NZFSS Lim Soc 2014

transcript

Robson-Whitlock

Water Resources Research, in press.

Water Resources Research

Galaxias paucispondylus

G. paucispondylus

G.paucispondylus

G. paucisponslyusG. paucispondylus

G. paucispondylus

MICROCYSTIS

MicrocystisMicrocystis

Microcystis

MicrocystisMicrocystis

Microcystis

MANAGED AQUIFER RECHARGE AS A CATCHMENT-SCALE MITAGATION TOOL FOR WATER QUALITY AND QUANTITY – HINDS/HEKEAO PLAINS, CANTERBURY

Bower R, 1 Sinclair B, 1 Durney, P2, Scott, L2, Ritson, J2

1 Golder Associates (NZ) Limited2 Environment Canterbury Regional Council

The Hinds/Hekeao Plains catchment is located in the Ashburton District on New Zealand’s Canterbury plains. The Hinds/Hekeao Plains subregional planning process established 26 community-recommended outcomes related to limit setting for water quality and quantity within the catchment. Groundwater plays a key role in the majority of these outcomes. Management of aquifers beneath the plains is therefore essential to achieving the quality and quantity objectives. Currently nitrate-N concentrations in groundwater beneath the plains are some of the highest in the country. Over-allocation of groundwater coupled with increased irrigation efficiencies, are leading to declining groundwater levels. These declines are in turn causing reduced baseflows and reliability inspring-fed waterbodies, which have cultural and groundwater-dependent ecological values (Bower, 2014). Through the development of a Solutions Package of mitigation measures, a Groundwater Replenishment Scheme (GRS) using the tools of MAR has been proposed. MIKE SHE modeling of a GRS applied to the catchment was undertaken during the early stages of a pilot test programme. The results show increased aquifer storage and subsequent increases in stream MALF and flow reliability, working toward a more sustainable yield (Figure 1).

Figure 1: Manage groundwater storage: baseline conditions versus Groundwater Replenishment Scheme (MAR).

Water quality modelling indicates that enhanced dilution, in targeted areas of high agriculture-related nitrogen leaching, could help improve groundwater quality (Error! Reference source not found.). Two design objectives for the GRS are to improve groundwater quality in areas of high nutrient leaching and to improve concentrations of nitrogen in the spring-fed waterbodies. This ‘targeted approach’ is equality relevant in meeting the quantity goals of ensuring that minimum environmental flows and reliability in spring-fed waterbodies are enhanced, without causing unwanted drainage

issues in the coastal areas. This paper presents the results of water quality and quantity modelling used to develop the GRS concept. It also summarizes the overall scheme structure including economics, consenting, revenue mechanisms and catchment scale assessment of infiltration site opportunities. This project seeks to develop ecologically, culturally and economically viable solutions to water management challenges that are common in New Zealand through the sustainable management of groundwater resources.

Figure 2 Conceptual catchment-scale groundwater replenishment scheme –targeting dilution aquifer contamination and increase groundwater levels to support minimum flows in spring-fed waterbodies.

Bower, R., 2014 Hinds/Hekeao Plains Technical Overview – Subregional Planning Development Process. Environmental Canterbury, In Press.

Golder, 2014 Hinds/Hekeao Plains Subregional Planning – Managed Aquifer Recharge (MAR) as a catchment-scale water management tool. Golder Report 1378110257, In Press.

PHORMIDIUM AUTUMNALE

Phormidium autumnale

P. autumnale

Phormidium autumnale

vs.vs.

Journal of Geophysical Research

Environment Canterbury Report No. R14/19

Tim Davie, Environment Canterbury, over 20 years’ experience: A well-established and respected Scientist and Environmental Leader, sharing his experiences and knowledge; integration of groundwater, hydrology, surface water and ecology. Expectations of an employer and how university differs from the employee working world.

Juliet Milne, Greater Wellington Regional Council, over 15 years’ experience. Freshwater scientists in regional councils work within the framework of the Resource Management Act (RMA) which underpins natural resource management in New Zealand. This presentation introduces the RMA and its hierarchy of important planning instruments and processes that span freshwater management at national, regional and local levels. These include National Environmental Standards, the National Policy Statement for Freshwater Management (and associated National Objectives Framework or NOF), regional policy statements, regional plans, and resource consents. Traditionally science input to resource management decision making was through council-led consultation-based processes. There is now an increasing shift towards more collaborative processes and early community engagement. This presents new challenges for freshwater scientists, particularly around the way we present and communicate science information.

Jeff Smith – Senior Scientist (Hydrology) at Waikato Regional Council, over 10 years’ experience. Overview of what hydrology is, what it involves, examples of different projects. Establishing water allocation and minimum flow limits – the importance of linking groundwater and surface water hydrology with ecological values.

