Republic of Tunisia

Tunisia split by where its land drains — to the sea, into a closed depression, or across the border — with 8,424 stream segments totalling 39,004 km — each with Strahler order, gradient, system and delegation — 427 drainage basins of 10 km² or more with their outlets, and a per-delegation drainage-density table.

In short

Shares of the country by drainage outlet are listed in the table.

8,424 stream segments, 39,004 km in total, highest order 6.

427 drainage basins of 10 km² or more, 196 of them ending in a closed depression.

Tunisia drainage basins and stream network: boundaries, order, gradient and where each basin drains — Reduced-resolution preview with a watermark; the full-resolution map is in the package.

Who it is for

Geography, water and civil engineering students, water-harvesting and hill-lake projects, and flash-flood and road-drainage studies.

Method: what we add to the raw data

Streams were derived from a 90 m elevation model: sinks up to 20 m deep were filled to remove model artefacts, leaving deeper ones (the chotts and major sebkhas) closed; then flow direction and accumulation were computed.
A stream is any path draining 10 km² or more, ranked by Strahler order.
Segment gradient = elevation difference between its ends divided by its length, in percent.
The land was split into drainage basins by outlet, and each was classified by what the data states with certainty: draining to the sea, ending in a closed depression (chott or sebkha), or leaving the border. No named-basin division was invented, since the official division does not publish digital boundaries and guessing at it would mislead.
Drainage density = stream length divided by area, in km per km², per delegation.

Product details

What you get	4 spatial layers in GeoPackage, 2 CSV tables, lyrx and qml symbology for ArcGIS Pro and QGIS, a PNG map at 220 dpi, and an Arabic and English guide
Formats	GPKG, CSV, lyrx, qml, PNG
Coordinate system	WGS 84 (EPSG:4326)
Licence	Commercial use allowed for you and the organisation you buy for; no resale or redistribution
Delivery	A private download link valid for 24 hours, within 6 hours of payment confirmation
Package size	ZIP 10.6 MB
Personal data	The product contains no personal data

Spatial layers

water_systems — polygons, 3: Land split by drainage outlet
drainage_basins — polygons, 427: Drainage basins (10 km² or more) with outlets
streams — lines, 8,424: Streams with order and gradient
delegations_drainage — polygons, 265: Delegations with drainage density

Tables

D099_water_systems.csv — 3 rows: Systems table
D099_delegations_drainage.csv — 265 rows: Drainage density per delegation

Limitations

Streams are derived from terrain, not field survey; on flat plains and chotts a path may deviate from the actual channel.
The product does not carry official basin names (Medjerda, Miliane, Zeroud…) because their digital boundaries are not published; it carries derived drainage-basin boundaries and where each one drains.
The surface model includes buildings and trees, so some streams may break inside cities.
The 10 km² threshold hides small gullies; a lower threshold can be applied to the supplied accumulation cells.
The 20 m fill depth is a deliberate choice: anything shallower is treated as a model artefact and filled, so shallow sebkhas appear to drain rather than stay closed. Deeper ones — the major chotts — remain closed.

FAQ

How long does delivery take?: Up to 6 hours after payment is confirmed.
How long does the download link last?: 24 hours, and it is renewed free on request.
Can I get a refund?: Digital products are not refundable once downloaded — unless the file is defective or does not match the description, in which case it is replaced or fully refunded.
What does the licence allow?: Commercial use is allowed for you and the organisation you buy for; resale or redistribution is not.

Tunisia drainage basins and stream network: boundaries, order, gradient and where each basin drains