Coverage of structural options within modelling tools - Revision history

Julia Glenday at 13:03, 28 October 2022

2022-10-28T13:03:38Z

Julia Glenday: /* SWAT2012 */

2021-06-09T09:38:08Z

SWAT2012

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:57:59Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:56:23Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:55:09Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:39:02Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:32:49Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:28:02Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:26:58Z

MIKE-SHE

Julia Glenday: /* MIKE-SHE */

2021-06-07T11:26:26Z

MIKE-SHE

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 This page clarifies the focus of coverage for each modelling tool reviewed in the wiki. '''''This is perhaps most important for MIKE-SHE which has the largest number of structural options.'''''
 == WRSM-Pitman ==
@@ Line 18: / Line 19: @@
 Another addition in both tools has been development of daily timestep versions. However these have been rarely applied to date and there has been less testing and experience in calibrating them. As such, '''WRSM-Pitman is described with a monthly timestep'''.
 == SPATSIM-Pitman ==
 In this wiki, '''SPATSIM-Pitman is described with the Hughes groundwater algorithm''' (Hughes, 2004) '''and a monthly timestep'''.  A daily timestep version exists, but has been rarely applied to date and there has been less testing and experience in calibrating it.
 == ACRU4 ==
 There is currently not an equivalent theory manual for ACRU4 comparable to the ACRU3 theory manual (Schulze, 1995) describing the available algorithms, so the ACRU3 manual was used as a reference. It should be noted that some of the process representation options presented in the ACRU3 theory documentation, such as modelling shallow groundwater tables, are only relevant when using subcatchments as the unit of calculation rather than HRUs, and are not available in ACRU4.
 == SWAT2012 ==
@@ Line 37: / Line 41: @@
 The choice of which option is applied in a model has relevance to several aspects of its process representation. The SCS-CN method is an empirical equation originally developed to predict runoff generation alone, rather than being part of a comprehensive catchment water balance model. If the SCS-CN approach is used, '''''canopy interception is not explicitly modelled.''''' This means the impact of canopy interception is implicitly considered in the calculations of other processes in the model, which changes how processes like infiltration and ET from soil can be viewed conceptually. The Green-Ampt Mein-Larson option does allow canopy interception to be calculated as a separate process in SWAT2012.
 == MIKE-SHE ==

@@ Line 36: / Line 36: @@
 * The SCS-CN approach has been used in SWAT versions since the tool originated and is the option more commonly applied at present, most likely due to data availability
-The choice of which option is applied in a model has relevance to several aspects of its process representation. The SCS-CN method is an empirical equation originally developed to predict runoff generation alone, rather than being part of a comprehensive catchment water balance model. If the SCS-CN approach is used, '''''canopy interception is not explicitly modelled.''''' This means the impact of canopy interception is implicitly considered in the calculations of other processes in the model, which changes how processes like infiltration and ET from soil can be viewed conceptually. The Green-Ampt Mein-Larson option does allow canopy interception to be calculated as a separate proces.
+The choice of which option is applied in a model has relevance to several aspects of its process representation. The SCS-CN method is an empirical equation originally developed to predict runoff generation alone, rather than being part of a comprehensive catchment water balance model. If the SCS-CN approach is used, '''''canopy interception is not explicitly modelled.''''' This means the impact of canopy interception is implicitly considered in the calculations of other processes in the model, which changes how processes like infiltration and ET from soil can be viewed conceptually. The Green-Ampt Mein-Larson option does allow canopy interception to be calculated as a separate process in SWAT2012.
 == MIKE-SHE ==

@@ Line 39: / Line 39: @@
 == MIKE-SHE ==
-[[File:MIKE-SHE algorithm options.jpg|thumb|867x867px|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities]]
+[[File:MIKE-SHE algorithm options.jpg|thumb|794x794px|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities|alt=]]
 MIKE-SHE includes a wider diversity of process algorithms, several with associated levels of spatial discretisation, than the other tools reviewed. It allows users to build models with very different levels of complexity. For most processes there are also representation algorithm options that are more conceptual, often needing fewer parameters, and those that are more physics-based. In any MIKE-SHE model a computational grid must be defined and several process algorithms will be solved by grid cell. However, parameters and climate inputs can be specified for zones, polygons of areas considered to have relatively uniform properties, rather than for each grid cell individually. Options are provided to model the flow of surface runoff across the landscape using a sequence of larger zones in a subcatchment (“simple overland flow routing”), rather than from grid cell to grid cell. Groundwater storage and flow can also be represented by linear reservoirs in subcatchments rather than in the full 3D finite-difference grid.
-A certain representation option for one process or component may only be compatible with a particular set of other structure and algorithm choices. A tree of the major structural options and compatibilities in MIKE-SHE is shown below.
+A certain representation option for one process or component may only be compatible with a particular set of other structure and algorithm choices. A tree of the major structural options and compatibilities in MIKE-SHE is shown to the right.
 To facilitate comparisons across tools within this review, '''MIKE-SHE is described for two model set-up approaches at opposite ends of the complexity spectrum:'''

@@ Line 39: / Line 39: @@
 == MIKE-SHE ==
 MIKE-SHE includes a wider diversity of process algorithms, several with associated levels of spatial discretisation, than the other tools reviewed. It allows users to build models with very different levels of complexity. For most processes there are also representation algorithm options that are more conceptual, often needing fewer parameters, and those that are more physics-based. In any MIKE-SHE model a computational grid must be defined and several process algorithms will be solved by grid cell. However, parameters and climate inputs can be specified for zones, polygons of areas considered to have relatively uniform properties, rather than for each grid cell individually. Options are provided to model the flow of surface runoff across the landscape using a sequence of larger zones in a subcatchment (“simple overland flow routing”), rather than from grid cell to grid cell. Groundwater storage and flow can also be represented by linear reservoirs in subcatchments rather than in the full 3D finite-difference grid.
@@ Line 51: / Line 52: @@
 ''It is important to note that these particular combinations of options are not enforced by the MIKE-SHE tool: other combinations can be used, as highlighted in the diagram. (See tool documentation for more details.)''
-[[File:MIKE-SHE algorithm options.jpg|none|thumb|867x867px|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities]]
 {| class="wikitable"

