80 lines
2.8 KiB
JSON
80 lines
2.8 KiB
JSON
{
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"title": "Comal River Floodline Predictor Constants",
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"author": "Amy Coates",
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"location": "New Braunfels, Texas",
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"date": "2026-07-18",
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"source_citations": [
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{
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"id": "usgs-gauge-08235500",
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"description": "USGS Streamflow Gauge Station 08235500 - Comal River at New Braunfels",
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"url": "https://waterdata.usgs.gov/tx/nwis/uv?site_no=08235500"
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},
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{
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"id": "june-2007-texas-flooding",
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"wikidata": "Q6312080",
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"description": "Historical precedent: June 2007 Texas flooding event",
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"url": "https://www.wikidata.org/entity/Q6312080"
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},
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{
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"id": "austin-waterway-ban-2026",
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"description": "Current event: Austin issues waterway ban due to recent floods",
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"url": "https://www.fox7austin.com/news/texas-flooding-austin-issues-waterway-ban-due-recent-floods"
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},
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{
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"id": "nbhs-1935-memoirs",
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"description": "New Braunfels Historical Society: 1935 flood oral histories",
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"archive": "local"
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}
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],
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"constants": {
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"alpha": {
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"value": 0.047,
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"unit": "ft_per_inch_rainfall",
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"description": "Aquifer response coefficient: limestone transmissivity factor",
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"derivation": "Mean of 1935, 1998, 2007 discharge curves normalized to rainfall input"
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},
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"beta": {
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"value": 0.12,
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"unit": "ft_per_hour",
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"description": "Base recession rate: spring-fed baseline drainage",
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"derivation": "Spring flow decay curve from Edwards Aquifer recharge zones"
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},
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"efficiency": {
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"value": 0.85,
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"unit": "dimensionless",
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"description": "Aquifer transmission efficiency: percentage of rainfall reaching river via conduit flow",
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"notes": "Accounts for evaporation loss during summer months (July-September)"
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},
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"flood_threshold": {
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"value": 3.2,
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"unit": "ft_above_mean_low_water",
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"description": "Historic bench elevation: 1935 plaza marker level",
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"validation": "Verified against 1998 flood watermark on library cornerstone"
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}
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},
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"equation": {
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"formula": "Δh = (α × R × ε) − (β × t)",
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"variables": {
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"Δh": "predicted river rise (ft)",
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"α": "aquifer response coefficient",
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"R": "accumulated rainfall upstream (inches)",
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"ε": "transmission efficiency",
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"β": "recession rate",
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"t": "hours since peak inflow"
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}
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},
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"usage_notes": [
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"Valid for July-October flood season when aquifer saturation exceeds 78%",
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"Does not account for sudden structural failures or upstream dam breaches",
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"Calibrated to mean annual discharge of 850 cfs at station 08235500",
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"For emergency evacuation decisions, always consult official NWS alerts"
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],
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"machine_legible": true,
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"format_version": "1.0",
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"linked_pages": [
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"/comal-flood-predictor.html",
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"/comal-heritage-map.html",
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"/new-braunfels-roots.html"
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]
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}
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