Impact of river channelization and riverfront development on fluvial habitat: evidence from Gomti River, a tributary of Ganges, India

Abstract

Riverfront development is one of the important pervasive modifiers of river morphology and processes affecting river corridors, floodplains and associated riparian zones. The Irrigation and Water Resources Department of Government of Uttar Pradesh, India's most populous state, undertook an ambitious project of riverfront development during April 2015 to March 2017 in the capital city of Lucknow on Gomti River, a meandering perennial tributary of Ganges which is fed by rainfall and groundwater. Under this project, straightening and shortening of the river channel was done by controlling its width, shape and riverbed through constructing a heavily reinforced diaphragm wall on both banks on an 8.1 km stretch. River floodplain width was restricted to 240 m out of 450 m and clear waterway to 100-125 m from existing 250 m to reclaim about 200 ha of land upstream and downstream of Gomti barrage in the city. This paper assesses the loss of river processes and ecosystems under changed hydraulic regimes post riverfront development project. We observed eight types of habitat in the undisturbed segments of the Gomti River, while only two major habitat types were present in the channelized segments. The paper argues that, due to heavy channel engineering led riverfront development and other related morphometric changes, there would be decline in freshwater species and water quality, lowering of groundwater tables in the city reach, resulting from diminishing base flow and flooding of the downstream areas. The river is fed by rainfall and groundwater, maintaining variable flow regimes with a very lean flow during the summer season. The reduction in flow, in the absence of water augmentation measures, will further impact the minimum environmental flows required to maintain the healthy ecosystems in the river broadening the area of ecological disturbances. This study can provide valuable insights for future projects on riverfront development and restoration measures in India and elsewhere.

Pollution mapping in the urban segment of a tropical river: is water quality index (WQI) enough for a nutrient-polluted river?

“…The last two sites (Lohia path, NH-27), in the downstream zone have moderate pollution levels because the river substantially recuperates in its progression. The sampling approach was such designed to understand the widespread pollution causes at important sites which characterize the river water quality by considering contributions from various pollution sources that influences the quality of water (Dutta et al 2018).…”

“…The current water quality index designates threatened quality of water in Gomti River attributable to recurrent release of waste effluents by numerous discharges poured down directly into the river by anthropogenic sources (Dutta et al 2018;Sharma and Kansal 2011). Gomti river has a fair index of water quality when it enters the Lucknow city nearby Ghaila, whilst as it advances within the city premises at sites like Pakka Pul, KGMC, Hanuman Setu, Birbal Sahani the index worsens to marginal (Table 5).…”

“…The decline in river water quality in Indian rivers results occasionally from natural processes (during flood pulses), but more profoundly due to anthropogenic activities like discharge of industrial effluents, domestic wastewater and municipal sewage, besides non-point agricultural drainage. Nonetheless, the industrial, domestic wastewater drainage as well as the agricultural run-off from the fields contributes to the enormous proportion of rivers' pollution (Dutta et al 2018). From a study by Akbarzadeh et al (2018), the untreated wastewater discharged from wastewater treatment plant (Seine Aval) of Paris municipality into lower Seine River, the dissolved oxygen level dropped significantly in the downstream at 100 km segment (Aissa-Grouz et al 2015).…”

Effective framework for Environmental-flows estimation for data deficient Indian rivers

“…Even today large sections of the rivers are getting modified due to damming, channelization and water diversion projects such as Mekong Basin Southeast Asia has more than 80 dams in process (Verma et al, 2009), Himalayas in India has over 300 (Grumbine and Pandit, 2013) and Andes has more than 150 (Finer and Jenkins, 2012) dams which are resulting in drought conditions in the lower basin areas of the rivers (Poff and Matthews, 2013). River Gomti had got channelized as a result it has lost its natural flow and biodiversity (Dutta et al, 2018). E-flows assessment method- ologies have been categorized into broad categories based their targeted areas, output requirements and resource and time requirements (Fig.…”

Dynamics of Vegetation Response to Seasonal Rainfall in the Gomati River Basin (India) using Earth Observation Data Sets

“…Mishra et al (2015) demarcated salt affected area using remote sensing techniques (using IRS LISS-III data) and it was found that the salt affected area is dominant along the right bank of the river. Dutta et al (2018) stated that the environmental flow in Gomati river ecosystem is not up to mark and suggested some measures to restore it back.…”