Technical English Language for Range and Watershed...
Transcript of Technical English Language for Range and Watershed...
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University of Tehran
Faculty of Natural Resources
Department of Arid and Mountainous Regions Reclamation
Technical English Language
for Range and Watershed Management
A. Moghaddam Nia
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Reference Books
• Principles of Language Learning and
Teaching, H. Douglas Brown, Prentice Hall
Regents.
• Second Language Teaching & Learning. David
Nunan. (1995). H& H.
• Other resources from the Internet
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Writing about the kind of change (increase/decrease)
1. Verbs: to increase/to go up/to rise ≠ to
decrease/to go down/to decline
2. Nouns: an increase/a rise ≠ a decrease/a
fall/a reduction
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Writing about the kind of change
(increase/decrease)
1. Verb + dramatically = dramatic + Noun
Example: The figure rose dramatically.
2. Verb + significantly = significant + Noun
Example: There was a dramatic rise.
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Writing about the kind of change
(increase/decrease)
1. Verb + a little = small + Noun
Example: The figure decreased slightly.
2. Verb + slightly = slight + Noun
Example: There was a slight decrease.
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Writing about the kind of change
(increase/decrease)
Examples:
• Between 1980 and 1990 the figure fell a little.
• Since 1980 it has increased slightly.
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Writing about comparing changes
• + whereas + Verb phrase
Example:
In 1980, 30% of rural dwellers had a drinking water
supply, whereas in 1990 50% had it.
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Writing about comparing changes
• more / fewer than
Example:
More urban dwellers have a water supply than rural
dwellers.
Fewer rural dwellers have a water supply than
urban dwellers.
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• Three stages of Reading Process (Wallace, 1992; 2003):
1. Pre-reading: the topic of the text, the choice of the topic, the
way the topic was written, alternative ways to cover the topic,
and the relationship between write and reader.
2. While-reading: deciphering the implications of the text and
negotiate them with other members of the discourse
community.
3. Post-reading: what happened after reading the text; is there any
change in attitudes or improvement of knowledge, for example?
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1. Sample Passage
A number of methods have been proposed for estimating the
initial abstraction. It can be assumed that the initial
abstraction consists of all rainfall that occurs prior to the
start of direct storm runoff. As an alternative, the initial
abstraction may be assumed to be a constant volume
(depth). The SCS method assumes that initial abstraction
is a fixed fraction of the maximum retention but varies
with soil and land use since the retention is a function of
the soil group and land use. Viessman (1968) found that
for small urban watersheds a value of 0.1 inch was
reasonable. For rural and forested watersheds, a larger
volume would be expected.
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1. Sample Passage
• The initial abstraction:
a) is dependent on the separation of baseflow.
b) can be a constant volume.
c) would be larger for an urban watershed than for rural
watershed.
d) is not a function of land use.
• The word “consists of” in line 2 is closest in meaning to
…………… .
a) comprise b) exclude c) undergo d) acquire
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2. Sample Passage
Designs based on peak discharges have a long historical basis. In a
historical review of the literature on engineering studies of
hydrologic determination of waterway areas, Chow (1963)
included a few of the historical events relating to design
methods using peak discharges. The early attempts at
hydrologic design suggest that dominant factors in peak
discharge estimation were recognized as the drainage area, land
use, rainfall intensity, and slope. These factors are the heart of
many of the equations used today. Current methods attempt to
develop more precise criteria for selecting values of the
empirical coefficients and include additional variables as input.
Although these additional variables are probably not as
important as drainage, land use, and rainfall, they should
nevertheless improve the accuracy of prediction.
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2. Sample Passage
• The word “relating to” in line 4 is closest in meaning to ………
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a) concern b) respect c) respectfulness d) concerning
• The word “precise” in line 8 is closest in meaning to ………. .
a) facile b) untrue c) exact d) reasonable
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3. Sample Passage
A primary design variable in hydrology is the peak
discharge, which corresponds to the maximum water surface
elevation during a storm event. Specifically, a peak discharge is
the maximum volume flow rate passing a particular location
during a storm event; it has units of volume per time, such as
cubic feet per second, cubic meters per second, or acre-feet per
hour.
The peak discharge is a primary variable for the design of
stormwater runoff pipe systems, storm inlets and culverts, and
small open channels. It is also used for some hydrologic
planning such as small detention facilities in urban areas. It is an
acceptable design variable for designs where the time variation
of storage is not a primary factor in the runoff process.
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3. Sample Passage
• According to the above passage, which one of the
following is true or false?
The peak discharge is:
1. a criterion for classifying hydrologic models.
2. a primary design variable.
3. the total volume of flood runoff.
4. the maximum volume flow rate passing the watershed outlet
during a storm event.
