Term
| Factors that Influence Mass Wasting |
|
Definition
* nature of materials involved (rocks, sediments, soil, ect.)
* steepness of slope
* water
* vegetation
* heights
* climate (such as freeze-thaw cycles)
* presence and orientation of planes of weakness (such as joints, bedding, foliations)
* some human activities |
|
|
Term
|
Definition
| the down slope (hill) movement of rock, soil, or sediment under the influence of gravity |
|
|
Term
|
Definition
| general term that applies to all slides, flows and falls that occur at a fast or moderately fast rate. |
|
|
Term
| Thistle landslide of 1983 |
|
Definition
| This Utah landslide began moving in the spring of 1983 in response to groundwater buildup from heavy rains the previous September and the melting of deep snowpack. Within a few weeks the landslide dammed the Spanish Fork River, obliterating U.S. Highway 6 and the main line of the Denver and Rio Grande Western Railroad. The town was inundated under the floodwaters rising behind the landslide dam. Total costs (direct and indirect) incurred by this landslide exceeded $400 million, most costly single landslide in U.S. history. |
|
|
Term
|
Definition
| a slow downhill movement of ground surfaces process based on wetting and drying (or freezing and thawing) cycles. Its signs are subtle, but building designs must account for damage danger of destroying foundation, highways, underground pipelines or railways. |
|
|
Term
|
Definition
| In _______, material moves as coherent mass along curved surfaces. This motion results in a slightly backward rotation of blocks. |
|
|
Term
|
Definition
| The distal end, ______ of the slump moves along a less steep surface. |
|
|
Term
|
Definition
| occurs at the slowest rate of mass wasting processes, often at a cm/year or less. |
|
|
Term
|
Definition
| fast-moving landslides that occur in a wide variety of environments. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. Materials carried can vary in size from mud to large boulders (and include other objects in their path, such as trees, trucks, pieces of houses, etc). The type of motion is a turbulent flow. |
|
|
Term
|
Definition
| commonly triggered by heavy rains on steep slopes that loose rock debris and soil. Many contain significant amounts of water, some have little or no water. |
|
|
Term
| factors that influence the infiltration versus runoff |
|
Definition
* the permeability of the surficial material
* the slope of the land
* amount and type of vegetation
* recent amounts of precipitation (degree of saturation of the land) |
|
|
Term
|
Definition
| Runoff occurs either as sheet flow, or it occurs in channels. Channelized runoff is referred to as a _______ |
|
|
Term
|
Definition
| amount of sediment that a stream can transport |
|
|
Term
|
Definition
| the amount of water flowing pass a point on a stream per unit time |
|
|
Term
|
Definition
| The largest particle a stream can transport ________, depends on its velocity. |
|
|
Term
|
Definition
| Depending on the _______ of a stream, sediment is carried either in suspension in the water column, or the sediment is dragged, rolls, or hops along the bottom (bed) of the stream channel. |
|
|
Term
|
Definition
| suspended load of mud and silt causes a stream to be ________ |
|
|
Term
| velocity & discharge are greater |
|
Definition
| During certain times when the stream's _________ and _______ are ________, this stream can carry suspended sand and move cobbles |
|
|
Term
| characters which define velocity of a stream |
|
Definition
* stream gradient (slope of surface over which it flows)
* the size and shape of the channel
* channel roughness
* discharge |
|
|
Term
|
Definition
| But streams are never perfectly straight, nor symmetrical in cross-section, so within streams are currents ___________________ |
|
|
Term
|
Definition
| In a straight stream having a channel with a symmetrical, U-shaped cross-section, the fastest current would be in the ______ of the stream, slightly below the water surface |
|
|
Term
|
Definition
| close to the bed and channel walls, velocity is slowed by _____ ______ |
|
|
Term
|
Definition
| Streams develop curves or bends called ________ |
|
|
Term
|
Definition
| Water flowing into a meander tends to "pile up" on the outside of the meader, and the stream velocity is ______ there on the outside of the bend, than it is on the inside. |
|
|
Term
|
Definition
