Statistical Model for Annual Trends and Magnitude of Climatic Variability across Locations from the Malwa Plateau Agroclimatic Zone of Madhya Pradesh, India

Abstract

Global climate change has affected the local weather patterns in different regions, especially in India. To manage the water resources effectively, it is important to quantify the local changes in the climatic variables. One of the key variables is precipitation, which is often used as an indicator of climate change. This study aims to examine the temporal variability of rainfall in the Malwa Agroclimatic Zone from 1991 to 2020 (30 years) and to assess its impact on the hydrological status of the districts in this zone. The Mann-Kendall and Sen's tests are used to detect the trend and magnitude of change in the annual precipitation time series. The autocorrelation effects are removed before applying the Mann-Kendall test. The results show that on an annual basis, Indore (Z 1.21 & Q 7.86), Mandsaur (Z 0.82 & Q 3.697), Neemuch (Z 1.03 & Q 3.488), Rajgarh (Z 0.93 & Q 0.5658), Ratalm (Z 0.64 & Q 3.525), Shajapur (Z = 0.57 & Q 3.164) and Ujjain (Z 0.11 & Q 0.692) have an increasing but not statistically significant trend in rainfall, while Dewas (Z -0.07 and Q -0.189) has a decreasing but not statistically significant trend in rainfall. The annual and monthly maximum temperature decreased in the Indore district, while the minimum temperature showed an increasing and decreasing trend. Dewas district also had a decreasing maximum temperature and an increasing minimum temperature. Ujjain district had a decreasing trend for maximum temperature and a significant annual increasing trend for minimum temperature. Shajapur district had a significant annual decreasing trend for maximum temperature and a significant annual and monthly (January and September) increasing trend for minimum temperature. Neemuch district had a significant annual increasing trend for both maximum and minimum temperature, as well as a significant monthly (January) increasing trend for minimum temperature. Ratlam district had a significant annual and monthly (January and September) increasing trend for minimum temperature. Mandsaur and Rajgarh districts had non-significant increasing trends for both maximum and minimum temperature, except for significant monthly (January and September) increasing trends.