Guide·me
Lakes-Hydro-Lab · first-use route · honest hydrology map

This is the calm route through the map. It starts with where you are, then adds how water moves, then adds evidence from history and live gauges. The aim is confidence without overclaiming.

Map first

Keep north at the top, match the big valleys and lakes to the ground, then add the science layers.

Evidence, not verdict

HAND, slope, TWI, gauges, and historic outlines are screening evidence. They do not decide property-level risk.

Click to check

After a broad view, click a point. The detail panel pulls the evidence together and says what each item cannot prove.

Start from a useful view

These open the live map with a sensible layer set already loaded. They are shortcuts, not separate versions of the truth.

Place orientation

Terrain, lakes, towns, and named rivers. Best for getting your bearings before analysis.

Open orientation view

Flood screening

Terrain, HAND, lakes, towns, historic outlines, gauges, warning zones, and rivers.

Open screening view

Hydrology research

TWI, extracted streams, lakes, and named rivers. Best for asking where water may gather and route.

Open hydrology view

Worked point: Keswick

Opens a shared point near Keswick so you can see how the detail panel reads evidence.

Open Keswick point

Map to ground

North is at the top of this map. In the Lake District, the big clues are the valleys, lakes, and high fells. If a valley runs north-south on the map, try to match that to what you can see on the ground before you start reading colours.

A normal map is like a careful bird's-eye picture of the land. This hydro map adds special evidence: relative height above nearby channels, slope, wetness tendency, historic flood outlines, warning zones, named rivers, and live gauges.

The trick is to keep the map and ground lined up in your head. Big features such as lakes, valleys, ridges, and towns are your anchors. The colour layers then help you ask better questions.

Junior mapper rule: first ask "Where am I?", then "Where is the water?", then "What evidence says that?"

The route through the layers

Ten minutes · useful for schools, public users, and engineers

STEP 01

Start with terrain alone

Hillshade map showing the ridges, valleys, and high ground of Cumbria before any flood evidence is added.
ON: DEM hillshade
OFF: other layers

The hillshade shows the shape of the land: fells, valleys, lake basins, and flatter lowlands. This is your base map.

Before looking at flood evidence, find a few anchors: Bassenthwaite, Derwentwater, Skiddaw, Helvellyn, Windermere, the Eden valley, or the west coast plain.

Try: use the Place orientation shortcut, then name three places you recognise before turning on risk-coloured layers.
STEP 02

Add HAND - height above drainage

HAND layer over the hillshade, with yellow low relative ground near channels and darker higher relative ground on ridges.
ON: DEM hillshade + HAND standard

HAND means Height Above Nearest Drainage. It estimates how high each readable cell sits above its nearest mapped channel.

Yellow means low relative ground near channels. Purple means higher relative ground. Transparent gaps mean the algorithm did not resolve a HAND value there.

Careful: HAND is terrain screening. It is not a flood depth, not a flood forecast, and not a property-level decision.
STEP 03

Add lakes as anchors

Lakes and tarns added to the hydrology map so the reader can recognise the Lake District landscape.
ON: DEM + HAND + Lakes

The lakes make the map readable quickly. They are also a useful check on the hydrology: water bodies should line up with low relative ground and drainage routes.

Use the big lakes as map-to-ground anchors. If you lose your place, reset mentally from the lakes and valleys before reading the colours again.

Try: find Derwentwater, Bassenthwaite, Ullswater, and Windermere. Then look at the valleys feeding them.
STEP 04

Add towns and named places

Built-up areas and named places added to show where settlement sits in relation to low ground and valleys.
ON: DEM + HAND + Lakes + Towns

Now the question becomes human. Cockermouth, Keswick, Kendal, Penrith, Workington, and smaller villages sit inside real catchments.

Look for overlap between settlement, low HAND, named rivers, and valley floors. That overlap is a reason to inspect further, not a final answer.

Try: search for Keswick. The map will mark the place and offer point details.
STEP 05

Add historic flood outlines

EA recorded flood outlines over the terrain and HAND map, showing where recorded events intersect low ground and towns.
ON: previous layers + Historic floods

EA recorded flood outlines show mapped extents from past events. They are one of the most useful reality checks on the terrain story.

Where red recorded outlines overlap yellow low HAND, the terrain evidence and history are pointing in the same direction. Where they differ, slow down and ask why.

Careful: no outline at a clicked point does not prove it never flooded. Records are useful, but not exhaustive.
STEP 06

Add live EA gauges

Live EA gauge points added to the Cumbria map, showing where current river level readings can be opened.
ON: previous layers + Live gauges

Red dots are Environment Agency water-level stations. Click one to load the latest public reading and a short 24-hour graph.

Gauge data helps with live context. It does not automatically describe every nearby field, street, or tributary.

Try: from any point-detail panel, use Show live gauge graph to jump to the nearest gauge.
STEP 07

Add EA warning zones

EA flood-warning zones overlaid as official alert geography, separate from the derived terrain layers.
ON: previous layers + EA warning zones

Warning zones are official alert geography. They show the areas the EA uses for public flood alerts and warnings.

The map checks the live public warning feed on page load. If warnings are active in Cumbria, matching zones are highlighted and a banner appears.

Careful: warning zones are not the same thing as HAND. One is official alert geography; the other is derived terrain evidence.
STEP 08

Use Hydrology research when asking why

Extracted stream network shown clearly over the hillshade, revealing the drainage structure used by the hydrology analysis.
PRESET: Hydrology research

This preset keeps the view lighter: DEM, TWI, extracted streams, lakes, and named rivers. It is for asking where water may gather and how it routes through valleys.

TWI is a wetness tendency index, not a puddle detector. Streams are algorithm-derived, not a legal watercourse record.

Try: search Cocker. The result should prefer River Cocker, fit the mapped line, and offer point details near it.
STEP 09

Compare HAND standard and HAND dense

Dense HAND comparison layer showing how changing the channel threshold changes the mapped hydrology evidence.
COMPARE: HAND standard vs HAND dense

The dense layer uses a smaller channel threshold and therefore finds more minor drainage. This can reveal detail, but it can also pull small ditches into the story.

Use it as an uncertainty check. If the conclusion changes dramatically between standard and dense HAND, that is a sign to investigate, not to pretend the answer is simple.

Useful controls once you know the route

Search

Find places and named waterways. Place results add a found marker; waterway results fit and flash the river line.

Point detail

Click the map for coordinates, nearest place, HAND, slope, TWI, historic outline hit/miss, and nearest gauge context.

Data status

The masthead pill lists which sources loaded and whether they are live, static, derived, or R2-hosted assets.

Legend descriptions

The HAND, slope, and TWI legend cards link to plain-language explanations of what each colour scale means.

Share view

Copy the current layer set, map centre, zoom, and open point-detail location into a reproducible link.

Keyboard

/ focuses search. Esc closes panels. Number keys toggle the first ten layer cards when you are not typing.