urban drainage

Question 1

what are the characteristics of drainage in urban areas?

Answer 1

surfaces are impermeable, designed to shed water quickly.
infiltration is low
precipitation is greater in urban areas so surface runoff is greater.
on hydrograph, has a short lag time and high peak discharge.

Question 2

what is catchment management?

Answer 2

way of managing rivers and improving drainage systems by looking at a whole river catchment, and the interaction between water and land.

Question 3

what is hard engineering?

Answer 3

involves man made structures such as dams, flood walls, reservoirs etc. but they can be expensive and can disrupt natural systems.

Question 4

what is soft engineering?

Answer 4

uses knowledge of the river basin, working with nature. can involve river restoration and conservation

Question 5

what are SUDs?

Answer 5

Sustainable Urban Drainage Systems - are used to imitate natural drainage systems. processes include;
vegetation trenches, decrease runoff and channel flow
vegetated roofs, intercept rainfall, evapotranspiration
containers, store rainwater for reuse.