Hydrological Calculations
1. Hydrological calculations are: ) a part of engineering hydrology dealing with development of methods for calculation of values for different conditions of hydrologic regime; b) a part of engineering hydrology dealing with calculation of vales for different conditions of hydrologic regime; c) a part of engineering-hydro-meteorological survey dealing with calculation of values for different conditions of hydrologic regime.
2. Calculation probability is: ) probability of hydrologic factor value to exceed a set of its all probable values; b) availability of hydrologic condition considered in building design to establish the parameter values of hydrologic regime determining the design solution; c) probability of exceeding the specified water discharge.
3. Runoff volume is: ) amount of water flowing through a given cross section of water flow per a year; b) amount of water flowing through a given cross section of water flow within a definite period of time; c) amount of water flowing through a given cross section of water flow per a second.
4. Water supply year is: ) calculated year period beginning from April; b) a year period including water accumulation and discharge period in a given river basin; c) calculated year period beginning from the highest water season;
5. Discharge record is: ) a graph of time change in water discharge per a year or a part of year (season, high water or flood) in a given cross section of water flow; b) a graph of time change in water levels per a year or a part of year (season, high water or flood) in a given cross section of water flow; c) a graph of time change in water discharge and level per a year.
6. Backwater (damming) is: ) an increased water level; b) increased water level due to ice clogging and jams; ) an increase in water level due to obstacles for its flowing.
7. To smooth and extrapolate an empirical distribution curve of year exceeding probabilities of calculated water discharge and level when performing engineering building survey it is recommended to apply in the Russian Federation: ) the Kritskiy-Menkel three-parameter distribution, the Pearson distribution of the third type and other distributions; b) only Kritskiy-Menkel three-parameter distribution, the Pearson distribution of the third type; c) the Gauss distribution and the Pearson distribution of the 3-d type.
8. Probability distribution parameters of hydrologic conditions at the final design stage are determined by the methods: ) the least likelihood, moments, graphical analytic; b) only the least likelihood and moments; c) calculation method is not specified.
9. Durability of observation period is considered to be sufficient if: ) a given period is representative, but relative average quadratic error of calculated value for a studied hydrologic condition does not exceed 10% for year or seasonal runoffs and 20% - for maximum and minimum runoffs; b) a given period includes more than 6-10 elements, but relative average quadratic error of a studied hydrologic condition does not exceed 10% for year and seasonal runoff s and 20% - for maximum and minimum runoffs; c) a given period includes more than 25 elements, but relative average quadratic error of calculated value of a studied hydrologic condition does not exceed 10% for year and seasonal runoffs and 20% - for maximum and minimum runoffs.
|
|
|
10. Choosing a river analogue one needs to take into consideration: ) only geographical proximity of water catchment; b) only one type of river analogue runoff and studied river; c) homogeneity of runoff formation conditions, similarity of climate conditions, uniformity of soil and hydrologic conditions, similar degree of lake surface, forestry area, boggy area, and catchment ploughness as well as other factors.
11. In the absence of hydrometric observations in a calculated cross section the distribution parameters and calculated value are determined: ) during field work as a part of engineering survey; b) by means of the following basic methods: water balance; hydrologic analogy; averaging in a homogeneous site; isoline mapping; plotting regional dependencies of runoff conditions on the basic physical-geographic conditions of catchment; plotting regional dependencies of yearly runoff conditions on runoff formation factors; c) only by means of the following basic methods: water balance; hydrologic analogy; isoline mapping; plotting regional dependencies of runoff conditions on the basic physical-geographic catchment conditions.
