Spatial interpolation of soil‐water retention and saturated hydraulic conductivity for precise water management in a watershed: A case study of coastal region of Odisha, India

The coastal ecosystem in India plays an important part in the production of food grains, covering an expansive area of around 10.78 million hectares. However, this region faces significant challenges, as crop productivity in the coastal zones is largely attributed to the unfavourable climatic, soil and hydrological conditions. In this study, an ordinary kriging of the geostatistical method was used for spatial interpolation of soil‐water retention and saturated hydraulic conductivity across the surface soils of a watershed of the coastal region of Odisha, India, by using a suitable semivariogram and making the best prediction model fit. The findings revealed significant variability in the water content at field capacity (0.153‐0.431 m 3 m −3 ), permanent wilting point (0.614‐0.202 m 3 m −3 ) and saturated hydraulic conductivity (0.09 to 2.84 cm h −1 ) within the watershed. The spatial autocorrelation analysis further demonstrated that while water retention at the permanent wilting point (PWP) exhibited moderate spatial dependence (nugget/sill: 30.98%), saturated hydraulic conductivity showed a strong degree of spatial correlation (nugget/sill: 51.57%). By correlating these soil water properties with factors such as soil texture, bulk density and organic carbon, the geographic variations were identified, providing invaluable insights for improving soil water management and enhancing crop productivity in the coastal regions.