Major ion chemistry and silicate weathering rate of a small Western Ghats river, Sharavati, southwestern India

Amrish, Vadakkeveedu Narayan and Arun, kumar and Nishitha, Dsouza and Balakrishna, K and Udayashankar, H N and Khare, Neloy (2022) Major ion chemistry and silicate weathering rate of a small Western Ghats river, Sharavati, southwestern India. Applied Geochemistry, 136. ISSN 0883-2927

[img] PDF
14405.pdf - Published Version
Restricted to Registered users only

Download (5MB) | Request a copy
Official URL: http://www.elsevier.com/locate/apgeochem

Abstract

Tropical, small mountainous rivers draining granite/granitic gneiss exhibit intense weathering rates and asso�ciated carbon dioxide sequestration, which has implications on the global CO2 budget. However, there is paucity of data from these catchments. This study aimed to understand silicate weathering rates (SWR) and CO2 sequestration rates (CCR) in a small tropical mountainous river, Sharavati in the southwestern India. Bi�carbonates, Cl− , Na+, Ca2+ and silica, are predominant in the river, indicating their source from catchment rocks and atmosphere. Groundwater shows a similar abundance of major ions, indicating identical sources. Intense chemical weathering due to hot and humid climate, heavy monsoonal rains and associated river discharge are the main controlling factors of major ion chemistry in the Sharavati river. The presence of clay mineral kaolinite in the catchment corroborates with the above controlling factors. The calculated silicate weathering rate (SWR) is 27 t km− 2 . y− 1 and associated carbon dioxide consumption rate (CCR) is 3.9 × 105 mol km− 2 . y− 1 . When compared to other small tropical river basins having similar climate and lithology, CCR of Sharavati is com�parable to Jiuhua Mountain rivers, (South China) and twice that of Sorocaba River (Brazil). CCR is 3.9 times higher than the global average on account of the peculiarity of the terrain. It can be concluded from a comparative study of small tropical rivers, that rainfall and runoff are the main parameters controlling the weathering rates irrespective of catchment lithology.

Item Type: Article
Uncontrolled Keywords: Major ion chemistry Tropical river Silicate weathering rate Carbon dioxide consumption Kaolinite Sharavati India
Subjects: Engineering > MIT Manipal > Civil Engineering
Depositing User: MIT Library
Date Deposited: 26 Mar 2022 08:47
Last Modified: 26 Mar 2022 08:47
URI: http://eprints.manipal.edu/id/eprint/158470

Actions (login required)

View Item View Item