工程水文学中国大学mooc作业答案

日期:2023-01-31 13:40:31

01 The introduction

Test 01

1、The occurrence of hydrological phenomena is .
    A、completely accidental
    B、completely inevitable
    C、completely random
    D、both inevitable and random

2、Hydrological analysis and calculation is to predict the probability distribution of the hydrological variable .
    A、during any period
    B、during a foreseeable period
    C、for a very long time in the future
    D、at a certain moment

3、Hydrological forecasting is to predict the scale and time course of a hydrological variable .
    A、during any period
    B、during a foreseeable period
    C、since a long time ago
    D、at a certain moment

4、The occurrence and development of hydrological phenomena are accidental, therefore, their occurrence and changes .
    A、is disorganized
    B、has statistical pattern
    C、is with complete certainty pattern
    D、has no pattern

5、Water is a type of .
    A、inexhaustible resource
    B、renewable resource
    C、non-renewable resource
    D、unlimited resource

6、The reason for making water resources regenerative is of natural.
    A、run-off
    B、hydrological cycle
    C、evaporation
    D、precipitation

7、The check flood level and design flood level of the Three Gorges Project on the Yangtze River are .
    A、185.0m、180.0m
    B、180.4m、175.0m
    C、175.0m、180.0m
    D、155.0m、145.0m

8、In natural world, the hydrological cycle between land and sea is called .
    A、Inland small cycle
    B、Small loop
    C、Large loop
    D、Ocean water cycle

9、The hydrological cycle in nature makes water resources .
    A、regenerative
    B、non-renewable
    C、random
    D、regional

10、We can trace many causes for the occurrence and development of hydrological phenomena. Therefore, the change in hydrological phenomena .
    A、has a completely deterministic pattern
    B、has a completely statistical pattern
    C、has causality pattern
    D、has no pattern

02 Formation Process of Watershed Runoff

Test 02

1、The drainage area refers to which is above a certain cross section of the river.
    A、the sum of the areas enclosed by the ground water watershed and the underground water watershed
    B、the horizontal projected area enclosed by underground watershed
    C、the area enclosed by the ground watershed
    D、the horizontal projected area enclosed by the ground watershed

2、If there are two heavy rains occured in a certain river basin, expect the occurance location, one occured in the upstream and the other in downstream, other conditions are the same. Then, the peak flow at the exit section of river basin caused by the upstream one will be than the one caused by the downstream.
    A、larger and later
    B、smaller and earlier
    C、larger and earlier
    D、smaller and later

3、The condition for the formation of heavy rain is .
    A、the area which has sufficient water vapor sources and high temperature
    B、the area which has sufficient water vapor sources and low temperature
    C、the area which has sufficient water vapor sources and strong upward movement of air
    D、the area which has sufficient water vapor sources and no strong upward movement of air

4、The characteristics of convective rainfall are .
    A、large rainfall intensity , large rain area and long rainfall duration
    B、small rainfall intensity, small,rain area and short rainfall duration
    C、large rainfall intensity, small rain area and short rainfall duration
    D、small rainfall intensity, large rain area and long rainfall duration

5、For relatively dry soil which is under sufficient water supply conditions, the physical process of infiltration can be divided into three stages, which are in turn.
    A、penetration stage-seepage stage-leakage stage
    B、leakage stage-seepage stage- penetration stage
    C、seepage stage-leakage stage-penetration stage
    D、seepage stage-penetration stage-leakage stage

6、is the main factor determining the stable infiltration rate of soil.
    A、Rainfall intensity
    B、Soil water content at the beginning of rainfall
    C、Rainfall duration
    D、Soil characteristics

7、The total evaporation of the watershed includes .
    A、water surface evaporation, land surface evaporation and plant evapotranspiration
    B、water surface evaporation, soil evaporation and land surface evapotranspiration
    C、land surface evaporation, plant evapotranspiration and soil evaporation
    D、water surface evaporation, plant evapotranspiration and soil evaporation

8、The amount of the daily water surface evaporation, observed by the E601 water surface evaporator, and of the daily water evaporation of large water body is (has) .
    A、that former one is smaller than the latter
    B、that former one is greater than the latter
    C、equal
    D、a certain correlation

9、The process of basin confluence mainly includes .
    A、the overflow of the slope and slope confluence
    B、concentration of river network and collection of river channels
    C、slope confluence and concentration of river network
    D、the overflow of the slope and slope concentration

