<div style="text-align: justify;">Dams or reservoirs have proven to be very beneficial for the sustained development of human beings since its evolution. The usefulness of dam depends upon its capacity to store water. Sedimentation is a process which involves deposition of silt carried by flowing water from erosion of soil of upstream catchment area. Sedimentation has proven to be very detrimental for the capacity of dams or reservoirs. Sedimentation results in huge loss of storage capacity of dams or reservoirs thus reducing its life. Many methods have developed to measure the reservoir sedimentation like hydrographic survey, inflow-outflow approaches, remote sensing method etc. Out of these, remote sensing method is widely used as it is very simple and involves very less human survey thus reducing the chances of error. In remote sensing method, revised water spread area at different levels of reservoir is calculated and used for computation of loss of capacities between these levels. The present study has been carried out on Kharkhara reservoirs situated in Chhattisgarh state. Multi&ndash;date satellite data of IRS-P6, LISS-III is used for Kharkhara dam to estimate revised capacity. The normalized difference water index (NDWI), band ratioing technique (BRT) and false color composite (FCC) along with field truth verification were used to differentiate water pixels from rest of image. As the revised water spread at dead storage and full reservoir levels were not available, best &ndash;fit curve has been used to get revised spreads on these levels. From the analysis, it has been observed that Kharkhara reservoir has lost 8.41 MCM of gross storage against its total capacity of 169.54 MCM during 50 years(1967-2017). The average rate of sedimentation in Kharkhara reservoir is 16.82 Ha-m per year.</div>

<div style="text-align: justify;">Assessment of sedimentation in kharkhara reservoir using digital image processing techniques</div>

<p><strong>Background:</strong> The water resources of Northeast (NE) Indian reservoirs have been largely overlooked, despite their immense potential in various aspects. A comprehensive analysis of water quality parameters was conducted to assess the physio-chemical changes and health status of Maphou or Mapithel reservoir, Manipur, NE, India.&nbsp;<br />
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<strong>Methods:</strong> Sub-surface water samples were collected from June 2021 to May 2022 to assess the spatio-temporal changes. Trophic State Index (TSI), Morpho Edaphic Index (MEI), Maximum Sustainable Yield (MSY) and fish yield potential were calculated. The average water spread area was calculated through Normalised Difference Water Index (NDWI) method.<br />
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<strong>Result:</strong> A total of eighteen (18) water quality parameters were examined following Standard Methods. ANOVA analysis indicated that all water quality parameters, except total alkalinity, exhibited significant seasonal variations (p&lt;0.05). Spatially, most of the water quality was found to be insignificant, except for Chl-a and depth (p&lt;0.05). All the water quality parameters were within acceptable ranges for the growth and survival of aquatic biotic resources. No signs of pollution were observed. The trophic status of the reservoir was found in an oligotrophic state. The MEI was estimated as 8.55 and the average fish yield for the reservoir was 14.98 kg ha<sup>-1</sup>, which is below the national average yield of small reservoir (49.9 kg ha<sup>-1</sup>). The MSY was estimated to be 21.46 kg ha<sup>-1</sup>. Heatmap cluster analysis revealed three distinct clusters of months. The actual average water spread area was determined to be 852.62 ha, hence the reservoir can be categorised as small reservoir.</p>


Assessment of sedimentation in kharkhara reservoir using digital image processing techniques

A Pioneering Assessment on the Physico-chemical and Health Status of a Small Sub-tropical Reservoir in North-Eastern, India