Source code for cwatm.hydrological_modules.miscInitial

# -------------------------------------------------------------------------
# Name:        MiscInitial
# Purpose:
#
# Author:      pb
#
# Created:     13.07.2016
# Copyright:   (c) pb 2016

# -------------------------------------------------------------------------

from cwatm.management_modules.data_handling import *

[docs]class miscInitial(object): """ Miscellaneous repeatedly used expressions Definition if cell area comes from regular grid e.g. 5x5km or from irregular lat/lon Conversion factors between m3 and mm etc. Note: Only used in the initial phase. **Global variables** ==================== ================================================================================ ========= Variable [self.var] Description Unit ==================== ================================================================================ ========= DtSec number of seconds per timestep (default = 86400) s twothird 2/3 -- MtoM3 Coefficient to change units -- InvDtSec cellArea Cell area [m²] of each simulated mesh cellLength length of a grid cell m InvCellArea Inverse of cell area of each simulated mesh m-1 DtDay seconds in a timestep (default=86400) s InvDtDay inverse seconds in a timestep (default=86400) s-1 MMtoM Coefficient to change units -- MtoMM Coefficient to change units -- M3toM Coefficient to change units -- con_precipitation conversion factor for precipitation -- con_e conversion factor for evaporation -- ==================== ================================================================================ ========= **Functions** """ def __init__(self, model): self.var = model.var self.model = model
[docs] def initial(self): """ Initialization of some basic parameters e.g. cellArea * grid area, length definition * conversion factors * conversion factors for precipitation and pot evaporation """ if checkOption('gridSizeUserDefined'): # <lfoption name="gridSizeUserDefined" choice="1" default="0"> # If option gridsizeUserDefined is activated, users can specify grid size properties # in separate maps. This is useful whenever this information cannot be derived from # the location attributes of the base maps (e.g. lat/lon systems or non-equal-area # projections) # Limitation: always assumes square grid cells (not rectangles!). Size of grid cells # may vary across map though # Length of pixel [m] # NOT needed only in routing # Area of pixel [m2] self.var.cellArea = loadmap('CellArea') else: # Default behaviour: grid size is derived from location attributes of # base maps. Requirements: # - Maps are in some equal-area projection # - Length units meters # - All grid cells have the same size # Area of pixel [m2] self.var.cellArea=np.empty(maskinfo['mapC']) self.var.cellArea.fill(self.var.cellLength ** 2) # self.var.PixelArea = spatial(self.var.PixelArea) # Convert to spatial expresion (otherwise this variable cannnot be # used in areatotal function) # ----------------------------------------------------------------- # Miscellaneous repeatedly used expressions (as suggested by GF) # self.var.InvCellLength = 1.0 / self.var.cellLength self.var.InvCellArea = 1.0 / self.var.cellArea # Inverse of pixel size [1/m] self.var.DtSec = 86400.0 self.var.DtDay = self.var.DtSec / 86400 # Time step, expressed as fraction of day (used to convert # rate variables that are expressed as a quantity per day to # into an amount per time step) self.var.InvDtSec = 1 / self.var.DtSec # Inverse of time step [1/s] self.var.InvDtDay = 1 / self.var.DtDay # Inverse of time step [1/d] # self.var.DtSecChannel = loadmap('DtSecChannel') # Sub time step used for kinematic wave channel routing [seconds] # within the model,the smallest out of DtSecChannel and DtSec is used self.var.MMtoM = 0.001 # Multiplier to convert water depths in mm to meters self.var.MtoMM = 1000 # Multiplier to convert water depths in meters to mm self.var.MtoM3 = 1.0 * self.var.cellArea # Multiplier to convert water depths in m to cubic metres self.var.M3toM = 1 / self.var.MtoM3 # Multiplier to convert from cubic metres to m water slice self.var.con_precipitation = loadmap('precipitation_coversion') self.var.con_e = loadmap('evaporation_coversion') self.var.twothird = 2.0 / 3.0