10、The amount of floods formed by the net rain depth of rainfall in river basin should be quantitatively .
    A、equal to the runoff depth of the flood
    B、larger than the runoff depth of the flood
    C、less than the runoff depth of the flood
    D、larger than or equal to the runoff depth of the flood

03-1 Hydrological Information Collection and Processing

Test 03

1、According to the funciton of the hydrologic station, it have two types. There are .
    A、water level station and rainfall station
    B、basic station and rainfall station
    C、basic station and dedicated station
    D、water level station and flow station

2、When the water level does not change much in a day, should be applied to calculate the daily average water level.
    A、Weighted average method
    B、Geometric average method
    C、Arithmetic average method
    D、Area bounding method

3、In the hydrological test, is the key to determine the flow through a cross section in river channel .
    A、measured cross-section
    B、observation of water level during flow measurement
    C、calculating the average velocity of vertical line
    D、measuring the velocity of measuring point

4、When using a flow meter to measure the velocity of a point, the time required for each measurement should be .
    A、the shorter the better
    B、the longer the better
    C、about 100s
    D、unrestricted

5、Measuring the flow velocity at a certain point with a flow meter, actually is to measure the of the flow meter at that point.
    A、Rotate speed
    B、Hydraulic pitch
    C、Friction constant
    D、Speed measurement duration

6、When a hydrologic station is affected by flood fluctuations, the relationship curve of water level and flow .
    A、will go up
    B、will go down
    C、will in the shape of a clockwise noose
    D、will in the shape of a counter-clockwise noose

7、The relationship of water level and flow in a hydrologic station is a single curve. When the messuring cross section is silted, .
    A、the curve will goes up
    B、the curve will goes down
    C、the curve will in the shape of a noose
    D、the curve will have no change

8、In the low water extension method of the relation curve of water level and flow, stage of no flow means (that) .
    A、the water level is zero
    B、the lowest point of the riverbed
    C、water level with no flow
    D、the water level of the dead water area in the section

9、are the indicators commonly used to characterize sediment transport.
    A、Sediment transport rate and flow
    B、Sand content and sediment transport rate
    C、Sand content and flow
    D、Sediment transport rate and quantity

10、People have found from continuous practice that when , there is a stable relationship between the average sediment content of the cross section and the sediment content of a vertical line or a certain measuring point of the cross section, by establishing its correlation, it can greatly Simplified the sediment test.
    A、the cross-section and the mainstream are relatively stable
    B、the cross section is relatively stable and the river channel is relatively narrow
    C、the cross section is relatively stable and the river channel is relatively wide
    D、the mainstream is stable and the river channel is relatively narrow

04-1 Basin yield confluence calculation

Test 04-1

1、Which of the following is wrong about the rainfall factors? .
    A、Rainfall duration is the duration of a rain;
    B、We can directly measure the areal rainfall of the watershed through the rain gauge;
    C、The unit of rainfall is generally expressed in millimeters;
    D、The rainfall in the period divided by the duration of the period is the average rainfall intensity during this period.

2、Which of the following is wrong about the temporal variation of rainfall: .
    A、The process of average rainfall intensity during the period is a ladder diagram;
    B、The cumulative rainfall process is a non-decreasing curve;
    C、The shape of the hourly precipitation process is the same as the average rainfall intensity during the period;
    D、The hourly precipitation process has the same unit as the ordinate of the average rainfall intensity during the period.

3、Generally speaking, the difference between the saturated water content of the soil layer and the field water capacity is equal to: .
    A、gravitational water
    B、capillary water
    C、molecular water
    D、surface silted water

4、Which question does not need to be answered in runoff calculation: .
    A、which the water will eventually flow into river networks?
    B、how much water will flow into the river networks?
    C、How does the rainwater flow into the river network?
    D、Which water will converge to the river network through the ground?

5、What divides the layer into the saturated and the unsaturated zones is: .
    A、ground
    B、impervious layer
    C、intermediate zone
    D、groundwater table

6、Since direct measurement of evapotranspiration is actually very difficult, is often used to estimate watershed evaporation capacity.
    A、soil evaporation
    B、vegetation emission
    C、utensil evaporation
    D、water surface evaporation

7、In the calculation of one-layer of evaporation, suppose the watershed evaporation capacity in a certain period is 10 mm, the storage and capacity of the tension water (capillary water) in the soil layer of the watershed are: 5 mm and 20 mm ,respectively, then the evaporation amount in the period is: .
    A、2.5 mm
    B、5 mm
    C、10 mm
    D、20 mm

8、According to the principle of saturation-excess runoff yield , which is wrong : .
    A、no infiltration-excess surface runoff yield;
    B、there will be runoff only when the whole watershed reaches the field water capacity;
    C、there will be saturated surface runoff;
    D、generally suitable for wet areas.

