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3.5
CHAPTER 4 3.5 – 3.6 streams (by Judy England, Environment Agency)

Sampling from intermittent rivers and ephemeral

Methods for sampling intermittent rivers
and ephemeral streams (also known as
temporary rivers) are still in development.

Three phases have been recognised in temporary rivers: One way to incorporate drying and temporary streams
flowing, ponded and dry. into monitoring programmes would be to take separate
samples for wet and dry areas. That would enable
Wet phases (flowing and ponded) are usually sampled current analytical methods such as RIVPACS to be
using the methods used for permanently flowing streams. applied, although that will need some development
The standard RIVPACS sampling only includes parts of because currently it only covers permanently flowing
the channel covered by water, despite being a pro rata streams. Dry phases can be sampled using methods
multi-habitat method in which all habitats are sampled in described in Section 3.4. The most commonly used
proportion to their cover. invertebrate groups for assessing the dry phase of
temporary and intermittent streams are beetles, ants
So, in temporary rivers and perennial streams during and spiders. There is no equivalent to RIVPACS for
drought, dry habitats are not sampled. That would make predicting the natural fauna of the dry phase or habitats
taking representative samples from drying perennial and therefore no way to assess the degree to which
streams and temporary rivers during the dry phase they might be damaged by anthropogenic pressures.
difficult to incorporate into existing monitoring networks Research is underway to address this gap.
for invertebrates. Alternative methods are needed for dry
areas and the dry phase. The most useful reference is Magland et al. (2020). (70)
See Figure 4.19.

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