<ptfkit/tiwary2014.h>¶
#include <ptfkit/tiwary2014.h>
Tiwary et al. (2014), hydraulic PTFs for two major soil regions of India.
Source¶
Tiwary, P., Patil, N. G., Bhattacharyya, T., Chandran, P., Ray, S. K., Karthikeyan, K., ... & Thakre, S. (2014). Pedotransfer functions: a tool for estimating hydraulic properties of two major soil types of India. Current Science, 1431-1439.
Scope¶
Territory: Indo-Gangetic Plains and black soil region of India
Dataset: 209 layers from 30 Indo-Gangetic Plains profiles and 275 layers from 62 black-soil profiles; equation-specific subsets are described below.
tiwary2014_ptf_result¶
typedef struct {
double w_33;
double w_100;
double w_1500;
double k_sat;
} tiwary2014_ptf_result;
| Field | Description |
|---|---|
w_33 | Gravimetric water content at 33 kPa. (%) |
w_100 | Gravimetric water content at 100 kPa. (%) |
w_1500 | Gravimetric water content at 1500 kPa. (%) |
k_sat | Saturated hydraulic conductivity converted from mm/h. (m/s) |
Functions¶
calc_ptf_tiwary2014_igp¶
Estimate saturated conductivity for Indo-Gangetic Plains soils.
static inline double calc_ptf_tiwary2014_igp(double sand, double bulk_density, double esp);
Parameters¶
| Name | Direction | Description |
|---|---|---|
sand | in | Sand content. (%) |
bulk_density | in | Bulk density. (Mg/m^3) |
esp | in | Exchangeable sodium percentage. (%) |
Returns¶
Saturated hydraulic conductivity converted from mm/h. (m/s)
Note
Equation 11 was calibrated on 100 layers from 20 Indo-Gangetic Plains profiles.
Warning
The legacy API's three water-retention outputs are intentionally excluded because the source defines them only for BSR soils.
calc_ptf_tiwary2014_bsr¶
Estimate water retention and saturated conductivity for the black soil region.
static inline tiwary2014_ptf_result calc_ptf_tiwary2014_bsr(double clay, double ph, double cation_exchange_capacity, double esp, double emp, double excm);
Parameters¶
| Name | Direction | Description |
|---|---|---|
clay | in | Clay content. (%) |
ph | in | Soil pH. (dimensionless) |
cation_exchange_capacity | in | Cation exchange capacity. (cmol(c)/kg) |
esp | in | Exchangeable sodium percentage. (%) |
emp | in | Exchangeable magnesium percentage. (%) |
excm | in | Exchangeable calcium-to-magnesium ratio. (dimensionless) |
Returns¶
A tiwary2014_ptf_result value.
Note
Water-retention equations used 75 layers from 14 profiles; equation 10 used 200 layers from 46 profiles.