Visiting India: Field trip December 2012

From 15-21 December 2012 the Hydroflux India team, comprising delegates from IIT Roorkee, IIT Kanpur, IISc Bangalore, UNESCO, University of Reading, the British Geological Survey and Imperial College London went on a field trip to visit some of the most important hydrological and cultural features of the Ganga Basin. Gina Tsarouchi, Simon Moulds and Jimmy O’Keeffe gathered their notes and impressions.

Roorkee to Srinagar

The first site visited was Haridwar, Uttarakhand, which is located on the Ganga and considered one of the seven most sacred Hindu sites in India. Here the Bhimgoda barrage diverts the majority of river water down two canals, one on each side of the river. Approximately 10,700 cusecs (cubic feet per second) is diverted to the Ganga Canal, past the famous Har Ki Purighat, and south westerly towards Roorkee. The smaller Eastern Ganga Canal, with an approximate discharge of 5,500 cusecs flows in a south easterly direction towards Najibabad. The Bhimgoda barrage, completed in 1982, is designed to supply water for irrigation via the two canals, to control flooding and to provide water for hydroelectric power production. Haridwar is where the river enters the Gangetic plains following its journey south from the Himalayas.

Photo 1: Haridwar (photo by W.Buytaert)

Located approximately five kilometres to the north east of Haridwar is the Chilla Dam. This was completed in 1968 and generates 144 megawatts (mw) of power from water diverted from the Ganga River by the Pashulok barrage south of Rishikesh. The water is channelled along a canal and accumulates approximately 30 feet of head at the dam. On the canal two floating 0.5 mw turbines were observed.

Following a stop in Rishikesh we continued north along National Highway 58 towards Srinagar. From here the landscape changes almost immediately, with hills and mountains towering at either side of the road. Moving upstream, the Ganga becomes narrower and its velocity increases with the gradient. Coniferous forests are the dominant land use type in the Western Himalayas near Srinagar. The mountainous landscape in this part of the catchment precludes the intensive farming observed in the Gangetic plains between Roorkee and Haridwar; instead, crops are grown on terraces. The dominant crop type visible from the road is rice. The land is irrigated by channelling water along a series of narrow ditches.

Highway 58 is a busy road and, due to the heavily fractured nature of the geology of the river valley, is prone to landslides, particularly following the monsoon season. Landslide scarps are a common feature in this area on both sides of the river bank with many of the landslides affecting the roadintegrity. 

Photo 2: The confluence of the Alaknanda (from the left) and Bhagirathi (from the top) rivers at Devprayag and the beginning of the Ganga river (photo by J.O'Keeffe)

Roorkee to Narora

The road from Roorkee to Narora takes you from Uttarakhand into Uttar Pradesh and through some of the most agriculturally productive land in the Ganga basin. Rice and sugar cane appeared to be the most common type of crop grown in this part of the state, with rapeseed and wheat also observed. Furthermore, it appeared that a common practice in the region was to plant fast growing teak trees in small plantations, or along field borders, which are subsequently pulped for paper manufacture.

Widespread groundwater abstraction was evidenton our journey to Narora. This was undertaken using a combination of diesel and electric pumps at permanent pump houses, or using tractor mounted pumps which appeared to circulate water around the smaller, field irrigation canals, or pump water directly into rice paddies. The pump houses were sometimes served by diesel pumps in addition to electric pumps, suggesting that these were used as backup during electricity blackouts. Also of note was the erection of electricity infrastructure directly to pump houses within fields, suggesting that an important part of rural electrification was the advancement of irrigation practices.

Photo 3: Narora barrage (photo by W.Buytaert)

On the journey a number of canals were seen, including the Ganga Canal, previously seen at Haridwar, which supply a significant proportion of the irrigation water used by the surrounding farmland. The Narora barrage diverts water from the Ganga into to the lower Ganga Canal, on the western bank of the river. This canal, approximately 77 metres wide at the barrage, supplies cooling water to the Narora Atomic Power Plant located 3 km to the southeast, from where it continues in a southerly direction towards Etawah.

A visit to the WWF-India at Narora was organised, where we met some of the team working to protect the Ganges River dolphin and their habitat. The construction of the Narora barrage has created a relatively safe environment upstream for the dolphin to live and breed in, and represents one of the only areas of the Ganga where dolphin populations have actually increased in recent years. This is mostly due to an improvement in water quality and habitatcombined with a reduction in hunting. Since 2005 the 82km stretch from Naroraup stream to Brijghat has been classified as a Ramsar site specifically for dolphin conservation. A short boat ride up the river with WWF staff confirmed this success as the dolphins seemed particularly sociable. We landed a short distance upstream on a sandy island in the centre of the meandering river. The island comprised fine to medium grained pale sand, patterned by the wind. This area is used for agriculture with long reed like rows of crop planted in the sand. Sugarcane and other cropping practices, including Pallaze, which involves growing cucurbitaceous crops, are relatively common where sand beds are produced by the meandering river. It is usual for water to be pumped from the river, or from river side wells to irrigate the crops, and in this case a shallow, hand dug well was found in the sand.

