(1) The annual runoff into a dam follows the normal distribution and the probability for an annual runoff between 50 and 150 MCM is 95%. What is the mean (μ) and standard deviation (SD) of the annual runoff?
μ=100 ΜCM, SD=50MCM
μ=100 ΜCM, SD=25MCM
μ=120 ΜCM, SD=25MCM
μ=100 ΜCM, SD=36 %
(2) The water supply for city A comes from a reservoir with a capacity of 20 MCM. The annual consumption of the city is 8 MCM, while the annual net inflow into the reservoir (transpiration and other losses deducted) is 9 MCM. At the end of September 2020, there is only 1 MCM in the reservoir. This means that:
It is certain that in at least one of the next two hydrological years there will be a water shortage.
It is possible that the water need for the city will not be covered in next hydrological year.
It is certain that in the next hydrological year the water needs of the city will be covered.
(3) The preliminary design of an irrigation reservoir was based on runoff data from the previous 15 years. Five years later it was decided to build the reservoir and the final study begins. Is it appropriate or not, to review the hydrological study and include the data of the last five years?
It is not advisable, since the sample of 15 years is sufficient and the addition of 5 years will have practically no effect on the design of the projects.
It is advisable, because the addition of 5-year measurements, in general, leads to an increase in the average annual flow.
It is advisable, because the addition of the 5-year measurements, generally leads to a more reliable estimate (Decrease of the confidence interval) of the average annual flow.
(4) The accuracy of the statistical forecast of a hydrological variable:
Is higher when the standard deviation is relatively small (relative to the mean)
Is higher when the standard deviation is relatively large (relative to the mean)
The standard deviation is not an indication of the accuracy
(5) Which of the following definitions is INCORRECT:
The active storage capacity of a reservoir is the volume between the minimum and maximum normal operating level of a reservoir. Essentially, it is the maximum volume we can reliably store for satisfying a certain water demand.
The flood storage capacity is the is the maximum flood volume that can be stored in the reservoir, assuming that on the onset of the design flood the water in the reservoir is at the maximum normal level.
Dead storage capacity is the volume from the bottom of the reservoir to the top of the bottom drain which we do not count on storage because it is too small.
(6) The picture shows the stage-discharge curve at a certain location on a river. Which of the following statement is INCORRECT:
At stage level equal to 313 m, the discharge is approximately 13 m3/s
At stage level equal to 314 m, the discharge is approximately 37 m3/s
To develop the stage-discharge curve, several flow measurements are required at various water levels at that river location.
The stage-discharge curve is much more accurate for estimating larger discharge values.
(7) The current approach to the management of water resources in Cyprus can be characterized as Supply-side Management, i.e. it aims at saving water while new water projects are limited. The reason for this approach is:
Large water projects cost tens of millions. Due to the current economic crisis, there are is a lag of funds for major water infrastructure projects.
The majority of the water resources of Cyprus have been developed during the past 4-5 decades; thus the need for major projects has been exhausted.
The European Union has posed limitations for new projects and demands that we pursue ecological policies and save water.
(8) Which of the following are elements of the river intake project with storage?
Τα Κυβερνητικά Υδατικά Έργα είναι η κυριότερη πηγή νερού για ύδρευση και επίσης σημαντική πηγή νερού για άρδευση. Από αυτά διοχετεύεται νερό για ύδρευση στις περισσότερες Τοπικές Αρχές Υδατοπρομήθειας, οι οποίες το διανέμουν στους καταναλωτές της περιοχής τους.
-Τα Κυβερνητικά Υδατικά Έργα είναι υδατικά συστήματα που αποτελούνται από φράγματα, έργα μεταφοράς νερού (αγωγοί, αντλιοστάσια κ.λπ.), διυλιστήρια νερού, δίκτυα άρδευσης, εμπλουτιστικά έργα, δίκτυα διανομής ανακυκλωμένου νερού κ.α
-Τα μεγάλα υδατικά έργα λειτουργούν με βάση τον περί Ενιαίας Διαχείρισης Υδάτων Νόμο, ως Κυβερνητικά Υδατικά Έργα (ΚΥΕ) υπό την ευθύνη του Τμήματος Αναπτύξεως Υδάτων.
Η κατασκευή του Νότιου Αγωγού ολοκληρώθηκε το 1960.
(10) Which of the following does NOT contribute to water conservation?
Reducing water loss at water distribution networks.