9、Regarding the three-water-source division in saturation-excess runoff yield calculation , which the following statement is correct: .
    A、the tension water will flow under the drive of gravity to form a runoff;
    B、there is free water in the non-runoff area;
    C、there is no tension water in the flow area;
    D、as long as there is free water, there will be interflow and baseflow.

10、Regarding the three-water-source division in saturation-excess runoff yield calculation , the water that will be evaporated is .
    A、tension water
    B、surface flow
    C、interflow
    D、baseflow

04-2 Basin yield confluence calculation

Test 04-2

1、Infiltration rate is always:
    A、equal to infiltration capacity;
    B、greater than infiltration capacity;
    C、less than infiltration capacity;
    D、less than or equal to infiltration capacity

2、Regarding the infiltration rate, which one is correct: .
    A、the drier the soil, the greater the infiltration rate;
    B、the wetter the soil, the greater the infiltration rat;
    C、With the increase of soil tension water storage, the infiltration rate will become smaller and smaller, and tend to zero;
    D、the infiltration rate has nothing to do with soil moisture.

3、As shown in the figure below, the spatial distribution curve of infiltration rate is a straight line, with an hour as the time interval. If the whole watershed receives 20 mm of rainfall within 1 hour . With the calculation principle of infiltration-excess runoff yield, this hour will produce infiltration-excess ground runoff: (mm).
    A、0
    B、2
    C、50
    D、100

4、Infiltration-excess runoff only yields surface runoff, and the runoff condition is:
    A、the rainfall time is long enough;
    B、the rainfall intensity is large enough;
    C、enough rainfall;
    D、the soil is moist enough.

5、Assume that the rainfall in the previous period on July 27, 28 and 29 are all 10mm, and the constant coefficient k = 0.1; then the recent rainfall index on July 30 is calculated as: mm
    A、0.1
    B、1.1
    C、1.11
    D、10

6、Assuming that the outflow process formed by one unit net rainfall and lasting for 2 hours is the reference process, according to the Unit Hydrograph's superposition and non-interference assumption, which description is correct: .
    A、2 unit net rainfall and lasted 2 hours, the outflow process increased by 2 times;
    B、1 unit net rainfall and lasted 4 hours, the outflow process increased by 4 times;
    C、1 unit net rainfall and lasted 1 hour, the outflow process unchanged;
    D、1 unit net rainfall and lasted 1 hour, the outflow process reduced by half.

7、Assuming that the Unit Hydrograph of 1hr10mm as: 0, 2, 5, 10, 8, 6, 4, 2, 0 (). If the rainfall lasts 2 hours, the net rainfall of 0:00-1:00 is 20mm,net rainfall of 1:00-2:00 is 30mm,then at 4:00,the outflow at the watershed outlet is (mm).
    A、14
    B、28
    C、34
    D、36

8、Which one is not the three elements of the Unit Hydrograph? .
    A、flood peak
    B、flood lag time
    C、total duration of the Hydrograph
    D、three-day flood

9、Assuming that the recession coefficient of the linear reservoir (note: not the storage constant) k = 0.6, the inflow of the linear reservoir at the beginning and end of the period are 100 and 200, and the outflow of the linear reservoir at the beginning of the period is 100, then the outflow of the linear reservoir at the end of the period is ‍ .
    A、60
    B、100
    C、120
    D、150

10、Assuming that the linear reservoirs are: Inflow I, Outflow Q, Storage capacity S, then the differential water balance equation is: .
    A、
    B、
    C、
    D、

05 Hydrological Statistics

Test 05

1、Hydrologic phenomenon is a natural phenomenon, which of the following property does it have?
    A、impossibility
    B、contingency
    C、inevitability
    D、inevitability and contingency

2、The task of hydrological statistics is to study which of the following property of the hydrological stochastic phenomenon?
    A、inevitable variation
    B、natural variation
    C、statistical variation
    D、possible variation

3、What is an event that may or may not occur in a randomized trial?
    A、certain event
    B、impossible event
    C、random event
    D、independent event

4、In the hydrological phenomenon, under such case which the probability of occurring major flood is smaller than that of minor flood, then, which of the following is its frequency density curve?
    A、negative bias
    B、symmetry
    C、positive bias
    D、hyperbolic function curve

