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Sobek will be integrated as 1D ModelFlow into DelftShell and thus it is the logical point of departure for DelftShell. The current implementation of Sobek has some aspects that need to be improved:

• The implementation in Sobek of structures seems unnecessary complex. There are for example 4 sorts of weirs
  -Compound structures are not implemented uniformly. Only river structures are supported.
  -Controllers and triggers are not implemented uniformly. River based structures can have up to 4 controllers and triggers. Non river based structures can have only 1 controller.
  HECRAS has less different types of structures but they are more complex. At the highest level they only support 4 types but internally they are more like the Sobek Structures.
  Mike11 has an approach like Sobek, but the number is more resticted and they have some additional structures like Control Stucture, Regulating which probably can be compared to Lateral Inflow, Extra Resistance, etc in Sobek.
  
  

  Sobek	HECRAS	Mike11
  River weir (0 - R)	Bridge/Culvert

• Deck/Roadway
  
• Pier
  
• Sloping Abutment
  
• Culvert
  
• Bridge|Weir|

  River advanced weir (1 - R)

  Inline Structure

• Weir/embankment
  
• Gate| |

  Weir (6)
  Universal weir (11- CS)
  Culvert, Siphon and Inverse siphon (10 - CS)		Culvert
  Orifice (7)
  General structure (2 - R)	Lateral Structure

• Weir/embankment
  
• Gate
  
• Culvert| |

  River pump (3 - R)	Pump Station	Pump
  Pump (9)
  Bridge (12 - CS)		Bridge
  Breach growth 1D Dam break node (13)		Dambreak Structure
  Breach growth 2D Dam break node (112)
  Database structure (4 - R)		User Defined
  		Tabulated Structure
  Compound Structure (#R)
  		Hydraulic Control

...

• [

...

• Controllers and triggers]

  Control Structure

...

• 		Regulating
  		Energy Loss

  Table 1.: structures in 1D modeling packages. For Sobek the number between brackets refer to the internal Sobek MDB type number (5 and 8 do not exist), R relates to River structures. Energy Loss is not available in Sobek 2.13 but will be covered by Extra Resistante in a next release. CS relates to structures in Sobek that have an internal Cross Section.
  The implementations of Sobek and Mike11 have much in common. HECRAS has a different approach in that it represents the physical reality more closely. This is also visible in the presentation. Mike11 and Sobek both use fixed symbols for displaying structures. Hecras draws structures as polygon on the map and in the structure editor displays a more realistic view of the structure. In fact the HECRAS structures are compound structures.
  
  Image Modified
  figure1. Bridge in HECRAS is drawn as a polygon that represents the physical entity.
  Image Modified
  figure 2. The structure dialog in HECRAS provides a more realistic view at the data.
  
  One of the requisitions of DelftShell is that it should be able to support the import of existing Sobek models to Model1DFlow. This makes a purely HECRAS approach less preferable. The uncertainty in translating the current Sobek structures to a HECRAS like setup is simply too big. The implicit use of compund structure is very nice but too restrictive for the current possibilities in Sobek. It should be more generic.
  What also could be nice is a presentation in the map view of structures as (multiple) polygon(s). A possibilty is a solution like cross sections in the network editor of DelftShell where they can be represented as a line or a symbol on the map.
  As for Mike11, their approach is like the Sobek implemtation and the User Interface is not very intuitive. The main difference is the implementation of a number of extra structure types.
  

  Dialog structure

  Another more cosmetic difference between Sobek on the one side and HECRAS and Mike11 on the other is the complexity of the structure dialogs.
  Mike11 has too complex and badly organised dialogs
  HECRAS dialogs are better structured but the possiblity to open multiple popups dialogs (7 for a bridge) can make things confusing
  Sobek also is better structured than Mike11, the usage of tabbed windows keeps items simple and reusable. On the other hand tabbed windows in Sobek do not allow the user to see multiple options simultaneaously. This is especially annoying when defining controllers and triggers for River based structures.
  

  Conclusions

• Make the use of compound structures implicit. If more than 1 structure (component) is defined at a location This solution can also be found in the 1D model Duflow, a stucture is placed at a stucture point, when a second strcuture is added to that point both are handled as paralel structures. this will be treated by the model engine as compound structure If restrictions apply they could be implemented like the topology rules in the network editor. The multiple structures component that make up the structure should be visisble on the map.
• Decrease the number of structure types
• implement controllers and triggers in a uniform and not restrictive way. This is an implementation like the River Structures but restricted to 4 controllers/triggers.