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As urban areas continue to grow land that
was once covered with more natural land
cover such as forests, fields, and lawns is
replaced by manmade land covers such as
roads, parking lots and rooftops.
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Reading • Choose the best heading from the options A,B,C or D for
the following paragraph.
The vast majority of people in the developing countries live in
rural areas, on farms, in villages or in rural market towns. In some countries, such as Rwanda, Burkina Faso and Malawi more than 90 per cent of the total population lives in the rural areas.
A. Rural poverty B. Insufficient access to education C. Rural populations of developing countries D. Education in developing countries
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Reading Comprehension
Read the following passage and choose the best choice (1), (2), (3) or (4).
In meteorology, precipitation (also known as one of the classes of hydrometers, which
are atmospheric water phenomena) is any product of the condensation of
atmospheric water vapor that is pulled down by gravity and deposited on the Earth’s
surface. The main forms of precipitation include rain, snow, ice pellets, and graupel.
It occurs when a local portion of the atmosphere becomes saturated with water
vapour and the water condenses, falling out of solution (i.e., precipitation).
1. We may understand from the passage that precipitation has a meaning ……….
1) if it reaches the Earth.
2) as one of the main branches of meteorology.
3) as rain, snow, ice pellets, and graupel.
4) if water vapour gets condensed.
Graupel : گفته کریستالها چسبيده بهم توده به) برف گلوله یا برف دانه .ملایم منجمد نيمه تگرگ :آلمانی کلمه ریشه (شود می
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Reading Comprehension
Two processes, possibly acting together, can lead to air becoming saturated: cooling the air
or adding water vapour to the air. Virga is precipitation that begins falling to the earth but
evaporates before reaching the surface; it is one of the ways air can become saturated.
Precipitation forms via collision with other rain drops or ice crystals within a cloud.
Moisture overriding associated with weather fronts is an overall major method of
precipitation production. If enough moisture and upward motion is present, precipitation
falls from convective clouds such as cumulonimbus and can organize into narrow rainbands.
1. The passage mentions that ……………
1) graupel is extremely saturated rainfall.
2) air can become saturated through vigra.
3) air can be cooled by adding water vapour it.
4) there are many tiny ice crystals in a cloud.
Virga : ابرهای از که هستند رگبار سنگين قطرات CB از قبل و رسند نمی زمين به هيچگاه قطرات این اما بارد، می . شوند می تبخير سریع بسيار زمين به رسيدن
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CLOZE TEST
It is extremely difficult for students to deal with such
cloze test due to the following problems:
1. difficulties in comprehending the text
2. unfamiliarity with sentence structures
3. insufficient mastery of grammar
4. vocabulary lack of knowledge of English
5. inadequate mastery of synonyms and prepositions
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• The more you have to say, the more people will want to talk with you.
• Notice what they say and how they act.
• Learn from people at school or work.
• Be a good listener, and let people talk about themselves.
• Have confidence in yourself.
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The population of the world is increasing rapidly. By 2020,
there could be 7.5 billion people on the earth. Will there be
enough food for all this people, or will we have a food
shortage?
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Urban farming has important advantages for city people. First, it's
good for the environment. The crops reduce the amount of carbon
dioxide (CO2) and increase the oxygen (O2) in the air. As a result,
they help clean the air. Second, locally grown food is fresher. It
doesn't have to travel long distances, so it is less expensive, too.
Urban residents also benefit from the enjoyment of farming. It can
reduce the stress of city life.
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Cloze Test
Read the passage and decide which choice (1), (2), (3), or (4) best fits each
space.
The effects of an earthquake are often (1) ---------.
Earthquakes have (2) ------- the death of many human beings, much suffering, and
great (3) --------.
1- 1) chemical 2) superior 3) terrible 4) formal
2- 1) provided 2) caused 3) required 4) designed
3- 1) damage 2) source 3) impression 4) variety
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Reading Effectively
The purpose of your reading determines how you will read. You are not
expected to read every reading on your reading list carefully from beginning to
end, word for word. Skimming, scanning and careful, deliberate reading, are
all skills which can be applied to reading academic texts, depending on the
‘purpose’ of your reading.
SKIMMING - If reading a chapter for background to a lecture, you might
quickly skim the reading. Read the introduction/conclusion; check the
headings and sub headings for main ideas; read the topic sentence for each
paragraph; read any bolded or italicised material; and look at any diagrams
or other visuals. Once you have established an overview of the main points in
the article, you would then review any sections relevant to your assignment.
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Reading Effectively
SCANNING - If you are looking for a specific piece of information e.g. the
answer to a question for a lab report, you might use scanning. Scanning
involves reading quickly to locate specific information. You use this skill when
you find a number in a telephone directory. To help locate the specific term
you are looking for, you could use the index of a book, chapter headings or
scanning quickly through the chapter.
