Drainage system of landscape space is design by experience or overestimated size because there is no criteria. This study is made for drainage design criteria or guide of landscpae space.
For the criteria, the Manning's formula and Conservation Equation is used and the construction feasibility of drainage system is set by best hydraulic section theory for minimum dimension and field experience for maximum dimension. And the hydraulic restriction, specially velocity of flow which is recommended is considered.
By analysis of drainage system of landscape spaces, a few of dimension of draiange system is allowed cause flow velocity and construction feasibility.