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Subsurface soil moisture movement in the unsaturated zone plays a critical role in the replenishment of groundwater table. This comprehension can be vital for the terrain with lateritic soil followed by the charnockite bedrock system. The conventional techniques to determine the subsurface soil moisture and its movement is cumbersome owing to high cost, large scale time consumption, field drudgery and greater possibility of manual errors. Among many other modern technologies for the measurement of volumetric water content, capacitance-based moisture sensors are capable and less expensive, thus, making them highly suitable for the research scholars worldwide. The study involves the use of TEROS 12 moisture sensors. The capacitance-based sensor TEROS 12, equipped with advanced soil moisture technique curtails the constraints in the conventional technique of soil moisture assessment and can provide precise measurements if suitably calibrated for the site specific soils. The study involves a soil specific calibration of TEROS 12 moisture sensor which was performed for the laterite soil to incorporate the sensor with the automated soil moisture monitoring system. The reliability of the sensor TEROS 12 was assessed by comparing its moisture measurements with that of the gravimetric method. The calibration was performed for three TEROS 12 moisture sensors in order to monitor the interflow at three varying soil depths in the vadose zone. The R2 values obtained from the calibration of sensors at depths of 0-0.4 m, and 0.8-1.2 m were 0.996, 0.994 and 0.992 respectively. Further, during validation it was found that the new measurements coordinated with the gravimetric measurements to a greater extent and increased the preciseness as compared to that of uncalibrated values of moisture contents, thereby establishing TEROS 12 capacitance-based sensor as a reliable and cost effective moisture sensor.

Morphometric analysis with the help of remote sensing and GIS is now widely used to prioritise micro watersheds for planning interventions for soil and water conservation. DEM is the main digital data used to perform the morphometric analysis. There are different types of DEMs available to perform morphometric analysis using GIS techniques. But, no authentic information is available on the degree of accuracy levels of these DEMs to quantitatively determine various morphometric parameters for the watersheds in Kerala, with typical undulating and sloping terrain features. Hence, this research has been initiated to evaluate the quality of three popular DEMs viz. SRTM(Shuttle Radar Topography Mission), CARTOSAT(Cartography and satellite) and ASTER(Advanced spaceborne thermal emission and reflection Radiometer), each with 30 m spatial resolution. Two small sub watershed of Bharathapuzha river basin have been chosen for the study which are lying near to Valanchery town in Malappuram district. More than 21 morphometric parameters including drainage network, basin geometry, basin texture and basin relief characteristics were computed using these three types of DEMs and the outputs compared with google earth map. The results shows that the SRTM 30m DEM is characterized by higher accuracy compared to CARTOSAT and ASTER and has got better matching with google earth map data sources.

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:Water availability is declining and the demand is increasing, leaving the gap between these two more wide day by day. Quantifying the elements of hydrologic processes at micro watershed scale and at weekly or monthly temporal scale is the prerequisite for water resources development of a locality. Hydrologic modeling is a very powerful technique in planning water resources of a locality. Valancheri watershed, which is a sub basin of Bharathapuzha river basin, Kerala is taken for the study. As the study watershed is ungauged one, calibration was done for Kunthipuzha basin which is having similar characteristics with the study area and the calibrated parameters were transferred to the study watershed (Regionalization technique).