Geographical environment of Jinxiang county

The geological structure of Jinxiang county is dominated by fault blocks, supplemented by wide and gentle wavy folds, which is a monoclinal structure inclined from south to north. Located in the northern wing of Heze and Yutai fault depressions, there are tertiary faults outside the southern boundary and Cambrian and Ordovician strata outside the northern boundary. The occurrence of strata is gentle, and the dip angle is generally between 8 ~ 15 degrees. Due to structural reasons, the dip angle of strata only increases in a few sections. Due to the fault block structure, the territory is naturally divided into south and north parts. The strike of the northern fault block is mainly near north-south, and that of the southern fault block is mainly near east-west. The four major faults are the natural dividing lines of the four major dividing lines in China. Namely: Heze fault in the north, Fushan fault in the south, Jinxiang fault in the west and Jiaxiang fault in the east. The active time is Paleozoic-Yanshanian.

The geomorphological features of Jinxiang County can be divided into two major landforms: the Yellow River Plain and low hills, and five micro-landforms: barren hills, terraced fields beside mountains, slightly inclined flat land, gentle slopes and depressions. The terrain inclines from southwest to northeast, and the natural slope is about 1/6000 ~ 1/8000. The altitude is between 34.50-39.50 meters, the height difference between north and south is 4. 1 meter, and the height difference between east and west is 3.9 meters.

Jinxiang Plain is the flood plain of the Yellow River. Due to the constant changes in the flow direction and velocity of the Yellow River when it overflows, complex landform features have been formed, including slightly inclined flat land, gentle slope land and depression.

Slightly flat, gentle terrain, the slope is generally less than 1/8000, the soil layer is deep, the groundwater resources are rich, and the soil is mostly fluvo-aquic soil, which is distributed in most areas of the county.

The gentle slope land is formed by river flooding and deposition, and can be divided into three types according to the ground morphology: gentle slope hill, hill slope and depression slope.

Depression is deposited by still water, which can be divided into shallow depression, trough depression with back river and dish depression according to ground morphology. The height difference between the bottom of the depression and the ground is 0.5 ~1.0m. ..

The hilly area of Jinxiang is very small, and there are only three places in Jihu Town: Yangshan, Geshan and Guoshankou. Its geological feature is Qingshishan, which is composed of CAMBRIAN limestone and Sinian limestone. It is a denuded low mountain with a gentle top and an island-like protrusion above the plain, with an altitude of 90.00 ~ 105.00 meters. From top to bottom, the hills are exposed rocks, barren slopes, terraces near mountains and micro-geomorphic units. Jinxiang county belongs to the continental climate of warm temperate monsoon, with the characteristics of winter and summer monsoon climate, with four distinct seasons, obvious differences between cold and hot seasons and dry and wet seasons, and uneven precipitation throughout the year.

Spring (March to May) is the transitional period of winter wind. The temperature rises rapidly and changes dramatically, with less precipitation, strong southwest wind, large evaporation and dry climate. During this period, the two climatic air currents in the north and south compete with each other, resulting in changeable weather and climate in spring. From April to May, there was a strong wind in the north and south, and the temperature rose rapidly. At this time, the warm air in the Pacific Ocean is beyond our reach, so the precipitation is scarce, so spring droughts often occur. However, in some years, warm and humid air is particularly active, and when cold and warm air meet in Huanghuai area, it will also cause rainy weather.

In summer (June-August), due to the control of continental warm and low pressure, the air pressure is the lowest in the whole year. The weather is hot and rainy, high temperature and high humidity, and there are often heavy rains, hail and even rainy days. The average temperature in summer is around 26 degrees, and it usually reaches the highest in July. Precipitation is concentrated in this season, accounting for about 65% of the whole year. Due to the northward retreat of Mongolian cold high, the activity of Pacific subtropical high is strengthened. Controlled by the warm and humid southeast monsoon, the territory is full of water vapor, precipitation and hot and humid. Generally, it enters the rainy season in late June and early July and ends in late August. Heavy rains are mostly concentrated in July and August. However, in some years, due to the control of the Pacific subtropical high, it is stable and less active, resulting in sunny, hot, high temperature and high pressure weather and summer drought.

In autumn (September ~165438+1October), the warm and humid maritime climate gradually recedes to the south, and the Mongolian high pressure increases rapidly. At this time, the temperature is suitable and gradually decreases, and the rainfall decreases. Because the subtropical high recedes to the south slower than the ground, the ground is cold and high, the upper air is warm and high, the vertical structure is stable, and there are few clouds and rains, so autumn is mostly sunny and brittle, and autumn drought often occurs. However, in some years, the cold air activity is weak, and the warm and humid air in the south is still very active, which leads to continuous autumn rain in the territory.

In winter (65438+February ~ February of the following year), Jinxiang County is located in the southeast of Mongolia High. Controlled by the powerful Mongolian high pressure. Cold air keeps invading south, prevailing northerly winds, less rain and snow, and the climate is dry and cold. Jinxiang County is located on the west side of Nansihu Lake in Huaihe River Basin and belongs to the alluvial plain in the lower reaches of the Yellow River. The water systems are all plain and sloping rivers, and most of them accept tourists' water. High water level in flood season is prone to waterlogging. The main rivers that directly enter the lake are Dongyu River, Laowanfu River, Xinwanfu River and Caihe River, which respectively accept the confluence of tributary rivers and form four major water systems.

