{"name": "Rain to Flood Analysis", "package_name": "Rain2Flood", "version": "3.0", "experimental": false, "qgis_min": "3.28.0", "qgis_max": "4.99.0", "downloads": 279, "uploaded_by": "rahulpandey696", "upload_datetime": "2026-09-20T05:26:37.226896", "changelog": "## Changelog\r\n\r\n### 3.0 \u2014 major correctness and workflow release\r\n\r\n**Pour-point workflow.** Set one pour point and the upstream catchment,\r\nlongest flow path and channel slope are all delineated from the DEM.\r\nDelineation uses pointer jumping over the D8 flow graph \u2014 1.44M cells in\r\n4.8 s. No catchment polygon is required anywhere in the plugin.\r\n\r\n**Flood extent corrected.** Depression filling was seeded from the array edge\r\nafter nodata had been replaced with the catchment mean elevation. On a\r\nclipped catchment that constant ring acts as a dam: the entire lower basin\r\nwas raised to a flat surface, HAND against it was ~0, and roughly 66% of the\r\ncatchment flooded *regardless of discharge* \u2014 a 1.9\u00d7 increase in Q moved the\r\nextent from 65.8% to 65.9%. Extents are now channel-scale and respond to\r\ndischarge.\r\n\r\n**Volume budget.** Mapped flood water can no longer exceed the runoff the\r\nstorm produced. Depth comes from Manning's normal depth at regime width\r\n`W = 3\u221aQ`; at small Q that width collapses while the valley it is spread\r\nacross does not, so a trickle was being rendered as a metres-deep flood. The\r\nconsistency check existed and warned every time, and nothing acted on it.\r\n\r\n**Channel slope.** Measured longitudinally as S1085 along the traced main\r\nstem, not from the DEM gradient magnitude \u2014 which has no sign, is dominated\r\nby the cross-section, and was returning ~30\u00d7 the true slope. Velocity goes as\r\n\u221aS, so that alone was inflating velocity about five-fold and driving the\r\nhazard classification.\r\n\r\n**HAND.** Computed by walking each cell's own D8 flow path down to the\r\nchannel it drains into, rather than taking the geometrically nearest stream\r\ncell, which reached across divides and put 16% of cells at zero.\r\n\r\n**Sub-basin routing.** Sub-basins are clipped to the analysis catchment, so\r\nbasins draining elsewhere are no longer summed into the hydrograph.\r\n\r\n**Method-range warnings.** The SCS lag equation reports when it is being\r\nextrapolated past its ~8 km\u00b2 validity range, and when time to peak exceeds\r\nthe design storm duration (the storm ends before the UH peaks, heavily\r\nattenuating the result).\r\n\r\n**Rainfall location check.** Warns when the rainfall point falls outside the\r\ndelineated catchment.\r\n\r\n**CN / LULC extent.** The CN tab takes an area of interest \u2014 layer extent,\r\ncanvas extent, or a rectangle drawn on the map \u2014 instead of demanding a\r\ncatchment polygon.\r\n\r\n**Tabs 1 and 2.** Catchment boundary now optional. Slope is computed before\r\nany clip, so boundary cells keep real neighbours in Horn's method instead of\r\ntaking their slope from missing data.\r\n\r\n**Interface.** Rebuilt with a contrast-checked light theme (every\r\ntext/background pair verified against WCAG AA), new raster colour ramps for\r\nDEM, slope, CN, LULC and Manning's n, and QGIS 4 / PyQt6 compatibility.", "external_deps": null, "download_url": "https://plugins.qgis.org/plugins/Rain2Flood/version/3.0/download/"}