Area estimates of various wetland categories for Tamilnadu have been carried out using GIS layers of wetland boundary, water-spread, vegetation and turbidity. 24684 wetlands have been mapped at 1:50,000 scale in Tamil Nadu. Total wetland area estimated is 902534 ha which is 6.92 % of the geographic area. As per National Wetland Atlas published by Space Application Centre, Ahmedabad.
Sr. No |
Wettcode |
Wetland Category |
Number of Wetlands |
Total Wetland Area |
% of Wetland area |
Open Water Area in ha |
|
---|---|---|---|---|---|---|---|
Post- monsoon Area |
Pre- monsoon Area |
||||||
|
1100 |
Inland Wetlands - Natural |
|||||
1 |
1101 |
Lakes/Ponds |
4369 |
316091 |
35.02 |
236456 |
45436 |
2 |
1104 |
Riverine wetlands |
2 |
127 |
0.01 |
121 |
41 |
3 |
1105 |
Waterlogged |
44 |
3928 |
0.44 |
3382 |
2168 |
4 |
1106 |
River/Stream |
194 |
136878 |
15.17 |
131049 |
131479 |
|
1200 |
Inland Wetlands-Man-made |
|||||
5 |
1201 |
Reservoirs/Barrages |
99 |
56419 |
6.25 |
46443 |
31064 |
6 |
1202 |
Tanks/Ponds |
19343 |
237613 |
26.33 |
164346 |
23078 |
7 |
1203 |
Waterlogged |
38 |
10811 |
1.20 |
9353 |
5816 |
|
|
Total – Inland |
24089 |
761867 |
84.41 |
591150 |
239082 |
|
2100 |
Coastal Wetlands - Natural |
|||||
8 |
2101 |
Lagoons |
74 |
25057 |
2.78 |
25041 |
22034 |
9 |
2102 |
Creeks |
17 |
3404 |
0.38 |
3339 |
3403 |
10 |
2103 |
Sand/Beach |
73 |
9798 |
1.09 |
- |
- |
11 |
2104 |
Intertidal mud flats |
84 |
33164 |
3.67 |
- |
- |
12 |
2105 |
Salt Marsh |
42 |
6108 |
0.68 |
5369 |
2596 |
13 |
2106 |
Mangroves |
78 |
7315 |
0.81 |
- |
- |
14 |
2107 |
Coral Reefs |
36 |
3899 |
0.43 |
- |
- |
|
2200 |
Coastal Wetlands –Man-made |
|||||
15 |
2201 |
Salt pans |
47 |
22889 |
2.54 |
22505 |
19733 |
16 |
2202 |
Aquaculture ponds |
144 |
10739 |
1.19 |
10457 |
9420 |
|
|
Total – Coastal |
595 |
122373 |
13.56 |
66711 |
57186 |
|
|
Sub-Total |
24684 |
884240 |
97.97 |
657861 |
296268 |
|
|
Wetlands (<2.25 ha), mainly Tanks |
18294 |
18294 |
2.03 |
- |
- |
|
|
Total |
42978 |
902534 |
100.00 |
657861 |
296268 |
Area under Aquatic Vegetation |
167273 |
531600 |
Area under turbidity levels |
|
|
Low |
314273 |
70189 |
Moderate |
247677 |
159206 |
High |
95911 |
66873 |
There are 30 districts. The geographic area of the districts varies from 178 sq.km (Chennai) to 8162 sq.km (Erode). The wetlands occupy as high as 18.05% of geographic area (Ramanathapuram District), and as low as 1.08% (Coimbatore). In terms of total wetland area (% wetland area), Kancheepuram is the leading district (80445 ha, 8.91%) and Chennai is the least (917 ha, 0.10%).
Lakes/Ponds and Tanks/Ponds are the dominant wetland types in almost all districts. In coastal areas, Lagoons, inter tidal mudflats and Saltpans are dominant wetland types.
District |
Geographic Area* |
Wetland Area |
% of total wetland area |
% of district geographic area |
---|---|---|---|---|
(sq.km) |
(ha) |
|||
Thiruvallur |
3422 |
53863 |
5.97 |
15.74 |
Chennai |
178 |
917 |
0.10 |
5.15 |
Kancheepuram |
7857 |
80445 |
8.91 |
10.24 |
Vellore |
6077 |
32640 |
3.62 |
5.37 |
Dharmapuri |
4498 |
18215 |
2.02 |
4.05 |
Thiruvannamalai |
6191 |
48130 |
5.33 |
7.77 |
Villupuram |
7222 |
64105 |
7.10 |
8.88 |
Salem |
5205 |
15270 |
1.69 |
2.93 |
Namakkal |
3363 |
7687 |
0.85 |
2.29 |
Erode |
8162 |
13570 |
1.50 |
1.66 |
The Nilgiris |
2453 |
3127 |
0.35 |
1.27 |
Coimbatore |
7469 |
8070 |
0.89 |
1.08 |
Dindigul |
6267 |
13815 |
1.53 |
2.20 |
Karur |
2896 |
16383 |
1.82 |
5.66 |
Thiruchirappalli |
4404 |
18626 |
2.06 |
4.23 |
Permabalur |
3690 |
8070 |
0.89 |
2.19 |
Ariyalur** |
1942 |
11042 |
1.22 |
5.69 |
Cuddalore |
3678 |
28135 |
3.12 |
7.65 |
Nagapattinam |
2716 |
47833 |
5.30 |
17.61 |
Thiruvarur |
2097 |
22591 |
2.50 |
10.77 |
Thanjavur |
3348 |
34184 |
3.79 |
10.21 |
Pudukottai |
4663 |
72402 |
8.02 |
15.53 |
Sivaganga |
4189 |
67172 |
7.44 |
16.04 |
Madurai |
3742 |
24614 |
2.73 |
6.58 |
Theni |
3242 |
5293 |
0.59 |
1.63 |
Virudhunagar |
4232 |
29071 |
3.22 |
6.87 |
Ramanathapuram |
4090 |
73808 |
8.18 |
18.05 |
Thoothukudi |
4621 |
37810 |
4.19 |
8.18 |
Tirunelveli |
6823 |
37709 |
4.18 |
5.53 |
Kanniyakumari |
1672 |
7937 |
0.88 |
4.75 |
Total |
130409 |
902534 |
100.00 |
6.92 |