# Example 7.1

# Part a
Alake = 9.4 km^2
Ke_const = 0.0000169 m / (km^0.9 kPa)   # Make Eqn. 7-19 dimensionally consistent
Ke = Ke_const*Alake^-0.05; m / (km kPa)

# Part b
Ts = 26.9 degC
e_const = 0.611 kPa   # MAKE Eqn. 7-4 dimensionally consistent
esStar = e_const*EXP( (17.3 * Number(Ts, degC))/(Number(Ts, degC) + 237.3) ); kPa   

# Part c
Ta = 27.2 degC
eaStar = e_const*EXP( (17.3 * Number(Ta, degC))/(Number(Ta, degC) + 237.3) ); kPa  # Eqn. 7-4 

# Part d
Wa = 0.69
ea = eaStar*Wa; kPa   # Eqn. 7-5

# Part e
Va = 581 cm/s
E = Ke*Va*(esStar - ea); mm/day   # Eqn. 7-1


# Example 7.2

# Part a
Kin = 30.6 MJ / m^2 day
a = 0.052
K = Kin*(1 - a); MJ/m^2 day   # Eqn. 7-25

# Part b
ew = 0.97   # Table D-1
Boltzmann = 4.9e-9 MJ/m^2 day degK^4
Ts = 26.9 degC
Lw = ew * Boltzmann * Ts^4; MJ / m^2 day   # Eqn. 5-35

# Part c
Lin = 34.4 MJ / m^2 day
L_long = Lin - (1 - ew)*Lin - Lw; MJ/m^2 day   # Eqn. 7-28

# Part d
L_net = K + L_long; MJ/m^2 day

# Part e
Lv_const = 0.00236 MJ/kg
Lv_offset = 2.5 MJ/kg
Lv = Lv_offset - Lv_const * Number(Ts, degC); MJ/kg   # Eqn. 7-8

# Part f
Ca = 1e-3 MJ / kg degK
Patm = 97.3 kPa
Ta = 27.2 degC
es = 3.56 kPa
ea = 2.50 kPa
Bowen_const = 0.622
Bowen = ( Ca * Patm *(Ts - Ta)) / (Bowen_const * Lv * (es - ea) )   # Eqn. 7-12

# Part g
Rho_water = 1000 kg/m^3
E = (K + L_long) / ( Rho_water * Lv * (1- Bowen)); mm/day   # Eqn. 7-24 (Assume G = Aw = DQ = 0)


# Example 7.3

# Part a
Ts = 26.9 degC
Slope = 2508.3*EXP(17.3*Number(Ts, degC)/(Number(Ts, degC) + 237.3)) / (Number(Ts, degC) + 237.3)^2   # Eqn. 7-6

# Part b
Ca = 1e-3 MJ / kg degK
Patm = 97.3 kPa
Lv = 2.44 MJ / kg
Pc = Ca * Patm/(0.622*Lv); kPa/degK   # Eqn. 7-13

# Part c
Lnet = 23.85 MJ / m^2 day
Ke = 1.51e-5 m / km kPa
Rho_water = 1000 kg / m^3
Va = 581 cm/s
units_correction = 1 km/day
eaStar = 3.62 kPa
Wa = 0.69
Slope = 0.21 kPa/degK
E = ( Slope * Lnet +  Pc * Ke * Rho_water * Lv * Number(Va, km/day)*units_correction * eaStar *(1 - Wa)) / (Rho_water*Lv*(Slope + Pc) ); mm/day   # Eqn. 7-33

# Part d
Lin = 34.4 MJ/m^2 day
ew = 0.97   # Table D-1
Boltzmann = 4.9e-9 MJ/m^2 day degK^4
Ta = 27.2 degC
Lnet_est = ew * Lin - ew * Boltzmann * (Ta)^4; MJ / m^2 day   # Eqn. 7-35


# Example 7.4

# Part a
Tspan = 27.5 degC   # Table 7-4
Vpan = 279 cm/s   # Table 7-4
Alpha_pan = 0.34 + 0.0117*Number(Tspan, degC) - 0.00000035 * (Number(Tspan, degC) + 17.8)^3 + 0.0135 *Number(Vpan, km/day)^0.36   # Eqn. 7-42

# Part b
Epan = 1.24 cm/day   # Table 7-4
Patm = 97.3 kPa
Ta = 27.2 degC
Efw =(0.7 mm/day) * (Number(Epan, mm/day) + 0.064 * Number(Patm, kPa) * Alpha_pan * (0.37 + 0.00255 * Number(Vpan, km/day)) * (Number(Tspan, degC) - Number(Ta, degC))^0.88); mm/day


# Example 7.5

# Part a
E1 = 10 mm/day
t1 = 3 day
F1 = E1*t1; mm   # Eqn. 7-43

# Part b
t = 10 day
Fsoil = F1 * (1 + 8/SQRT(pi())*ln(t/t1)); mm   # Eqn. 7-44

# Part c
Fsoil = (8/SQRT(pi())) * E1 * (t1 / t); mm/day   # Eqn. 7-45