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  Weiti Stream sediment yield trends: Pre- versus post-forest harvesting.

NIWA is currently carrying out a study for Auckland Council and Waikato Regional Council collating and analysing data on suspended sediment yields across the Northland, Auckland and Waikato regions. The aim of this study is to develop a predictor model of catchment suspended sediment yields based on various catchment characteristics. As an additional task in this study Auckland Council has commissioned NIWA to assess the Weiti Stream suspended sediment dataset for evidence of a trend or change in sediment loads that can be related to forestry harvesting activities. The data support analysis that looks for temporal change in the ‘rating’ relationship between suspended sediment yield (SSY) and event peak discharge (Qpeak). We are interested in whether the rating relationship between SSY and Qpeak for the period prior to forestry harvesting (2008-2012) still adequately predicts SSY for the period during (2013) and following (2014) forestry harvesting. The data analysis is summarised in plots that show: The rating relationship between event suspended sediment yield (SSY) and event peak discharge (Qpeak) for the pre-harvesting period. The during- and post-harvest data are also included on the plot, but the rating is based on the pre-Harvest data only. The during- and post-harvest period data all plot above the rating trendline, but are within the bounds of the preharvest data. A further two plots show the relationships between the residuals derived from the previous plot and time over the pre-Harvest period and time over the full data period respectively. It is the gradient of the trendlines in these two plots that we test to see if each is statistically different from zero.
 
Citation proposal
. . https://dc.niwa.co.nz:/niwa_dc/srv/api/records/ac31b8db-95cc-3413-eff0-668a5963dc3a
 

Simple

Date ( Creation )
2015-06-11T06:19:00
Date ( Revision )
2015-06-11T06:19:00
Purpose
Predictive modelling of catchment suspended sediment yields after forest harvesting. 
Credit
Hoyle, J. (2015). Weiti Stream sediment yield trends: Pre- versus post-harvest. NIWA Report No: CHC2015-007. NIWA Project: ARC15501. p. 5. Funding was provided by the Prepared for Auckland and Waikato Regional Councils. 
Status
On going  

  Point of contact

NIWA  
Spatial representation type
Vector  
Topic category
  • Inland waters
Description
Auckland Region 
N
S
E
W


TimePeriod
2008-01-01T00:00:002012-12-31T00:00:00 
TimePeriod
2013-01-01T00:00:002013-12-31T00:00:00 
TimePeriod
2014-01-01T00:00:002014-12-31T00:00:00 
  • catchment suspended sediment yields, forest harvesting, predictive modelling, Weiti Stream
NIWA Project Codes
  • ARC15501
Use limitation
Data are owned by Auckland and Waikato Regional Councils. Contact Jo Hoyle (NIWA) using email details above, as first step. 
Use limitation
Data are owned by Auckland and Waikato Regional councils. Predictive modelling methodology owned by NIWA. Contact Jo Hoyle (NIWA) using email details above, as first step. 
Classification
Restricted  
Title
Hoyle, J. (2015). Weiti Stream sediment yield trends: Pre- versus post-harvest. Prepared for Auckland and Waikato Regional Councils. February 2015. NIWA Report No: CHC2015-007. NIWA Project: ARC15501. p. 5. 
Association Type
Larger work citation  
Language
English  
OnLine resource

Point of truth URL of this metadata record

OnLine resource

ARC15501

mdb:MD_Metadata

Metadata identifier
ac31b8db-95cc-3413-eff0-668a5963dc3a

Language
English  
Character encoding
UTF8  

  Custodian

NIWA National Institute of Water and Atmospheric Research  
301 Evans Bay Parade
Hataitai
Wellington
6021
New Zealand
 
Resource scope
Dataset  
Date info ( Creation )
2015-06-15T13:55:52
Title
ISO 19115-3 
 
 

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ac31b8db-95cc-3413-eff0-668a5963dc3a   Access to the portal Read here the full details and access to the data.

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