Misplaced Pages

#726273

53-663: Gullies resemble large ditches or small valleys , but are metres to tens of metres in depth and width, are characterized by a distinct 'headscarp' or ' headwall ' and progress by headward (i.e., upstream) erosion . Gullies are commonly related to intermittent or ephemeral water flow, usually associated with localised intense or protracted rainfall events or snowmelt. Gullies can be formed and accelerated by cultivation practices on hillslopes (often gentle gradients) in farmland , and they can develop rapidly in rangelands from existing natural erosion forms subject to vegetative cover removal and livestock activity. The earliest known usage of

106-533: A UNESCO World Heritage Site . The site shows the remains of at least seven large aqueducts of up to 30 miles (48 km) in length feeding large supplies of water into the site. The gold-mining operations were described in vivid terms by Pliny the Elder in his Natural History published in the first century AD. Pliny was a procurator in Hispania Terraconensis in the 70s AD and witnessed

159-577: A nozzle called a "monitor", came about in the 1850s during the California Gold Rush in the United States. Though successful in extracting gold-rich minerals, the widespread use of the process resulted in extensive environmental damage , such as increased flooding and erosion , and sediment blocking waterways and covering farm fields. These problems led to its legal regulation. Hydraulic mining has been used in various forms around

212-685: A community to draw down local water tables when and where necessary without exacerbating drought problems at other times. Particularly in Colorado , the term ditch is also applied to open aqueducts that traverse hillsides as part of transbasin diversion projects. Examples include the Grand Ditch over La Poudre Pass , the Berthoud Pass Ditch, and the Boreas Pass Ditch. Herbicides may be used to maintain

265-422: A concentration plant. The facility processes nearly two million tons of tailings each month at a processing cost of below US$ 3.00/t (2013). Gold is recovered at a rate of only 0.20 g/t, but the low yield is compensated for by the extremely low cost of processing, with no risky or expensive mining or milling required for recovery. The resulting slimes are pumped further away from the built-up areas permitting

318-486: A ditch. Primarily this is done to deny refuge to weeds that would progress into the adjacent field, but may instead involve only broadleaf herbicides specifically to produce forage and/or hay. Ditches can provide forage or be harvested for hay . If herbicides are used, however, the resulting manure cannot necessarily be used in crop fields, because in some cases herbicides will pass through and produce crop injury. Hydraulic mining Hydraulic mining

371-804: A dyke is what a ditch is in the south of England, a property-boundary marker or drainage channel. Where it carries a stream, it may be called a running dike as in Rippingale Running Dike , which leads water from the catchwater drain , Car Dyke, to the South Forty Foot Drain in Lincolnshire (TF1427). The Weir Dike is a soak dike in Bourne North Fen , near Twenty and alongside the River Glen . Drainage ditches play major roles in agriculture throughout

424-500: A giant iron nozzle , called a "monitor". The extremely high pressure stream was used to wash entire hillsides through enormous sluices. By the early 1860s, while hydraulic mining was at its height, small-scale placer mining had largely exhausted the rich surface placers, and the mining industry turned to hard rock (called quartz mining in California) or hydraulic mining, which required larger organizations and much more capital. By

477-453: A natural stream sinuosity and a multi-terraced channel cross section appear to be key to maintain both peak ditch drainage capacity, and minimum net pollution and nutrient transport. Flooding can be a major cause of recurring crop loss—particularly in heavy soils—and can severely disrupt urban economies as well. Subsurface drainage to ditches offers a way to remove excess water from agricultural fields, or vital urban spaces, without

530-400: A study examined the geoenvironmental causes driving gully erosion. It focuses on catchment management for gully erosion and geotechnical analysis. Through fieldwork, data was gathered utilizing GIS and GPS methods. According to the study, gully erosion occurs throughout, with Nanka/Oko having the highest concentration. The gully characteristic map shows variations in length and depth, emphasizing

583-797: A trail of toxic waste, called " slickens ," that flowed from mine sites in the Sierras through the Sacramento River and into the San Francisco Bay. The slickens would contain harmful metals such as mercury . During this period, the industrial mining industry released 1.5 billion yards of toxic slickens into the Sacramento River. As the slickens traveled through California's water arteries , it deposited its toxins into local ecosystems and waterways. Nearby farmland became contaminated, which led to political pushback against