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Breach growth 1D Dam break node (13)

Wiki Markupid = id of the structure definition nm = name of the structure definition ty = structure type id = id of the structure definition
nm = name of the structure definition
ty = structure type (13=Sobek dambreak)
cl = crest level = Initial top level w.r.t. reference level \ [m\]
cs= crest shape
0 = broad crest (default)
cw = crest width - initial width/gap \ [m\]
ml = minimum level w.r.t. reference level \ [m\]
td = type of dambreak-formula 1 = vdKnaap
1 = vdKnaap (2000) \ [optional\] 2 = ]
2 = Verheij-vdKnaap(2002) (to be implemented in SOBEK version 2.09) 3 =
3 = ... not defined yet \\
f1 = alpha constant for Verheij-vdKnaap(2002) (note: it is f1= F + one)
f2 = beta constant for Verheij-vdKnaap(2002)
uc =critical flow velocity sediment/soil \ [m/sec\] for Verheij-vdKnaap(2002)
ce = coefficient of discharge (not used)
rt = possible flow direction (relative to the branch direction):
0 : flow in both directions (default and only possible value) \\
The following parameters are only used to generate the controller table
eq 0 = sand for vdKnaap (2000) formula (if type of dambreak formula = vdKnaap; thus td = 1)
eq 1 = clay for vdKnaap (2000) i.e td = 1 (if type of dambreak formula = vdKnaap; thus td = 1)
ts = time start in 'yyyy/mm/dd;hh:mm:ss'
dt = elasped time after the time start to reach lowest level ml in 'dd:hh:mm:ss'
ec = maximum breach width in m - for vdKnaap (2000) 0 200 = constant width of 200 m \\ Note: td 1 is by default and can be optional. For backward compatibility. Initial top level
0 200 = constant width of 200 m
Note: td 1 is by default and can be optional. For backward compatibility.
Initial top level w.r.t. reference level \ [m\] - maximum initial opening depth \ [m\] = minimum level w.r.t. reference level \ [m\] \\

Breach growth 2D Dam break node (112)

...

• Anchor
  wp1129777 wp1129777

  Branch Name: Name of the river branch in which the pump is located.

• Anchor
  wp1129778 wp1129778

  Chainage: Chainage at which the pump is located.

• Anchor
  wp1129779 wp1129779

  ID: String identification of the pump. Used for identification of the pump in case of multiple structures at the same location. Specification of pump ID is recommended.

• Anchor
  wp1138822 wp1138822

  Type: The lcation type may be Regular, Side Structure or Side Structure + Reservoir. See section 2.3 Tabular view: Structures for details

Weir
Attributes
Type:

