Studies on crop growing period and NDVI in relation to water balance components

424-434The primary water balance components such as rainfall, water need, actual evapotranspiration, water deficit and water surplus, are studied for All Andhra Pradesh for the south-west monsoon months of 1999 to 2002 on daily basis. Crop growing periods for the selected stations over Andhra Pradesh (AP) are reported to understand the climatic potentialities of the region for crop and irrigation schedule under consideration. The investigation also addresses the spatiotemporal variability of the integrated normalized difference vegetation index (INDVI) in relation to the pattern of soil moisture adequacy. Using mean daily water deficit and water need, aridity index is obtained and studied to understand drought monitoring over Andhra Pradesh in relation to INDVI. The present study shows that the crop growing periods are high to the north of 15° latitude compared to south. The relation of the rainfall with NDVI is found to be weak when the rainfall is taken for the 10-day periods compared to soil moisture adequacy. But in the case of cumulative rainfall, the results revealed better positive correlation with NDVI