| Because the stream velocity and discharge increases along the outside of the meander, a stream will begin to _______ ___ _____ _____, by eroding the bank and deeping the channel there. |
|
|
Term
|
Definition
| In ____ ______, a stream channel can becomes assymetrical - deeper near the cut-bank and shallower near the point bar. |
|
|
Term
|
Definition
| As erosion over steepens the ____ _____, it undergoes mass wasting. Some to much of this addition to the sediment load of the stream might be deposited along ____ _____, farther down stream. |
|
|
Term
| stream velocity / point bars |
|
Definition
| Because ____ _____ on the inside of a meander slows down, this loss of energy results in the stream depositing some of the sediment it is carrying. This deposition begins to fill in the channel along the inside of the curve forming ______ ______. |
|
|
Term
|
Definition
| generally sand or gravel, the ____ _____ can be seen as the white to tan areas (beaches) along the river channels and on the inside of meanders. |
|
|
Term
|
Definition
| Process of deposition of point bars (filling channels on the inside of meander bends) and cutting back banks on the outside of meander bends, results in meanders becoming more winding. It also is a way in which streams can _____ ______, across their flood plains |
|
|
Term
|
Definition
| As the cut banks of small meanders are eroded back and point bars on the opposite sides of the channels advance, two small meanders will migrate toward each other. When they converge, a ________ will form. |
|
|
Term
|
Definition
| a crescent-shaped lake lying alongside a winding river. The ____ ______ is created over time as erosion and deposits of soil change the river's course. |
|
|
Term
|
Definition
| typical ____ _____ of a stream represents the elevation of point along the length of a stream. |
|
|
Term
|
Definition
| Near the headwaters (source) of a stream its gradient is the _______. |
|
|
Term
|
Definition
| With increasing distance downstream the gradient becomes ______. |
|
|
Term
|
Definition
| Where the stream is close to base level (near its mouth), its gradient becomes _______ ____, thus it has little ability to deepen its channel by downward erosion. |
|
|
Term
|
Definition
| It is along reaches of a stream where it is far above base level, where its ______ __ _____, that down-cutting of stream valleys is most active. |
|
|
Term
|
Definition
| that level below which a stream can not erode. |
|
|
Term
|
Definition
| For rivers that flow in to an ocean, base level is _____ _____. ____ ____ can be considered the ultimate base level for all streams. |
|
|
Term
|
Definition
| As a stream deepens its valley, by downward erosion, over steepened valley walls undergo mass wasting, thereby feeding sediment to the stream to be carried away. Valley walls thus retreat away from the stream, i.e. valleys widen and highland divideds between valleys become lower and less extensive. Widened valley floors provide larger areas over which meanders migrate and flood plains expand. So as streams evolve in their long profile - toward base level, so too does the landscape across which streams flow. Tectonic forces raise the land often to great heights above sea level, and the streams lower and sculpture the landscale. Were tectonic forces to cease forever, streams (and glaciers) eventually would reduce the land surface of the Earth to an almost horizontal plain, slightly above the ocean tidal zone. |
|
|
Term
| mass wasting, (Rio Grande River) |
|
Definition
| The steep valley walls meet the channel - there is very little to no flood plain. As the stream downcuts the steep valley, the valley walls rereat by _____ _____. Here meanders are only midly expressed, as the stream does most of its erosion work cutting down and not laterally. |
|
|
Term
| characteristics of streams far above base level |
|
Definition
* V-shaped valleys
* steep valley walls
* actively downcutting channel and valley
* absent to narrow flood plain
* fairly straight channels (no well developed meander belt)
* steep stream gradients |
|
|
Term
|
Definition
| ______ ____ widens the valley profile. River bends become more pronounced producing meanders. A flood plain begins to form on the valley floor. |
|
|
Term
|
Definition
| The ____ ______ of the stream is the width of the meanderbelt (note the outside of each meander bend cuts into the valley wall). |
|
|
Term
| characteristics of streams near base level |
|
Definition
* they are contained in very broad valleys
* very low stream gradients (nearly flat long profile)
