Along one river, select a pair of reaches, one perennial, the other experiencing drying (flow cessation or complete disappearance of surface water). A reach is defined as 10Ă—the average width of the active channel. Ideally, the perennial reach should be upstream, but a downstream reach is also acceptable. If the whole river network is intermittent, select the closest perennial reach in another river.

The paired reaches should be morphologically as similar as possible in terms of substrate, channel width, topography as well as exposure to human impacts. Avoid sites where there are bars in the channel or other obstacles.

For participants who were involved in the previous coordinated 10000IRP experiment, try to focus on the same reaches so you already have many environmental variables estimated/measured.