remote sense imaging and field investigation, while Huangdao and Tuandao were not in the list of islands any longer as they had lost their attribution of island. At present, there’re 69 islands in Qingdao, in which Water Island, Donkey Island, Little Qingdao Island, Xiaomaidao Island, Tuandao Nose Island, Ox Island and Ji Island are connected to the continent by artificial embankments and only 62 islands are surrounded by sea. The total area of the 69 islands is 13.82 km2 with a coastline of 106.08 km in total. Most of the islands are small. Only Tianheng Island and Lingshan Island have an area of more than 1 km2, while the area of the other islands is all less than 0.6 km2 each. Among the 69 islands, only 10 islands are inhabited by permanent residents.
Tides: Qingdao is a regular semi-diurnal tidal harbor with two high tides and two low tides on each lunar day (24 hours and 48 minutes). The average tidal range is approximately 2.8 m. The spring tidal range occurs 2 or 3 days after the 1st or the 15th date of the lunar month (the first quarter or the last quarter). The tide level in August is normally 0.5 m higher than that in January. In China, the average tide level observed at Qingdao Tide Station is taken for the average sea level of the Yellow Sea. The height of Qingdao Tide Station is 72.289 m lower than China national base leveling origin on Qingdao Observatory Hill. Since 1957, this height has been taken as the zero point for calculating the terrain elevation of the Mainland China.
The Climate
Qingdao is located in the monsoon region of the North Temperate Zone and belongs to the monsoon climate of medium latitudes. The downtown has obvious characteristic of marine climate due to the direct regulation of marine environment and influence of southeast monsoon, ocean current and water mass coming from the ocean. It has moist air, abundant rainfall, moderate temperature and distinct four seasons. Spring comes one month later than inland and the temperature rises slowly; in summer, it’s humid, hot and rainy but there are seldom very hot days; in autumn, the sky is clear and the air is crisp with less rainfall which is evaporated quickly; in winter, the windy and cold weather lasts long. According to the meteorological documents of over 100 years since 1898, the annual average temperature of the downtown is12.7℃, the extremely high temperature was 38.9℃(July 15th, 2002) and the extremely low temperature was -16.9℃(January 10th, 1931). August is the hottest month of the year with an average temperature of 25.3℃; January is the coldest month with an average temperature of -0.5℃. On the average, there’re 11.4 days per year with the maximum temperature higher than 30℃ while 22 days per year with the minimum temperature lower than -5℃. The annual average rainfall is 662.1 mm and the rainfalls of spring, summer, autumn and winter represent 17%, 57%, 21% and 5% of the total annual rainfall respectively. The maximum annual rainfall is 1,272.7 mm (1911) and the minimum is 308.2 mm (1981), and the annual variability of rainfall is 62%. On the average, there’re only 10 days per year with snowfall. The annual average air pressure is 1,008.6 Mbar. The annual average wind speed is 5.2 m/sec dominated by south wind and east wind. The annual average relative humidity is 73% with the maximum humidity of 89% in July and the minimum humidity of 68% in December. Qingdao is foggy and the sea fog occurs frequently. On the average, there’re 51.3 days with smog and 108.2 days with mist every year.
The Soil
Overview: According to the land classification system of the second national soil survey, the soil of Qingdao is divided into 5 categories: brown soil, mortar black soil, alluvial soil, cinnamon soil and saline soil.
Brown soil occupies an area of 493,700 hectares representing 59.8% of total soil area of Qingdao. It’s the soil kind that has the widest distribution and occupies the largest area in Qingdao. It’s mainly distributed in mountains, hills and piedmont plains. The degree of development of the soil is influenced by topographic location. It is divided into 3 families: young brown earth, brown earth and meadow brown earth. The young brown earth is mostly used for forestry and animal husbandry due to its higher topographic location, bigger gradient, thin soil layer, serious erosion and lower fertility while the brown earth and the meadow brown earth serve as the planting soil for main food and economic crops of Qingdao.
Mortar black soil occupies an area of 176,900 hectares representing 21.42% of the total soil area of Qingdao. It’s mainly distributed in the depression in the southwest of Laixi, in the southwest of Pingdu, in the northwest of Jimo and in the north of Jiaozhou. This category of soil is deep, thick and sticky. The topsoil is from light loam to heavy loam with poor physical characteristics, inconsistent water conductivity, air permeability, heat conductivity and low content of available nutrient.
Alluvial soil occupies an area of 14.49 hectares representing 17.55% of the total soil area of Qingdao. It’s mainly distributed in the downstream flatland of Dagu River, Wugu River and Jiaolai River. Due to different distance from the river way, the soil quality and the soil structure are very different. The salinized alluvial soil is formed in the offshore area which are frequently influenced by sea salt, so the fertility and the usage of the soil are very different.
Cinnamon soil occupies an area of 6,333.33 hectares representing 0.77% of the total soil area of Qingdao. It’s sporadically distributed in the middle and upper part of monadnock of limestone in Pingdu, Laixi and Jiaonan.
Saline soil occupies an area of 3,666.67 hectares representing 0.44% of the total soil area of Qingdao. It’s distributed in coastal lowland and bottomland.
