Hydrochemical Analysis and Forecasting of Lesser Zab River Discharge Using Innovative Trend Analysis and Mann–Kendall Method at Dukan Dam Site, NE of Iraq.

Volume 28 , Issue 1 , June 2026 , Pages 146-170

Authors

Sherko Mustafa 1 ; Diary Al-Manmi 2

1 Department of Earth Science and Petroleum, College of Science, University of Sulaimani

2 Department of Petroleum and Energy. Technical College of Engineering, Sulaimani Polytechnic University, Kurdistan Region, Iraq.

DOI logo 10.17656/sujpas.1164

Keywords

Abstract

Planning and managing water resources successfully requires an understanding of hydrochemistry and hydroclimatic element trends, especially inputs to dams. This study uses surface water sampling and Innovative Trend Analysis (ITA) and the Modified Mann-Kendall (MMK) test to analyze water quality and both inflow and outflow to examine streamflow patterns of the Lesser Zab River at Dukan Dam. To determine the size and importance of trends, monthly, seasonal, and yearly streamflow data from 2000–2001 to 2024–2025 were analyzed. All water samples are suitable for drinking and other purposes according to the WHO and Iraqi standards and the water type is Ca-HCO3. While January showed a non-significant growing trend, MMK data for inflow showed primarily non-significant falling trends with negative magnitudes over the majority of months, seasons, and the yearly scale. Similarly, neither the yearly nor the seasonal outflow study showed any noteworthy changes; while certain months and seasons showed non-significant declining trends, others showed non-significant rising trends. ITA data, however, revealed substantial declining patterns in inflow throughout all seasons and months except for January, including a highly significant yearly drop that impacted low, medium, and high flow categories. While certain months and seasons showed no discernible patterns and high-flow clusters remained unclear, outflow ITA data showed falling trends in low and medium flows throughout several months, seasons, and the yearly period. Climate change, rising water demand, and the Iranian Tropical Water Project , which significantly changed regional hydrological regimes and affected water availability, agriculture, and ecological balance in the Lesser Zab River basin. Decision making on the management of water resources is made easier by examining patterns and turning points in dam inflows.

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  • First online25 June 2026
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