5、The normal frequency curve is a drawn on the frequency grid paper.
    A、Straight line
    B、S-curve
    C、Symmetrical bell curve
    D、Asymmetric bell curve

6、The second central moment is .
    A、Arithmetic mean
    B、Mean square error
    C、variance
    D、Coefficient of variation

7、As shown in figure 1-4-1, there are two Pearson III frequency density curves, then, .
    A、Cs1﹤0,Cs2﹥0
    B、Cs1﹥0,Cs2﹤0
    C、Cs1﹦0,Cs2﹦0
    D、Cs1﹦0,Cs2﹥0

8、A hydrological frequency curve, when ,Cv is constant and Cs is increased, the line will .
    A、Lifting at both ends and lowering in the middle
    B、Pan up
    C、Turn clockwise
    D、Turn counterclockwise

9、What are the principles of good wiring when calculating the frequency with the wiring method? .
    A、The principle of minimum sampling error
    B、The principle of minimum error of statistical parameters
    C、The principle of the theory frequency curve and the experience frequency point data match the best
    D、The principle of the design values are biased towards safety

10、Which of the following aspects is correlation analysis mainly used in hydrologic analysis calculation?
    A、Derive the design value
    B、Derive the frequency curve
    C、Calculate correlation coefficient
    D、Interpolate and extend the hydrological series

06 The Calculation of design annual runoff

Test 06

1、Runoff is formed by precipitation, so the relationship between annual runoff and annual precipitation is which of the following?
    A、must be close
    B、must not be close
    C、close in humid areas
    D、Close in dry areas

2、Generally, the influence of human activities on the average annual precipitation in the basin is
    A、Great significant
    B、Significant
    C、No significant
    D、Nothing influential

3、Human activities (such as the construction of reservoirs, irrigation, water and soil conservation, etc.) indirectly affect the annual runoff by changing the nature of the underlying surface,which generally causes the
    A、Evaporation is basically unchanged, thus increasing the annual runoff
    B、Evaporation increases, thus reducing annual runoff
    C、Evaporation is basically unchanged, thus reducing the annual runoff
    D、Evaporation increases, thus increasing annual runoff

4、Through the analysis and calculation of the measured annual runoff data, the annual runoff mean value and departure potential coefficient of the two rivers A and B are obtained as follows: A river: =100, =0.42; B river: =500, =0.25, by comparing the two rivers, it can be seen that
    A、A river is rich in water resources and its runoff varies greatly from year to year
    B、A river is rich in water resources, and the annual change of runoff is small
    C、B river is rich in water resources and its runoff varies greatly from year to year
    D、B river is rich in water resources, and the annual change of runoff is small

5、In the analysis and calculation of design annual runoff, the purpose of extending short series data to long series data is to
    A、Increase the representativeness of the series
    B、Increase the reliability of the series
    C、Increase the consistency of the series
    D、Consider safety

6、When using the contour map of annual average runoff depth to calculate the annual average runoff of small watershed, its value is equal to
    A、Isoline value at the outlet of the basin
    B、Isoline value at the center of gravity of the basin
    C、Average of the above two values
    D、Isoline value of the farthest point from the outlet of the basin

7、In the selection of typical years, when more than one typical year is selected, irrigation engineering should select
    A、The year when the runoff in the irrigation period is relatively dry
    B、The year when the runoff in the non-irrigation period is relatively dry
    C、The year when the dry season is longer and the runoff is dry
    D、The year when the wet season is longer, but the runoff is dry during the dry season

8、In the selection of typical years, when more than one typical year is selected, should be selected for hydropower projects.
    A、The year when the runoff of irrigation water demand period is relatively dry
    B、The year when the runoff of non-irrigation water demand period is relatively dry
    C、The year with a long dry season and relatively dry runoff
    D、The year with long wet season but relatively dry runoff in dry season

9、The variation of runoff in dry season is quite stable, because it mainly comes from
    A、overland runoff
    B、Underground water storage
    C、water storage in channel network
    D、snowmelt runoff

10、In the calculation of frequency, when referring to the dry water flow of a certain recurrence period, it is usually
    A、expressed as the probability greater than the runoff
    B、expressed as the probability of greater than and equal to the runoff
    C、expressed as the probability of less than the runoff
    D、expressed as the probability less than and equal to the runoff

07 Design Flood Calculation

Test 07

1、Design flood refers to
    A、the flood that meets the requirements of design standards
    B、the maximum flood of design section
    C、the random frequency flood
    D、the historical mega flood

