<ptfkit/dharumarajan2019.h>¶
#include <ptfkit/dharumarajan2019.h>
Dharumarajan et al. (2019) hydraulic PTFs for the Karnataka Plateau.
Source¶
Dharumarajan, S., Hegde, R., Lalitha, M., Kalaiselvi, B., & Singh, S. K. (2019). Pedotransfer functions for predicting soil hydraulic properties in semi-arid regions of Karnataka Plateau, India. Current Science, 116(7), 1237-1246. https://doi.org/10.18520/cs/v116/i7/1237-1246
DOI: 10.18520/cs/v116/i7/1237-1246
Scope¶
Territory: Karnataka Plateau, India
Dataset: Field capacity and permanent wilting point were modeled from 512 soil samples in the Northern Karnataka Plateau and 228 samples in the Southern Karnataka Plateau; infiltration was modeled from 100 Karnataka soil observations.
dharumarajan2019_water_retention_result¶
typedef struct {
double field_capacity;
double permanent_wilting_point;
} dharumarajan2019_water_retention_result;
| Field | Description |
|---|---|
field_capacity | Soil water content at -33 kPa matric potential. (%) |
permanent_wilting_point | Soil water content at -1500 kPa matric potential. (%) |
Functions¶
calc_ptf_dharumarajan2019_nkp¶
Estimate field capacity and wilting point for Northern Karnataka soils.
static inline dharumarajan2019_water_retention_result calc_ptf_dharumarajan2019_nkp(double clay, double sand, double cation_exchange_capacity);
Parameters¶
| Name | Direction | Description |
|---|---|---|
clay | in | Clay content. (%) |
sand | in | Sand content. (%) |
cation_exchange_capacity | in | Cation exchange capacity. (C mol p+/kg) |
Returns¶
A dharumarajan2019_water_retention_result value.
Note
The model was fitted to 512 soil-layer observations.
Note
Reported cross-validation RMSE values are 5.25% for FC and 3.71% for PWP.
Warning
The paper does not state whether its water-content percentages are gravimetric or volumetric.
Warning
The source gives inconsistent profile counts and district lists for the Northern dataset; see the scientific notes.
calc_ptf_dharumarajan2019_nkp_clay¶
Estimate Northern Karnataka field capacity and wilting point from clay.
static inline dharumarajan2019_water_retention_result calc_ptf_dharumarajan2019_nkp_clay(double clay);
Parameters¶
| Name | Direction | Description |
|---|---|---|
clay | in | Clay content. (%) |
Returns¶
A dharumarajan2019_water_retention_result value.
Note
The paper recommends this model when clay content is the only available predictor.
Note
Reported cross-validation RMSE values are 7.05% for FC and 4.74% for PWP.
Warning
The paper does not state whether its water-content percentages are gravimetric or volumetric.
Warning
The source gives inconsistent profile counts and district lists for the Northern dataset; see the scientific notes.
calc_ptf_dharumarajan2019_skp¶
Estimate field capacity and wilting point for Southern Karnataka soils.
static inline dharumarajan2019_water_retention_result calc_ptf_dharumarajan2019_skp(double clay, double sand, double cation_exchange_capacity);
Parameters¶
| Name | Direction | Description |
|---|---|---|
clay | in | Clay content. (%) |
sand | in | Sand content. (%) |
cation_exchange_capacity | in | Cation exchange capacity. (C mol p+/kg) |
Returns¶
A dharumarajan2019_water_retention_result value.
Note
The model was fitted to 228 soil samples from 43 profiles.
Note
Reported cross-validation RMSE values are 3.05% for FC and 2.17% for PWP.
Warning
The paper does not state whether its water-content percentages are gravimetric or volumetric.
calc_ptf_dharumarajan2019_skp_clay¶
Estimate Southern Karnataka field capacity and wilting point from clay.
static inline dharumarajan2019_water_retention_result calc_ptf_dharumarajan2019_skp_clay(double clay);
Parameters¶
| Name | Direction | Description |
|---|---|---|
clay | in | Clay content. (%) |
Returns¶
A dharumarajan2019_water_retention_result value.
Note
The paper recommends this model when clay content is the only available predictor.
Note
Reported cross-validation RMSE values are 5.39% for FC and 3.13% for PWP.
Warning
The paper does not state whether its water-content percentages are gravimetric or volumetric.
calc_ptf_dharumarajan2019_infiltration¶
Estimate infiltration rate for Karnataka soils from texture fractions.
static inline double calc_ptf_dharumarajan2019_infiltration(double sand, double silt, double clay);
Parameters¶
| Name | Direction | Description |
|---|---|---|
sand | in | Sand content in the Karnataka infiltration dataset. (%) |
silt | in | Silt content in the Karnataka infiltration dataset. (%) |
clay | in | Clay content in the Karnataka infiltration dataset. (%) |
Returns¶
Soil infiltration rate measured with a double-ring infiltrometer. (mm/h)
Note
The model was fitted to 100 Karnataka soil observations.
Note
The reported model R-squared is 41%, and the reported RMSE is 6.71%.
Warning
Predictor calibration ranges are not reported for the 100-observation dataset.