Morphological Study of Sharda River Using Remote Sensing Techniques
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FINAL REPORT MORPHOLOGICAL STUDY OF SHARDA RIVER USING REMOTE SENSING TECHNIQUES Prepared by Prepared for Indian Institute of Technology Morphology Directorate Roorkee Central Water Commission Uttarakhand New Delhi PROJECT TEAM Dr. Z. Ahmad, Professor (PI) Dr. P.K. Garg, Professor Dr. Deepak Kashyap, Professor Dr. R.D. Garg, Assoc. Professor Dr. P. K. Sharma, Assoc. Professor Dr. Rajat Agarwal, Research Associate Mr. Suresh S. Dodamani, Project Associate Ms. Tanushree Mukherjee, Project Associate Mr. Rajeev Ranjan, Project Associate Mr. Sandeep Chauhan, Project Assistant Department of Civil Engineering INDIAN INSTITUTE OF TECHNOLOGY ROORKEE ROORKEE April 2018 (ii) Executive Summary 1. River morphology deals with the plan form, cross-section and its dimension, bed forms, aggradation, degradation etc. Such morphology changes due to river hydrodynamics. Indian rivers experience large seasonal fluctuations in discharge and sediment load resulting in significant changes in their morphology. Shifting of the river course is generally accomplished by erosion of habitated and pricey agricultural area that causes tremendous losses. The sediments deposited and eroded in the river have a tremendous effect on the river cross-section and its gradient, sediment transport rate, discharge etc. Understanding of changes in the morphology of the rivers is required in the engineering projects for their planning, design and execution. With this in mind, CWC, New Delhi desires to carry out morphological study of the major Indian rivers. In this direction, CWC awarded a project entitled "Morphological study of rivers Ganga, Sharda and Rapti using remote sensing techniques" to IIT Roorkee. 2. Following were broad objectives of the study a) Compilation of river drainage map in GIS; changes in Land use/Land cover, flood affected areas, rainfall-runoff, geology etc. b) Hydrological analysis: Probability curve and flow rates corresponding to return period of 1.5 year and 2 years. c) Decadal stream banks shifting and also changes in its Plan form (Sinuosity & Plan form Index) from the base year 1970 to till 2010. d) Work out erosion and siltation based on the banks shifting. e) Evaluate the impacts of major hydraulic structures on the river morphology. f) Identification of critical and other vulnerable reaches and to suggest suitable river training/protection works. g) Reconnaissance survey for ground validation of outcomes of the study. h) Recommendations in the respect of actionable points. i) Suggestions for the further study. 3. Sharda river, a river of northern India and western Nepal, rises as the Kali River in northern Uttarakhand and then flows towards south-west, where it constitutes the border between Uttarakhand and Nepal. Descending from the mountains, it enters the Indo-Gangetic Plain at Barmdeo Mandi (Nepal). Downstream of this point, it is known as the Sharda River which continues to flow south-eastward into India through northern Uttar Pradesh state before joining the Ghaghara River - southwest of Bahraich. Drainage area of the river in India is 5132.81 km2. Important tributaries of the Sharda river (iii) in the reach of present study are Bamni, Ghaghi, Jagbura, Old Chauka. Important habitations near the Sharda rivers are Tanakpur, Banbasa, Palia Kalan, Nighasan and major water resources projects are Tanakpur Barrage, Banbasa Barrage, Lower Sharda Barrage and Sharda canal. The reach of the river Sharda which is studied herein is from Tanakpur to confluence point of Sharda and Ghaghra which lies between longitudes 80°00' E to 81°20' E and latitudes 27°36' N to 29°10' N. The area is entirely an alluvial plain and the land is highly fertile. The total length of the Sharda river studied in this report is 283 km. 4. Various aspects of the Sharda basin related to topography, soil, climate, geology, meteorological stations, land use land cover, flood map etc. are compiled in this report from the different sources like, GSI, WRIS, NRSC. Like most of northern India, Sharda basin has an extreme humid subtropical with dry winter type of climate. Summers are hot with temperatures rising up to 40°C. Geologically, the Sharda river basin may be divided into three zones: (i) The northern mountain zone or Shiwalik Himalaya, (ii) The tarai zone, and (iii) The plain zone. The studied area is mainly in plain zone. Geological map of the Sharda river indicates that it is consisted of fluvial. Land use and land cover map of the basin indicates that it is dominated by crop land followed by forest plantation. Scrub land can be seen along the Sharda river. Flood hazard zone map of Sharda river indicates moderate flooding in the areas along the river flow. 5. Hydrological data of Ganga river that comprises of annual maximum and minimum discharges and water levels; ten daily average discharge, sediment, and gauge at different gauging stations and were obtained from CWC, offices while relevant satellite images were procured from the National Remote Sensing Centre (NRSC), Hyderabad and downloaded from United States Geological Survey (USGS) website. SOI toposheets were obtained from SOI, Dehradun. 