The geographical environment of Wonju-gu

The territory spans the Sino-Korean quasi-platform and the Kunlun-Qinling geosyncline fold area. As far back as the Caledonian period, the ancient continental ridge running through the north and south of the territory rose along with the geosyncline fold faults, and large faults occurred on both sides of the ridge. Since the Mesozoic Era, after many uplifts and sedimentations, especially the Himalayan Movement at the end of the Tertiary Period of the Cenozoic Era, Liupanshan folds have risen from the ground, forming the terrane framework within the territory.

Except for the lack of Silurian, Devonian, Carboniferous and Permian strata within the territory, strata from other periods are exposed, such as: Sinian Great Wall System, Sinian Jixian System, Cambrian Series, Ordovician, Jurassic, Lower Cretaceous, Tertiary and Quaternary. In particular, the Quaternary system develops very widely, accounting for about 90% of the total area.

The rocks are mainly sedimentary rocks and metamorphic rocks, with only sporadic exposures of magmatic rocks. Such as intruding diabase and intruding Yunhuangite.

Wuanzhou District spans two structural units: the platform and the geosyncline. It is bounded by the Shijinghe to Haodian fault, the Qilian Mountains fold system corridor transition zone to the west, and the Ordos Platform Au, a quasi-platform between China and North Korea, to the east. After the Jinningian, Caledonian and Himalayan tectonic movements, the geosyncline history of this area ended. Especially the Yanshan and Himalayan movements led to strong new structures.

There are a variety of mineral deposits in the territory, which can be divided into four categories and 15 types: fuel minerals, metal minerals, building materials minerals and chemical raw material minerals. It is located in the middle of the hills of the Loess Plateau in southern Ningxia and the northeastern part of the Liupan Mountains. It has many mountains and few rivers. The south and west are the Liupan Mountains, the east are the loess hills, and the middle and the north are the Qingshui River Valley plains.

Liupan Mountains are located in the southwest of the territory, accounting for 33.2% of the total area of ??the county. It is composed of Daguan Mountain and Xiaoguan Mountain. The two mountains are arranged parallel to each other, running north-south. The base of the mountain is composed of sandstone, shale, conglomerate and limestone. Tertiary red soil is distributed on both sides of the mountain, and loess is accumulated in the foothills and piedmont hills.

Loess hills are widely distributed in the northeast of the county, accounting for 46.3% of the total area of ??the county. Except for bedrock exposure in a few places, the rest is covered by Quaternary loose loess. Due to erosion by running water, the terrain is fragmented with criss-crossing ravines, alternating beams and hills.

The Qingshui River Valley Plain is located in the north-central part of the county. It is a fault valley, embedded between Liupan Mountain and Gululiang. It starts from the county seat in the south and reaches Haiyuan and Tongxin counties in the north. The total length is 80 kilometers and the width is 15-20 kilometers. It is based on Paleozoic crystalline limestone, on which huge thicknesses of Cretaceous, Tertiary and Quaternary materials were deposited. The landform consists of loess plateau, piedmont alluvial fan and flood and alluvial plains.

The main peaks in the territory are: Liupan Mountain, Xianglu Mountain, Madu Mountain, Xumi Mountain, Heicheng Beishan, Watingliang, Huangmao Mountain, Dongyue Mountain, Chenger Mountain, Yunwu Mountain, and Tan Mountain. Wonju District is located in the warm temperate semi-arid zone. Because it is located inland, the terrain is high, and it is controlled by the air masses of the Eurasian continent and the Qinghai-Tibet Plateau, resulting in long and cold winters, variable temperatures in spring, short and cool summers, and rapid cooling in autumn; less rainfall in spring and early summer, and disastrous weather There are many climate characteristics such as large differences in regional precipitation.

The annual average temperature in the territory is about 6℃-6.2℃, with the coldest place at the top of Liupan Mountain being about 1℃, and the warmest place at Qiying being about 7.7℃. January, the coldest month in the year, has an average temperature of -14.3℃ and an extreme minimum temperature of -28.1℃; July, the hottest month in the year, has an average temperature of 24.7℃ and an extreme maximum temperature of 34.6℃. Due to different topography and altitude, regional temperature differences are large. The continental climate is very strong, so the temperature difference between day and night is large

The territory has sunny weather and sufficient sunshine. The average annual sunshine hours are 2518.2 hours, and the annual sunshine percentage is 57.3%. The sunshine percentage in December was as high as 7.%, and in September it was at least 47.3%. The sunshine hours decrease from north to south. The Qingshui River Valley plain in the north is flat and can reach full sunshine; the Liupan mountainous area in the southwest and the hilly area in the northeast reduce the sunshine hours because the hills block it.

Affected by the geographical environment, the territory has formed two precipitation characteristics: First, the precipitation gradually increases from north to south, forming a precipitation center in Liupan Mountain, with an annual precipitation of more than 600 mm, which is the highest level of surface water in Yuanzhou District. Second, the terrain is complex, the temperature difference between day and night is large, and the cold air from the northwest causes frequent heavy rains, rapid rainfall, and many flash floods. There are three systems of surface moisture: Qingshui River system, Jinghe River system, and Weihe River system. Among them, the Qingshui River system includes Qingshui River, Dongzhi River, Zhonghe River, Jianma River and Shijing River; the Jinghe River system includes Jiehe River and Ruhe River; and the Weihe River system includes Zhangyi River.

Groundwater is mainly distributed in the Qingshui River Valley plain and the southern mountainous area. The groundwater in the northeastern hills is poor and deeply buried. The water quality is good in the south and poor in the north. The total land area of ??the district is 5,826,048 acres, of which 5,461,526 acres are soil area, and 364,522 acres are river ditches, roads, towns, villages, and water areas. The county's soil is divided into 8 soil categories, 20 subcategories, 37 soil genera, and 119 soil species.

Black soil is a zonal soil formed under the bioclimatic conditions of semi-arid grasslands. It is widely distributed in loess hilly areas, covering an area of ??4,313,566 acres, accounting for approximately 74% of the total area. The soil layer is deep and the parent material is Quaternary loess. The soil particles are mainly coarse silt and are medium soil and light loam. It is divided into five subcategories: ordinary black soil, light black soil, eroded black soil, meadow black soil and black soil.

Meadow soil is a type of water-formed soil that is distributed on clear water riverbanks and beside ditches and rivers with long flowing water. The area is 16,838 acres, accounting for only 0.3% of the total area. It is divided into four subcategories: cultivated meadow soil, salted meadow soil, swamp meadow soil and swamp meadow soil.

New soil is a type of soil formed by alluvial, alluvial and wind accumulation. Due to the short deposition time, there is no obvious soil formation process, and the characteristics of the parent material at the time of original deposition are basically maintained. It covers an area of ??34,248 acres and is divided into five subcategories: new alluvial soil, new alluvial soil, new aeolian alluvial soil, new padded soil and new new soil.

Gray-brown soil, also known as mountain gray-brown soil, is the main vertical zonal soil in this county. The soil-forming parent material is mainly sandstone, shale residues and accumulations, and loess and laterite parent material are also found in some areas. The area is 1,066,708 acres, accounting for 18.3% of the total area, second only to black soil. It is divided into five subcategories: neutral gray-brown soil, calcareous gray-brown soil, dark gray-brown soil, erosional gray-brown soil, and gray-brown soil.

There are also soil types such as mountain meadow soil, mountain coarse bone soil, salt soil and exposed rocks.