Dongyu river system

Dongyu River (formerly known as Hongwei River) is the largest drainage river in Nansi Lake Basin. It is 1967 newly excavated large-scale backbone drainage channel, which is used to adjust the water system in the west of the lake, reduce the burden of the large catchment area of Nanyang Lake, and control the flood disaster in the lower reaches of Wanfu River Basin (mainly Jinxiang and Yutai). Because this river was excavated at the climax of the Cultural Revolution, it was named "Hongwei River". 1985 was renamed dongyuhe (meaning dongming county to Yutai county) in the national geographical names census. In Heze section, South Branch, North Branch and Shengli River are the three major tributaries of Dongyu River. The tributaries in Jinxiang are Baima River and Hui River in the upper reaches.

Laowanfu drainage system

The old Wanfu River was originally called Wanfu River, also known as Liulin River or Liuhe River. 1957 When the water system was adjusted, the part above Liutangba was merged into Nandaliao, and it was named Xinwanfu River after cutting and straightening, and the original Wanfu River below Liutangba was renamed Laowanfu River. There are Jinji River, Laihe River, Donggou River, Suhe River and Baima River in the lower reaches of the territory.

Xinwanfu water system

The new Wanfu River was named after the original upper section of Liutangba of Wanfu River was merged into Nanda Slip from 1956 to 1957 and was cut and straightened. Originated from the interception of Yu He River in the east branch of Daxuezhuang in Dingtao County, it flows through Dingtao, Chengwu and Juye, enters Jinxiang County in the west of Chen Hai Village in Mamiao Town, leaves the country in the east of Zhangshaobing Village in Buji Township, and enters Nanyang Lake in the south of Dazhou Village in Rencheng District. The total length is 77.4 kilometers, of which Jinxiang County is 30.9 kilometers long. The tributaries in China include Jincheng River, Youyigou, He Peng, Laoxigou, Dasha River and Wuhe River.

Caihe river system

Cai He and Beidaliu meet in the north of Wanche Village in Rencheng, and then enter Nanyang Lake after 6.5 kilometers. Before 1996, Beidaliu was called the main stream. When Jining Water Conservancy Records (1997 edition) divided lakes and rivers, it was named Caihe as the main stream. Caihe River, formerly known as Jinshan River and Jining River, entered the lake directly in history, originating from Huangpangzhuang, Jiaxiang County, entering Shangzhuang North of Jihu Town, leaving Jihupan Zhuangdong, and entering Nanyang Lake in the southeast of Dawanglou Village, rencheng district. The total length is 44 kilometers, and the county seat is 12 kilometers long. The tributaries in China are Beidaliu and Yushan River.

The geology of this county is a combination of uplift and depression. Its structural characteristics are mainly fault blocks, supplemented by wide and gentle wavy folds. The surface layer is Quaternary loose layer, and the overburden layer is 677.5 meters thick, which is mainly composed of mottled clay, clayey sand, gravel and gravel, belonging to impact flood deposition. The vertical distribution of groundwater is shallow-salty-light three-layer structure. The buried depth of shallow freshwater bottom interface is generally10 ~ 30m, which is an ideal available groundwater source. The buried depth of the interface between the middle layer and the salty bottom is generally 120 ~ 250 meters, and the water quality of this layer far exceeds the water quality standards for human and animal drinking water and industrial and agricultural water. Deep fresh water is buried deeply, so it is difficult to develop and replenish its source. The dynamics of shallow groundwater in this area is mainly affected by rainfall and industrial and agricultural water consumption, which changes periodically during the year. The groundwater level dropped significantly in spring, and it was the driest in late June. After the flood season, with the increase of rainfall, the groundwater level rose sharply and reached the peak in the following year 1 month. In the south of Jinxiang (hereinafter referred to as "Jinnan"), the upstream water was intercepted by the rubber dam in Cao Zhuang, Duyu River, Sima Town, and introduced into the inland rivers and ditches of the county for storage; In the northern part of the county, the Yellow River water is continuously introduced into Nansi Lake through the Ji Liang Canal, and the water level of the lake is increasing year by year. The groundwater level can be continuously increased by recharging groundwater. The arable land in Jinxiang county is mainly fluvo-aquic soil, and the soil surface texture is sandy soil, light soil, medium soil, heavy soil and clay in turn from west to east. Light soil and middle soil have the largest area, and their main characteristics are loose soil, easy to cultivate and suitable for the growth of fibrous roots crops. Especially after years of fertilization and improvement, the soil fertility is relatively high. According to the laboratory analysis, the pH value of the 0-20 cm topsoil in Jinxiang County is 7.0-8.0, which is weakly alkaline, the organic matter content is 1. 1%- 1.8%, the alkali-hydrolyzable nitrogen is 60-90 ppm, and the available phosphorus is 10. The contents of trace elements such as calcium, magnesium, sodium, manganese, iron, zinc and copper are high and comprehensive, which can effectively promote the normal growth and development of garlic and increase the yield per unit area.