Line data Source code
1 : !> \file mo_runoff.f90
2 : !> \brief \copybrief mo_runoff
3 : !> \details \copydetails mo_runoff
4 :
5 : !> \brief Runoff generation.
6 : !> \details This module generates the runoff for the unsaturated and saturated zones and provides runoff accumulation.
7 : !> \authors Vladyslav Prykhodko
8 : !> \date Dec 2012
9 : !> \copyright Copyright 2005-\today, the mHM Developers, Luis Samaniego, Sabine Attinger: All rights reserved.
10 : !! mHM is released under the LGPLv3+ license \license_note
11 : !> \ingroup f_mhm
12 : MODULE mo_runoff
13 :
14 : USE mo_kind, ONLY : dp
15 : USE mo_common_constants, ONLY : eps_dp
16 :
17 : IMPLICIT NONE
18 :
19 : PUBLIC :: runoff_unsat_zone
20 : PUBLIC :: runoff_sat_zone
21 : PUBLIC :: L1_total_runoff
22 :
23 : PRIVATE
24 :
25 : ! ------------------------------------------------------------------
26 :
27 : CONTAINS
28 :
29 : ! ------------------------------------------------------------------
30 :
31 : ! NAME
32 : ! runoff_unsat_zone
33 :
34 : ! PURPOSE
35 : !> \brief Runoff generation for the saturated zone.
36 :
37 : !> \details Calculates the runoff generation for the unsaturated zone.
38 : !> Calculates percolation, interflow and baseflow.
39 : !> Updates upper soil and groundwater storages.
40 :
41 : ! INTENT(IN)
42 : !> \param[in] "REAL(dp) :: k1" Recession coefficient of the upper reservoir,lower outlet [TS-1]
43 : !> \param[in] "REAL(dp) :: kp" Percolation coefficient [TS-1]
44 : !> \param[in] "REAL(dp) :: k0" Recession coefficient of the upperreservoir, upper outlet [TS-1]
45 : !> \param[in] "REAL(dp) :: alpha" Exponent for the upper reservoir [-]
46 : !> \param[in] "REAL(dp) :: karst_loss" Karstic percolation loss [-]
47 : !> \param[in] "REAL(dp) :: pefec_soil" Input to the soil layer [mm]
48 : !> \param[in] "REAL(dp) :: unsat_thresh" Threshold water depth in upper reservoir(for Runoff contribution) [mm]
49 :
50 : ! INTENT(INOUT)
51 : !> \param[inout] "REAL(dp) :: sat_storage" Groundwater storage [mm]
52 : !> \param[inout] "REAL(dp) :: unsat_storage" Upper soil storage [mm]
53 :
54 : ! INTENT(OUT)
55 : !> \param[out] "REAL(dp) :: slow_interflow" Slow runoff component [mm TS-1]
56 : !> \param[out] "REAL(dp) :: fast_interflow" Fast runoff component [mm TS-1]
57 : !> \param[out] "REAL(dp) :: perc" Percolation [mm TS-1]
58 :
59 : ! HISTORY
60 : !> \authors Vladyslav Prykhodko
61 :
62 : !> \date Dec 2012
63 :
64 : ! Modifications:
65 : ! LS Feb 2006 - fast response
66 : ! LS Feb 2007 - MaxInter
67 : ! RK May 2007 - fracArea, errors in Qmod
68 : ! LS Dec 2012 - variable names and process sat. zone
69 : ! LS Jan 2013 - total runoff accumulation L11
70 : ! JM Aug 2013 - ordering of arguments changed
71 : ! Robert Schweppe Jun 2018 - refactoring and reformatting
72 :
73 :
74 76647048 : SUBROUTINE runoff_unsat_zone(k1, kp, k0, alpha, karst_loss, pefec_soil, unsat_thresh, sat_storage, unsat_storage, &
75 : slow_interflow, fast_interflow, perc)
76 : implicit none
77 :
78 : ! Recession coefficient of the upper reservoir,lower outlet [TS-1]
79 : REAL(dp), INTENT(IN) :: k1
80 :
81 : ! Percolation coefficient [TS-1]
82 : REAL(dp), INTENT(IN) :: kp
83 :
84 : ! Recession coefficient of the upperreservoir, upper outlet [TS-1]