* broad and complex meander belts with such features as cutoffs andoxbow lakes
* flood plains are many times wider than meander belt |
|
|
Term
|
Definition
| stream with V-shaped valley and no flood plane (stream far above base level). However, it also possess a complex and broad meander belt (stream close to base level). evidence that the stream was once close to base level (when it developed the meanders across a broad flood plain). Now the stream is far above base level and therefore spending its energy down cutting into the rock. |
|
|
Term
| characteristics of rejuvenated stream |
|
Definition
* entrenched meanders
* paired river terraces
* terraces |
|
|
Term
| entrenched (incised) meanders |
|
Definition
| Those meanders cut down into deep and steep V-shaped valleys are referred to as ______ ________. |
|
|
Term
|
Definition
| ___________ can occur either by changes in base level (such as sea level changes between ice ages and warmer periods) or tectonic changes in the elevation of the land (uplift or subsidence. |
|
|
Term
|
Definition
| Streams are _________ when they are suddenly brought far above their base level, after having evolved closed to base level. |
|
|
Term
|
Definition
| The flat surfaces up on the valley walls are _____ _____. They are what is left of the old flood plain of the stream. |
|
|
Term
|
Definition
| As rain sinks into the ground, it becomes ________ , the mass of water stored beneath the Earth's surface. |
|
|
Term
|
Definition
| Each of the environments in which water is stored is a ________ . The oceans, glaciers, polar ice, undergound waters, lakes, rivers, the atmosphere and even the biosphere are considered natural _________ of water on the earth. |
|
|
Term
| human interference with hydrological cycle |
|
Definition
# Evaporation is increased by the use of irrigation waters in dry areas.
# Runoff patterns are altered when water is diverted from one region to another. |
|
|
Term
| human interference with hydrologic cycle |
|
Definition
# Paving that covers Earth's surface with highways, parking lots, and buildings decreases infiltration.
# contributions to global and local warming can lead to melting of glacial ice and changes in the balance of water in other reservoirs.
# Removal of natural vegetation and forest decreases infiltration and changes in vegetation can affect transpiration. |
|
|
Term
|
Definition
| The only space available for water to move underground is the ____ ____ between grains of sand and other particles that make up the soil and bedrock and the space in fractures. ______ are found in every kind of rock and soil, and the largest amounts of ____ ____is found in sandstones and limestones. |
|
|
Term
|
Definition
| The amount of pore space in rock, soil or sediment is the ______, or the percentage of its total volume that is taken up by pores. _______ depends on the size and shape of the grains and how they are packed together. The smaller the particles and the more they vary in shape, the more tightly they will fit together. |
|
|
Term
|
Definition
| The ability of a solid to allow fluids through is its _______, this also depends on the sizes of the pores, how well they are connected, and how tortuous the path water must travel to pass through the material. |
|
|
Term
|
Definition
| At shallower depths, the rock and soil is _________; that is, the pores contain some air and are not completely filled with water. This level is called the _______ ______ . |
|
|
Term
|
Definition
| the level in which the pores of the soil or rock are completely filled with water. |
|
|
Term
| groundwater table / water table |
|
Definition
| The saturated and unsaturated zones can be in either unconsolidated material or bedrock. The boundary between these two zones is the ________ ____, also known as just the "______ ______". |
|
|
Term
|
Definition
| _______ is the infiltration of water into any subsurface formation, often by infiltration of rain or snow meltwater from the surface |
|
|
Term
|
Definition
| ______ may also take place through the bottom of a stream where the stream channel lies at an elevation above that of the water table. Streams that ______ in this way are called ______ streams , and they are most characteristic of dry, arid regions, where the water table is deep. |
|
|
Term
|
Definition
| ________ is the opposite of recharge: the exit of groundwater to the surface. When a stream channel intersects the water table, water _________ from the groundwater to the stream as an effluent stream. These streams are typical of humid areas. |
