ENVE-205
Environmental Engineering Hydrology
CHAPTER V: Watershed Characteristics and Infiltration
In this chapter, effects of topographical watershed
characteristics such as slope and those of watershed soil characteristics such
as permeability on the hydrograph shape formation from a discharge point will
be discussed. Soil infiltration
calculation methods such as Green-Ampt, NRCS, and Horton will be discussed in
detail.
Study Plan:
·
Learning
the directly connected impervious area and not directly connected impervious
area concepts (Section 5.1.1).
·
Learning
the effects of drainage system, land cover, and area storm coverage properties
on the hydrograph shape (Sections 5.1.2, 5.1.3).
·
Learning
the “time of concentration” concept for overland flow, pipe flow, and channel
flow conditions. In this context,
Izzard’s Equation, Kerby’s Equation, and NRCS Equation for overland flow will
be discussed. In addition, Manning’s
Equation for pipe flow and channel flow will be examined (Sections 5.2.1,
5.2.2, 5.2.5, 5.2.8). Example problem 5.2 (see the additional information).
·
Learning
the NRCS hydrologic soil classification (Section 5.3.1). See Fig. 5.9.
·
Learning
the Green-Ampt Method in infiltration calculations (Section 5.3.2). See
formula derivation. Example problem
5.3.
·
Learning
the NRCS Curve Number (CN) Method in infiltration calculations (Section 5.3.4).
See
formula derivation in Fig. 5.10.
Discuss the moisture condition modifications for CN and composite curve
number concept. Example problems 5.4,
5.5.
·
Learning
about the Horton’s Equation in infiltration calculations (Section 5.3.5).
·
Learning
the concepts of water quality such as pollutant load, event mean concentration,
and loading rate (Section 5.5).
·
See
some infiltration measurement devices.
· Homework problems 1, 2, 3, 9, 12, 13.