Spatio-Temporal Trend of Monthly and Annual Rainfall in Mahi Lower River Basin, Gujarat, India

Worldwide attention has increased on climatic variability, notably rainfall. As India is an agricultural developing country, thus it is crucial to evaluate how the monthly and annual rains are affected by the changing climate in order to determine what cropping practices would need to be modified. Based on annual and monthly rainfall data, this paper analyzes the rainfall trends in Gujarat, India's lower Mahi River Basin. Using data from the State Data Center from 1990 to 2020, the effect of a changing climate on rainfall has been evaluated. Sen's slope estimator (SS), the Mann–Kendall (MK) non-parametric statistical test, and linear regression analysis (LRA) have all been used to identify rainfall trends. IDW, or inverse distance weighting, has been used to spatially portray the trend. Both a monthly time period and an annual time period have been used to illustrate the spatial distribution of the rainfall trend. The month of August results in a strong increasing trend, according to Z-statistics and Sen's slope, while the month of June exhibits a negative trend across practically the whole research region. July, September, and October showed a non-significant increasing trend. The above analysis indicated that monsoon season tends to start late. The results will be helpful for cropping practices adapted to the study area.