Jersey Coastal Intelligence Platform

Sources

Source 01

Weather

Open-Meteo

Source 02

Tides

Harmonic M2

Source 03

Erosion

Risk engine

Source 04

Ports

opendata.gov.je

Segments

Run log

Air Temp

—

°C · St Helier

Wind Speed

—

km/h

Next High Tide

—

height m

Coastal Risk

—

composite / 100

Jersey — Channel Islands · 7 coastal segments

24-Hour Trend

−24H−12HNOW

Master Truth Table

AWAITING PIPELINE…

Timestamp (UTC)	Source	Metric	Value	Unit	Segment	Risk
LOADING…

Risk Methodology

The composite score (0–100) fuses three live signals, each weighted by its empirical contribution to coastal erosion events recorded around Jersey's 70 km coastline.

Wind — 30 pts max

Speed scaled to 50 km/h reference. SW–W winds (200°–280°) receive a ×1.2 direction multiplier — Jersey's west-facing bays have open Atlantic fetch, generating larger waves and sediment transport from that quadrant.

Tide — 40 pts max (dominant)

Jersey's tidal range reaches 11 m on springs. Current height as fraction of 7 m reference carries the largest weight — high tides extend wave reach far up dune faces, the primary erosion driver.

Precipitation — 20 pts max

Rainfall saturates cliff faces and raises pore-water pressure, accelerating mass movement — especially relevant on the N coast cliffs at Plemont and Grosnez.

raw = (wind/50 × 30)
+ (tide/7 × 40)
+ (precip/5 × 20)

score = min(raw × dir_factor, 100)

dir_factor = 1.20 if wind 200°–280°
dir_factor = 0.85 all other directions

Risk Bands

LOW

0 – 34

MED

35 – 64

HIGH

65 – 100

Geomorphic Offsets

Each segment applies a ±8 pt offset. Open sandy beaches (St Ouen's, St Brelade) score higher — loose sediment mobilises easily. Rocky coves and reef flats (Rozel, La Rocque, St Aubin) score lower — rock structure dissipates wave energy before reaching erodible substrate.

Data Sources

WEATHER api.open-meteo.com
TIDES M2 harmonic → tidesatlas.com
PORTS opendata.gov.je
EROSION your endpoint → fetchErosion()

JERSEY COASTAL INTELLIGENCE