SOIL AND WATER RESOURCE CONSERVATION ENGINEERING Flashcards

1
Q

Implies utilization without wastes

A

Conservation

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2
Q

Continuous high level of crop production while improving environment quality

A

Conservation

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3
Q

True or False. Soil and water conservation is based on full integration of engineering, atmospheric, plant and soil science. It requires knowledge of the soil -plant-water interactions, particularly conserving the soil physical, chemical and engineering characteristics.

A

True

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4
Q

One major cause of water pollution

A

Soil erosion

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5
Q

It is said that agriculture contributes to 60-80% of total water use . 40% of irrigation water was not available to crops. Give the causes of this water loss

A

Conveyance, seepage, percolation, evaporation, transpiration

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6
Q

Enumerate some physical means of retaining raifall in soil and reducing evapotranspiration

A

Level terracing, reservoirs, contouring, pitting, water harvesting techniques, modified tillage, crop management techniques

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7
Q

Total land area of Philippines

A

30 M ha

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8
Q

Agricultural land in the Philippines is about 42%. What is its value in terms of ha

A

12.57 M ha

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9
Q

PD 1067 is also known as

A

Water Code of the Philippines

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10
Q

Located below 50 m above mean sea level

A

Shallow well areas

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11
Q

Located above 50 m above mean sea level

A

Deep well areas

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12
Q

Geologic features lying at a depth more than 20 meters below the ground

A

Aquifers

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13
Q

Areas with insufficient data to be classified as either shallow or deep well areas because of varying depth

A

Difficult areas

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14
Q

Average growing rate of Philippine population

A

2.3 %

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15
Q

On 1990, how much of the total land area of the country was affected by soil erosion?

A

45%

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16
Q

Annual average nutrient loss in terms of fertilizer requirement. In tons, how much N, P, K were lost?

A

194,000 tos N, 40, 000 tons P, 30,000 tons K

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17
Q

Issues and problems attendant to soil and water conservation and utilization.

A

Land and water resource degradation, allocation, data availability and reliability, support

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18
Q

Major sources of water

A

Rainwater, surface water, ground water

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19
Q

Movement of water on the earth’s surface and through the atmosphere

A

Hydrologic cycle

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20
Q

Water vapor in the atmosphere

A

Humidity

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21
Q

Any aqueous deposit in liquid or solid form, that develops in a saturated atmospheric environment and generally falls from clouds

A

Precipitation

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22
Q

True or false. Evaporation from ocean surface is the chief source of moisture for precipitation

A

True

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23
Q

Four primary reasons of condensation or sublimation of atmospheric moist

A

Adiabatic cooling, mixing of air masses of varying temperatures, radiation cooling, contact cooling

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24
Q

Tiny liquid water droplets. 0.1-0.55 mm diameters and usually falls less than 1 mm per hour and also appears to float

