Stage Discharge Rating Curves

The development of river stage vs. discharge curves is a key step in any hydrographer’s work.  The field measurements, the cross sectional survey data, the dynamic river conditions such as backwater, scour, fill, and weed growth among others, all have to be taken into account when calculating discharge. The accuracy of your computed discharge data is critically dependent on your rating curves.  AQUARIUS puts all the information you need at your finger tips so you can be confident in the rating curve that you build.

Shifting Rating Curves

The relationship between river stage and discharge is very seldom completely stable.  Rivers scour and fill, debris builds up on control features, and ice and plant growth can all dramatically affect a rating curve.  Calculating accurate river flows from a rating curve means adjusting the curve to account for these changes to a river's controls. Accounting for these changes has traditionally been a time consuming and arduous task often involving re-drawing an entire curve or tweaking with least squares fitting weights. The AQUARIUS Rating Development toolbox removes this drudgery and lets you once again focus on the hydrology.  Shift adjustments to a rating curve can easily and quickly be drawn in the dedicated rating shift diagram editor (the V-Diagram).  Rating shifts can be applied as constants or can be phased in through time to avoid jumps in the calculated hydrograph.

Follow the Standards

The science and art of drawing rating curves has been fine-tuned over the last 100+ years of dedicated work by the world’s leading hydrometric agencies.  International standards have been developed and published by both ISO, the World Meteorological Organization (WMO), and in USGS Technical References. AQUARIUS allows you to conform to these standards since AQUARIUS is the tool used by the very agencies who are the leaders in writing the international standards.

The Rating Curve Development toolbox that is included in the AQUARIUS Workstation is the tool used by the USGS (AQUARIUS GRSAT), Water Survey Canada, and a host of other leading organizations for development and maintenance of their stage vs. discharge curves.