|
|
Term
|
Definition
| In ________ _______, the water travels through beds that extend with more or less uniform permeability to the surface, in both discharge and recharge areas. The level of the reservoir in an __________ _______ is the same as the height of the water table |
|
|
Term
|
Definition
| Many permeable aquifers are bounded above and below by shale beds of low permeability, these relatively impermeable beds are ________ , and groundwater either cannot flow through them or flows through very slowly. |
|
|
Term
|
Definition
| When aquicludes lie both over and under an aquifer, they form a ________ ______ in which water flow is contained under pressure. |
|
|
Term
|
Definition
| Water in a confined aquifer is known as an ________ _____and is under pressure equivalent to the weight of all the water in the aquifer above that point. |
|
|
Term
|
Definition
| A well that is drilled into a confined aquifer at a point where the elevation of the ground is lower than that of the water table at the recharge area is an ______ _____ and is free flowing, that is, it requires no pumping to get the water to the surface. |
|
|
Term
|
Definition
| The water table in the shallower aquifer is called a ________ water table because it is above the main water table in the lower aquifer. |
|
|
Term
|
Definition
| When a well pumps water out of an aquifer faster than recharge can replenish it, the water level in the aquifer is lowered in a cone shaped area around the well, called a ______ ___ _______. The extreme withdrawal of water not only can deplete the aquifer but may also cause another undesireable environmental effect, sink like depressions. |
|
|
Term
|
Definition
| For a given aquifer and distance of travel, the rate at which water flows from one point to another is directly proportional to the drop in elevation of the water table between the two points. As the difference in elevation _________, the rate of flow ______. |
|
|
Term
|
Definition
| The rate of flow for a given aquifer and given difference in elevation is inversely proportional to the flow distance the water travels. As the distance ________, the rate decreases. |
|
|
Term
|
Definition
| The ratio between the elevation difference and the flow distance is known as the ________ _______ . Just as a ball runs faster down a steeper slope than a gentler one, groundwater flows more quickly down a steeper _______ ______. |
|
|
Term
|
Definition
| In the western plains, the slopes are gentle and waters move _____ through the aquifers, redcharging them at low rates. At first, many of these wells were artesian and water flowed freely. As more wells were drilled, the water levels dropped, and the water had to be pumped to the surface. As extensive pumping withdraws water from some aquifers faster than the slow recharge from far away can fill them, the reservoirs are being depleted. |
|
|
Term
|
Definition
| In the air filled caverns, water saturated with ____ _______ may drip from the ceiling causing deposites of calicum carbonate to form on the ceiling at the point where the droplets fall and on the floor where the droplets touch down. The deposits grow on themselves forming tooth-like formations called stalactites and stalagmites . |
|
|
Term
|
Definition
| Stalactites form from the ____ ____ and stalagmites form from the _____ _____ . |
|
|
Term
|
Definition
| In some places, dissolution may thin the roof of a limestone cave so much that it collapses suddenly, producing a ________ , a small, steep depression in the land surface above the cavernous limestone formation. |
|
|
Term
|
Definition
| ______ _______ is characterized by sinkholes, caverns, and a lack of surface streams. Underground drainage channels replace the normal surface drainage system of small and large rivers |
|
|
Term
|
Definition
| ________ ________ is a system in equilibrium, one in which there exist a balance of the erosional and depositional processes. It is a stream that is transporting just that amount of sediment it is capable of, for its velocity and discharge. |
|
|
Term
|
Definition
| The amount of sediment that a stream can transport |
|
|
Term
|
Definition
| capacity depends on its ______(the amount of water flowing pass a point on a stream per unit time). |
|
|
Term
|
Definition
| The largest particle a stream can transport __________ , depends on its velocity |
|
|
