Table 4.4 (continued)
Case
study Predictors
Method
Reference
Alkalinity
Digital elevation model
Slope
Topographic wetness index
Hydrologic flux index
Topographic convergence index
Geological formation
3
Elevation
Logistic regression
Winkel
et al.
(2008)
Slope
Distance to rivers
Evapotranspiration
Precipitation
Runoff
Temperature
Irrigated areas
Topsoil clay content
Topsoil silt content
Topsoil sand content
Subsoil clay content
Subsoil silt content
Subsoil sand content
Subsoil cation exchange capacity
Soil drainage code
Coarse textured soils
Medium textured soils
Fine-textured soils
Subsoil nitrogen content
Subsoil organic carbon content
Subsoil pH
Pre-Holocene deposits
Organic-rich deposits
Other Holocene deposits
Tidal deposits
Deltaic deposits
Flood plain deposits
Alluvial deposits
4
Elevation
Regression analysis
Amini
et al.
(2008a)
Slope
Adaptive neuro-fuzzy
inferencing
Geology age
Evapotranspiration
Precipitation
(continued)
86
S. K. Singh et al.