85 : REAL(dp), INTENT(IN) :: k0
86 :
87 : ! Exponent for the upper reservoir [-]
88 : REAL(dp), INTENT(IN) :: alpha
89 :
90 : ! Karstic percolation loss [-]
91 : REAL(dp), INTENT(IN) :: karst_loss
92 :
93 : ! Input to the soil layer [mm]
94 : REAL(dp), INTENT(IN) :: pefec_soil
95 :
96 : ! Threshold water depth in upper reservoir(for Runoff contribution) [mm]
97 : REAL(dp), INTENT(IN) :: unsat_thresh
98 :
99 : ! Groundwater storage [mm]
100 : REAL(dp), INTENT(INOUT) :: sat_storage
101 :
102 : ! Upper soil storage [mm]
103 : REAL(dp), INTENT(INOUT) :: unsat_storage
104 :
105 : ! Slow runoff component [mm TS-1]
106 : REAL(dp), INTENT(OUT) :: slow_interflow
107 :
108 : ! Fast runoff component [mm TS-1]
109 : REAL(dp), INTENT(OUT) :: fast_interflow
110 :
111 : ! Percolation [mm TS-1]
112 : REAL(dp), INTENT(OUT) :: perc
113 :
114 :
115 : !---------------------------------------------------------------
116 : ! SOIL LAYER BETWEEN UNSATURATED AND SATURATED ZONE
117 : !---------------------------------------------------------------
118 : ! HERE input is from last soil Horizon...
119 : !pefec_soil = Cell1_soil(k, nHorizons_mHM)%infil
120 76647048 : unsat_storage = unsat_storage + pefec_soil
121 :
122 : ! FAST INTERFLOW WITH THRESHOLD BEHAVIOUR
123 76647048 : fast_interflow = 0.0_dp
124 76647048 : if(unsat_storage > unsat_thresh) then
125 : fast_interflow = MIN((k0 * (unsat_storage - unsat_thresh)), &
126 5975469 : (unsat_storage - eps_dp))
127 : end if
128 76647048 : unsat_storage = unsat_storage - fast_interflow
129 :
130 : ! SLOW PERMANENT INTERFLOW
131 76647048 : slow_interflow = 0.0_dp
132 :
133 76647048 : if(unsat_storage > eps_dp) then
134 : slow_interflow = min((k1 * (unsat_storage**(1.0_dp + alpha))), &
135 76647048 : (unsat_storage - eps_dp))
136 : end if
137 76647048 : unsat_storage = unsat_storage - slow_interflow
138 :
139 : !--------------------------------------------------------
140 : ! PERCOLATION FROM SOIL LAYER TO THE SATURATED ZONE
141 : !--------------------------------------------------------
142 76647048 : perc = kp * unsat_storage
143 :
144 : ! Taking into account for the KARSTIC aquifers
145 : !*** karstic loss gain or loss if Karstic aquifer is present...
146 76647048 : if(unsat_storage > perc) then
147 76647048 : unsat_storage = unsat_storage - perc
148 76647048 : sat_storage = sat_storage + perc * karst_loss
149 : else
150 0 : sat_storage = sat_storage + unsat_storage * karst_loss
151 0 : unsat_storage = 0.0_dp
152 : end if
153 :
154 76647048 : END SUBROUTINE runoff_unsat_zone
155 :
156 : ! ------------------------------------------------------------------
157 :
158 : ! NAME
159 : ! runoff_sat_zone
160 :
161 : ! PURPOSE
162 : !> \brief Runoff generation for the saturated zone.
163 :
164 : !> \details Calculates the runoff generation for the saturated zone.
165 : !> If the level of the ground water reservoir is zero, then
166 : !> the baseflow is also zero.
167 : !> If the level of the ground water reservoir is greater than zero, then
168 : !> the baseflow is equal to baseflow recession coefficient times the level
169 : !> of the ground water reservoir, which
170 : !> will be then reduced by the value of baseflow.
