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Calhoun County, Iowa
Calhoun County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 9,927. Its county seat is Rockwell City. History Calhoun County was formed on January 15, 1851, from open land originally named ''Fox County''. It was renamed in 1853 after the seventh US vice president secessionist John C. Calhoun. When the tracks of the Illinois Central Railroad were laid through the county in 1870, the county seat was moved from Lake City to Rockwell City. The first train reached Rockwell City on August 7, 1882, and the population count doubled in the same year. The first courthouse, built of wood, burned to the ground in 1884 and the county government moved into a nearby hotel. In 1913, the current courthouse was built. On July 6, 1893, Pomeroy was struck by a tornado that measured F5 on the Fujita scale. With a damage path wide and long, the tornado destroyed about 80% of the homes in Pomeroy. The tornado killed 71 people and injured 200. Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calhoun County Courthouse (Iowa)
The Calhoun County Courthouse, located in Rockwell City, Iowa, United States, was built in 1914. It was listed on the National Register of Historic Places in 1981 as a part of the County Courthouses in Iowa Thematic Resource. The courthouse is the fourth structure to house court functions and county administration. History When Calhoun County was established in 1855 there were no buildings suitable for a courthouse, so officials used their own homes. After Lake City was chosen as the county seat the following year a small structure was built for a courthouse. Additions were added to the building as space needs increased. The county seat moved to Rockwell City in 1877 and a new courthouse built for just over $2,000. County officials had their offices on the first floor and a courtroom was located on the second floor. The building was destroyed by fire in 1884. The county rented a hotel and a building in town for $1 a day to house offices and functions. Officials built another cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Corn Belt Plains
The Western Corn Belt Plains is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Iowa. It has been subdivided into fifteen Level IV ecoregions. Description Once covered with tallgrass prairie, over 75 percent of the Western Corn Belt Plains is now used for cropland agriculture and much of the remainder is in forage for livestock. A combination of nearly level to gently rolling glaciated till plains and hilly loess plains, average annual precipitation of 26–37 inches, which occurs mainly in the growing season, and fertile, warm, moist soils make this one of the most productive areas of corn and soybeans in the world. Major environmental concerns in the region include surface and groundwater contamination from fertilizer and pesticide applications as well as impacts from concentrated livestock production. Level IV ecoregions Northwest Iowa Loess Prairies (47a) The Northwest Iowa Loess Prairies ecoregion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ditch
A ditch is a small to moderate trench created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches are commonly seen around farmland, especially in areas that have required drainage, such as The Fens in eastern England and much of the Netherlands. Roadside ditches may provide a hazard to motorists and cyclists, whose vehicles may crash into them and get damaged, flipped over, or stuck and cause major injury, especially in poor weather conditions and rural areas. Etymology In Anglo-Saxon, the word ''dïc'' already existed and was pronounced ("deek") in northern England and "deetch" in the south. The origins of the word lie in digging a trench and forming the upcast soil into a bank alongside it. This practice has meant that the name ''dïc'' was given to either the excavation or the bank, and evolved to both the words "dike"/" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Tile
Tile drainage is a form of agricultural drainage system that removes excess sub-surface water from fields to allow sufficient air space within the soil, proper cultivation, and access by heavy machinery to tend and harvest crops. While surface water can be drained by pumping, open ditches, or both, tile drainage is often the most effective means of draining subsurface water. The phrase "tile drainage" derives from its original composition from ceramic tiles of fired clay, which were similar to terracotta pipes yet not always shaped as pipes. In the 19th century a C-shaped channel tile commonly was placed like an arch atop a flat tile, denominated the "mug" and "sole", respectively. Today, tile drainage is any variation of this original system that functions in the same mode. Commonly HDPE and PVC tubing denominated "tile line" is used, although precast concrete and ceramic tiles are still used. Typical pathways for agricultural drainage and the occasionally used pathways for tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetland
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially in the soils. Wetlands form a transitional zone between waterbodies and dry lands, and are different from other terrestrial or aquatic ecosystems due to their vegetation's roots having adapted to oxygen-poor waterlogged soils. They are considered among the most biologically diverse of all ecosystems, serving as habitats to a wide range of aquatic and semi-aquatic plants and animals, with often improved water quality due to plant removal of excess nutrients such as nitrates and phosphorus. Wetlands exist on every continent, except Antarctica. The water in wetlands is either freshwater, brackish or saltwater. The main types of wetland are defined based on the dominant plants and the source of the water. For example, ''marshes'' ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Prairie
Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina, Brazil and Uruguay, and the steppe of Romania, Ukraine, Russia, and Kazakhstan. Lands typically referred to as "prairie" (a French loan word) tend to be in North America. The term encompasses the lower and mid-latitude of the area referred to as the Interior Plains of Canada, the United States, and Mexico. It includes all of the Great Plains as well as the wetter, hillier land to the east. From west to east, generally the drier expanse of shortgrass prairie gives way to mixed grass prairie and ultimately the richer and wetter soils of the tallgrass prairie. In the U.S., the area is constituted by most or all of the states, from north to south, of North ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iowa Great Lakes
The Iowa Great Lakes, often referred to as ''Okoboji'', is a group of natural lakes in northwestern Iowa in the United States. There are seven lakes in the region totaling with the three principal lakes of the group being Big Spirit Lake, West Okoboji Lake, and East Okoboji Lake.''Okoboji, Milford, Spirit Lake, and Spirit Lake SE, Iowa''; 7.5 Minute Topographic Quadrangles, USGS, 1970 They are the largest natural lakes in the state of Iowa. The largest, Spirit Lake, is 5,684 acres (2,300 ha). The lake area extends to the north into Jackson County, Minnesota. The headwaters of Little Sioux River flow past the west side of the lake area. History The area around the Iowa Great Lakes was not known for permanent settlement by the Sioux The Sioux or Oceti Sakowin ( ; Dakota/ Lakota: ) are groups of Native American tribes and First Nations people from the Great Plains of North America. The Sioux have two major linguistic divisions: the Dakota and Lakota peoples (tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loess Hills
The Loess Hills are a formation of wind-deposited loess soil in the westernmost parts of Iowa and Missouri, and the easternmost parts of Nebraska and Kansas, along the Missouri River. Geology The Loess (, , or ) Hills are generally located between east of the Missouri River channel. The Loess Hills rise above the flat plains forming a narrow band running north–south along the Missouri River."Geology of the Loess Hills, Iowa" USGS These hills are the first rise in land beyond the , forming something of a "front range" for Iowa, and parts of Missouri and Nebraska adjacent to the Missouri River. The Loess land formations of Iowa extend north into South Dakota and is a feature of three st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loess
A loess (, ; from ) is a clastic rock, clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loesses or similar deposition (geology), deposits. A loess is a periglacial or aeolian processes, aeolian (windborne) sediment, defined as an accumulation of 20% or less of clay with a balance of roughly equal parts sand and silt (with a typical grain size from 20 to 50 micrometers), often loosely cemented by calcium carbonate. Usually, they are homogeneity and heterogeneity, homogeneous and highly Porosity#Porosity in earth sciences and construction, porous and have vertical capillaries that permit the sediment to fracture and form vertical cliff, bluffs. Properties Loesses are wikt:homogeneous, homogeneous, Porosity#Porosity in earth sciences and construction, porous, friable, pale yellow or buff (color), buff, slightly wikt:coherent, coherent, typically non-stratum, stratified, and often calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outwash Plain
An outwash plain, also called a sandur (plural: ''sandurs''), sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the glacier terminus, terminus of a glacier. As it flows, the glacier grinds the underlying rock surface and carries the debris along. The meltwater at the snout of the glacier deposits its load of sediment over the outwash plain, with larger boulders being deposited near the terminal moraine, and smaller particles travelling further before being deposited. Sandurs are common in Iceland where geothermal activity accelerates the melting of ice flows and the deposition of sediment by meltwater. Formation Sandurs are found in glaciated areas, such as Svalbard, Kerguelen Islands, and Iceland. Glaciers and icecaps contain large amounts of silt and sediment, picked up as they erosion, erode the underlying rocks when they move slowly downhill, and at the snout of the glacier, meltwater can carry this sediment away from the glacier and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kettle (landform)
A kettle (also known as a kettle hole, kettlehole, or pothole) is a depression or hole in an outwash plain formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of dead ice left behind by retreating glaciers, which become surrounded by sediment deposited by meltwater streams as there is increased friction. The ice becomes buried in the sediment and when the ice melts, a depression is left called a kettle hole, creating a dimpled appearance on the outwash plain. Lakes often fill these kettles; these are called kettle hole lakes. Another source is the sudden drainage of an ice-dammed lake and when the block melts, the hole it leaves behind is a kettle. As the ice melts, ramparts can form around the edge of the kettle hole. The lakes that fill these holes are seldom more than deep and eventually fill with sediment. In acidic conditions, a kettle bog may form but in alkaline conditions, it will be Mire, kettle peatland. Overview Kettles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hummock
In geology, a hummock is a small knoll or mound above ground.Bates, Robert L. and Julia A. Jackson, ed. (1984). "hummock." Dictionary of Geological Terms, 3rd Ed. New York: Anchor Books. p. 241. They are typically less than in height and tend to appear in groups or fields. Large landslide avalanches that typically occur in volcanic areas are responsible for formation of hummocks. From the initiation of the landslide to the final formation, hummocks can be characterized by their evolution, spatial distribution, and internal structure. As the movement of landslide begins, the extension faulting results in formation of hummocks with smaller ones at the front of the landslide and larger ones in the back. The size of the hummocks is dependent on their position in the initial mass. As this mass spreads, the hummocks further modify to break up or merge to form larger structures. It is difficult to make generalizations about hummocks because of the diversity in their morphology and se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
