Master of Engineering in Applied Hydrology
http://dl.lib.uom.lk/handle/123/13627
2024-03-28T22:00:53ZEvaluation of hydro power potential in Uma Oya basin
http://dl.lib.uom.lk/handle/123/13625
Evaluation of hydro power potential in Uma Oya basin
Siriwardena, WADLW
A substantial quantity of untapped hydro energy will still exist in Sri Lanka, even after the completion of the Accelerated Mahaweli Programme, as still a number of rivers and tributaries will remain unexploited. Hence it is imperative to launch a project on formulating a methodology to calculate the quantity of technically feasible hydro energy of a river basin as accurately as possible. The actual hydropower available depends on technical, economical, political and physiographic factors.
This dissertation formulates a methodology to evaluate available hydropower potential in the Uma Oya basin, which is a sub catchment of the river Mahaweli, at four different levels of gross and net potentials.
They are,
(a) Gross precipitation potential
(b) Gross surface runoff potential
(c) Gross river potential
(d) Net potential with individual reservoirs
The relationships between different levels of gross and net potentials are analysed and the technical feasibility of the Uma Oya basin for the development of hydropower is examine
Comparison of some techniques for design flood estimation
http://dl.lib.uom.lk/handle/123/1224
Comparison of some techniques for design flood estimation
Batuwitage, LP
Sri Lanka, a country with abundant water resources, has a predominantly agriculture oriented economy. Hence, hydrological development plays an important role, not only in the vast irrigation development efforts, but also in meeting the energy requirements of the country through hydro-power.
Many hydrologic design problems require simply an estimation of the peak flow rate generated by a river system under specific conditions. Several methods are available for the estimation of peak flow rate, but many of these are quite inadequate to produce results which are consistent within the accuracy required for hydrologic analysis and design.
In this study several different flood estimation methods have been considered for sixteen catchments to determine their applicability to Sri Lankan catchments. A frequency analysis is also carried out for each of the catchments and their flood peaks are compared with the design floods obtained by different methods.
It is observed that the findings of this thesis lead to various research areas, for further detailed studies with regard to some of the methods of analysis.
Rainfall runoff model for Uma-Oya basin
http://dl.lib.uom.lk/handle/123/1223
Rainfall runoff model for Uma-Oya basin
Ekanayake, STB
The Rainfall-Runoff model presented here could be used to predict the monthly runoff values at the unengaged site of Uma Oya confluence, "and hence monthly runoff values at the Mnipe anicut in the Mahaweli river.'These estimated, monthly runoff values are needed for the operation of the control gates of Minipe right bank and left bank main canals in order to divert water to system B,C and E respectively. Although there are long periods of rain fall records over the Uma Oya basin the availability of runoff records is limited and are available for
the two upstream gauging stations at Welimada and Talawa kanda across the Uma Oya . As the location of the Uma Oya confluence is different from the locations of the river gauging stations the model parameters need to be renationalized so that the runoff at any location of the Uma Oya river could be estimated.
A deterministic black-box regression model for rainfall-runoff simulation in the two sub-basins at Welimada & Talawakanda is developed. The model is mathematically expressed as;
Qp.t = nt [∑_(1=0)^k▒〖a 〗t2l Pip1t] I = 01I………K
t = 1.2 …….12
The model structure depends on two key parameters which are;
1. An Order parameter- K (an integer, greater than or equal to 1)
2. A Memory parameter- nt ( t = l,2,3........12) An order parameter K, characterizes the runoff behavior of the Das in .ie. When K=l, the catchment is linear and for K >1, the catchment is non-linear. A memory parameter nt characterizes the memory of the rainfall-runoff process The order parameter K is determined from monthly rainfa 11-runoff functional relationships and the model coefficients 0t,1 are estimated for the same functional relationships by the least-square technique for both sub basins. Finally the model coefficients are regionalized over the Uma Oya basin, so that the model can be used to estimate monthly runoff at the unqauged site of Uma Oya confluence. These estimated runoff values have been compared with the runoff values of observed differences
between . Rantambe and Randenigala of Mahaweli river, before application of the model.
Analysis of pumping test results of North West aquifer using numerical techniques
http://dl.lib.uom.lk/handle/123/892
Analysis of pumping test results of North West aquifer using numerical techniques
Hangilipola, RMPTB
This report is intended to analyze the pumping test results of North west aquifer using nu1nerical techniqu-2s. The pumping test results were taken from Water Resources Board , Sri Lanka. These pump tests were carried out during the period March l980- m arch l98l. in analyzing the flow to a pumped well, the radial flow can be represented by a differential equation, which is derived from Darcy's law. There are various approaches to solve this differential equation of radial flov1 to an aquifer. These methods are dependent on the type of aquifer and the condition of flow. Therefore suitable method should be selected for particular problem.
Most of these approaches are graphical methods. A numerical method was introduced by K.!{. Ruston (Ruston, K.R. & Chan, Y.K. ~976). In graphical methods, the differential equation of radial flov1 are solved using analytical expressions. Generally these analytical expressions contain-~ infinite integrals
and summations of higher transcendental functions. Therefore the evaluation of these analytical expressions is sometimes difficult. But the values of aquifer parameters can be obtai;1ed by matching the theoretical curves derived from analytical expressions with the field data.
The same differential equation can be solved by using numerical techniques. In one such technique a discrete space -discrete time model is introduced to represent the radial flovJ in an aquifer. Thus, the saoe differential equation for radial flow can be replaced by the discrete space- discrete time numerical
mode1 • The number of assumptions can be reduced in using numerical technique compared to the graphical methods. In addition to that, most of the actual field conditions can be included in to a single numerical solution. These field conditions are leakage, variable saturated depth