171 :
172 : ! INTENT(IN)
173 : !> \param[in] "REAL(dp) :: k2" Baseflow recession coefficient [TS-1]
174 :
175 : ! INTENT(INOUT)
176 : !> \param[inout] "REAL(dp) :: sat_storage" Groundwater storage [mm]
177 :
178 : ! INTENT(OUT)
179 : !> \param[out] "REAL(dp) :: baseflow" Baseflow [mm TS-1]
180 :
181 : ! HISTORY
182 : !> \authors Vladyslav Prykhodko
183 :
184 : !> \date Dec 2012
185 :
186 : ! Modifications:
187 : ! JM Aug 2013 - ordering of arguments changed
188 : ! Robert Schweppe Jun 2018 - refactoring and reformatting
189 :
190 :
191 76647048 : SUBROUTINE runoff_sat_zone(k2, sat_storage, baseflow)
192 : implicit none
193 :
194 : ! Baseflow recession coefficient [TS-1]
195 : REAL(dp), INTENT(IN) :: k2
196 :
197 : ! Groundwater storage [mm]
198 : REAL(dp), INTENT(INOUT) :: sat_storage
199 :
200 : ! Baseflow [mm TS-1]
201 : REAL(dp), INTENT(OUT) :: baseflow
202 :
203 :
204 76647048 : if (sat_storage > 0.0_dp) then
205 76647048 : baseflow = k2 * sat_storage
206 76647048 : sat_storage = sat_storage - baseflow
207 : else
208 0 : baseflow = 0.0_dp
209 0 : sat_storage = 0.0_dp
210 : end if
211 :
212 76647048 : END SUBROUTINE runoff_sat_zone
213 :
214 :
215 : ! ------------------------------------------------------------------
216 :
217 : ! NAME
218 : ! L1_total_runoff
219 :
220 : ! PURPOSE
221 : !> \brief total runoff accumulation at level 1
222 :
223 : !> \details Accumulates runoff.
224 : !> \f[ q_{T} = ( q_0 + q_1 + q_2 ) * (1-fSealed) + q_{D} * fSealed \f],
225 : !> where fSealed is the fraction of sealed area.
226 :
227 : ! INTENT(IN)
228 : !> \param[in] "REAL(dp) :: fSealed_area_fraction" sealed area fraction [1]
229 : !> \param[in] "REAL(dp) :: fast_interflow" \f$ q_0 \f$ Fast runoff component [mm TS-1]
230 : !> \param[in] "REAL(dp) :: slow_interflow" \f$ q_1 \f$ Slow runoff component [mm TS-1]
231 : !> \param[in] "REAL(dp) :: baseflow" \f$ q_2 \f$ Baseflow [mm TS-1]
232 : !> \param[in] "REAL(dp) :: direct_runoff" \f$ q_D \f$ Direct runoff from impervious areas [mm TS-1]
233 :
234 : ! INTENT(OUT)
235 : !> \param[out] "REAL(dp) :: total_runoff" \f$ q_T \f$ Generated runoff [mm TS-1]
236 :
237 : ! HISTORY
238 : !> \authors Vladyslav Prykhodko
239 :
240 : !> \date Dec 2012
241 :
242 : ! Modifications:
243 : ! RK Jul 2013 - A Mosiac approach is implemented for processes accounted within the permeamble & impervious area.
244 : ! ST May 2015 - updated equation in the documentation
245 : ! Robert Schweppe Jun 2018 - refactoring and reformatting
246 :
247 :
248 76647048 : SUBROUTINE L1_total_runoff(fSealed_area_fraction, fast_interflow, slow_interflow, baseflow, direct_runoff, &
249 : total_runoff)
250 : implicit none
251 :
252 : ! sealed area fraction [1]
253 : REAL(dp), INTENT(IN) :: fSealed_area_fraction
254 :
255 : ! \f$ q_0 \f$ Fast runoff component [mm TS-1]
256 : REAL(dp), INTENT(IN) :: fast_interflow
257 :
258 : ! \f$ q_1 \f$ Slow runoff component [mm TS-1]
259 : REAL(dp), INTENT(IN) :: slow_interflow
260 :
261 : ! \f$ q_2 \f$ Baseflow [mm TS-1]
262 : REAL(dp), INTENT(IN) :: baseflow
263 :
264 : ! \f$ q_D \f$ Direct runoff from impervious areas [mm TS-1]
265 : REAL(dp), INTENT(IN) :: direct_runoff
266 :
267 : ! \f$ q_T \f$ Generated runoff [mm TS-1]
268 : REAL(dp), INTENT(OUT) :: total_runoff
269 :
270 :
271 : total_runoff = ((baseflow + slow_interflow + fast_interflow) * (1.0_dp - fSealed_area_fraction)) + &
272 76647048 : (direct_runoff * fSealed_area_fraction)
273 :
274 76647048 : END SUBROUTINE L1_total_runoff
275 :
276 : END MODULE mo_runoff
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