Cartographer calculates River Condition outputs by correlating groups of 5 MoRPh surveys (collectively referred to as a MoRPh5) with a single River Type survey. The correlation is based on five fields from the survey forms:
- Project code
- River name
- Reach name
- Subreach name
- Module number
This page describes how these fields are used and provides some best practices for completing them in complex situations.
How MoRPh5s are Calculated
When you enter five MoRPh surveys in close proximity to one another, Cartographer automatically generates a marker on the MoRPh5 map. It uses the following rules to work out whether surveys should be grouped together:
- the surveys must be recorded within 2 weeks of one another;
- the surveys must be recorded within 5km of one another;
- the surveys must either have module numbers 1 to 5 or module numbers 6 to 10;
- the surveys must have the same river name, reach name, subreach name, and project code fields.
How River Condition is Calculated
When you enter five MoRPh surveys and a matching River Type survey, Cartographer automatically generates a marker on the River Condition map containing outputs for Biodiversity Metric 2.0. It uses data from the MoRPh5 map, which is correlated with data from the River Type map using the following rules:
- the MoRPh5 and River Type surveys must refer to locations within 50km of each other;
- the surveys must have the same project code fields.
Rule 1 casts a wide net that compares surveys in the right general area. Rule 2 prevents accidental correlation between different river reaches and projects.
How to Code Surveys for Complex Projects
The rules above work well for simple cases where you have a single river reach for your River Type survey, which contains one or more MoRPh5 surveys. For more complex cases, such as where a large project includes several rivers or several different reaches of the same river, it is critical to use a different project code on the MoRPh and River Type survey forms for each individual river or reach. In this way, sub-groups of MoRPh surveys can be uniquely linked to particular rivers or reaches.