GENERAL GEOLOGY

Detailed explanation-1: -(e) Land use: Urbanisation reduces infiltration by increasing flow velocity, thereby decreasing the base period and increasing the peak of the hydrograph.

Detailed explanation-2: -Due to urbanization, there will be a proper drainage system in the catchment so the peak of hydrograph will come earlier and time base will get reduced.

Detailed explanation-3: -The results of this study clearly show the effect that land cover has on lag time between precipitation and discharge peaks. Urbanization reduces infiltration and speeds up runoff, effectively reducing lag time, increasing the frequency and magnitude of flooding.

Detailed explanation-4: -Urbanization generally results in increased magnitude and frequency of peak flows. However, baseflow effects typically are more variable, with studies showing a range of responses in urban streams [Lerner 2002, Brandes et al.

Detailed explanation-5: -Urbanization reduces the minimum threshold rainfall for runoff generation, resulting in multi-peak hydrographs reflecting the contribution of both pervious and impervious surfaces. Urban roof water harvesting increases catchment lag time, but reduces downstream peak and total discharge, baseflow and flow velocity.