TR63 · Hatay · Kahramanmaraş · Osmaniye

Water in the
TR63
Sub-region

Rivers, storage, rainfall, the summer deficit and flood risk

PLN 401 Planning Studio VII · Environment Group · October 2026

Study area

Three provinces,
one water system

0km² · 33 districts
0mm of rain and snow a year
0km of rivers and streams
0km³ stored in lakes and dams
0km² flooded in a 100-year flood
0months a year with a water deficit
Chapter 1

Where water flows

Rivers, stream order and river basins

01
River network of TR63 by stream order
River network

Rivers drain from the mountains to two seas

0km
m of river per km² · up to m³/s on the lower Ceyhan
HydroRIVERS (HydroSHEDS) · stream order (Strahler) · Map H01
Stream order

Half of the network is headwater streams

53% of the length
Order 1: streams with no tributaries
↑ ↓ change the order
HydroRIVERS · Strahler order: 1 = smallest headwater, 6 = main river
Streams and drainage basins derived from the elevation model
Drainage basins

The terrain sets the watersheds

Copernicus DEM GLO-30 · drainage basins from the elevation model
Official river basins
River basins

The Ceyhan drains two thirds of the region

% drains to the Asi
a transboundary river that reaches Hatay from Syria and the sea at Samandağ
Official river basins of Türkiye (DSİ) · HydroRIVERS · Map H02 · arrows show flow direction
Drainage density

Wet slopes carry the densest networks

HydroRIVERS · metres of river per km² of district
Chapter 2

Where water is stored

Reservoirs, lakes, wetlands and irrigated land

02
Lakes and reservoirs
Lakes and reservoirs

Almost all stored water sits behind dams

0water bodies
0km² of water
0km³ stored
HydroLAKES (HydroSHEDS) · water bodies larger than about 10 ha · Map H03
The Ceyhan dam chain

Three dams on one river hold % of the stored water

HydroLAKES · elevation and volume of each reservoir · schematic long profile, not to scale horizontally
Water bodies, water courses and wetlands
Land cover

Open water and wetland are rare

0km²
water bodies, water courses and marshes · about 1% of the region
CORINE Land Cover 2018 · Map L10
Permanently irrigated land
Irrigation

The plains below the dams are irrigated

0km² irrigated
CORINE Land Cover 2018 · class 212, permanently irrigated land · Map L06
Chapter 3

When water arrives

Precipitation, its season and snow

03
Mean annual precipitation
Annual precipitation

Six times more rain on the coast than on the plateau

CHELSA V2.1, 1981–2010 · Map T01
Precipitation through the year
January
0mm, region mean
CHELSA V2.1 monthly climatology, 1981–2010 · one colour scale for all months · Map C02
Precipitation through the year · Map C02
CHELSA V2.1 monthly climatology, 1981–2010 · same colour scale as the previous slide
Share of precipitation falling October to March
Seasonality

Three quarters of the year's water falls October to March

0% Oct–Mar
CHELSA V2.1, 1981–2010 · Map C05
Main towns

Every town shares the same dry summer

CHELSA V2.1, 1981–2010 · monthly precipitation at the town centres · ordered from the coast to the plateau
Snow-cover days per year
Snow

Snow above m feeds spring rivers

0km² with 30+ snow days
CHELSA V2.1 snow-cover days, 1981–2010 · Map C06
Chapter 4

Where the summer runs short

Evaporative demand, aridity and the water deficit

04
Monthly water balance

For 7 months the air demands more water than falls

0mm summer shortfall
0mm winter surplus
PrecipitationEvaporative demand (PET)
CHELSA V2.1, 1981–2010 · PET: potential evapotranspiration · ↑ ↓ change the province
Potential evapotranspiration
Evaporative demand

The air could evaporate more than all the rain

0mm PET a year
0mm precipitation
CHELSA V2.1, 1981–2010 · Map C08
Relative humidity in July
Summer humidity

Dry inland air pulls water from soil and crops

0% humidity in July
CHELSA V2.1, 1981–2010 · Map C10
Aridity index
Aridity

Only the crests have water to spare

0aridity index
precipitation ÷ evaporative demand · below 1 means a yearly deficit
CHELSA V2.1, 1981–2010 · Map C09
Mean climatic water deficit
Climatic water deficit, 1991–2023

The deficit is getting larger

0mm more since 2007
TerraClimate (Abatzoglou et al., 2018) · Map T06
Drought stress
Drought stress

A third of the region is under drought stress

0% of the region
water deficit of 800 mm or more a year
TerraClimate, 1991–2023 · Map R12
Chapter 5

When water is too much

River floods, the Amik Plain and the low coast

05
Water depth in a 1-in-100-year flood
River flood · 1 in 100 years

Floods spread over the flat plains

0km² under water
JRC Global River Flood Hazard Maps (Baugh et al., 2024) · Map R07
Flood frequency

The same land floods again and again

0km² · 10-year flood
JRC Global River Flood Hazard Maps · return periods 10–500 years · Map R08 · ↑ ↓ change the return period
Amik Plain flood depth
Amik Plain · zoom

The old lakebed fills again

0km² · 10-year flood
JRC Global River Flood Hazard Maps · Antakya, Kırıkhan, Reyhanlı and Kumlu · Map R09 · ↑ ↓ change the return period
Low-lying coastal land
Low-lying coast · zoom

Land within reach of the sea

0km² below 1 m
0 km² of it built up
Copernicus DEM GLO-30 · GHSL built-up surface · Map R10 · ↑ ↓ raise the level
Water hazards compared

Each province faces a different water problem

Share of each province's area · flood: 100-year flood covers 10% or more of a 1 km cell · drought: deficit 800 mm or more · heat: July maximum 33 °C or more
District explorer

Annual precipitation

All 33 districts · ↑ ↓ change the indicator · hover a district for its value
Planning proposals

Five moves for the regional plan

Thank you

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