SECTION 10

#1732772094727

636-631: A variety and combination of processes. The erosion processes include incision and bank erosion by water flow, mass movement of saturated or unsaturated bank or wall material, groundwater seepage - sapping the overlying material, collapse of soil pipes or tunnels in dispersive soils, or a combination of these to a greater or lesser degree. Hillsides are more prone to gully erosion when they are cleared of vegetation cover through deforestation , over-grazing , or other means. Gullies in rangelands can be initiated by concentrated water flow down tracks worn by livestock or vehicle tracks. The flowing water easily carries

689-461: Is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin , the resulting water-sediment slurry is directed through sluice boxes to remove the gold. It is also used in mining kaolin and coal . Hydraulic mining developed from ancient Roman techniques that used water to excavate soft underground deposits. Its modern form, using pressurized water jets produced by

742-1027: Is a severe environmental problem that lowers crop quality and may cause famine and food shortages. It also causes the soil to lose organic content, which has an impact on plant viability. As items washed from fields end up in rivers, streams, or vacant land, erosion also contaminates the ecosystem. Because of increased population expansion and increasing land demand, erosion also threatens the natural ecosystem, encroaching on natural forests. Important assets including homes, power poles, and water pipelines may also be destroyed. Effective land management techniques can prevent gullies. These techniques include keeping vegetation along drainage lines, using more water, classifying drainage lines as distinct land classes, stabilizing erosion, preventing vermin, distributing runoff evenly, keeping soil organic matter levels high, and avoiding over-cultivation. These tactics guarantee uniform rates of penetration and robust plant coverage. One serious environmental problem endangering sustainable development

795-551: Is gully erosion. Gullying prevention and control methods are dispersed and lacking, and they have low success and efficacy rates. This review attempts to make a valuable contribution to effective gully prevention and management techniques by combining information from previous research. It is possible to stop the creation of gullies by changing how land is used, conserving water and soil, or implementing specific actions in areas with concentrated flow. Plant leftovers and other vegetation barriers can prevent erosion, although their usefulness

848-595: Is limited. The biophysical environment, terrain, climate, and geomorphology are examples of external elements that affect gully prevention and control. Stabilizing gullies entails altering water flow to lessen scouring, sediment buildup, and revegetation. Water can be securely moved from the natural level to the gully floor using a variety of structures, including drop structures, pipe structures, grass chutes, and rock chutes. Structural modifications can be required along steep gully floors. Vegetation can reestablish itself thanks to sediments deposited over flatter gradients. Until

901-562: Is localized in the Coastal Plain Sands, Nanka Sands, and Nsukka Sandstone of the Anambra-Imo basin region. The most affected deposits are unconsolidated or poorly consolidated and have short dispersion times. Public education is essential for a sustainable termination strategy, and collaboration between the government, donors, the private sector, and rural people is crucial. Gullies are widespread at mid-to high latitudes on

954-1009: Is the principal way that kaolinite clay is mined in Cornwall and Devon , in South-West England. Egypt used hydraulic mining methods to breach the Bar Lev Line sand wall at the Suez Canal, in Operation Badr (1973) which opened the Yom Kippur War . On the South African Rand gold fields, a gold surface tailings re-treatment facility called East Rand Gold and Uranium Company (ERGO) has been in operation since 1977. The facility uses hydraulic monitors to create slurry from older (and consequently richer) tailings sites and pumps it long distances to

1007-478: The California Gold Rush . Matteson used canvas hose which was later replaced with crinoline hose by the 1860s. In California, hydraulic mining often brought water from higher locations for long distances to holding ponds several hundred feet above the area to be mined. California hydraulic mining exploited gravel deposits, making it a form of placer mining . Early placer miners in California discovered that

1060-460: 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. In Anglo-Saxon , the word dïc already existed and was pronounced [diːk] ("deek") in northern England and [diːtʃ] "deetch" in