• Broad Crested Weir: The calculation of Q/h relations assumes critical flow at the crest.
• Special Weir: The Q/h relationship table must be specified.
• Weir Formula 1: A standard weir expression is applied. See the Reference Manual.
• Weir Formula 2 (Honma): The Honma weir expression is applied. See the Reference Manual.
  Valve:
• None: No valve regulation applies.
• Only Positive Flow: Only positive flow is allowed, i.e. whenever the water level downstream is higher than upstream the flow through the structure will be zero.
• Only Negative Flow: Only negative flow is allowed, i.e. whenever the water level upstream is higher than downstream the flow through the structure will be zero.
  Head Loss Factors
  Negative
• Inflow
• OutFlow
• Free Overflow
  Positive
• Inflow
• OutFlow
• Free Overflow
  Geometry
  Level-Width: The weir geometry is specified as a level/width table relative to the datum.
  Cross Section DB: The weir geometry is specified in the cross section editor. A cross section with a matching branch name, Topo ID and chainage must exist in the applied cross section file. The Topo ID is assumed to be the same as that specified in the Branches Property page, see Topo ID .
  Datum: Offset which is added to the level column in the level/width table.
  Level/Width: Weir shape defined as levels and corresponding flow widths. Values in the levels column must be increasing.
  Weir formula Parameters (only weir formula 1)
  Width: Width of the flow.
  Height: Weir height. See Figure 2.9
  Weir Coeff.: Multiplication coefficient in the weir formula.
  Weir Exp.: Exponential coefficient in the weir formula.
  Invert Level: Bottom datum level. See Figure 2.9
  Weir formula 2 Parameters (only weir formula 2 (Honma))
  Weir coefficient (C1): Multiplication coefficient in the Honma weir formula.
  Weir width: Width of the flow.
  Weir crest level: Weir level.
  Weir formula 3 Parameters (only weir formula 2 (Honma))
  QH Relation
  Culvert
  Image Modified
  Attributes
  Upstream Invert: Invert level upstream of the culvert.
  Downstr. Invert: Invert level downstream of the culvert.
  Length: Length of the culvert.
  Manning's n: Manning's bed resistance number along the culvert.
  No. of Culverts: Number of culvert cells.
  Valve Regulation:
  None: No valve regulation applies.
  Only Positive Flow: Only positive flow is allowed, i.e. whenever the water level downstream is higher than upstream the flow through the structure will be zero.
  Only Negative Flow: Only negative flow is allowed, i.e. whenever the water level upstream is higher than downstream the flow through the structure will be zero.
  Section Type: Closed or Open.
  Head Loss Factors
  Negative
• Inflow
• OutFlow
• Free Overflow
• Bends
  Positive
• Inflow
• OutFlow
• Free Overflow
• Bends
  Geometry
  The cross sectional geometry of a culvert can be specified as:
  Rectangular: The width and height specify the geometry.
  Circular: The geometry is specified by the diameter.
  Irregular Level-Width Table: The geometry is specified using a level/width table. Values in the level column must be increasing.
  Irregular Depth-Width Table: The geometry is specified using a depth/width table. Values in the width column must be increasing.
  Section DB: The geometry is specified by a cross section
  Pump
  Image Modified
  Control Parameters
  Start Level: Water level at the inflow that activates the pump.Note that for pumps with internal outlet the inflow is situated at the previous h-point (previous with regard to chainage) in case of positive discharge and at the next h-point with regard to chainage) in case of negative discharge. The sign of the discharge follows from the specifications made under Pump Data.
  Stop Level: Water level at which the pump starts closing down.
  Start-up Period: Period for changing pump discharge from zero to full. The pump discharge is changed linearly in time.
  Close Down Period: Period for changing pump discharge from full to zero. The pump discharge is changed linearly in time.
  Pump Data
  Outlet:
  Internal: Water is pumped internally in the river branch.
  External: Water is pumped out of the river branch.
  Specification Type:
  Fixed Discharge: Pump rate independent of the local water head expect for the start/stop control.
  Tabulated Characteristic: Pump rate controlled by specified characteristic (Q-dH-curve) and the water level difference between upstream water level and outlet level/downstream water level.
  Discharge: Pump rate when applying "Fixed Discharge".
  Outlet Level: Level of pump outlet. The outlet may be submerged or free. Relevant only in case of "Tabulated Characteristic".
  Q-dH-curve: Q-dH-characteristic of the pump.
  Bridge
  Image Modified
  The following types are supported:
  FHWA WSPRO
  USBPR
  Submerged Bridge
  Arch Bridges (Biery and Delleur)
  Arch Bridges (Hydraulic Research (HR))
  Bridge Piers (D'Aubuisson)
  Bridge Piers (Nagler)
  Bridge Piers (Yarnell)
  Energy Equation
  YFHWA WSPRO
  USBPR
  Submerged Bridge
  Arch Bridges (Biery and Delleur)
  Arch Bridges (Hydraulic Research (HR))
  Bridge Piers (D'Aubuisson)
  Bridge Piers (Nagler)
  Bridge Piers (Yarnell)
  Energy Equation
  TODO: fill out all options
  Dambreak Structure
  TODO: fill out all options
  User Defined
  Used to write plugins (dll's) with their own structure
  Tabulated Structure
  The Tabulated Structure property page is used for defining a structure regulated by a user defined relation between the discharge through the structure and the up- and downstream water level. The relation is defined in a table.
  Calculation Mode:
• Q = f(h U/S, h D/S)
• H U/S= f(h D/S, Q)
• H D/S= f(h U/S, Q)
  Number of Columns
  Number of Rows
  Water level datum
  Discharge factor
  Hydraulic Control
  Control Structure
  Regulating
  TODO: fill out all options
  Energy Loss
  Image Modified
  Apply energy loss
  Alignment change
  Roughness coefficient
  Positive energy flow loss coefficient
  Negative energy flow loss coefficient
  

  Appendix HECRAS

  
  
  Bridge/Culvert
  Image Modified
  Image Modified
• Deck/Roadway
  Image Modified
• Pier
  Image Modified
• Sloping Abutment
  Image Modified
• Bridge Modeling approach
  Image Modified
• Culvert
  Image Modified
• Multiple Opening Analysis
  Image Modified
  
• HTab Param
  Image Modified
• Bridge Design
  Image Modified
  Inline Structure
• Weir/embankment
  This is the geometry of the weir cross section
  Image Modified
  HECRAS inline structure
  Image Modified
  HECRAS inline structure - Weir/ Embankment
  
• Gate
  
  Image Modified
  HECRAS inline structure - Gate
  
  Lateral Structure
  Image Modified
  
• Weir/embankment
  Image Modified
  
• Gate
  Image Modified
• Culvert
  Image Modified
• Diversion RC
  Image Modified
  Pump Station
  Image Modified
  Image Modified