DEEP READING - After skim reading through a series of relevant
articles/chapters for an essay, deep reading is necessary. You must read each
slowly and carefully, making notes as you go, critiquing the reading and
outlining in your own words what the material is about.
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Useful Resources / Websites
http://unilearning.uow.edu.au/reading/1a.html
http://www.lc.unsw.edu.au/onlib/read.html
http://www.monash.edu.au/lls/llonline/reading/effective-reading/index.xml
http://cms.unimelb.edu.au/studentservices/asu/reading/strategies
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Watershed Water Balance
From a hydrologic viewpoint, the first step of watershed management is to evaluate past,
present, and proposed management practices on a watershed with respect to the watershed
water balance. Watershed water balance refers to the balance between the inflow of water
to a watershed as precipitation and the outflow of water from the watershed as
evapotranspiration, ground water discharge, and stream flow. Basically, watershed water
balance is an accounting tool to keep track of the hydrologic cycle of a watershed over time.
When the watershed water balance concept is used in conjunction with probability analysis
one can evaluate the hydrologic, economic, and ecological feasibility of past, present, and
potential activities on a watershed.
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Vegetation effects on hydrologic processes
Infiltration and runoff are regulated by the kind and amount of vegetation, edaphic, climatic,
and topographic influences. Vegetation is the primary factor that influences the spatial and
temporal variability of soil surface processes, which affects infiltration, runoff, and interrill
erosion rates on arid and semiarid rangelands. Each plant-soil complex exhibits a
characteristic infiltration pattern.
The impact of vegetative cover to infiltration is not constant from one range-soil complex to
another. In semiarid climates, vegetal cover has a minimal influence on infiltration: the
erosion process is more complex and is a function of plants, soils, and storm dynamics.
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Each plant community type must be evaluated in terms of what variables affect hydrology
on the site. No one factor ever varies alone, especially with regard to hydrologic processes.
Some variables are not consistently correlated in natural rangeland plant communities. The
variables include:
• above- and below-ground plant morphology
• total production
• production of individual plant species
• total canopy cover
• canopy cover of individual plant species
• plant architecture
• sod forming growth form
• bunchgrass growth form
• interspace
• shrub coppice
• soil physical properties
• soil chemical properties
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Semiarid rangelands throughout the Western United States have significant spatial and
temporal variations with regard to hydrologic and erosion processes. The spatial distribution
of the amount and type of vegetation has been shown to be an important factor in
modifying infiltration and interrill erosion rates on rangelands. On rangeland, shrub-coppice
sites have a significantly higher infiltration rate under both frozen and unfrozen soil
conditions than that in interspace areas.
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WATERSHED Development
• Watershed Characteristics.
• Hydrology of watershed.
Watershed (ha) Classification
50,000-2,00,000 10,000-50,000 1,000-10,000 100-1,000 10-100
Watershed Sub-watershed Milli- watershed Micro-watershed Mini-watershed
Parameters of Watershed
• Size
•Shape
•Physiography
•Climate
•Drainage
•Land use
•Vegetation
•Geology and Soils
•Hydrology
•Hydrogeology
•Socioeconomics
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Climate change is likely to affect soil erosion by water through its effects on
rainfall intensity, soil erodibility, vegetative cover, and patterns of land use.
Estimates of changes in erosion risk can be made from a knowledge of projected
changes in these factors. General circulation models (GCMs) can provide a range
of climate scenarios, but these alone are not sufficient to predict future erosion
risk, particularly because GCMs are currently poor predictors of changes in
rainfall intensity and surface windspeed. In addition to more regionally reliable
GCMs, accurate and reliable databases of parameters such as vegetation cover,
soil properties, land use, and management systems are needed. These databases
are important for the assessment of biophysical processes and biomass
productivity (Rosenzweig et al., 1993) and are needed at scales appropriate to
regional and global degradation processes (Bliss, 1990; Bouwman, 1990; Batjes et
al., 1994). Such databases have not yet been developed.
Erosion by Water
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Soil erosion occurs when wind transports soil particles by suspension, surface creep,
or saltation over distances ranging from a few centimeters to many kilometers. Wind
erosion not only transports soil particles around arid and semi-arid landscapes but
provides inputs into ecosystems around the world and may even alter global climatic
patterns. Wind erosion is particularly problematic on sandy and organic soils
subject to low soil moisture, patchy vegetation, sporadic rainfall, and periodic
winds. Even soils resistant to wind erosion can be blown away if the soil is damaged
by trampling of animals, loosening by ploughing and tillage, pulverization by traffic
(human and animal), and denudation of natural vegetation by the expansion of
agriculture, excessive grazing, or fire. Wind erosion is mainly a feature of arid and
semi-arid conditions but may occur in moister zones where soil damage occurs
during or just prior to periods of high wind velocity.
