obviating the need to differentiate between the formulations for simple and complex terrain (as

required with previous regulatory models) .

The general concentration equation, which applies in stable or convective conditions is

given by

where C x y z is the total concentration, is the contribution from the T r r r { , , } C x y z c,s r r r { , , }

horizontal plume state (subscripts c and s refer to convective and stable conditions, respectively),

C x y z is the contribution from terrain-following state, f is the plume state weighting c,s r r p { , , }

function, {x , y , z } is the coordinate representation of a receptor (with zr defined relative to r r r

stack base elevation), z z z is the height of a receptor above local ground, and zt is the p r t = −

terrain height at a receptor. Note that in flat terrain, z , , and the concentration t = 0 z z p r =

(eq. (48)) reduces to the form for a single horizontal plume. It is important to note that for any

The formulation of the weighting factor requires the computation of Hc. Using the receptor

specific terrain height scale (hc) from AERMAP, Hc is calculated from the same algorithms

found in CTDMPLUS as:

where u {Hc} is the wind speed at height Hc, and N is the Brunt-Vaisala frequency.

The height scale, hc, characterizes the height of the surrounding terrain that most dominates the

flow in the vicinity of the receptor.

The weighting between the two states of the plume depends on the relationship between Hc

and the vertical concentration distribution at the receptor location. Assuming that the wind

n951 - n952 - n953 - n954 - n955 - n956 - n957 - n958 - n959 - n960 - n961 - n962 - n963 - n964 - n965 - n966 - n967 - n968 - n969 - n970 - n971 - n972 - n973 - n974 - n975 - n976 - n977 - n978 - n979 - n980 - n881 - n982 - n983 - n984 - n985 - n986 - n987 - n988 - n989 - n990 - n991 - n992 - n993 - n994 - n995 - n996 - n997 - n998 - n999 - n1000

english:

castellano: DISPER CUSTIC DESCAR RADIA    italiano:

français:    português:

deutsch:

deutsch: DIS CUS  DES  RAD

castellano: DIS CUS DES  RAD   english: DIS CUS DES RAD

português: DIS CUS DES RAD   italiano:   DIS CUS  DES RAD

français:  DIS CUS DES RAD