The report presents a sedimentation study in which sedimentation rate and volume have been determined using remote sensing data in the Ukai reservoir constructed across the Tapti River in Gujarat.
The post-monsoon period of the year 1993-94 was chosen for analysis. The remote sensing data of IRS-1B satellite and LISS-II sensor was acquired for eight different dates and the revised water spread areas were extracted. The original elevation-area capacity curves and the reservoir levels on the eight dates of pass of satellite were obtained from the dam authorities.
Using the trapezoidal formula, the revised capacity in between the maximum (104.446 m) and minimum (92.196 m) observed levels was obtained. The loss of capacity (324.6 mcum) was attributed to the sediment deposition in the zone of study of the reservoir. The results of this study have been compared with the results of hydrographic survey, which was carried out in the year 1992-93.
Limitation of remote sensing technique is that the sedimentation in the portion below the lowest observed level and above the highest observed level can be determined. This limitation is not significant since the zone of interest of sedimentation analysis, from the point of view of operation, is the live storage zone only.
Further, if sedimentation analysis is required for the whole of the reservoir, then the hydrographic survey for the water spread area at the lowest observed elevation can be carried out and the results can be combined.
Download the report here:
/articles/reservoir-sedimentation-study-ukai-dam-using-satellite-data-research-report-national