Taryn Wilks, Pattle Delamore Partners Ltd, 8 years’ experience: How the consultancy world differs from governmental agencies, expectations and reality. Purpose of an AEE, preparation of an AEE, reading/review of an AEE. How to improve consent applications and delivery of AEE’s. A must see for all freshwater scientisits who want to improve thier skill set!

Natasha Petrove, Department of Conservation, 5 years experience. Tips and tools at your finger tips which make you a better scientist! Publically available information and increasing awareness of what is available for Environmental Practitioners. Tips and guidance for career progression and how to prepare for interviews.

International Review of Hydrobiology,

Freshwater Biology

Hydrobiologia,

Freshwater BiologyFisheries

aquatic science

Marineand Freshwater Research

Freshwater Biology,

Wairau Diversion

MBLMBL

et al.

AN INVESTIGATION INTO THE WATER QUALITY AND PERIPHYTON COMMUNITY OF A DAM FED RIVER IN SOUTH CANTERBURY

Graeme Clarke1, Adrian Meredith1

1Environment Canterbury

The Opuha dam was completed in 1998, and soon after completion a number of issues with the water quality of the water being discharged to the Opuha River were noted. The lake continued to discharge largely anoxic water until physical aeration of the lake began. Community disquiet around the state of the periphyton community downstream in the Opuha River and parent Opihi River, resulted in a study to look at the effectiveness of current resource consent conditions in preventing the discharge of reduction type compounds. A range of physico-chemical parameters were analysed along the Opuha River, predominantly during the summer months. In conjunction with NIWA, periphyton surveys were completed at the same sites.

The dam continues to discharge higher concentrations of iron and manganese particularly during periods of stratification. Concentrations are higher than inflowing tributaries or rivers in similar sized catchments, despite the dam meeting current resource consent conditions requiring management ofanoxia of the hypolimnion. Concentrations of dissolved inorganic nitrogen and dissolved reactive phosphorus in the dam discharge are low, which is expected from water sourced from a mesotrophic lake or reservoir. It is likely the low dissolved reactive phosphorus concentrations partly drive the structure of the periphyton community, with Didymomosphenia geminata dominating throughout the Opuha River. Iron concentrations sourced from Opuha may contribute to cyanobacterial growths in the Opuha River and nuisance growths in the lower Opihi River catchment.

This study indicates that our increased understanding of the nutrient requirements of different algal groups allows for greater consideration of the potential effects of on-river storage dams, and responsive resource consent conditions to avoid adverse environmental outcomes.

Paranephrops planifrons

Ameiurus nebulosus Anguilla dieffenbachii

A. australis

in-situin-situ

in-situ

Chiemarrichthys fosteri

Streams Version 2.02 System Theory and Design

multiple

surface area

A AA A

versus

Onchorhynchus mikyss

Escherichia coliE. coli

DISCARIA TOUMATOU

Discaria toumatou

Galaxias maculatus.

G.maculatus

G. maculatus

WAIRAU VALLEY INDICATORSKnowledge use in decision making(rubric)Connected community (rubric)Cultural Health IndexRiver recreation indexCatchment Earnings before Interest& Tax (EBIT)% employment in catchmentReliability of water supplyTerrestrial MitigationCommon Bully Habitat in Mill CreekNitrate concentration in Mill CreekE Coli in Mill CreekMean river flow at the Narrows

Galaxias maculatus and G. brevipinnis

G. maculatus G. fasciatus G. argenteus G. brevipinnis G. postvectis

G. maculatusG. argenteus

G. fasciatus G.postvectis

Tradescantia fluminensis Holcus lanatus

Xanthocnemis

Sigara

Xanthocnemis

Puffinus huttoni

http://www.gw.govt.nz/fpgisdemo

USE OF LIDAR ANALYSIS TO SUPPORT RIVER MANAGEMENT INTERVENTION FROM DECEMBER 2011 FLOOD IN THE AORERE RIVER

Giles Griffith1, Eric Verstappen1, Richard Lowe1 ,Tonkin & Taylor, Aurecon, Taylors Contracting Ltd 1Tasman District Council