2、The three elements of design flood are
    A、the design flood standards, the design flood volumn and the duration of design flood
    B、flood peak discharge, total flood volumn and flood hydrograph
    C、design flood peak discharge, one-day and three-day flood volumn
    D、design flood peak discharge, total design flood volumn and design flood hydrograph

3、In the correlation analysis of peak discharge and flood volumn, the statistical duration of flood volumn gets longer, the relevancy of this two varibles
    A、becomes higher
    B、becomes lower
    C、remains the same
    D、is unknown

4、When calculates the design flood by amplifying the typical flood with same multiples (the multiples of peak discharge),
    A、the peak discharge and flood volumn both are the design value
    B、the peak discharge is the design value while the flood volumn is not
    C、the flood volumn is the design value while the peak discharge is not
    D、neither the peak discharge and flood volumn are the design value

5、The selection priciplee of typical flood are return period and harmful influence. When select the typical flood by consindering harmful influence,
    A、the flood has centralized flood shape of hydrograph and flood peak occurs ahead
    B、the flood has centralized flood shape of hydrograph and flood peak is in the middle.
    C、the flood has centralized flood shape of hydrograph and flood peak occurs latter.
    D、the flood has long duration and large volumn.

6、Smoothing the amplified design flood is based on
    A、the hydrograph
    B、the similarity of typical flood hydrograph
    C、the water balance equation
    D、the change trend of typical flood hydrograph

7、Reservoir inflow flood includes
    A、reservoir inflow section flood, interval flood and control area flood
    B、peak discharge, flood volumn and flood hydrograph
    C、surface flood, subsurface flood and reservoir control area flood
    D、upstream flood, middle stream flood and downstream flood

8、The period of design flood stage is determined by
    A、the area of design basin and project scale
    B、the flood seasonal regularity in design basin and project requirement
    C、design standard of water-related project
    D、design principle

9、When calculating design flood from storm data, it is generally assumed that
    A、the frequency of design storm is greater than that of design flood
    B、the frequency of design storm is less than that of design flood
    C、the frequency of design storm is equal to that of design flood
    D、the frequency of design storm is greater than or equal to that of design flood

10、Nash instantaneously unit hydrograph is completely determined by the
    A、parameter m1 and n
    B、parameter m2 and n
    C、parameter n and K
    D、parameter m1、m2、n and K

08 Hydrological forecast

Test 08

1、As shown in the figure below, variation curve of the flood flow (Q) along the river channel (x) at two points of time (t), then the flow at the position marked “1” in the figure, the corresponding flow is:
    A、A
    B、B
    C、C
    D、D

2、There are three parameters in the flood calculation of the Muskingum Routing Method. Which the parameter of the following is not the calculation equations parameter:
    A、storage constant K
    B、flow ratio x
    C、water storage W
    D、time length of the time-step △t

3、In the flood calculation of the Muskingum Routing Method, the unit of the storage constant K is:
    A、
    B、hour
    C、
    D、dimensionless

4、The following figure shows the results obtained by taking the Muskingum trial algorithm to determine the parameters of different flow ratio (x). From this, the flow ratio can be estimated as:
    A、(A)
    B、(B)
    C、(C)
    D、(D)

5、The following picture shows the rainfall and flood process diagram, then the forecast at the time point is an advanced forecast.
    A、(A)
    B、(B)
    C、(C)
    D、(D)

6、In the evaluation of prediction, which the following one is correct:: .
    A、The operational forecast is mainly based on the diachronic observation data and making simulated forecasts
    B、The plan forecast is an actual real-time forecast to guide engineering applications
    C、The greater the certainty coefficient, the higher the prediction accuracy
    D、The greater the tolerance, the lower the qualified rate

7、As can be seen from the corresponding flow forecast chart below, when the upstream station observes a flood peak flow of 80 at 12:00 on 2019-7-30, the peak flow () and the occurrence time respectively are: .
    A、80 and 16:00
    B、60 and 13:00
    C、50 and 15:00
    D、40 and 14:30

8、The staged cofferdams for reservoir construction are mainly used in: .
    A、small river
    B、middle river
    C、big river
    D、small and middle rivers

9、For the prediction of flows in open channel during diversion period, generally speaking, the water level is decreasing from upstream to downstream, and the kinetic energy of the water flow: .
    A、increase
    B、unchanged
    C、decrease
    D、increase first and then decrease

10、After the open channel diversion cofferdam, compared with the state of the natural river, for the same flow, the water level of the upstream cofferdam will:
    A、decrease
    B、barrage
    C、unchanged
    D、none of the above