10 REM POND-6.BAS FROM DIELPOND.BAS E.C. & H.T ODUM
12
14 REM GRAPHICS
16 SCREEN 12, 0
18
20 LINE (0, 0)-(639, 360), 3, B
21 LINE (0, 0)-(100, 360), 3, B
22 LINE (0, 60)-(639, 60), 3, B
24 LINE (0, 120)-(639, 120), 3, B
26 LINE (0, 180)-(639, 180), 3, B
28 LINE (0, 240)-(639, 240), 3, B
30 LINE (0, 300)-(639, 300), 3, B
32
34 REM INSOLATION ARRAY AT i1 HOUR INTERVALS
36 REM MEGAJOULES PER SQUARE METER
48
50 REM WIND ARRAY AT 1 HOUR TIME INTERVALS
52 REM IN MILES PER HOUR
54
66 REM SCALING FACTORS
68 DT = .001
70 T0 = .03125: REM 0.5
72 N0 = .2
74 G0 = .04: REM 2
76 S0 = .08: REM .11
78 X0 = 1.5
80 P0 = .3
82 R0 = .3
84 W0 = .4: REM .5
86 HR = 1
88
100 REM STARTING VALUES
102 Z = .4
104 J = .1
106 JG = .625
108 XS = 6
110 X = 6
112 N = 3
114 Q = 100
116 P = .2
118 R = .2
120
122 REM COEFICIENTS
124 K0 = 19
126 K1 = 35
128 K2 = 14
130 K3 = .001
132 K4 = .0004
134 K5 = .000022
136 K6 = .000833
138 K8 = .68
140 K9 = .01
142 L1 = .000166
144 L2 = .000417
146
148 REM PLOTTING TIME CURVES
150 REM SUN IN YELLOW
152 PSET (T / T0, 60 - S / S0), 14
154 REM WIND IN WHITE
156 PSET (T / T0, 60 - W / W0), 7
158 REM NUTRIENTS IN BRIGHT BLUE
160 PSET (T / T0, 120 - N / N0), 9
162 REM OXYGEN IN RED
164 PSET (T / T0, 180 - X / X0), 4
166 REM NET PRODUCTION RATE IN PINK
168 PSET (T / T0, 240 - (P - R) / P0), 5
170 REM TOTAL PRODUCTION IN GREEN
172 PSET (T / T0, 300 - P / P0), 2
174 REM TOTAL RESPIRATION IN ORANGE
176 PSET (T / T0, 300 - R / R0), 6
178 REM PERMANEN ORGANIC DEPOSITION IN BRIGHT RED
180 PSET (T / T0, 360 - G / G0), 12
182
184 REM EQUATIONS
186 S = 3.2 + .8 * (SIN(T) * .017 * 40)
188 W = 4! + 3! * (SIN(T + 4.51) * .017 * 30)
192 K7 = K9 * W
194 I = S / (1 + K0 * N)
198 DN = J - (K8 * I * N) - (K6 * N) - (K5 * X * Q)
200 DQ = (K2 * I * N) - (K4 * X * Q) + JG - (L1 * Q) - (L2 * Q)
202 DX = (K1 * I * N) - (K3 * X * Q) + (K7 * (1 - (X / XS)))
204 DG = L2 * Q
206
208 REM NEXT VALUES
210 N = N + DN * DT / Z
212 Q = Q + DQ * DT
214 X = X + DX * DT / Z
216 G = G + DG * DT
218 P = K1 * I * N
220 R = K3 * X * Q
222 T = T + DT
224
228 REM GO BACK AND REPEAT:
230 IF ((T / T0) < 639) GOTO 152
232
236 END