Territory Stories

Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981



Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981

Other title

Alligator Rivers Region - Regional Surface Water Quality Monitoring, Volumes 1,2,3 (Plus draft)


Northern Territory. Department of Transport and Works. Water Division, Environmental Section


E-Publications; E-Books; PublicationNT; Report ; 49/1983




At head of title: Water Division, Dept. of Transport &​ Works, Northern Territory. "April 1983".




Water quality -- Northern Territory -- Alligator Rivers Region; Hydrology -- Northern Territory -- Alligator Rivers Region

Publisher name

Northern Territory Government

Place of publication



Report ; 49/1983


3 volumes. ; 30 cm

File type



Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government



Related links

https://hdl.handle.net/10070/672725 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_1.pdf]; https://hdl.handle.net/10070/672727 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_2.pdf]; https://hdl.handle.net/10070/672729 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_3.pdf]

Parent handle


Citation address


Related items

https://hdl.handle.net/10070/672729; https://hdl.handle.net/10070/672727

Page content

Technical Report WRD83049 Viewed at 14:07:10 on 29/07/2010 Page 26 of 440. Turbidity Suspended solids Filterable residue Dissolved oxygen 2 5. I This is a colour measurement depending primarily I on scatter of light by suspended particles. A high turbidity may cause a low transmittance of light which may in turn jeopardize life processes. I The turbidity depends upon suspended solids concentration as well as particle size, shape and colloidal factors, in fact the latter is very important. Some turbidity is caused naturally J during the dry season dry-up, some by rlli~off and other by animal activity. As suspended solids may settle quickly, and colloidal balances can I be destroyed on storage, the measurement should be carried out in situ. This is the weight of material which may be tra~sferred to a filter. Non-filterable residue is defined as that which may be transferred to a l.2~m glass fibre paper. It is independent of the size, shape and type of material and its determination is much more reproducable than turbidity. It is suceptable to similar effects to turbidity. This is an expression of the dissolved material in solution when a filtered sample is evaporated to dryness and the residue weighed. When a 1.2wm glass fibre paper is used for filtration the term is defined as filterable residue. It is a measure of the concentration of ionic material, and a relation will be evident between this and conductivity. Like conductivity it needs to be determined as soon as possible after collection. This is an important measurement in gauging the ability of the water body to support animal life. It changes diurnally and is affected by water temperature and many other factors. Much care must be taken in sampling, as near the surface water is saturated with oxygen. So to give consistent and comparable results samples must be taken at constant depth (below saturated layer) and at a similar time each day. The analysis should be done in situ, or the sample preserved on site. I I I I I I I I GENERAL PARAMETER ANALYSIS 1 I Calcium Magnesi U.'TI SodiU\1\ Potassium These cations are the major ions present in most systems, and their concentrations may be used as indicators of varying conditions. Calcium and magnesium presence may indicate an influx of groundwater, and their concentrations may indicate the type of rock from which the groundwater is derived. Sodium and potassium may be used for a similar purpose, but to a lesser extent. I I I I I

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