Assessment of the status of surface waterlogging in Sarda Sahayak Command area of Uttar Pradesh, India using IRS-1A, LISS-1 Data
Results and discussions
The Sarda Sahayak system has led to excessive seepage of water which has led to extensive waterlogging and resultant increase of soil salinity in the command. During field checking, surface water logged areas were observed mainly along the feeder channel from head to ch. 160km and also on both sides of Dariyabad branch from 0 to 50km. Some areas in the downstream reaches of the command also showed surface water logging. About 200 ground observation points were accordingly selected in the field and the depths of standing water. KCB Raju et. al. (1985) had identified water logged and sanility areas in parts of the Nagarjuna Sagar Canal command using Landsat data. The water logged areas are characterized by the prevalence of high soil moisture areas, Standing shallow surface water areas and presence of perennial vegetation.
The maximum likelihood supervised classification algorithms for both general and depth classifications were used during digital image analysis of IRS-IA, Liss-1 data. The draining sets located on survey of India's toposheets on the basis of ground observations, were integrated with the IRS-IA and Liss-1 data through an interactive Pericolor (PC-2001) terminal of the image processing system configured around VAX 11/780 for both the classifications. The spectral signature keys for the classifications were developed on the basis of their tonal characteristics. The classification statistics and confusion matrix of each class were evaluated and the classifications have been found most useful in different various categories of aquatic vegetation in waterlogged areas and surrounding level-I, landuse classes. The classified outputs were geometrically rectified and stored in PCT using fire-format algorithms. The estimated of areas of the different categories of surface water logged land were computed. The first five categories shown in
table 1 correspond to the different status of water logging and the remaining refer to the major land use classes. The digital computation shows that a total of 9595.04 sq km land in the entire Sarda Sahayak command are of 56,332.76 sq. km was surface water logged in February 1989. It has also been possible to digitally enhance and discriminate the different levels of standing water in the immediate vicinity of feeder channel between ch 40km & ch. 104.2 km. The areas of different levels of standing water were computed within the waterlogged lands and are given as under :
- Standing surface water upto 15 cm depth extends over 438.11 sq. km
- Standing surface water between 15 cm to 75 cm depth extends over 168.56 sq. km
- Standing surface water more than 75cm depth extends over 44.9 sq km.
Additionally, band rationing of bands 1 and 4 and Principal component analysis algorithms were also carried out enhancing the surface waterlogged features.
A comparative study of Landsat MSS classified data of December 1983 IRS-IA, Liss-1 data of February 1989 has been made for change detection in the surface water logged lands. It has been found that some areas to the east of left bank of feeder channels i.e. north of Sarda River and south of Ganghra river upto their confluence and also the area lying to the area south of Sarda river have shown improvement in the status of water logging during the last six years period. however, the areas lying to the west of Laharpur and north of Lucknow show a marginal increase it extend of salt affected lands compared to the status of 1983.
Table 1: Area estimation of surface waterlogged lands
and landuse
calsses in Sarda Sahayak Command area using supervised
classification algorithms
| Class No. |
Class Name |
Number of
Pixels |
Area in
Sq km |
Percentage
% |
| 1. |
Moist soil |
683622 |
3583.1276 |
6.380 |
| 2. |
Water with stubble of paddy |
642249 |
3369.2661 |
5.992 |
| 3. |
Water with grass |
238094 |
1249.0434 |
2.221 |
| 4. |
Water with weeds |
59204 |
310.6177 |
0.552 |
| 5. |
Clear water |
15783 |
82.960 |
0.147 |
| 6. |
Saline land |
567278 |
2676.499 |
5.293 |
| 7. |
Sand |
45905 |
240.7213 |
0.430 |
| 8. |
Ravine land |
724712 |
3792.4362 |
6.762 |
| 9. |
Cropland |
4334501 |
22718.162 |
40.444 |
| 10. |
Forest land |
78584 |
412.3573 |
0.733 |
| 11. |
Pond/reservoir |
24658 |
129.1094 |
0.230 |
| 12. |
River |
39547 |
207.4066 |
0.369 |
| 13. |
Canal |
68288 |
358.198 |
0.637 |
| 14. |
Unclassified |
3194866 |
23052.197 |
29.810 |
| Total |
10717291 |
56332.762 |
100.000 |
Conclusion
The computer processed classified and enhanced IRS, Liss-1 satellite data integrated with ground truth inputs has given accurate and timely results for assessing the surface water logged lands in the Sarda Sahayak command area using supervised classification. The different categories of aquatic vegetation biz., water with stubble of paddy, water with grass, and water with weeds were digitally discriminated with the water logged ranging fro high soil moisture through 5 cm to more than 150 cm were also identified within the water logged lands along the feeder channel between ch. 40 km. & ch. 104.2 km length. It has also been possible to detect changes in the status of water logging along the feeder channel section between head and 104.2 km stretch. It is noted that some areas have been relieved from acute surface water logging as a result of measures taken up by the state irrigation department during the last six years.
Acknowledgement
The authors are grateful to Director, Remote Sensing applications Centre, Uttar Pradesh, Lucknow for permission to submit the paper to the 10th Asian conference on Remote Sensing.
Reference
- Anon., (1984) Waterlogging and its remedial measures in Sarda Sahayak Command Area: A report of working group., October 1984.
- Anon., (1985) An assessment of surface water logged areas in a part of Sarda Sahayak canal system covering parts of Lakhimpur and Sitapur District, Uttar Pradesh: A report by Remote Sensing Applications Centre, Uttar Pradesh.
- K.C.B. Raju et. al (1985) Application of Remote Sensing techniques in the study of water logging in parts of the Nagarjuna Sagar Canal Command Area: proc. Of VIth Asian conference on Remote Sensing, Nov. 21-26, 1985 Hyderabad.
- Usha Chatrath, (1983) problems in water resources, assessment, development and management in Sarda Sahayak command area development project: Proc. Of Sym. On Remote Sensing in development & Management of water resources, at Ahemdabad, October 25-27 1983.
