Spatial Variability of Rainfall Trends in Sri Lanka from 1989 to 2019 as an Indication of Climate Change

Niranga Alahacoon,Mahesh Edirisinghe

doi:10.3390/ijgi10020084

Abstract

Analysis of long-term rainfall trends provides a wealth of information on effective crop planning and water resource management, and a better understanding of climate variability over time. This study reveals the spatial variability of rainfall trends in Sri Lanka from 1989 to 2019 as an indication of climate change. The exclusivity of the study is the use of rainfall data that provide spatial variability instead of the traditional location-based approach. Henceforth, daily rainfall data available at Climate Hazards Group InfraRed Precipitation corrected with stations (CHIRPS) data were used for this study. The geographic information system (GIS) is used to perform spatial data analysis on both vector and raster data. Sen’s slope estimator and the Mann–Kendall (M–K) test are used to investigate the trends in annual and seasonal rainfall throughout all districts and climatic zones of Sri Lanka. The most important thing reflected in this study is that there has been a significant increase in annual rainfall from 1989 to 2019 in all climatic zones (wet, dry, intermediate, and Semi-arid) of Sri Lanka. The maximum increase is recorded in the wet zone and the minimum increase is in the semi-arid zone. There could be an increased risk of floods in the southern and western provinces in the future, whereas areas in the eastern and southeastern districts may face severe droughts during the northeastern monsoon. It is advisable to introduce effective drought and flood management and preparedness measures to reduce the respective hazard risk levels.

Highlights

IntroductionThe global climate system has undergone unprecedented changes due to global warming since the 1950s, and continuous climate change will affect many countries, increasing the risk of flood and drought and other natural disasters, which will adversely affect the agricultural economy [1,2,3,4]
As described in the sections above, a cross validation process was performed on CHIRPS data as an additional task
The CHIRPS data were analyzed according to the steps stated above and mapped the spatial distribution of rainfall trends at the district and climatic zone levels

Summary

Introduction

The global climate system has undergone unprecedented changes due to global warming since the 1950s, and continuous climate change will affect many countries, increasing the risk of flood and drought and other natural disasters, which will adversely affect the agricultural economy [1,2,3,4]. Climate change studies have become an essential part of understanding and predicting climate change as it exacerbates the effects of natural disasters such as floods, droughts, heavy rainfall, and temperature [5]. A significant increase in rainfall has been observed in Brazil’s northern Amazon region, it has been shown to show a tendency to decrease rainfall as it extends to the southern regions [15].

Methods

Results

Discussion

Conclusion