A

Drizzle or mist

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25
Liquid water drops greater the 0.5 mm diameter
Rain
26
Defined as the amount of liquid precipitation
Rainfall
27
Ice coating generally clear and smooth formed on exposed surfaces by the freezing of supercooled water deposited by rain or drizzle
Glaze
28
Specific gravity of glaze
~0.8 to 0.9
29
White opaque deposit of ice granules separated by trapped air and formed by rapid freezing of supercooled water drops
Rime
30
Specific gravity of rime
~0.2-0.3
31
Composed of ice crystals, chiefly in complex, branched hexagonal form, and often agglomerated into snowflakes
Snow
32
The average diameter for snowflakes
~ 100 mm
33
Balls of ice produced in convective clouds
Hail
34
Transparent, globular, solid grains of ice formed by the freezing of raindrops or refreezing of melted ice crystals as it falls in a layer of sub freezing air near the surface
Sleet
35
It represents the saturation of air near the ground surface
Fog
36
A process wherein acid pollutants from the atmosphere are being deposited in dry and wet forms to the Earth's surface
Acid Deposition
37
Wet deposit of acid pollutants
Acid Precipitation
38
Occurs when radiant energy from the sun heat water, causing water molecules to rise into the atmosphere
Evaporation
39
The combined evaporation of the soil surface and the plants
Evapotranspiration
40
Rain that falls through the vegetation without being intercepted
Through fall
41
The movement of water from precipitation into the soil
Infiltration
42
Water that doesn't infiltrate the soil flows on the surface as
Runoff
43
True or falls. The Earth's continent experience runoff because of the imbalance between precipitation and evaporation
True
44
Plot of discharge against time
Hydrograph
45
Difference between peak rainfall and peak discharge
Lag time
46
The height at which a flood could occur, variable from river to river
Bankfull discharge
47
A line in the hydrograph that shows how much water is in the river
Discharge line
48
Ground water runoff, normal discharge of the river or stream or channel
Base flow
49
Volume of water reaching the river from surface runoff
Direct runoff
50
Factors affecting runoff
Climate, physiographic factors
51
Also called the concentration curve; represents the increase in discharge due to gradual build up of storage in channel and over the catchment area
Rising limb
52
True or False. Fan shaped or nearly circular shaped basin/catchment has slower discharge than fern-shaped
False. The reverse is true. It is because the time of concentration of the catchment is much lower than the fern or leaf shaped.
53
Indicates the peak flow or the maximum amount of flow at the basin outlet
Crest segment
54
From point of inflection at the end of crest segment to base flow.
Falling limb
55
The time required for water to flow from the most remote point to the mouth of the watershed once the soil has become saturated and minor depression filled
Time of concentration
56
The ratio of the peak runoff rate to the rainfall intensity
Runoff coefficient
57
a process by which soil is removed from the Earth's surface by exogenetic processes such as wind or water flow, and then transported and deposited in other locations.
Erosion
58
natural erosion (soil-forming and soil eroding processes) which maintain the soil in favorable balance.
Geological erosion
59
removal of surface soil takes place at much faster rate than it can be built up by the soil forming processes
Accelerated erosion
60
Two interactive processes of erosion
Detachment and Transport
61
EROSION SUB-PROCESSES
Detachment by rainfall Transport by rainfall Detachment (scour) by runoff (overland or channelized flow) Transport by runoff
62
Factors affecting erosion by water
Climate Soil Vegetation Topography Disturbances
63
The greatest natural disturbances in the ecosystems
Fires
64
soil detachment and transport resulting from the action of raindrop the first stage of soil erosion by water
Raindrop erosion or splash erosion
65
the removal of soil in thin layers by raindrop impact and shallow surface flow its soil detaching and transporting capabilities are small
Sheet erosion
66
results in loss of the finest soil particles that contain nutrients and organic matter in the soil
Skimming
67
The intermittent process of transforming to gully erosion. Common in bare agricultural land, overgrazed land and freshly tilled soil where soil structure has been loosened
Rill erosion
68
common in bare agricultural land, overgrazed land and freshly tilled soil where soil structure has been loosened. It can be obliterated by tillage
Rill erosion
69
The advanced stage of rills. It is formed when the depth and width of the rill is > 50 cm
Gully erosion
70
4 classes of gully
G1, G2, G3, G4
71
Depth, width and side slope of G3
3.0-9.0 m, 18 m, 6-12 %
72
Stages of Gully Development
FORMATION STAGE DEVELOPMENT STAGE HEALING STAGE STABILIZATION STAGE
73
Processes of gully formation
Waterfall erosion Channel erosion Alternate freezing and melting of snow Undercutting, landslides, mass movements of soil
74
It can be used to predict soil erosion losses ,guide the selection of agricultural practices such as cropping and management systems , guide in determining the on-site effects of land use and crop management changes , and provide baseline data for conservation planning
UNIVERSAL SOIL LOSS ESTIMATION
75
It can be used to predict soil erosion losses ,guide the selection of agricultural practices such as cropping and management systems , guide in determining the on-site effects of land use and crop management changes provide baseline data for conservation planning
76
it estimates sheet erosion as the product of a series of terms for rainfall, soil, slope gradient, slope length, crop and cover management and conservation factors this permits the extensive tabulations of individual factors, incorporating vast amounts of research data
Universal Soil Loss Estimation
77
Standard agricultural plots
72.6 feet long and 6 feet wide, with 9% slope
78
a quantitative measure of erosion potential of rain, allows for spatial estimation of basic erosion risks in different areas.
Rainfall erosivity
79
The detachment and transport of soil by a concentrated flow of water and the detachment and transport of soil by a concentrated flow of water
Rill erosion
80
The ratio of the circumference of a circle of the same area as the basin to the basin perimeter
Circulatory ratio
81
A stream that flows only in direction response to precipitation
Ephemeral stream
82
Hydrograph with a unit volume of direct runoff for a given storm duration
Unit hydrograph
83
When the viscous forces are weak relative to inertial forces, the flow is
Turbulent
84
A channel having a steep slope
Chute
85
The distance between adjacent terraces
Vertical interval
86
What percentage of the water extracted by plant roots is transpired
95-99%
87
suggested that splash erosion is a function of soil and rainfall properties
Ellison
88
slope-practice equation
Musgrave equation
89
developed an expression for the claypan soils of Missouri
Smith and Whitt
90
Precipitation associated with the movement of air masses due to a difference in barometric pressure
Cyclonic
91
The method of determining average areal precipitation which accounts for the effect of topography and unequal gage density
Arithmetic average and Thiessen method
92
An equation or method used in the estimation and representation of evapotranspiration rate
Hargreaves Equation
93
The rate of evapotranspiration occurring under the field conditions for the given crop, soil moisture and meteorological conditions
Actual crop evapotranspiration
94
Fraction of sheet and rill erosion that actually reaches has reference point of discharge
Sediment delivery ratio