Role of Relief and Slope in Agricultural Land Use: A Case Study in Valapattanam River Basin in Kannur District, Kerala Using GIS and Remote Sensing

The land is a delineable area of the earth's surface, encompassing all attributes of the biosphere immediately above or below this surface. Physical characteristics of the land determine agricultural land use. Among them, relief and slope play an important role. Aim of this study is to establish the relationship of relief and slope with agricultural land use in Valapattanam River basin in Kannur district using GIS and Remote sensing.

The Survey of India Topographic maps in 1:50000 scale was used as a base map for delineating the basin. Contours were digitized and Digital Elevation Model (DEM) was generated. Agricultural land use map was prepared using satellite digital data by the digital image processing method using ERDAS IMAGINE image processing software. Agricultural land use map was intersected with the relief and slope classes in ArcGIS software. Areas were calculated and the trend of agricultural land use patterns was studied. The study revealed that there is a strong correlation between Agricultural land use and relief and slope in the Valapattanam River basin.

Most of the area under paddy, coconut, mixed crops like banana and tapioca concentrated below 20 m height in the coastal plain and valley regions of the basin. Rubber mostly cultivated between 100 and 300 meters with slopes between 3 to 12 degrees. Agriculture is limited up to 18-degree slope and 300 m height. Areas of more than 300 m height are occupied mostly by forest.