Developer Resources

PFM-01: Overtopping Erosion

PFM-01 models overtopping erosion of embankment dams. Each PFM-01 location represents one embankment section being evaluated (e.g., "Main Embankment", "Left Abutment"). The module uses the three-table SRP pattern: a DST-calculated SRP, a user-defined SRP, and an active SRP that is synced from one of the two sources based on the user's selected mode.

Table Relationships

Pfm0135 columns

1 : 1 · CASCADE

Pfm01_DstSrp6 columnsPfm01_UserSrp5 columnsPfm01_ActiveSrp5 columns

---

Pfm01

35 colsImplemented

PFM-01 location entity. Each row represents one embankment section being evaluated.

Column

Type

Constraints

▸Identity5

▸SRP Mode1

▸Geometry3

▸Materials3

▸Erodibility Coefficient (kd)6

▸Critical Shear Stress (τc)6

▸Manning's Roughness (n)6

▸Analysis2

▸UI State1

▸Timestamps2

Notes

1. Distribution parameters (Kd, TauC, ManningsN) follow a pattern: DistributionType selects the distribution family, then the relevant parameters (Min/Mode/Max or Mean/Std) are populated.
2. Indexes: PK on Id, Index on ScreeningId, Index on Index column.

Pfm01_DstSrp

6 colsImplemented

Stores System-Response calculation results and nodal probability adjustments.

Column

Type

Constraints

Id

UUID

PK= gen_random_uuid()

Pfm01Id

UUID

→ pfm01UQIDX

CurvesJson

JSONB

?JSONB

NodalJson

JSONB

?JSONB

LastCalculatedAt

TIMESTAMP

?

LastNodalEditAt

TIMESTAMP

?

CurvesJson Structure — System-Response calculation output curves

{
"systemResponseCurve": [
  { "headwater": 0.0, "probability": 0.0 },
  ...  // 50 points: overtopping depth (ft) vs probability of failure
],
"grassRemovalCurve": [...],       // Node 2 — grass cover removal
"conditionalBreachCurve": [...],  // Node 5 — conditional breach
"durationCurve": [
  { "depth": 0.5, "duration": 12.0 }, ...
]
}

Point types:
CurvePointDto:    { headwater: double, probability: double }
DurationPointDto: { depth: double, duration: double }

NodalJson Structure — 5-node event tree nodal probability tables

{
"originalHeadwaters": [0.1, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0],
"nodes": {
  "node1": {
    "name": "Overtopping Initiates",
    "headwaters": [...],
    "dstEstimate": [...],       // read-only (from System-Response)
    "revisedEstimate": [...],   // user overrides; null = use DST
    "justification": null
  },
  "node2": { ... }, "node3": { ... }, "node4": { ... }, "node5": { ... }
},
"totalSrp": {
  "headwaters": [...],
  "dstEstimate": [...],         // product of all nodes
  "revisedEstimate": [...]
}
}

Pfm01_UserSrp

5 colsImplemented

Stores manually-entered SRP curves computed outside DST by the user.

Column

Type

Constraints

Id

UUID

PK= gen_random_uuid()

Pfm01Id

UUID

→ pfm01UQIDX

CurveJson

JSONB

?JSONB

Notes

VARCHAR(4000)

?

LastModifiedAt

TIMESTAMP

?

CurveJson Structure — User-defined SRP curve (headwater vs probability)

[
{ "headwater": 0.0, "probability": 0.0 },
{ "headwater": 0.5, "probability": 0.01 },
{ "headwater": 1.0, "probability": 0.05 },
...  // Variable number of points (user-defined)
]

Point type: { headwater: double, probability: double }

Pfm01_ActiveSrp

5 colsImplemented

Active SRP curve used in risk calculations. Synced from DstSrp or UserSrp based on SrpMode.

Column

Type

Constraints

Id

UUID

PK= gen_random_uuid()

Pfm01Id

UUID

→ pfm01UQIDX

CurveJson

JSONB

?JSONB

SourceMode

VARCHAR(20)

?

LastSyncedAt

TIMESTAMP

?

Notes

1. When SrpMode = 'dst': Syncs totalSrp.revisedEstimate from Pfm01_DstSrp.NodalJson.
2. When SrpMode = 'user': Copies CurveJson from Pfm01_UserSrp.
3. Sync triggers: mode switch, DST calculation complete, user-defined curve save.

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Three-Table SRP Pattern

The SRP (System Response Probability) pattern is central to PFM-01 and will be replicated across all future PFM modules:

1. DstSrp — Curves and nodal tables computed by the DST System-Response library. Read-only from the user's perspective (though users can revise individual nodal estimates).
2. UserSrp — A manually-entered SRP curve computed outside DST. Fully user-defined.
3. ActiveSrp — Denormalized cache of whichever SRP is currently "active" based on the parent entity's SrpMode. When 'dst', synced from DstSrp's total SRP. When 'user', synced from UserSrp.

Data is never deleted when switching modes — switching from DST to User mode does not erase DST calculations, and switching back does not erase user-entered curves.

Enum Values

SrpMode

Value	Database String	Description
Dst	"dst"	DST-based SRP: System-Response library calculates probabilities
User	"user"	User-defined SRP: User manually defines the complete SRP curve

EmbankmentErodibility

Value	Database String	Description
VeryErodible	"veryErodible"	Very erodible material
Erodible	"erodible"	Erodible material
ModeratelyResistant	"moderatelyResistant"	Moderately resistant material
Resistant	"resistant"	Resistant material
VeryResistant	"veryResistant"	Very resistant material

GrassCoverQuality

Value	Database String	Description
None	"noGrassCover"	No grass cover
Poor	"poorCover"	Poor grass cover
Average	"averageCover"	Average grass cover
Good	"goodCover"	Good grass cover