Identification and Characterization of the Soils of Paschimi Nayyar River Watershed in Lesser- Himalayan Region of India

Abstract

Soils of Paschimi Nayyar river watershed in Pauri Garhwal district of Uttarakhand, India were identified and characterized using remote sensing and GIS techniques. They area falls in warm humid Himalayan ecosystem. On the basis of interpreted remote sensing image data and field checks four major physiographies viz., escarpments, hill/ridge tops, side/reposed slopes and valleys were identified which were further sub divided into 8 physiographic units based on image elements and slope functions. The physiographic land units map (PLU) was generated by integrating the physiographic units and land use. Based on inventory of soil resources (field study and characterisation) 8 types of soils (P1 to P8) were identified in different PLUs of the watershed. Soils of hill/ridge tops (P1 to P3) occur on steep to very steep slopes and are mostly shallow to very shallowin depth, gravelly loamy sand to gravelly sandy loam in texture and have A-C and A-AC-C horizons. They are classified as sandy skeletal and loamy skeletal Lithic Udorthents and rated as Class IV lands. Soils of side/reposed slopes (P4 to P6) occur on moderately steep to very steep slopes and are mainly extremely shallow to moderately shallow in depth, gravelly loamy sand, gravelly sandy loam and sandy loam in texture and have A, A-C, A-AC-C horizons with patches of A-B-C horizons in lower slopes. They are classified under sandy skeletal and loamy skeletal Lithic/Typic Udorthents and coarse loamy Typic Dystrudepts and rated as class IV lands. Soils of valleys (P7 and P8) occur on gentle to moderate slopes and are comparatively well developed. They are moderately deep to very deep in depth, sandy loam to loam and clay loam in texture and have A-B-C horizons, being classified as Typic Dystrudepts and Dystric Eutrudepts and rated under class II and III lands. The study revealed that the area suffers from various kinds of soil and land degradations and hence, appropriate soil and water conservation measures are to be undertaken to arrest further losses, maintain soil health and sustainable productivity.