Photo 4: WWF-India (photo by W.Buytaert)

Kanpur meetings

The first formal project meeting of the trip was held at IIT Kanpur. This involved a review of progress to date, and tasks for the coming months, with particular attention given to the acquisition of data. In addition a number of presentations were given highlighting some of the work done to date, including land classification and estimation of actual evapotranspiration from satellite data.

In the afternoon we had the opportunity to attend a meeting which involved a number of projects, all of which look at the changing water cycle in India. The Hydroflux India project was also presented to delegates from Indian departmental and governmental bodies, including the Indian Ministry of Earth Science, along with a number of Indian Universities.

Photo 5: Hydroflux India team meeting

Kanpur to Allahabad

A cliff face exposed by the Ganga River was visited upstream of Kanpur at Bithur. Here the river has incised the sandy clay deposits on the southern bank exposing a section of approximately 20 metres, leaving an upland geomorphology very different from the northern bank. A large meander scar is present on the northern bank of the Ganga at this location. This is likely to have been created by a river system with much higher water and lower sediment budgets than the current braided river system. There is approximately 3 to 4 km of sediment sitting on the underlying bedrock at this point. Agricultural use of the sandy river islands was again evident at this point with extensive rows of crops planted. In many of these locations pumps were taking water directly from the water for irrigation.

Groundwater depth varies throughout the Gangetic plains. In this region it was understood that two aquifers are present: a shallow aquifer of less the 200 metres below ground level, and a deeper aquifer, approximately 400 metres below ground level. In addition, shallower, perched groundwater is available in many areas, much of which is abstracted by hand pump. Due to its proximity to the surface and the probable high transmissivity of the superficial deposits, the perched groundwater and, to some extent, the shallow aquifer, is prone to contamination. To overcome this problem deeper boreholes have been drilled in some places to tap into the lower aquifer. In fact, IIT Kanpur receives much of its water from a borehole over 400 metres below ground level. Due to the financial constraints of drilling boreholes of this depth the practice is not a widespread practice in agriculture. Due to its depth the water stored in this lower aquifer is considered to be effectively a finite resource.

Photo 6: Agriculture on sandy river island (photo by W.Buytaert)

Kanpur barrage is located just upstream of Kanpur. It represents part of Kanpur’s flood defences and also diverts water to a water treatment plant which at present is only partly operational. This is important to replace groundwater abstraction which is currently the primary source of drinking water in Kanpur. This region experiences much lower annual rainfall than more western parts of Uttar Pradesh, reflected by different agricultural practices revealing that water scarcity is a major issue.

The Yamunariver, a major tributary to the Ganga, flows south of Kanpur and joins the Ganga at Allahabad. At Kalpi, south west of Kanpur, the Yamuna exhibits similar characteristics to the Ganga River. Here a bend in the river and a slight topographical tilt has lead to the creation of an incision in the southern bank witha much shallower slope evident on the northern bank, similar to that at Bithur.

Allahabad to Patna

Allahabad is of great significance to Hindus and hosts the KumbhMela, a major religious gathering, every 12 years. Preparations were well under way in the city for MahaKumbhMela, due to begin in January 2013. We arrived at the confluence of the Yamuna and the Ganga. At this point the Yamuna is considerably wider than the Ganga, and a clear distinction can be made between the more sediment laden Ganga and the clearer, faster flowing Yamuna. Up to 100 million people are expected to come to Allahabad for the KumbhMela over the course of the seven mainbathing days.

Varanasi is located approximately 245 km downstream of Allahabad. By this point the Ganga has widened considerably and has a higher water budget. Including the flood plain, the river here is approximately 1.5 km wide. The basin valley margin however is relatively narrow at Varanasi, measuring approximately 1.8 km, reduced from 14.2km downstream of Allahabad. The river is relatively sinuous along this stretch, moving from side to side frequently within the valley.

Patna

Following the final group meeting in Patna we were taken to the Mahatma Gandhi Setu, a bridge traversing a 5 km stretch of the Ganga River. While visibility was poor due to fog, a common occurrence in Patna at this time of the year, it was easy to make out a number of longitudinal bars in the river. Water levels appeared quite low, and many of the boatmen on the river were using poles to test the depth in front of their vessels.

The Kosi is another important tributary to the Ganga, flowing in a south easterly direction from Nepal and entering the Ganga at Patna. This river is susceptible to flooding, dropping from a higher elevation with greater velocity than the Ganga. During periods of heavy rainfall this can result in back flooding up the KosiRiver. As a result embankments have been constructed along the river upstream as far as Nepal.

Whilst flooding is common along this stretch of the basin, the main concern to land users are the problems caused by persistent water logging and salinisation. This occurs following the evaporation of floodwater and soil moisture brought to the surface by capillary action, both of which contain dissolved salts, and prevents the land from being used for agricultural purposes.

Photo 7: Hydroflux India team

Acknowledgements

On behalf of all participants we would like to extend our gratitude to Professor Rajiv Sinha for organising the field trip. His willingness to share his expert knowledge and broad experience of working on the Ganga basin significantly contributed to the success of the visit.

We would also like to thank IIT Roorkee, IIT Kanpur and IISc Bangalore for hosting, at various times, the participants of the field trip.