Soil Suitability Evaluation Using Remotely Sensed Data and GIS: A Case Study from Kumaon Himalayas

Soil resource characterization of Kumaon hills of Himalayas was carried out through soil survey and established soil-physiography relationship after identification and delineation of six physiographic units in Khulgad watershed of Almora district, Uttarakhand. The satellite image characteristics identified through the visual/digital interpretation of IRS-1D LISS-III fused with PAN data on 1:12,500 scale were utilized in the present study. Based on the characteristics of soils developed on different physiographic units, the soils were evaluated for land capability classification and suitability for major crops in the region for sustainable development of the study area. GIS technique was used to develop decision trees employing various soil-site parameters for assessing crop suitability. The results revealed that deep to moderately deep soils with high clay content on the stable terraces and valley lands mostly appearing as dark blue to blackish blue in satellite imagery grouped under land capability classes II and III were interpreted as suitable for wheat, rice, finger millet and mustard crops. Moderately deep to deep soils occurring on moderately steep hill slopes and upper terraces were suitable for potato, mustard and finger millets. Soils on degraded hills with terraced tops having forest in patches (showed mix tone of grey and pink in imagery) categorized into class IV were found to be marginally suitable for wheat, mustard and potato with constraints of soil and topography, while soils on upper hill slopes, degraded hill tops/slopes with thin forest/grazing land and rocky ridges with dark to light blue, white and greyish mixed tone and dark blue with pale pink mixed tone in the imagery placed under land capability classes VI to VII were presently not suitable for crops cultivation and moderately suitable for grassland pasture or silvipasture purposes. The extent of suitability of soils for various crops has also been highlighted using GIS software and the maps were prepared. GIS is found to be helpful in processing spatial and non-spatial remote sensing data and conventional data of highly folded and faulted chain of Kumaon Himalayas to evaluate soil-site parameters for assessing crop suitability for optimum utilization of land.