Once Upon a River Map | Maps We Love

Why we love it

This map application is deceptively simple upon first glance, but rewards your curiosity with every mouse click. As you explore each river you find rich details and stunning patterns. Move your cursor over a river to see its network and a month-by-month chart of water flow for 2014. We also love this feature: Put your cursor at the center of the radial chart, and slowly pull downward to navigate a river from where it meets the ocean or international border.

Why it works

On this map, every pixel is data. It does not have unnecessary ornamentation, not even the traditional basemap, borders, and text labels. Now the data and its patterns take center stage. This interactive map shows us how river flow changes throughout the year, and how the timing of maximum flow changes based on geographic region. This same technique could be used to map rail, logistics, shipping, or telecommunications.

Important steps

Create network from data

Create a river network from the USGS National Hydrographic Dataset.

Learn more and download here
Ensure clarity for use

Adjust features to ensure connectivity, direction of flow, and generalization for use in small scale mapping.

View preview application
Attribute features

Attribute features with USGS flow data

Download USGS WaterWatch
Configure the source code

Download the source code for this application and configure it to the river network you created.

Data and software

You need a river network, represented as connected linear features, each with a direction of flow and volume of flow. Software used: ArcGIS Desktop, ArcGIS Spatial Analyst, ArcGIS Geostatistical Analyst, ArcGIS Network Analyst.
Analysis

Validate that all network segments are connected, and that direction of flow is correctly indicated. Volume of flow is joined to the features.
Time

It will take several days, depending on the size and complexity of the source data and experience with network datasets.

Pre-process the information for fast performance

The fast performance of the application is due to the connectivity information being pre-processed and made available in a JavaScript file.
Show the flow

The connectivity allows the application to show upstream and downstream flow statistics from any point on the map or graph.

Understand connectivity