1113-529: The Sacramento River , then the Feather River to Marysville where they would unload their passengers and cargo. Marysville eventually constructed a complex levee system to protect the city from floods and sediment. Hydraulic mining greatly exacerbated the problem of flooding in Marysville and shoaled the waters of the Feather River so severely that few steamboats could navigate from Sacramento to

SECTION 20

#1732772094727

1166-490: The Sacramento Valley . Once the rivers reached the relatively flat valley, the water slowed, the rivers widened, and the sediment was deposited in the floodplains and river beds causing them to rise, shift to new channels, and overflow their banks, causing major flooding , especially during the spring melt. Cities and towns in the Sacramento Valley experienced an increasing number of devastating floods , while

1219-610: The world . Improper drainage systems accelerate water contamination , excessively desiccate soils during seasonal drought , and become a financial burden to maintain. Industrial earth-moving equipment facilitates maintenance of straight drainage trenches, but entrenchment results in increasing environmental and eventually profound economic costs over time. Sustainable channel design can result in ditches that are largely self-maintaining due to natural geomorphological equilibrium. Slowed net siltation and erosion result in net reduction in sediment transport . Encouraging development of

1272-664: The 1870s, hydraulic mining became a mainstay of alluvial tin mining on the Malay Peninsula . Hydraulicking was formerly used in Polk County, Florida to mine phosphate rock . In addition to its use in true mining, hydraulic mining can be used as an excavation technique, principally to demolish hills. For example, the Denny Regrade in Seattle was largely accomplished by hydraulic mining. Hydraulic mining

1325-599: The Marysville docks. The sediment left by such efforts were reprocessed by mining dredges at the Yuba Goldfields , located near Marysville. The spectacular eroded landscape left at the site of hydraulic mining can be viewed at Malakoff Diggins State Historic Park in Nevada County, California . The San Francisco Bay became an outlet for polluting byproducts during the Gold Rush. Hydraulic mining left

1378-501: The deeper subsurface is also a possible explanation for the formation of some Martian gullies. 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

1431-439: The economic development of land close to commercially valuable areas and previously covered by the tailings. The historic yellow-coloured mine dumps around Johannesburg are now almost a rarity, seen only in older photographs. Uranium and pyrite (for sulfuric acid production) are also available for recovery from the process stream as co-products under suitable economic conditions. High-pressure water jets have also been used in

1484-443: The eroded soil after being dislodged from the ground, typically when rainfall falls during short, intense storms such as thunderstorms . A gully may grow in length through headward (i.e., upstream) erosion at a knick point . This erosion can result from interflow and soil piping ( internal erosion ) as well as surface runoff . Gully erosion may also advance laterally through similar methods, including mass movement, acting on

1537-426: The erosion rates and pollution transport that results from direct surface runoff . However, excess drainage results in recurring drought induced crop yield losses and more severe urban heat island or desiccation issues. Controlled subsurface drainage from sensitive areas to vegetated drainage ditches makes possible a better balance between water drainage and water retention needs. The initial investment allows

1590-432: The gully walls (banks), and the development of 'branches' (a type of tributary ). Gullies reduce the productivity of farmlands where they incise into the land and produce sediment that may choke downstream waterbodies and reduce water quality within the drainage system and lake or coastal system. Because of this, much effort is invested into the study of gullies within the scope of geomorphology and soil science , in

1643-412: The least important issue. This implies a notable variation in the average evaluations across impacted individuals, underscoring the necessity for long-term repair approaches. Reducing soil loss, raising public knowledge of environmental issues, passing environmental legislation, and giving residents funds to strengthen their coping mechanisms are all advised by the study. In Agulu-Nanka, Southeast Nigeria,

Gully - Misplaced Pages Continue

1696-509: The mid-1880s, it is estimated that 11 million ounces of gold (worth approximately US$ 7.5 billion at mid-2006 prices) had been recovered by hydraulic mining . While generating millions of dollars in tax revenues for the state and supporting a large population of miners in the mountains, hydraulic mining had a devastating effect on riparian natural environment and agricultural systems in California. Millions of tons of earth and water were delivered to mountain streams that fed rivers flowing into