@@ Line 51: / Line 51: @@
 ''It is important to note that these particular combinations of options are not enforced by the MIKE-SHE tool: other combinations can be used, as highlighted in the diagram. (See tool documentation for more details.)''
-[[File:MIKE-SHE algorithm options.jpg|thumb|867x867px|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities]]
+[[File:MIKE-SHE algorithm options.jpg|none|thumb|867x867px|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities]]
 {| class="wikitable"
@@ Line 60: / Line 60: @@
 |-
 | style="vertical-align: center" |'''Surface  runoff (overland flow)  routing'''
-| style="background: #F5FCFF; vertical-align: center" |Simple overland flow routing (across  series of zones within subcatchments)
+| style="background: #F5FCFF; vertical-align: center" |Simple overland flow routing (across series of zones within subcatchments)
-| style="background: #F5F8FF; vertical-align: center" |Finite difference diffuse wave  (flow between grid cells)
+| style="background: #F5F8FF; vertical-align: center" |Finite difference solution of diffuse wave (flow between grid cells)
 |-
 | style="vertical-align: center" |'''Evapotranspiration'''

← Older revision		Revision as of 11:39, 7 June 2021
Line 51:		Line 51:

	''It is important to note that these particular combinations of options are not enforced by the MIKE-SHE tool: other combinations can be used, as highlighted in the diagram. (See tool documentation for more details.)''		''It is important to note that these particular combinations of options are not enforced by the MIKE-SHE tool: other combinations can be used, as highlighted in the diagram. (See tool documentation for more details.)''
		+	[[File:MIKE-SHE algorithm options.jpg\|thumb\|867x867px\|Schematic diagram of process representation algorithm options in MIKE-SHE and their compatibilities]]

	{\| class="wikitable"		{\| class="wikitable"

@@ Line 54: / Line 54: @@
 {| class="wikitable"
 |+<span id = "MIKE options - Table Anchor"> <big> MIKE-SHE set-up option combinations used in inter-comparisons </big></span>
-! scope="col" | Process
+! scope="col" style="width:15em"| Process
-! scope="col" style="background: #CEE6F2; width:12em" |MIKE-SHE, semi-distributed, more conceptual
+! scope="col" style="background: #CEE6F2;" |MIKE-SHE, semi-distributed, more conceptual
-! scope="col" style="background: #CEDAF2; width:12em" |MIKE-SHE, fully-distributed, more physical
+! scope="col" style="background: #CEDAF2;" |MIKE-SHE, fully-distributed, more physical
 |-
-| style="vertical-align: top" |'''Surface  runoff (overland flow)  routing'''
+| style="vertical-align: center" |'''Surface  runoff (overland flow)  routing'''
-| style="background: #F5FCFF; vertical-align: top" |Simple overland flow routing (across  series of zones within subcatchments)
+| style="background: #F5FCFF; vertical-align: center" |Simple overland flow routing (across  series of zones within subcatchments)
-| style="background: #F5F8FF; vertical-align: top" |Finite difference diffuse wave  (flow between grid cells)
+| style="background: #F5F8FF; vertical-align: center" |Finite difference diffuse wave  (flow between grid cells)
 |-
-| style="vertical-align: top" |'''Evapotranspiration'''
+| style="vertical-align: center" |'''Evapotranspiration'''
-| rowspan="2" style="background: #F5FCFF; vertical-align: top" |“Two-layer” method  (by grid cell)
+| rowspan="2" style="background: #F5FCFF; vertical-align: center" |“Two-layer” method  (by grid cell)
-| style="background: #F5F8FF; vertical-align: top" |Kirstensen  & Jensen method (by grid  cell)
+| style="background: #F5F8FF; vertical-align: center" |Kirstensen  & Jensen method (by grid  cell)
 |-
-| style="vertical-align: top" |'''Soil water (unsaturated zone) storage  & movement'''
+| style="vertical-align: center" |'''Soil water (unsaturated zone) storage  & movement'''
-| style="background: #F5F8FF; vertical-align: top" |Richard’s  equation method or gravity flow method (by grid cell, many layers allowed)
+| style="background: #F5F8FF; vertical-align: center" |Richard’s  equation method or gravity flow method (by grid cell layer)
 |-
-| style="vertical-align: top" |'''Interflow & groundwater processes'''
+| style="vertical-align: center" |'''Interflow & groundwater processes'''
-| style="background: #F5FCFF; vertical-align: top" |Linear reservoirs (within subcatchments)
+| style="background: #F5FCFF; vertical-align: center" |Linear reservoirs (within subcatchments)
-| style="background: #F5F8FF; vertical-align: top" |Finite  difference solution of Darcy’s Law (between 3D grid elements)
+| style="background: #F5F8FF; vertical-align: center" |Finite  difference solution of Darcy’s Law (between 3D grid elements)
 |}

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 * '''using all the semi-distributed, more conceptual options (simpler calculation)'''
-* '''using all the  fully-distributed, more physical options (full complexity).'''
+* '''using all the fully-distributed, more physical options (full complexity).'''
 These approaches are highlighted in the options tree diagram and the algorithm options for each are also listed in a table below.
 ''It is important to note that these particular combinations of options are not enforced by the MIKE-SHE tool: other combinations can be used, as highlighted in the diagram. (See tool documentation for more details.)''