Erosion by Wind
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More than 60 years of experience are available in the development of conservation
techniques and soil protection, following the U.S. Dust Bowl and similar phenomena
elsewhere in the world (Kirkby and Morgan, 1980; FAO, 1983; Morgan, 1986;
Schwertmann et al., 1989; Lal, 1990). A serious problem, however, is that many of
these conservation techniques have not been adopted. Nevertheless, they are
available and could be used for or adapted to changing climatic conditions. The
most important requirement is that governments recognize the problem of soil
erosion and set in motion the appropriate conservation mechanisms. Future erosion
risk is more likely to be influenced by increases in population density, intensive
cultivation of marginal lands, and the use of resource-based and subsistence farming
techniques than by changes in climate.
Adaptive Strategies for Mitigating the Impact
of Climate Change on Soil Erosion
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Agroforestry may play an extremely important role in the development of semi-arid
and arid lands and in the struggle against desertification (Le Houérou, 1980;
Baumer, 1987; Le Houérou and Pontainier, 1987). Agroforestry techniques have
been developed for centuries in some rural civilizations—such as Kejri [Prosopis
cineraria (L) Druce] in northwest India (Rajasthan); Faidherbia albida (Del.) Chev.
in various parts of intertropical Africa; saltbushes in various arid zones of the
world; Argania spinosa (L.) Sk in southwest Morocco; Quercus ilex L. and Q. suber
L. in Spain and Portugal; and Espino (Acacia caven Mol.) and Algarrobo (Prosopis
spp) in Latin America. Such techniques permit high rural population densities in
arid zones (e.g., 60–80 people/km2) with Faidherbia in southern Sahel, and similar
densities in Rajasthan with Prosopis cineraria and in southern Morocco with
Argania (the latter region receives <150–300 mm/yr rainfall).
Agroforestry
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An important question in hydrology is how much stream flow
occurs in a river in response to a given amount of rainfall.
To answer this question:
we need to know where water goes, when it rains, how long does
water reside in a watershed, and what pathway does water take to
the stream channel.
These are the questions addressed in the study of rainfall – runoff
processes, or more generally surface water input – runoff processes.
Rainfall – Runoff Processes
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Label the locations depicted in the figure associated with runoff
generation processes.
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Label the Rainfall-Runoff processes depicted in the figure.
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Infiltration excess overland flow occurs anywhere that surface
water input exceeds the infiltration capacity of the surface.
This occurs most frequently in areas devoid of vegetation or
possessing only a thin cover. Semi-arid rangelands and
cultivated fields in regions with high rainfall intensity are
places where this process can be observed. It can also be seen
where the soil has been compacted or topsoil removed.
Infiltration excess overland flow is particularly obvious on
paved urban areas.
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High intensity short duration rainfall is much more likely to exceed
the capacity of the soil to infiltrate water and result in overland
flow than a longer less intense rainfall. In arid climates with deep
water tables, spatially concentrated rainfall on a small area may
generate local runoff that then infiltrates downriver, whereas a
more humid area with shallow water tables is less likely to be
subject to stream infiltration losses and even gentle rainfall when
widespread and accumulated over large areas may lead to large
stream flows.
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Infiltration excess overland flow is more likely to occur in:
1) A short gentle rainstorm
2) A short intense rainstorm
3) A long gentle rainstorm
4) A snow blizzard
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Infiltration capacity is also referred to as infiltrability. When surface water
input exceeds infiltration capacity the excess water accumulates on the soil
surface and fills small depressions. Water in depression storage does not
directly contribute to overland flow runoff; it either evaporates or
infiltrates later. With continued surface water input, the depression
storage capacity is filled, and water spills over to run down slope as an
irregular sheet or to converge into rivulets of overland flow. The amount of
water stored on the hillside in the process of flowing down slope is called
surface detention. The transition from depression storage to surface
detention and overland flow is not sharp, because some depressions may
fill and contribute to overland flow before others.
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Interception of precipitation by vegetation can play a significant
role in reducing runoff, especially in forested environments. Much
intercepted water is eventually evaporated back to the atmosphere.
Water retained in the vegetation canopy for some period, however
short, after rain has struck the vegetative material above the soil
surface (Tischendorf, 1969).
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Interception is most likely to
1) Result in a large capillary fringe
2) Increase the infiltration capacity
3) Reduce the infiltration capacity
4) Increase erosion
5) Occur in an urban area
6) Lead to increased infiltration excess overland flow
7) Reduce the amount of runoff generated in a forested area