Lateritization cycles and their relation to the formation and quality of kaolin deposits in south Kerala, India

Soman, K.; Slukin, A. D.

doi:10.1016/0009-2541(87)90132-x

Cited by 4 publications

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On a global scale, the sediment yield of the Kallada River is extremely low-up to one order of magnitude lower than that of other tropical rivers and also much lower than the sediment yield of nontropical rivers (Table 5). The major reason for this may lie in the Wrm nature and, consequently, reduced erodibility of the predominant laterite soils and the Precambrian basement rocks of Kerala (Soman and Slukin 1987). This reduced erodibility also aVects the dissolved silicate yield of the Kallada River, which is lower than that in other tropical rivers despite high runoV and high runoV temperature, both of which are favourable conditions for chemical weathering (Table 5; Gaillardet et al 1999;Jennerjahn et al 2006).…”

Section: Budgets Of Dissolved Nutrients and Suspended Mattermentioning

confidence: 92%

Effect of land use on the biogeochemistry of dissolved nutrients and suspended and sedimentary organic matter in the tropical Kallada River and Ashtamudi estuary, Kerala, India

et al. 2008

Self Cite

View full text Add to dashboard Cite

The eVect of land use on the biogeochemistry of small tropical rivers and their estuaries was studied using the Kallada River and Ashtamudi estuary located in the State of Kerala, India, as a model system. Water, suspended matter and sediments collected during the monsoon and intermonsoon periods in 2002 and 2003 were analyzed for dissolved nutrients (nitrate, nitrite, phosphate, silicate) and for phytoplankton abundance and composition, amino acid contents and stable carbon (C)) and nitrogen (N) isotope ratios. Seasonal and spatial variations of dissolved nutrients and suspended matter along the course of the river point to distinct diVerences in the C and N sources that are controlled by hydrology, geology and land use. Unusually low concentrations of dissolved silicate and suspended matter suggest low erosion rates of the Precambrian basement rocks and the Wrm lateritic soils in non-agricultural areas. Most dissolved nutrients and suspended particulate organic matter originated from fertilized agricultural soils. The biogeochemistry of sedimentary organic matter indicates that most of the Kallada River load is deposited in the upper Ashtamudi estuary, while the middle and lower parts have a stronger marine inXuence. The spatio-temporal variation of dissolved and particulate river Xuxes clearly indicates an eVect of land use and land cover on the biogeochemistry of the Kallada River. While the phosphate yield was high (6 £ 10 3 mol km ¡2 year ¡1 or 185 kg km ¡2 year ¡1 ), the N yield was relatively low (10 £ 10 3 mol km ¡2 year ¡1 or 141 kg km ¡2 year ¡1 ), which is unlike the situation in many other densely populated regions of tropical Asia.

show abstract

Section: Budgets Of Dissolved Nutrients and Suspended Mattermentioning

confidence: 92%