Hydrographic study of Shatt Al-Arab estuary in the context of climate change

Abstract

This paper presents key results (at the first time) for the impacts of the North Atlantic Oscillation (NAO), the Indian Ocean Dipole Mode (DMI) and the Southern Pacific Ocean Oscillation (SOI) events on the hydrographic and climatic parameters at the mid of Shatt Al-Arab estuary (i.e. Basrah city centre) by using correlation analysis and standard ordinary linear regression as an autoregressive process of order 1. The analysis examined the discharge, salinity, sea surface water temperature and air temperature over the period 2005-2014 (i.e. interannual, monthly and seasonal datasets). The formal regressions have been estimated by using the first-degree autoregressive AR (1) model, which includes calculations of the GLS-Generalized Least Square Error Minimization regression method, for obtaining more stable solutions in the context of climate change. The correlation is accounted for using the standard ordinary bivariate linear regression method. The main results indicate that the hydrographic and climatic variables in the study the region experienced general trends of decrease in discharge of 2.0936 (m³/sec), increase in salinity of 0.0071 (‰), increase in air temperature of 0.0178 (⁰C) and an increase in sea surface temperature of 0.0098 (⁰C). Significant correlations, as well as prediction equations, were found between discharge and SOI, then, salinity and sea surface temperature with NAO, and finally between air temperature with NAO/DMI/SOI. The Pardé coefficients reflect the Karun influence during spring in the context of climate change. 

Keywords

• Shatt Al-Arab estuary; North Atlantic Oscillation; Dipole Mode; Southern Oscillation; Parametric methods

Supporting Institution

Marine Science Center, University of Basrah

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