Prediction of agricultural water deficiency and its management using long-term rainfall trends

The present study is focused on the rainfall trend analysis of Punjab state in India. In this regard, thirty-three rain gauge stations were considered. The rainfall trend was predicted using the innovative trend analysis and compared with the Mann–Kendall test and Sen Slope estimator. The analysis reveals that most of the semi-urban areas of the Punjab state are experiencing a declining trend of rainfall, whereas urban and rural areas are experiencing an increasing annual rainfall trend at 5% level of significance in the last two decades of the twentieth century. The effect of declining trend of rainfall on frequency of occurrence drought was analysed using standardised precipitation index (SPI) and observed that the frequency of occurrence of drought is more in last two decades in the semi-urban areas of Punjab state. The effect of negative rainfall trend and drought condition is causing a significant rise in rain water deficit for agriculture and is expected to lie in a range of 30–48% of current water demand in next 15 years for Patiala district. The deficit rainwater will cause more extraction of groundwater for agriculture and the stress on groundwater may lead to food security issue. The stress on groundwater can be relieved by identifying the potential rainwater harvesting zone and it is observed that around 60% area of the Patiala district have good potential for rainwater harvesting. The spatio-temporal variation of rainfall trend, and drought analysis of the present study is expected to help in better planning and efficient management of agricultural practices.