Sediment-related water quality of small hill-country streams near Whatawhata,New Zealand. Response to integrated catchment management (ICM) |
| |
| Authors: | Rob Davies-Colley Andrew Hughes |
| |
| Institution: | 1. National Institute of Water and Atmospheric Research Ltd (NIWA), Hamilton, New Zealand davies-colley@niwa.co.nz rob.davies-colley@niwa.co.nz https://orcid.org/0000-0002-3431-998X;3. National Institute of Water and Atmospheric Research Ltd (NIWA), Hamilton, New Zealand https://orcid.org/0000-0001-8839-8524 |
| |
| Abstract: | ABSTRACT Degradation of aquatic ecosystems by fine sediment is a global environmental problem, and damages reflect particle properties as well as mass concentration. We studied sediment-related water quality (SRWQ) of small streams in hill-country near Whatawhata, NZ, that have been monitored since 1995. In 2001, an integrated catchment management (ICM) plan was implemented in the Mangaotama (originally sheep-beef) catchment – including conversion of steep headwaters to pine plantation, cattle exclusion, and native riparian plantings. The long-term SRWQ within the Mangaotama catchment was examined with reference to a nearby native-forested control catchment. Correlations between visual clarity, suspended particulate matter concentration and related variables were moderate to fairly strong. The ICM has not improved SRWQ as expected – plausibly because removal of cattle disturbance has been offset by decline in pasture ground cover under increasing shade of tree plantings. Worsening SRWQ is expected over the next several decades as channels widen towards a ‘forest’ morphology. |
| |
| Keywords: | Suspended particulate matter water quality small streams suspended sediment visual clarity turbidity cattle integrated catchment management (ICM) |
|
|
![ORCID Icon]({"type":"image","src":"/templates/jsp/images/orcid.png"} "ORCID Icon")
https://orcid.org/0000-0002-3431-998X;3. National Institute of Water and Atmospheric Research Ltd (NIWA), Hamilton, New Zealand