AMIE Study Circle Blog

Flood-frequency computations for the river Chambal at Gandhisagar dam, by using Gumbel’s method, yielded the following results: Return period T (years) Peak flood (m 3 /s) 50 40,809 100 46,300 Estimate the flood magnitude in this river with a return period of 500 years. (AMIE Summer 2021)  Solution Using Gumbel's equation \({x_T} = \bar x + K{\sigma _{n - 1}}\) \(\begin{array}{l}{x_{100}} = \bar x + {K_{100}}{\sigma _{n - 1}}\\{x_{50}} = \bar x + {K_{50}}{\sigma _{n - 1}}\\({K_{100}} - {K_{50}}){\sigma _{n - 1}} = {x_{100}}{x_{50}}\\ = \,46300 - 40809 = 5491\end{array}\) But,  \(\begin{array}{l}{K_T} = \frac{{{y_T}}}{{{S_n}}} - \frac{{{{\bar y}_n}}}{{{S_n}}}\\{\rm{where }}{{\rm{S}}_n}\,and\,{{\bar y}_n}\,{\rm{are constants}}{\rm{.}}\end{array}\) \(\begin{array}{l}\therefore \,({y_{100}} - {y_{50}})\frac{{{\sigma _{n - 1}}}}{{{S_n}}} = 5491\\{\rm{Using equation}}\\{{\rm{y}}_T} =  - \left[ {\ln .\ln \...

Answer the following questions Enlist the parameters that constitute the water quality and their tests. Physical parameters Turbidity Temperature Colour Taste and odour Solids Electrical conductivity (EC) Chemical parameters pH Acidity Alkalinity Chloride Chlorine residual Sulfate Nitrogen Fluoride Iron and manganese Copper and zinc Hardness Dissolved oxygen Biochemical oxygen demand (BOD) Chemical oxygen demand (COD) Toxic inorganic substances Toxic organic substances Radioactive substances Biological parameters Bacteria Algae Viruses Protozoa Name the instruments that a typical hydrometeorological station should contain. The common instruments of measure are anemometer, wind vane, pressure sensor, thermometer, hygrometer, and rain gauge. What are the meaning of the terms "correlation", and "spurious correlation"? A correlation is a measure of the direction and the size of two or more variables in a data set. This means that when looking at statistical models, if o...

Answer the following in brief Explain the term ‘planning’ in the light of water resources planning. Reducing the frequency and/or severity of the adverse consequences of droughts, floods, and excessive pollution are common goals of many planning and management exercises. Other reasons include the identification and evaluation of alternative measures that may increase the available water supplies, hydropower, improve recreation and/or navigation, and enhance water quality and aquatic ecosystems.  Some multiple purposes served by a river can be conflicting. A reservoir used solely for hydropower, or water supply, is better able to meet its objectives when it is full of water. On the other hand, a reservoir used solely for downstream flood control is best left empty, so it can store more of the flood flows when they occur. A single reservoir serving all three purposes introduces conflicts over how much water to store in it and discharge from it, i.e., how it should be operated. In bas...

Define present worth factor and its mathematical formula. The present value (PV) factor is used to derive the present value of a receipt of cash on a future date. The concept of the present value factor is based on the time value of money - that is, money received now is worth more than money received in the future, since money received now can be reinvested in an alternative investment to earn additional cash.  The PV factor is greater for cash receipts scheduled for the near future, and smaller for receipts that are not expected until a later date. The factor is always a number less than one. The formula for calculating the present value factor is: P = [1 / (1 + r)n] Where: P = The present value factor r = The interest rate n = The number of periods over which payments are made What is cumulative distribution function and probability distribution function? The Cumulative Distribution Function (CDF) of a real-valued random variable, say “X”, which is evaluated at x, is the prob...

Write short notes on the following (2 x 10) Systems modelling Systems analysis may be said to be a formalization of the operation of the total system with all of its subsystems together. Systems analysis is usually understood as a set of mathematical planning and design techniques, which includes some formal optimization procedure. When scarce resources must be used effectively, systems analysis techniques stand particularly promising (for example, in optimal crop water allocation to several competing crops, under conditions of limited water supply).  Probability distribution function The probability distribution function is the integral of the probability density function. This function is very useful because it tells us about the probability of an event that will occur in a given interval. Gamma distribution The gamma distribution term is mostly used as a distribution which is defined as two parameters – shape parameter and inverse scale parameter, having continuous probability d...

Choose the correct answer for the following (2 x 10) 1. The method used to determine the live storage capacity of a reservoir is  (a) Hydrologic Modelling (b) Moodi's Method (c) Sequent Peak Method (d) None of these 2. The name of the graphical method to determine the capacity of a reservoir is (a) Double mass curve technique (b) Mass Curve Technique (c) None of these (d) Regression technique 3. The different capacities of reservoir are given in various options. Which is the right sequence from bottom to top? (a) Dead Storage, Active Storage, Flood Control Storage and Surcharge Storage (b) Flood Control Storage, Active Storage, Dead Storage, and Surcharge Storage (c) Surcharge Storage, Active Storage, Dead Storage, and Flood Control Storage (d) None of these 4. If the feasible region of an LPP is empty, the solution is ---------. (a) Infeasible (b) Unbounded (c) Alternative (d) None of the above 5. The chi-square goodness-of-fit test can be used to test for (a) Significance of samp...