1749-415: The more gravel they could process, the more gold they were likely to find. Instead of working with pans, sluice boxes, long toms, and rockers, miners collaborated to find ways to process larger quantities of gravel more rapidly. Hydraulic mining became the largest-scale, and most devastating, form of placer mining. Water was redirected into an ever-narrowing channel, through a large canvas hose, and out through

1802-544: The most renowned legal fight of farmers against miners, the farmers sued the hydraulic mining operations and the landmark case of Woodruff v. North Bloomfield Mining and Gravel Company made its way to the United States District Court in San Francisco where Judge Lorenzo Sawyer decided in favor of the farmers and limited hydraulic mining on January 7, 1884, declaring that hydraulic mining

1855-563: The necessity of considering gully vulnerability and giving erosion hazards immediate attention. Gullies can be formed or enlarged by several human activities. Artificial gullies are formed during hydraulic mining when jets or streams of water are projected onto soft alluvial deposits to extract gold or tin ore . The remains of such mining methods are very visible landform features in old goldfields such as in California and northern Spain. The badlands at Las Medulas , for example,

1908-540: The operations himself. The use of hushing has been confirmed by field survey and archaeology at Dolaucothi in South Wales , the only known Roman gold mine in Great Britain . The modern form of hydraulic mining, using jets of water directed under very high pressure through hoses and nozzles at gold-bearing upland paleogravels, was first used by Edward Matteson near Nevada City , California in 1853 during

1961-543: The prevention of gully erosion, and the in remediation and rehabilitation of gullied landscapes. The total soil loss from gully formation and subsequent downstream river sedimentation can be substantial, especially from unstable soil materials prone to dispersion . When water is directed over exposed ground, gully erosion removes soil near drainage lines. This may result in divided properties, loss of arable land, diminished amenities, and decreased property values. Additionally, it can lead to sedimentation, discoloration of

2014-652: The rainier months. Gullies develop when a rill is neglected for an extended time, thickening and expanding as soil erosion persists. The factors influencing gully erosion were investigated in Zaria, Kaduna state, Nigeria, utilizing SRTM data, soil samples, rainfall data, and satellite imagery. The findings indicated that the factors that had the biggest effects on gully erosion were slope (56%) and rainfall (26%), land cover (12%), and soil (6%). The investigation concluded that each particular component significantly influenced soil loss. The loss of fertile farmland due to gully erosion

2067-406: The restoration is finished, damaged areas should be walled off. Eastern Nigeria's people and ecology are seriously threatened by gully erosion. A research project focused on 370 families and nine risk regions evaluated the region's gully erosion issues. The greatest perceived problem, according to the results, was biodiversity loss. In contrast, damage to properties, roads, and walkways was ranked as

2120-478: The rising riverbeds made navigation on the rivers increasingly difficult. Perhaps no other city experienced the boon and the bane of gold mining as much as Marysville . Situated at the confluence of the Yuba and Feather rivers, Marysville was the final "jumping off" point for miners heading to the northern foothills to seek their fortune. Steamboats from San Francisco , carrying miners and supplies, navigated up

2173-493: 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"/"dyke" and "ditch". Thus Offa's Dyke is a combined structure and Car Dyke is a trench, though it once had raised banks as well. In the English Midlands and East Anglia ,

Gully - Misplaced Pages Continue

2226-522: The surface of Mars and are some of the youngest features observed on that planet, probably forming within the last few 100,000 years. There, they are one of the best lines of evidence for the presence of liquid water on Mars in the recent geological past, probably resulting from the slight melting of snowpacks on the surface or ice in the shallow subsurface on the warmest days of the Martian year. Flow as springs from deeper seated liquid water aquifers in

2279-834: The term is from 1657. It originates from the French word goulet , a diminutive form of goule which means throat . The term may be connected to the name of a type of knife used at the time, a gully-knife. Water erosion is more likely to occur on steep terrain because of erosive pressures, splashes, scour, and transport. Slope characteristics, such as slope length and amounts proportionate to slope length, affect soil erosion. Relief and soil erosion are positively correlated in southeast Nigeria. There are three types of topography: mountains, cuesta landscapes, and plains and lowlands. While highlands with stable lithology avoid gullying yet allow for vigorous runoff, uplands with friable sandstones are more prone to erosion. Gully erosion can progress through

