---
title: "Dissolved Oxygen Data Fields | Definitions"
slug: "dissolved-oxygen-data-fields"
description: "Learn about data input and the required datafile format for dissolved oxygen in the water quality solver."
tags: ["1D river modelling"]
updated: 2022-09-22T14:47:36Z
published: 2022-09-22T14:47:36Z
canonical: "help.floodmodeller.com/dissolved-oxygen-data-fields"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.floodmodeller.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Dissolved Oxygen Data Fields

## Data Input

In order to input the required information for this pollutant into the Water Quality model, the user needs to make sure that the Tab Dissolved Oxygen appears in the WQ General Tab (please follow the description on the page [Preparing a Water Quality Datafile](/v1/docs/preparing-a-water-quality-datafile) for this). Then the user needs to select the Tab Dissolved Oxygen and type in the necessary information for this pollutant in the fields which are shown on this Tab. Alternatively the necessary information for this pollutant can be typed in the .con file opened in a Textpad editor in the datafile format mentioned below.

## Datafile format

Line 1 DISSOLVED OXYGEN

Line 2 faircm, alpair, constc

Line 3 rkb20, alphab, sbrate

Line 4 rkn20, alphan, snrate

Line 5 rkam20, alpham, betam, salam, epsam1, epsam2, epsam3

Line 6 rkno20, alphn2

Where:

DISSOLVED OXYGEN = keyword

faircm = Reaeration parameters: reaeration coefficient (m/hour). if faircm is set negative then Owen's, O'Conner and Dobbin's and Churchill's equations are applied).

alpair = temperature dependency factor for reaeration

constc = additional reaeration coefficient used at all structures

rkb20 = BODdecay parameters: rate constant at 20C (day)

alphab = BODdecay parameters: temperature coefficient

sbrate = BODdecay parameters: speed of slow decay rate as fraction of fast decay rate.

rkn20 = Organic nitrogen decay parameters: rate constant at 20C (day)

alphan = Organic nitrogen decay parameters: temperature coefficient

snrate = Organic nitrogen decay parameters: speed of slow decay rate as fraction of fast decay rate

rkam20 = Ammonia oxidation parameters: rate constant at 20C (day)

alpham = Ammonia oxidation parameters temperature coefficient

betam = Ammonia oxidation parameters salinity coefficient

salam = Ammonia oxidation parameters base salinity (ppt)

epsam1= Ammonia oxidation parameters suspended solids coefficient

epsam2 = Ammonia oxidation parameters base suspended solids (mg/l)

epsam3 = Ammonia oxidation parameters multiplication factor for base suspended solids

rkno20 = Nitrite to nitrate oxidation parameters: rate constant at 20C (day)

alphn2 = Nitrite to nitrate oxidation parameters: temperature coefficient.

---

Overview [Dissolved Oxygen](/v1/docs/dissolved-oxygen)