Micro-level delineation of agro meteorological zones in the Sivagangai district of Southern India using remote sensing and GIS techniques

摘要

Different zonations like agro climatological and agro-ecological zonations are already available for crop planning, but they have not included inventories like length of growing period, soil textures, biomass, etc which are needed for efficient usage for agriculture. The study used the integration of remote sensing and geographical information system based on a weighted overlay approach to demarcate the micro-level agro meteorological zones for agricultural planning of Sivaganga district, Tamil Nadu, India using spatial analysis tools in ArcGIS 10.5 software. Rainfall and satellite images were used to prepare five thematic layers such as land-use/land-cover, length of growing period (LGP), biomass, soil texture, and elevation and generated maps were converted into the raster format. Sivagangai had LGP classes of (L1 (9-13 weeks), and L2 (14-17) weeks, which had a period of two to four months. Biomass was categorized into four classes viz., poor, moderate, good and excellent based an NDVI values of 0.06 - 0.10, 0.10 - 0.20, 0.20 - 0.40 and ＞ 0.4, respectively. In district B4 category (excellent) covered larger area followed by B3 (good). Soil texture was broadly classified under four categories viz., S1, S2, S3 and S4, based on the likely performance of crop in respect of the group. Here the category S4 which had a loamy texture occupied most of the area indicating better suitability for cropping. Elevation was classified under three categories as E1 (＜500 m). E2 (501-1000 m) and E3 (＞1000 m). Sivagangai had E1category alone, owing to its proximity to east coast. The results revealed that the study area can be categorized into 16 agro-micro meteorological zones. This could be attained by efficient planning and utilization of available natural resources.