2332-620: The use of hydraulic mining. The slickens flowed through the Sacramento River before depositing itself into the San Francisco Bay. Currently, the San Francisco Bay remains dangerously contaminated with mercury. Estimates suggest that it will be another century before the Bay naturally removes the mercury from its system. Vast areas of farmland in the Sacramento Valley were deeply buried by the mining sediment. Frequently devastated by flood waters, farmers demanded an end to hydraulic mining. In

2385-409: The water supply, and creating a haven for rodents. Water rushing over exposed, naked soil creates gullies and ridges that erode rock and soil. When water rushes across exposed terrain, it erodes or pushes dirt away, creating rills. Gravity causes rift erosion on a downward slope, with steeper slopes generating greater water flow. Sandier terrains are more commonly affected by rills most prevalent during

2438-402: The water was then quickly released. The resulting wave of water removed overburden and exposed bedrock. Gold veins in the bedrock were then worked using a number of techniques, and water power was used again to remove debris. The remains at Las Médulas and in surrounding areas show badland scenery on a gigantic scale owing to hydraulicking of the rich alluvial gold deposits. Las Médulas is now

2491-616: The water-delivery hydraulic mining infrastructure had been destroyed by an 1891 flood, so this later stage of mining was carried on at a much smaller scale in California. Although often associated with California due to its adoption and widespread use there, the technology was exported widely, to Oregon ( Jacksonville in 1856), Colorado (Clear Creek, Central City and Breckenridge in 1860), Montana ( Bannack in 1865), Arizona ( Lynx Creek in 1868), Idaho ( Idaho City in 1863), South Dakota ( Deadwood in 1876), Alaska ( Fairbanks in 1920), British Columbia ( Canada ), and overseas. It

2544-543: The world. Hydraulic mining had its precursor in the practice of ground sluicing, a development of which is also known as " hushing ", in which surface streams of water were diverted so as to erode gold-bearing gravels. This technique was developed in the first centuries BC and AD by Roman miners to erode away alluvium . The Romans used ground sluicing to remove overburden and the gold-bearing debris in Las Médulas of Spain, and Dolaucothi in Great Britain . The method

2597-579: Was "a public and private nuisance" and enjoining its operation in areas tributary to navigable streams and rivers. Hydraulic mining on a much smaller scale was recommenced after 1893 when the United States Congress passed the Camminetti Act which allowed licensed mining operations if sediment retention structures were constructed. This led to a number of operations above sediment catching brush dams and log crib dams . Most of

2650-633: Was also used in Elizabethan England and Wales (and rarely, Scotland ) for developing lead , tin and copper mines. Water was used on a large scale by Roman engineers in the first centuries BC and AD when the Roman empire was expanding rapidly in Europe. Using a process later known as hushing, the Romans stored a large volume of water in a reservoir immediately above the area to be mined;

2703-662: Was called hydraulic sluicing . One notable location was at the Oriental Claims near Omeo in Victoria where it was used between the 1850s and early 1900s, with abundant evidence of the damage still being visible today. Hydraulic mining was used extensively in the Central Otago gold rush that took place in the 1860s in the South Island of New Zealand , where it was also known as sluicing . Starting in

SECTION 50

#1732772094727

2756-788: Was created during the Roman period by hushing or hydraulic mining of the gold-rich alluvium with water supplied by numerous aqueducts tapping nearby rivers. Each aqueduct produced large gullies below by erosion of the soft deposits. The effluvium was carefully washed with smaller streams of water to extract the nuggets and gold dust. Gully initiation results from localized erosion by surface runoff, often focusing on areas where forest cover has been removed for agricultural purposes, uneven compaction of surface soils by foot and wheeled traffic, and poorly designed road culverts and gutters. Termination of gully processes requires water-resource management, soil conservation, and community migration. Gully erosion

2809-704: Was used extensively in Dahlonega, Georgia and continues to be used in developing nations, often with devastating environmental consequences. The devastation caused by this method of mining caused Edwin Carter , the "Log Cabin Naturalist", to switch from mining to collecting wildlife specimens from 1875–1900 in Breckenridge, Colorado , US. Hydraulic mining was used during the Australian gold rushes where it

#726273