Model Library

Capabilities

• User-friendly interface;
• It accounts for diurnal fluctuations in temperature and dissolved oxygen (Mohamad Noor et al., 2024);
• It is effective in assessing and managing river water quality, especially in regions with limited data availability (Al-Dalimy and Al-Zubaidi, 2023);
• The model converts algal death to carbonaceous biochemical oxygen demand, making it suitable for systems with significant macrophyte interactions (Cope et al., 2020; Kannel et al., 2011).

Limitations

• QUAL2K is limited in 1D steady state condition (Nakhaei and Shahidi, 2010);
• Performing simulations in a non-permanent way and the impossibility to change the internal structure of the model, i.e., insert equations that better represent the reality (Gonçalves, 2009; Bottino et al., 2010);
• Zooplankton and bacteria compartment are not considered (Srinivas and Singh, 2018);
• It can simulate the main stem of the river system but not its branches (Chapra and Pelletier, 2008; Darji et al., 2022);
• Highly sensitive to oxidation rate, depth coefficient and moderate to point sources flow, TN, CBOD, and nitrification rate (Kannel et al. 2007; Babamiri et al. 2021, Darji et al., 2022);
• It requires manual calibration (Mohamad Noor et al., 2024).

Inputs

Manning's roughness coefficient, Rating curve parameters for discharge estimation, Meteorological data, Flow and water quality at the headwater, Point source discharges and abstractions, River reach characteristics such as length, bed width, bank slopes, and bed slopes.

Outputs

The model simulates the transport and fate of various constituents, including temperature, biochemical oxygen demand, dissolved oxygen, phytoplankton, nitrogen, phosphorus, pH, alkalinity, inorganic suspended solids, pathogenic bacteria, and bottom algae.

References

Al-Dalimy, S. Z., & Al-Zubaidi, H. A. M. (2023). One-dimensional model predictions of carbonaceous biological oxygen demand and dissolved oxygen for Hilla River water quality, Iraq. Ecological Engineering & Environmental Technology, 24(7), 258–265. https://doi.org/10.12912/27197050/170100

Wan, L., Wang, X. H., & Peirson, W. (2022). Impacts of climate change and non-point-source pollution on water quality and algal blooms in the Shoalhaven River Estuary, NSW, Australia. Water, 14, 1914. https://doi.org/10.3390/w14121914

Objectives

The objective of the study were: 1) to use the QUAL2K model to simulate the levels of carbonaceous biological oxygen demand (CBOD) and dissolved oxygen (DO) in the Hilla River in Iraq; 2) to assess the water quality of the Hilla River and identify potential spill locations that may be impacting the water quality; 3) to evaluate the suitability of the Hilla River water for safe usage, such as drinking water.

The objective of the study were: (1) to preliminarily understand Shoalhaven River water quality by analyzing monitoring data and setting appropriate water quality indicators, including water temperature, dissolved oxygen (DO), total nitrogen (TN), and total phosphorus (TP) concentration and (2) to investigate the water quality and algal bloom responses to climate change and NPS pollution scenarios by setting future scenarios in QUAL2K.