geosciences Comment A Note on “Metal Distribution and Short-Time Variability in Recent Sediments from the Ganges River towards the Bay of Bengal (India)” by Bonnail et al. (2019) Mohammad Ayaz Alam Departamento de Geología, Facultad de Ingeniería, Universidad de Atacama, Avenida Copayapu 485, Copiapó, Región de Atacama 1531772, Chile; [email protected]; Tel.: +56-9-5739-1631 Received: 30 November 2019; Accepted: 3 February 2020; Published: 5 February 2020 Abstract: A careful reading of Bonnail et al. (2019)’s work points out some issues in the description of the Ganges River, e.g., describing it in a way that gives impression to the readers unfamiliar with the Indian rivers that it flows by the national capital New Delhi, after reading “it receives inputs from highly populated cities of India, including New Delhi and ::: ”. However, as a matter of fact, it is not the Ganges, but the Yamuna River, a tributary of the Ganges, that passes through the National Capital Region of Delhi. Moreover, authors identify the studied river as the Ganges, whereas it is one of the distributaries of the Ganges called Hooghly (anglicized version of its local name Hugli). They have referred to the seasonality of the studied river; however, the flow of the studied (Hooghly) river is controlled by a barrage on the Ganges River. Moreover, Hooghly River receives input from its own tributaries; viz., Mayurakshi and Damodar, flowing through highly mineralized and coaliferous areas of Jharkhand state of India. Bonnail et al. (2019) have attributed the contamination of the river sediments to anthropogenic activities alone, by not evaluating likely natural sources. A correction factor for the underestimated total organic carbon (TOC) content obtained using Walkley-Black method should have been applied before using TOC values for factor analysis to overcome the underestimation issue with this method. This work intends to serve as a compendium, rather than a critique, to otherwise commendable work by Bonnail et al. (2019). Keywords: Ganges; Hooghly; Hugli; river contamination; Total Organic Carbon; TOC 1. Introduction Bonnail et al. [1] have studied the distribution and short-time variability in the recent sediments near the mouth of the River Hooghly, a distributary of the Ganges River. However, the authors have described the former as the Ganges River itself. This could be misleading for the readers unfamiliar with the Indian rivers. This paper, as a compendium to Bonnail et al. (2019)’s work [1], intends to make its readers familiar with the Ganges River, through a brief description of its numerous tributaries and two major distributaries—Padma and Bhagirathi-Hooghly, the former being the main course of the Ganges River following its bifurcation after Farakka in the Indian state of West Bengal [2]. On the other hand, Bonnail et al. [1] describe the Ganges River as a seasonal river (incorrectly attributing it to Coleman [3]). They also mention that it receives inputs from highly populated cities of India, including New Delhi, which might mislead the readers about the river’s trajectory. This issue has been addressed in this paper through a detailed description of the Ganges River Basin (Figure1). Finally, an observation has been made about potentially underestimated total organic carbon (TOC) content, to let the readers correct the reported TOC values before using them for factor analysis. Geosciences 2020, 10, 61; doi:10.3390/geosciences10020061 www.mdpi.com/journal/geosciences Geosciences 2020, 10, 61 2 of 8 Geosciences 2020, 10, x FOR PEER REVIEW 2 of 8 2. Ganges River 2. Ganges River Although officially (by the Indian government institutions and agencies) as well as popularly Although officially (by the Indian government institutions and agencies) as well as popularly referred to as Ganga in Sanskrit, Hindi and other Indian languages (Figure1), internationally it is referred to as Ganga in Sanskrit, Hindi and other Indian languages (Figure 1), internationally it is known as the Ganges [2,4]. All the major tributaries and distributaries are shown in the map of the known as the Ganges [2,4]. All the major tributaries and distributaries are shown in the map of the Ganges Basin, together with its sub-basins as insets (Figure1). The Ganges River originates in the Ganges Basin, together with its sub-basins as insets (Figure 1). The Ganges River originates in the Lower Himalayas and drains almost one-fourth of the Indian Territory (see the inset map of India, Lower Himalayas and drains almost one-fourth of the Indian Territory (see the inset map of India, Figure1) spread over the Indian states of Uttarakhand, Uttar Pradesh, Bihar, and West Bengal [ 2]. Figure 1) spread over the Indian states of Uttarakhand, Uttar Pradesh, Bihar, and West Bengal [2]. Moreover, some of its tributaries drain the other five Indian states of Haryana, Rajasthan, Madhya Moreover, some of its tributaries drain the other five Indian states of Haryana, Rajasthan, Madhya Pradesh, Jharkhand