Drought is a natural phenomenon which is considered as an indicator of changing climatic conditions. The growth of crops is significantly affected by the lack of soil moisture caused by insufficient rainfall over a specific period. This study examines the occurrence of drought over seven districts in Kerala, India, by utilizing drought indices, namely the standardized precipitation index (SPI) and the agricultural standardized precipitation index (aSPI). The measured data pertaining to rainfall and computed data of crop yield of the seven districts have been gathered to analyze the teleconnections of crop yield. Modified standardized yield residual series (M-SYRS) of different crops are prepared by the proposed approach of empirical mode decomposition-based detrending. The correlation between aSPI and M-SYRS exhibits a higher magnitude compared to the correlation that SPI and M-SYRS, confirming the significance of aSPI in the analysis of agricultural yield. The wavelet coherence analysis yields the values of percentage of significant coherence (PoSC) and average wavelet coherence (AWC) for the time scales of 3, 6, and 12 months, with respect to the variables aSPI and crop yield. The crop with the greatest AWC value of 0.71 and PoSC value of 62 is banana, which holds a dominant position in the agricultural landscape of Kottayam district. It is further noted that the short to medium seasonal droughts have profound impact on the agricultural yield of the different districts.

干旱是一种自然现象，被认为是气候条件变化的指标。特定时期降雨不足导致土壤水分不足，对农作物的生长产生显着影响。本研究利用干旱指数，即标准化降水指数（SPI）和农业标准化降水指数（aSPI），调查了印度喀拉拉邦七个地区的干旱发生情况。收集七个地区的降雨实测数据和农作物产量计算数据，分析农作物产量的遥相关性。不同作物的修正标准化产量残差序列（M-SYRS）是通过所提出的基于经验模式分解的去趋势方法来准备的。与SPI和M-SYRS的相关性相比，aSPI和M-SYRS之间的相关性表现出更高的幅度，证实了aSPI在农业产量分析中的重要性。小波相干性分析得出 3、6 和 12 个月时间尺度的显着相干性百分比 (PoSC) 和平均小波相干性 (AWC) 相对于变量 aSPI 和作物产量的值。AWC值为0.71、PoSC值为62最大的作物是香蕉，在Kottayam地区的农业景观中占据主导地位。值得注意的是，中短期季节性干旱对不同地区的农业产量产生了深远影响。