Statistical analysis of extreme weather events in the Diyala River basin, Iraq

Abstract

Extreme climate and weather events have direct impacts on human life, the environment, and resources. The Diyala River basin is shared between Iraq and Iran, which makes it vulnerable not only to climate change effects but also to upstream control. Therefore, understanding and predicting extreme events is an essential step to help decision-makers make proactive plans to reduce expected damages. The pattern of extreme events has been identified using climate extreme indices developed by the World Meteorological Organization and Expert Team on Climate Change Detection Indices using ClimPACT2 software. Data were obtained from three meteorological stations in Iraq (Sulaymania, Khanakin, and Baghdad) and one in Iran (Sanandaj) over a period of 20 years (2000–2020). Results for temperature showed seven statistically significant positive trends for only three indices (annual number of days with daily maximum temperature of >35°, difference between daily maximum and daily minimum temperatures, and percentage of days with maximum temperature of >90th percentile, indicating an increase in that temperature). Baghdad station had positive temperature trends for all indices. Trends for precipitation were nearly all nonsignificant and difficult to anticipate compared with those for temperature. Percentile-based indices showed more dry and warm events than wet and cold.

Extreme weather events and Spatio-temporal characterization of climate change variables in Bangladesh during 1975–2019

“…Until now, different statistical nonparametric models, such as Mann-Kendall (MK) test [ [4] , [5] , [6] ], Pettitt test [ 7 ], Spearman’s rho [ 8 ] and Sen’s slope estimator [ 9 ], have been applied to assess the changes in the trends of rainfall and temperature. Many studies [ [10] , [11] , [12] , [13] , [14] ], have been conducted to determine the trends of rainfall and temperature data for different parts of the world.…”

“…Additionally, several indices have been defined by the World Meteorological Organization (WMO) expert panel on climate change to create a consistent framework for climate change analysis at various spatial and temporal scales [ 29 ]. Studies [ [30] , [31] , [32] , [33] , [34] ] have been undertaken at different areas to understand the changes in climatic indices for the adaptation plan. These indicators are used as analytical instruments for describing the climatic system of a region [ 32 ].…”

Quantifying Diyala River basin rainfall-runoff models for normal and extreme weather events

“…The HEC-HMS model used by Hamdan et al (2021) to imitate the Al-Adhaim river basin's runoff discharge peaks. Naqi et al (2021) conducted statistical research for the Diyala River basin to determine trends in extreme temperature and precipitation indices, finding that temperature trends were more significant than precipitation trends, implying an increase in maximum temperature over minimum temperature.…”

“…Maximum, minimum, mean and standard deviation for precipitation (P) and temperature (T),Naqi et al (2021) …”

An investigation of spatially-temporal hydro-climatic data trends and patterns in the Iraqi Diyala River Basin

“…and hydrological (stream ow) datasets by parametric (linear regression) and non-parametric (MK, Pettit) methods in many regions [13,14,15,16,17,18,19,20,21,22,23,24,25]. Although many recent studies have conducted trend analysis tests of hydro-climatic variables in Iraq [26,27,28,29,30,31], However, they either considered parametric or nonparametric tests without considering the change point in the data. Accordingly, the main aim of this research is to examine the inconsistency and changing points in the hydro-climatic time-series using the sequential Mann-Kendall and Pettit tests, respectively.…”