In late December 2010 extremely heavy rainfall occurred in the north-western area of the Kahurangi National Park. This produced the largest ever recorded flood flow in the Aorere River, of 3560 cumecs (187 year ARI, Devils Boots gauging site some 13km from the rivermouth.Data recorded since March 1976). This area of Golden Bay receives in the order of 6,000mm of rain per year. The Aorere River has the largest flow of all rivers in Tasman district, with a Mean Annual Flood flow of 2050 cumecs. The river discharges into the Ruataniwha Inlet at Collingwood in the far west of Golden Bay. Like most of Tasman’s Rivers, the headwaters are located in steep mountainous conservation land rising to 2000m in elevation. The river is relatively short with a semi- braided behaviour and steep gradient in the upper floodplain, with generally a relatively short time to peak flow of several hours. The lower valley and floodplain has become increasingly developed in recent decades with high production dairy farming the dominant land use.The Dec 2010 flood caused significant floodplain flows as well as unprecedented bank and bed erosion in a number of locations. Central government funding was obtained to assist in repair works to re-establish main channel capacity and location and stabilise key riverbank sites where the river had threatened to cut itself a new channel over the floodplain. Despite the size of the flood event, there was relatively little damage to Collingwood or to public infrastructure like roads and bridges. Due to its remote location and relatively sparse population in the valley, the Aorere river has not attracted attention as a source of aggregate for commercial or other uses, has never been subject to riverbed monitoring via a network of river cross sections, or been subject to proposals for stopbank works or other flood mitigation schemes. These have been the preserve of its eastern neighbour, being the Takaka River and township. Subsequently little data is available on sediment input and transportation volumes, mean bed level trends and the like. The lower 12km is fully maintained by Council along with 5.75km of the Aorere’s major tributary, the Kaituna River which drains the eastern side of the Wakamarama Ranges bordering the valley along the west coast. For several years,Tasman District Council has had a regular programme of LIDAR capture for key areas of the district such as the townships, coastal margins, progressively including river valleys and floodplain areas. High resolution LIDAR capture of the coastal plain of NW Golden Bay had commenced in October 2010, fortuitously including several km of the lower Aorere river just before the flood event. The opportunity was taken to refly LiDAR for the lower reaches of the river in April 2011, to evaluate the usefulness of LIDAR as a tool to assess river morphological change and gravel balance. In a river reach some 1.4-2.4km upstream of the Aorere Bridge at Ferntown, locals observed that riverflow breakout was occurring at much lower flows compared to previously. Using off-the-shelf software, changes in above-water riverbed morphology was undertaken. Cross section “slices” of the river can be undertaken at any chosen location and the pre and post flood profiles plotted, enabling classic end-area calculations of bed volume change at a much higher resolution than normal cross section location would allow. However, as the beach location had remained relatively stable, above-water bed volume change could be calculated with a high degree of accuracy from the pre and post-flood LiDAR beach surfaces. This confirmed significant net bed deposition of some 14000 cubic metres had occurred as a result of the flood. LiDAR has its limitations with respect to assessing bed morphology and gravel volume change, in that it cannot determine bed change beneath water level. Nevertheless, if river beaches and bars are relatively stable in location, analysis of LiDAR data provides a significantly improved understanding of riverbed change above water level over the traditional end-area method of often widely spaced river cross sections, particularly if supplemented with additional on-site survey below water. While it is still early days, LIDAR data for river analysis further complements its established use for floodplain and stormwater modelling, and has been used to support river works already undertaken. It has become a very useful aid in consenting for future river management intervention to restore main channel capacity and developing river management programs to reduce continuing active erosion.

0255075

100125150175

5Storm

rainfallde

325616 Botanical Gardens: Observed 48 hour rainfall5 year 10 year 20 year 50 year 100 year Observed floods

Post earthquakesPre earthquakes

PHORMIDIUM

Phormidium

Phormidium.Phormidium

Phormidium

PHORMIDIUM

Phormidium

170%No

.ofsite

Change in Mean Annual Flood

201 sites, current / old

Galaxias maculatus

LAWA websiteTrends in Southland’s water quality: a comparison between national and Southland

monitoring sites for groundwater and rivers In pressState and trends in the National River Quality Network (1989-2005)

New Zealand River Environment Classification User Guide

Galaxias macronasus

E.coli

in situ

A guide to the development of on-site sanitation

Culex pervigilans Aedes notoscriptus

Oncorhynchus kisutch

Gobiomorphus hubbsi

Q t vs.Q

Journal of Hydrology

Hydrology and Earth System Sciences

Journal of Hydrology

Journal of Applied Mathematics. 2013

Hydrology and Earth System Sciences Discussions.

Monthly Weather Review

Presented at the ASAE International Meeting

Computer Networks,

Computer Communications,

Ecological Modelling,

Computers and Geosciences,

Journal of Environmental Modelling & Software,Journal of Environmental Modelling

& Software,Computer Networks,

Geochimica et Cosmochimica Acta

Journal of Geophysical Research

New Zealand Journal of Marine and FreshwaterResearch

Didymosphenia geminata)

Development of an RFID approach to monitoring bedload sediment transport and a field case study.

In:Tools in Fluvial Geomorphology.

