How does the capacitive nature of transmission lines affects its working?

With the increase in length of the transmission lines, the line charging currents and the shunt admittance become more and more dominant, hence due to this line capacitance the magnitude of receiving end voltage at no-load or lightly loaded conditions becomes greater than the magnitude of sending end voltages.

At low load the (series)inductive(L=do/di, variation of flux with variation of current) effect of line reduces, and hence the parallel capacitive(C=dq/dv, variation of charge with variation of voltage) effect be comes dominant, which rises the voltage, at receiving end. 

This is a case of stray capacitance being considerable, affecting the whole line , causing an increase in voltage at receiving end.