Premium
Soil carbon dioxide and weathering potentials in tropical karst terrain, peninsular Malaysia: A preliminary model
Author(s) -
Crowther J.
Publication year - 1984
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.3290090502
Subject(s) - weathering , karst , groundwater recharge , geology , soil water , hydrology (agriculture) , groundwater , aquifer , soil science , geochemistry , geotechnical engineering , paleontology
CO 2 concentrations at depths of 15,30, and 50 cm were determined over a one‐year period in six karst soils in the Malay peninsula. Evidence suggests that the highest single CO 2 value (MAXCO 2 , per cent) recorded at each site/depth provides the best estimate of conditions during groundwater recharge events. Soil depth (cm) and bulk density (BDEN) are the best predictors of MAXCO 2 , with the equation loglo(MAXCO 2 ) = 1·146 (BDEN) + 0·00698 (DEPTH) ‐ 1·227 accounting for 86 per cent of the variation. This equation is used to model MAXCO 2 at seven, more remote sites. Soil throughflow patterns and groundwater recharge points are estimated from slope pantometer and soil depth surveys in order to assess the CO 2 concentration with which soil waters ultimately equilibrate before entering the limestone. Limestone weathering seems to be predominantly of the open system type, the overall mean MAXCO 2 of 1·65 per cent corresponding with a weathering potential of 167 ppm CaCO 3 . Weathering potentials vary markedly, ranging from 62–82 ppm on rocky hilltops to more than 280 ppm on certain tower karst footslopes in Selangor and the Kinta Valley and on moderate hillslopes developed in impure limestones in the Boundary Range.