External inflows#

Note

Engine: OpenSWMM 6 — refactored.

External inflows, dry-weather flows, RDII, unit hydrographs, and inflow-area decay all live behind solver.inflows.

Reference: openswmm_inflows.h.

Quickstart#

from openswmm.engine import Solver

with Solver("model.inp") as s:
    # External inflow — node accepts id or index.
    s.inflows.add_external("J1", "FLOW", ts_name="rain1")

    # Dry-weather flow.
    s.inflows.add_dwf(
        "J1", "FLOW",
        avg_value=0.5,
        hourly_pattern="DLY1",
    )

    # RDII inflow with unit hydrograph.
    s.inflows.add_rdii("J1", uh_name="UH1", area=2.5)

    # Inspect counts.
    print(s.inflows.external_count, s.inflows.dwf_count, s.inflows.rdii_count)

    # Per-row read (RDII, hydrographs, decay — C API supports get).
    rdii = s.inflows.get_rdii(0)
    print(rdii.node_index, rdii.uh_name, rdii.area)

Methods#

External inflows ([INFLOWS])#

  • add_external(node, constituent, *, ts_name, type, m_factor, s_factor, baseline, pattern)

  • external_count property

Dry-weather flow ([DWF])#

  • add_dwf(node, constituent, *, avg_value, monthly_pattern, daily_pattern, hourly_pattern, weekend_pattern)

  • dwf_count property

RDII ([RDII])#

  • add_rdii(node, uh_name, area)

  • get_rdii(idx) -> RDIIEntry

  • rdii_count property

Unit hydrographs ([HYDROGRAPHS])#

  • add_hydrograph(uh_name, month, response, r, t, k, *, dmax, drecov, dinit)

  • get_hydrograph(idx) -> HydrographEntry

  • hydrograph_count property

  • add_hydrograph_gage(uh_name, gage_name) / get_hydrograph_gage(idx) -> HydrographGageEntry

  • hydrograph_gage_count / hydrograph_group_count properties

  • get_hydrograph_group_id(idx)

RDII decay ([RDII_DECAY])#

  • add_rdii_decay(uh_name, response, k_dep, k_0, k_T, T_ref, theta_rec, T_freeze)

  • get_rdii_decay(idx) -> RDIIDecayEntry

  • rdii_decay_count property

All node/link/subcatchment/gage arguments accept int | str.

C API constraint#

The C side only exposes add + count for external inflows and DWF — there is no per-row delete / set / get. The Python view doesn’t pretend to be a MutableSequence for those families. RDII, hydrographs, and RDII decay all have get accessors so per-row reading works.

See also#