Chapter 2

In general, this chapter is well structured and well written, but contains certain grammatical and other errors that need to be corrected before the document is presented in final form (see below).
Page 16, paragraph 1: You may want to replace "water storage and conveyance" with "water conveyance and storage." In channels, conveyance is of first order, while storage is of second order. In reservoirs, there is no conveyance.
Page 16; paragraph 1: Replace "sophisticated set of rules" with "predetermined set of rules." (Overstated)
Page 16; paragraph 3: Replace "high level abstractions" with "high-level abstractions"
Page 17, paragraph 1, bullet 3: Replace "complicated" with "complex"
Page 17, last paragraph, into Page 18: "important" repeated three times; please reword.
Page 18, Section 2.2, paragraph 2: "without regard to the type of discretization." In reality, overland flow, groundwater flow, and canal flow have different characteristics celerities and diffusivities under unsteady flow. How can all these physical characteristics be reconciled under one time step and space step? Please clarify to help justify the above statement.
Page 18, Section 2.2, paragraph 3: "those who may not be familiar with OO methods". This phrase is condescending. Reword or eliminate.
Page 19, Section 2.3, paragraph 1: Replace "Reynolds transport theorem" for "The Reynolds transport theorem"
Page 20, Figure 2.3: Move "groundwater" to the left so that the "r" can be better seen.
Page 20: Is Eq. 2.2 correct with respect to dV? Reference to it on Page 22 differs from it.
Page 21, paragraph 1: Replace "The bottom shear stress can be explained" with "The bottom shear stress can be expressed"
Page 21, paragraph 1: The neglect of inertia terms renders the resulting "diffusion flow" unable to circulate. As long as 2-D convection is the primary mechanism being modeled, this may be an expedient assumption. Is 2-D circulation unimportant in all RSM applications?
Page 21, paragraph 2: The 1-D diffusion flow (wave) applicability criteria may be applicable to the modeled conditions. What is required is a long-period wave or event. Seasonal variations would be certainly covered; rapid changes involving changes occurring in a few days may not.
Page 22, section 2.4, paragraph 1: A stage-volume relationship implies the existence of a unique rating curve. In general, unsteady flow rating curves are not unique. The manual needs to state here that the unique rating assumption is "approximately" consistent with the diffusion flow assumption.
Page 22, section 2.4.1, equation 2.13: Replace partial derivative ∂ for total derivative d (for consistency with text immediately below and Figure 2.4)
Page 23, section 2.4.2, paragraph 1: Replace "described next." with" described below."
Page 24, section 2.4.4: Eqs. 2-19 and 2-20 are only valid for rectangular channels. How about trapezoidal channels?
Page 25, paragraph 1: Replace "pure sources" with "sources"
Page 25, paragraph 2: Replace "gradient driven" with "gradient-driven"
Page 25, last line: Replace "current diffusion flow formulation" with "diffusion flow formulation"
Page 26, section 2.5.1: Define T_mn
Page 26, section 2.5.1: Question the usage of "If" at the beginning of the sentence. What other equations are used, besides the Manning equation?
Page 26, section 2.5.1: Does the model issue a warning when S_tol is activated? (Equation 2.24)
Page 31, section 2.5.5, paragraph 2: Which method is used in the structure flow water mover? Lookup tables or regression equations? Why?
page 31, section 2.5.6: Replace "(Equation 2.21)" with "Equation 2.21"
Page 32: Replace "The case" with "For the case"
Page 34, section 2.6.2, bullet 1: Do you mean "precipitation-runoff transform"? Usually the conversion of precipitation to runoff is not considered routing (an exception to this would be the Cascade of Linear Reservoirs).
Page 37, paragraph 2: Replace "landuse" for land-use
Page 39, section 2.8, paragraph 1: What is the reason for going fully implicit (α = 1) in order to avoid the iteration? Slightly off-centered (α = 0.6) can be more accurate for all wavelengths.
Page 39, section 2.8, paragraph 2: Replace "one thousand cell discretization" with "one-thousand cell discretization" or "a discretization of one thousand cells"
Page 39, section 2.8, paragraph 3: Replace "values used;α" with "values used; α"
Page 39, section 2.8, paragraph 3: Are there sensitivity tests available showing the benefits of α = 1 as opposed to α = 0.6-0.8?
Page 40, paragraph 2: Replace "involved mainly for" with "involved for"
Page 40, section 2.8.1, paragraph 1: How is Equation 2.49 (average water velocity in a cell) reconciled with unsteady flow?
Page 40, section 2.8.1: delete "/cite"
Page 41, paragraph 2: Replace "EPMs are being developed to simulate landscape and habitat" with "EPMs simulate landscape and habitat"