7. Planform of the rivers may be described as straight, meandering or braided. There is, in fact, a great range of channel patterns from straight through meandering to braided. Straight and meandering channels are described by sinuosity which is the ratio of channel length to valley length. 8. Sharda river behaves as sinuous from Tanakpur to its confluence with Ghaghra river except from Chainage 200-225 km near Sampurnnagar in which it had behaved as meander river before year 1990. The meanders of (iv) the river are not stable and keep on changing. The river has followed a relatively straight path over the years in the reaches 0-80 km and 210-240 km while meandering has increased in the reaches 100-140 km and 170-200 km. Axial wave length, amplitude and radius of curvature of the meanders are of the order of 4 km, 3 km and 1.5 km, respectively. 9. Sharda river may be considered moderately braided river in its major length from Tanakpur to its confluence with Ghaghra river. However, near Jagdispur, downstream of Banbasa barrage and Dodhara braiding of the river is high. At other locations, like Chandrika Gauri and Ghosiyana, it was highly braided in past. High braiding in the Sharda river in its upper reach i.e, Tanakpur, Banbasa, Dodhara is primarily due to aggradation which occurs as the river is incompetent to transport the sediment load that it is bringing from the relatively steep reach. 10. For the computation of shifting of course of the river, center line of the river as in year 2010 is perpendicularly bisected at a regular interval of 2 km and shift of left bank, right bank and center line in either directions has been computed for the years 1970, 1980, 1990 and 2000 with respect to year 2010 in GIS software. Remarkable shifting of the course of the Sharda river from 1970 to 2010 has been noticed. The maximum shift is of the order of 7 km at some locations. The confluence point of Sharda and Ghaghra rivers has shifted 15 km downwards in year 2010 w.r.t. year 1970. 11. Width of the active channel of the river and river width based on the extreme banks have been estimated using the satellite images of years 1970-2010. There is no definite progressive change in the width of the active channel of the river over the span of year 1970-2010 in the whole studied reach of the Sharda river. From chainage zero to 225 km, the average width of the river is almost constant and is equal to about 300 m, however, in the upper reach i.e., Chainage 225 km to 248 km, the average width is about 240 m. 12. Erosion and siltation studies have been carried out for the Sharda river from Tanakpur to its confluence with Ghaghra river using SOI toposheets and post-monsoon decadal satellite images from years 1970 to 2010. The extreme left and right banks have been identified based on the sand deposit and vegetation and based on the shifting of these banks, the erosion and deposition have been estimated for duration from year 1970 to year 2010 and is expressed in the terms of area in km2. 13. In the studied reach of the Sharda river, the total eroded area is 7544.79 ha, total deposited area is 21426.02 ha and total eroded and deposited area is 25513.79 ha on span of year 1970 to 2010, while net deposited area is 13881.23 ha. (v) 14. Erosion and siltation are noticeable throughout the entire reach of Sharda River from Tanakpur to the confluence point (Durgapur). This is due to shifting and meandering nature of the river course. Noticeable amount of siltation has occurred near Tanakpur and Durgapur - the starting and ending points of the river. In addition to the above locations, major silting has also taken place near Nai Ratauli, Jamdari, Gudaria, Baleha, Ghosiyana, Tirkaulia, Mallaha Purva, Madhotanda and Tanakpur while erosion has taken place at Nandura, Mohammadpur, and Ramnagar Kalan due to frequent shifting of the river course in these areas. Major erosion plus deposition has occurred in the reach 50-250 km on the span of year 1970- 2010 especially at Nauwapur, Bhadpur, Baleha and Ramnagar Kalan. 15. Available measured cross-sections of the Sharda river at the gauging stations have been used to study the aggradation and degradation in the river bed. Measured cross sections of the Sharda river for different years at gauging station of Palian Kalan, indicate no progressive aggradation or degradation, however, adjustment in the cross-sections of different years may be seen. 16. There are three barrages, namely Tanakpur, Banbasa, and Lower Sharda at chainages 277 km, 269 km and 92 km on Sharda river, respectively.