Know your river
Your fieldwork question and sub-hypotheses from step 1. If you have not written the nulls yet, go back; you will want them before you touch the data.
- A locational map you have made, with all five conventions
- Two or three sentences describing where the study reach is
- A reason why this river suits this question
- A note of which sites sit in engineered or restored reaches
A map is not an illustration. It is one of the three things Criterion A (Fieldwork question and geographic context) is marked on.
The descriptor names it: one or more locational maps, following mapping conventions, giving clear information about the fieldwork location. A screenshot dropped in to break up the text scores in the middle band no matter how good your writing is.
The Asse rises on the flank of the Dôle massif at the foot of the Jura and runs about 13.5 km into Lake Geneva. Only the final 5 km lie inside the commune of Nyon, including the river's mouth. Our nine sites drop from 711 m at the top to 413 m at the bottom, across just under 9 km of channel.
That range is why the river suits the question. It is short enough to sample from close to the source down into the lower course in a single day, steep enough for the upper sites to look genuinely different from the lower ones, and accessible enough that a class with tape measures is not a safety problem.
It is also a river people keep rebuilding. Reaches were straightened and confined long ago, and that is visible in the channel today. Since about 2019 a combined flood-protection and renaturation scheme, Protection contre les crues et renaturation de l'Asse, has covered the roughly 4.5 km inside Nyon: studies first, with the first physical measures planned from about 2025 to 2026 and a further million francs in the commune's 2026 budget. So some of that reach has been reshaped, some has not been yet, and which is which depends on exactly where you are standing. A separate project reconnected the Calèves, a tributary diverted away from the Asse decades earlier when the A1 motorway was built; those works finished in 2019.
In May 2015 heavy rainfall flooded the Asse, and that event is why the project exists: it confirmed the need to improve flood protection while restoring the river's natural functions. The known trouble spots are the Asse plain near the Route de Saint-Cergue, the railway crossing, the lake outlet, and the Paléo festival site, which is to say, beside our sites 5 and 6. The engineers' hydraulic model was rebuilt on flow data from 2009 to 2021.
Among the ecological aims is free fish passage, letting species like trout move up and down the river again, by removing or bypassing barriers and improving the channel's ecomorphology. A barrier removed for a trout is also a barrier removed from your gradient and your bedload.
Find out, before you write a word of analysis, which of your sites sit in engineered, restored or untouched reaches, and check what has actually been built there rather than what is merely planned. Where a channel has been rebuilt, its width, depth and gradient are partly a human decision rather than a product of distance from the source, and that is the single most useful thing you can know when a site refuses to fit the trend.
Everything below is how we suggest you actually do it.
Five conventions, on every map you make
Mr Reid's mnemonic at Campus des Nations is BOLTS, and it is worth memorising because it applies to every map in the report, not just the locational one.
The map is a figure with an edge, not a picture bleeding into the page.
A north arrow.
Every symbol you have added, explained.
Figure number, and what the map shows.
A scale bar, which survives being resized. Not "1:25,000" alone.
The one that actually separates reports
Those five conventions get you out of the bottom band. What gets you into the top band is personalisation: the map has to carry your investigation on it. Your nine sites plotted and numbered. The source and the mouth marked. Your study reach picked out from the rest of the river. Distances or altitudes labelled.
The IB has said this in subject report after subject report, and it is one of the few places where they have been unusually direct about what they want.
Hand-drawn is not a fallback. Three of the four subject reports behind this advice mention hand-drawn maps favourably, because drawing one forces exactly the personalisation the descriptor asks for.
The same four things come back year after year in the reports on this criterion, whichever kind of map you use: it has to be big enough, clear, carry all the conventions, and be personalised, meaning it shows your study area and your sites rather than a general view of the region.
Hand-drawn maps are treated as fully equal to computer-generated ones, and the best-performing centres use either. A downloaded map or a satellite image is fine too, on exactly the same conditions: big, clear, conventions, and your own inputs added.
So the discriminator is not the tool you used. It is whether a reader can see what you did to the map.
Making the map
The Swiss federal mapping portal, map.geo.admin.ch, is the best basemap available for this river and it is free. It also carries the layers that let you say something about the catchment rather than just pointing at it: geology, land use, soils, inland waters, habitat and nature-protection maps, and a time series going back to 1864.
Use the Draw & Measure tool to add your sites, then Print to PDF and convert to an image. A second map showing one relevant layer, geology under the upper sites, land use along the lower reach, is often worth more than a bigger version of the first.
Right-clicking any point gives you its coordinates. Take them in WGS 84 decimal degrees (46.409795, not 46° 24' 35.26" N): that is the format the mapping tools in step 5 need, and collecting them in the wrong format is an annoying hour you can avoid now.
Whatever basemap you build on, acknowledge it under the figure, the source, and the date you took it. It is a formal requirement for every secondary source in the report, it takes six words, and those words sit outside your word count as part of the caption furniture.
There are drone photospheres of the fieldwork sites, taken at 80 m. They are the fastest way to see what the channel and its surroundings actually look like at a site, useful when you are writing about a reading you took months earlier and cannot remember the place.
They are also a legitimate source for an annotated figure, as long as you say where the image came from.
What "geographic context" means in 150 words
Not a history of Nyon. The context that earns marks is the context that bears on your question: where the reach is, how long the river is, how much altitude it loses, what the catchment is made of, and what people have done to the channel.
Three or four sentences, each carrying a fact a reader could check. Settlement, approximate distance from source, height above sea level, and what has been done to the river.
"The River Asse is a beautiful river located in the canton of Vaud in Switzerland, near the historic town of Nyon which sits on the shores of Lake Geneva and has a population of around 21,000."
Nothing here changes a single measurement you took.
"The Asse falls from 711 m to 413 m over the 8.9 km sampled, a mean gradient of 3.3%. The lower 4.5 km inside Nyon has been under a flood-protection and renaturation scheme since 2019, so sites 8 and 9 sit in the reach the scheme covers."
Every clause is doing work you will cash in during step 6.
The locational map is one of the few visible places where a shared investigation can look copied. If ten reports contain the same screenshot with the same nine dots on it, that is what a moderator sees.
Make your own. Same basemap, same sites, your design: which layer you chose, what you labelled, what you left out.
It can explain a general idea you meet while reading, what renaturation is, why engineers straighten channels, what a catchment's geology has to do with its flow.
It cannot tell you about the Asse. It is a 13.5-kilometre river in a small commune, and a language model asked about it will produce fluent, confident, invented detail. Everything specific in your report has to come from the map, the site, or a source you can cite.
Ready for step 3?
0 of 9The map is the one thing on this page you cannot do later from memory. Everything else can be written the night before; a good map takes an evening of tinkering.
Step 3 is Criterion B (Method(s) of investigation): the eight variables, how each is measured, what goes wrong with each technique, and why the sampling strategy matters more than the equipment.
Anything marked “our river” is specific to the fieldwork we do together on the River Asse at Nyon: the sites, the equipment and the way we collect the data. Site coordinates and altitudes are from our own fieldwork records and the exact list can change from year to year, so check them against the sheet you are given on the day. Photographs are the author’s own, taken at the river.