SPATIO-TEMPORAL STUDY OF BRAHMAPUTRA RIVER ISLANDS (CHARS) FOR AGRICULTURE EXPANSION IN ASSAM, INDIA

Abstract. The present paper aims to understand the spatio-temporal dynamics of the Brahmaputra river islands locally known as chars in Assam for agriculture crop expansion using long term multispectral satellite data and Google Earth Engine. This study also provides information on existing agriculture lands on these chars. For the study Landsat data is analysed to find the long term stable islands (1988–2018) and the present status of these islands for seasonal crop expansion. Validation of results was performed by using high-resolution satellite data. It is found that total area of vegetative chars has increased in past three decades and approximately 146 thousand hectares area of char is stable from past ten years. This study also reveals that the major crop cultivation is in Lower Brahmaputra Valley (LBV). In Upper Brahmaputra Valley (UBV), the crop cultivation is almost negligible compared to the large islands size. It can be inferred that less stable chars which are mostly located in upper Assam has negligible agriculture. It is also observed that at many places in lower Assam, double cropping system is followed. This study can be further extended by including factors like soil type, soil texture, rainfall, socio-economic etc. to study suitability for different crops. Proper facilities and incentives are to be provided to farmers of this region for better food security.