How resistance effect the Transmission lines?

Though the contribution of line resistance to series line impedance can be neglected in most cases it is the main source of line power loss.Thus while considering transmission line economy,t he presence of line resistance must be considered.
The effective A C resistance is given by
R= (average power loss in conductor in watts) / ( square of current)
where Current is the rms current in the conductor in amperes.
Ohmic or DC resistance is given by the formula
R= (ρl) / (A)
where ρ = resistivity of the conductor, (ohm-m)
                    / = length, (m)
 A = cross-sectional area, (meter^2)
The effective resistance given by 1st Equation is equal to the DC resistance of the conductor given by 2nd equation only if the current distribution is uniform throughout the conductor.
For small changes in temperature, the resistance increases with temperature in accordance with the relationship.
Rt = R(1+α0t)
where R = resistance at temperature 0 C
          α0= temperature coefficient of the conductor at 0 C
Above Equation  can be used to find the resistance Rt2 at a temperature t2  if resistance Rt1  at temperature t1 is known
((Rt2 ) / (Rt1 ) ) = (( 1+α0 t1) / ( 1+α0 t2))