Abstract
Precipitation is the most critical element of hydrological cycle that might influences the frequency of flood or drought. Therefore, for drought and flood forecasting, it is mandatory to know the precipitation pattern and its trend. The objective of the research is to estimate the monthly, seasonal, and annual precipitation trend employing statistical (Mann–Kendall (MK) test and Sen's Slope (SS) estimator) and graphical (Innovative Trend Analysis (ITA) method) for the Hanumangarh district of N-E Rajasthan. The mean monthly precipitation data were gathered from the India-WRIS for the period of 1901–2022 (122 years). Seasonal and annual precipitation trend variations were examined by the statistical method (MK test and SS estimator) and compared with graphical methods (ITA). The results of the study conclude that precipitation trends showed variability for the SW monsoon season from the graphical method to the statistical method. For the SW monsoon season, a decreasing trend was seen by using the statistical method, whereas the graphical method revealed an increasing trend. During the annual precipitation, an increasing trend was seen by using both statistical and graphical methods. It is found that the ITA method is more efficient in finding trend, because it does not assume any assumptions like that of the MK test.
HIGHLIGHTS
Trends in seasonal and annual precipitation time series are assessed using both statistical and graphical methods and then results are compared.
The results of the statistical method are well-matched with the graphical method.
ITA method is easier to apply for finding trends.
The ITA method is more accurate because it does not consider any assumptions.