Watershed

Watershed divisions

The total land area of Iran is divided into six main basins, including Caspian Sea basin, Persian Gulf & Oman Sea Basin, Uremia Basin, Central Plateau Basin, Hamoon Basin, Gharqhoom Basin that in turn, form 30 sub-basins with subsequent divisions including sub-catchments, watersheds, sub-watersheds and finally micro-watersheds/catchments in lower levels based on their scales respectively. The total annual volume of precipitation equals 412 billionm3 of which 43.2 billionm3 are controlled and managed for utilization.

 

Area (ha.)

 

Sub-Basins

Main Basins

 

4001017

1-Aras river sub-basin

1- The Caspian Sea Basin

 

680934

2-Talesh river sub-basin

 

5917424

3-Sefidroud river sub-basin

 

1090255

4-Sefidroud & Haraz rivers sub-basin

 

1827267

5-Haraz river & Haraz-Gharesou rivers sub-basin

 

1308529

6-Gharesou & Gorgan rivers watershed

 

2679992

7-Atrak river watershed

 

17505418

Sub-total

 

3945210

1-Western border rivers sub-basin

2-The Persian Gulf & Oman Sea Basin

 

5146527

2-Karkheh river sub-basin

 

6616990

3-Karoun river sub-basin

 

4059940

4-Jarrahi & Zohreh rivers sub-basin

 

2125026

5-Helleh river watershed

 

4773157

6-Mand river & Basteheram, Karian & Khonj sub-basin

 

6247553

7-Kal & Mehran rivers sub-basin

 

4504688

8-Bandar Abbas and Sadij rivers watershed

 

4897421

9-Southern Baloichestan rivers watershed

 

42343512

Sub-total

 

5195775

1-Urmia lake sub-basin

3-Urmia Basin

 

5195775

Sub-total

 

9246329

1-Salt lake sub-basin

4- Central Plateau Basin

 

4148736

2-Gavkhoni sub-basin

 

3153282

3-Tashk, Bakhtegan & Maharlou rivers sub-basin

 

5716702

4-Abarghou- Sirjan sub-basin

 

6984459

5-Jazmorian sub-basin

 

20600128

6-Loot desert sub-basin

 

22621363

7-Central Kavir watershed

 

4870830

8-Siyahkouh, Rigzarrin and Deghsorkh deserts sub-basin

 

5052843

9-Daranjir & Saghand deserts sub-basin

 

82403672

Sub-total

 

3298598

1-Degh patargan- Khaf sub-basin

5- Western Border Basin

 

3371551

2-Hirmand sub-basin

 

3665860

3-Mashkil sub-basin

 

10336009

Sub-total

 

4402526

1- Ghar-e-Ghum sub-basin

6- Ghar-e-Ghum Basin

 

4402526

Sub-total

 

162186912