and Odisha (formerly known as Orissa) and National Capital Region that comprise Pradesh, Jharkhand and Odisha (formerly known as Orissa) and National Capital Region that the entire National Capital Territory (NCT) of Delhi and several districts surrounding it from the comprise the entire National Capital Territory (NCT) of Delhi and several districts surrounding it aforementioned states of Haryana, Uttar Pradesh and Rajasthan [2]. from the aforementioned states of Haryana, Uttar Pradesh and Rajasthan [2]. Figure 1. MajorMajor tributaries tributaries of of the the Ganges Ganges River River (Ganga) (Ganga) with with its basin its basin boundary, boundary, together together with with its sub its- sub-basinsbasins and andtheir their location location within within the the map map of ofIndia India as as inset inset (Note (Note:: This This m mapap is is drawn drawn b basedased on thethe oofficialfficial mapmap ofof thethe IrrigationIrrigation andand WaterWater ResourcesResources DepartmentDepartment ofof thethe UttarUttar PradeshPradesh GovernmentGovernment ofof IndiaIndia forfor illustrativeillustrative purposespurposes only).only). 2.1. Ganges and Hooghly (Hugli) After traversing a distance of about 3000 km and crossing the Indian states of Uttar Pradesh, Bihar, JharkhandJharkhand and and West West Bengal, Bengal, the Gangesthe Ganges Rivers Rivers bifurcates bifurcates into Padma into and Padma Bhagirathi and (namesakeBhagirathi of(namesa one ofke the of headwatersone of the headwaters of the Ganges of the in Ganges the Himalayas in the Himalayas described described in the next in the Section next S 2.2ection) rivers 2.2) shortlyrivers shortly after Farakka after Far (Figureakka (Figure2) in Murshidabad 2) in Murshidabad District District of West of Bengal West Bengal [ 4,5]. While [4,5]. While the Padma the Padma River flowsRiver flows SE through SE through Bangladesh, Bangladesh and, after and meetingafter meeting Jamuna Jamuna and Meghnaand Meghna rivers, rivers, empties empt itselfies itself into into the Baythe Bay of Bengal, of Bengal, the the other other distributary, distributary, i.e., i.e., Bhagirathi Bhagirathi River, River flows, flows within within the the Indian Indian statestate ofof West Bengal [[2]2].. After meandering for about 150 km km,, it is joined by a a tributary tributary Jalangi, Jalangi, near near Nabadwip Nabadwip [ [5]].. AfterAfter thetheconfluence confluence of of the the Bhagirathi Bhagirathi and and Jalangi, Jalangi, the the Bhagirathi Bhagirathi River River is known is known as the as Hooghly the Hooghly River, whichRiver, emptieswhich empties itself into itself the Bayinto of the Bengal Bay afterof Bengal passing after through passing Kolkata through and DiamondKolkata and Harbour Diamond [6,7]. TheHarbour complete [6,7]. stretchThe complete of Bhagirathi stretch and of Bhagirathi Hooghly together and Hooghly is known together as Bhagirathi-Hooghly is known as Bhagirathi River.- TheHooghly lower River. reach ofThe the lower Bhagirathi reach wasof the named Bhagirathi as Hooghly was named after the as busyHooghly port after town the of Hugli, busy port well-known town of inHugli, the 16th well and-known 17th in centuries the 16th by and the 17 Portugueseth centuries settlers by the livingPortuguese on its settlers banks [ 8living]. on its banks [8]. Moreover, water from the Ganges River is diverted by the Farakka Barrage through Farakka Feeder Canal near the town of Tildanga in Malda district of West Bengal to the Bhagirathi River, and Geosciences 2020, 10, 61 3 of 8 Moreover, water from the Ganges River is diverted by the Farakka Barrage through Farakka Feeder Geosciences 2020, 10, x FOR PEER REVIEW 3 of 8 Canal near the town of Tildanga in Malda district of West Bengal to the Bhagirathi River, and eventually toeventually the Hooghly to the River Hooghly [5]. According River [5]. to According a World Bank to a commissionedWorld Bank commissioned study [9], Farakka study Barrage[9], Farakka was constructedBarrage was by constructed the Government by the of IndiaGovernment between of 1961 India and between 1975 to ensure1961 and that 197 the5 Bhagirathi-Hooghly to ensure that the RiverBhagirathi would-Hooghly receive, River however would low rece theive, flow however of the low Ganges the flow River of maythe Ganges be, up toRiver 40,000 may cubic be, up feet to per second (cusecs, about 1130 m3) of water diverted from the Ganges and the remaining 10,000 to 40,000 cubic feet per second (cusecs, about 1130 m3) of water diverted from the Ganges and the 15,000 cusecs (about 280 to 425 m3) would be released to East Pakistan (now Bangladesh). For this, an remaining 10,000 to 15,000 cusecs (about 280 to 425 m3) would be released to East Pakistan (now 3 assumptionBangladesh) was. For made this, thatan assumption even in the was driest made season, that50,000 even in to the 55,000 driest cusecs season (about, 50,000 1410 to to 55,000 1560 mcusecs) of water would be available in the Ganges River at Farakka [9].