Atmospheric analysis

Across the North Island, the past week once again featured little if any rainfall for most locations. Soil moisture levels in the lower South Island have improved markedly from last week.

A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.

Aucklanders should not expect any decent rain for more than 10 days, says NIWA principal scientist and forecaster Chris Brandolino.

The SHMAK method for rubbish involves collecting and identifying all the rubbish (litter) in the stream and on the stream banks.

The SHMAK visual habitat assessment gives your stream a score that you can use to assess changes over time or compare streams.

Two methods for describing streambed composition: the visual assessment method is quicker while the Wolman walk is more accurate.

Use an ice-cream tray to isolate and separate your invertebrates. The Benthic Macroinvertebrate Field Guide helps you with identification.

Before you look at what animals you have collected, follow these methods to clear away debris (stones, sand, leaves, twigs) from your sample in the net.

If your stream has a muddy-bottom or soft-bottom (made of silt or mud), you need to use a different method than if your stream has a stony-bottom.

Use a net & the kick-net method to collect a greater range of benthic macroinvertebrates and more accurately assess the diversity of the community.

If you don’t have a net, you can collect stones from the streambed and collect the invertebrates that are clinging to the stones.

Macrophytes are large aquatic plants. How to assess macrophyte cover with just a measuring tape and a willingness to get wet.