PhormidiumDidymosphenia geminata

Phormidium

Spatial and temporal variability in Phormidium mats and associated anatoxin-a and homoanatoxin-a in two New Zealand rivers

Dam Design can Impede Adaptive Management of Environmental Flows: A Case Study from the Opuha Dam, New Zealand

Multiple Stressors in Agricultural Streams: A Mesocosm Study of Interactions among Raised Water Temperature, Sediment Addition and Nutrient Enrichment

versus

Analysis of temporal trends in New Zealand’s groundwater quality based on data from the National Groundwater Monitoring Programme

Directive 2006/EC of the European Parliament and of the Council of 12 December 2006 on the Protection of Groundwater against Pollution and Deterioration

E. coli

E. coli E. coli

Sci Total Environ,

Water, Air, and Soil Pollution,

Aquatic Ecology,

Water Res,

E. COLI

E. coli

E. coliE. coli

E. coli

Campylobacter

E. coli

Campylobacter

E. coli

Campylobacter

E. coli

Campylobacter

E. coli

Campylobacter

E. coli

Campylobacter

E. coli

Enterococci

Campylobacter

et al.E. coli

Campylobacter

Escherichia coli

“THERE IS NO SHORTAGE OF WATER IN THE DESERT”: MOVING TOWARDS INTEGRATED WATER MANAGEMENT IN THE LINDIS CATCHMENT

Dean Olsen1, Matt Dale1 & Matt Hickey 1Otago Regional Council, 70 Stafford Street, Private Bag 1954, Dunedin

Water in the Lindis catchment is heavily over-allocated as a result of historic “deemed permits” or mining rights, which entitle the holder to take water, often much more than is usually available, with no consideration for the environment. The result is that the lower Lindis River dries in most years, resulting in a lack of connectivity with the upper Clutha and Lake Dunstan.

With mining rights due to expire in 2021, water users will have to apply for permits to take water under the RMA process and will be subject to catchment minimum flows. The Otago Regional Council is currently working through the process to set a minimum flow for the Lindis catchment and the impending expiration of these water rights is seeing many water users move to more efficient irrigation methods and to consider alternative sources of irrigation water. Water quality monitoring shows improving trends for dissolved reactive phosphorus and E. coli, but increasing nitrate-nitrite nitrogen concentrations, consistent with the changes in irrigation method. The move to more efficient irrigation methods, along with water quality limits set under ORC’s Plan Change 6A are already changing land use in the Lindis catchment and will set the path for future management of the Lindis catchment.

et al.

(or to be updated into this abstract later).

E. coli

Water Research

E. coli

E.coli E. coli

Nomodelcolloids

E. coli Kaolinite Goethite

Relativ

econcen

tration(Cmax/Co)

Experiments in the presence and absence ofmodel colloids

Peak concentration

Low flow rateHigh flow rate

0.000.100.200.300.400.500.600.700.800.901.00

Nomodelcolloids

Relativ

emassrecovery

Relative mass recoveryLow flow rateHigh flow rate

Nomodelcolloids

Transportretardatio

nfactor

Retardation factor

012345678910

Nomodelcolloids

E. coli Kaolinite GoethiteRate

ofadsorptio

sorptio

Rate ratio

PARANEPHROPS PLANIFRONS

characteristic curve (h) saturated unsaturated hydraulic conductivity K( ) . K( )

K( ) (h)

K( ) K

soils; unsaturated hydraulic conductivity; pedotransfer functions.

MICROCYSTIS

Microcystis

E. coli

Evaluation of existing helicopter electromagnetic measurements for aquifer characterisation in the Otago Region, New Zealand

Shut down of pumping4 Oct 2009 14 Jan 2010Gr

Elevation(m

w.r.t.O

Datum)

WaterML 2.0: Part 1- Timeseries, OGC Implementation Standard 10-126r4

versus

Integrated Methods in Catchment Hydrology

kmm3/year

Proteobacteria FirmicutesAcidobacteria

Actinobacteria Cyanobacteria Planctomycetes Verrucomicrobia

Proteobacteria

PULSE EMISSION OF METHANE FROM A SMALL EUTROPHIC LAKE

Arianto B. Santoso1 and David P. Hamilton1

1School of Science, University of Waikato, Hamilton, New Zealand

Abstract Production of methane (CH4) in lakes is mostly from incomplete oxidation of organic material during its degradation phase. Due to variability in the pathway of degradation of organic matter (as CO2 or CH4) and the internal cycles of carbon (e.g. including sedimentation), as well as the emission pathway of CH4,estimates of CH4 production from lakes are very difficult. We investigated CH4 dynamics of a relatively small eutrophic lake (Lake Okaro, New Zealand) in order to better understand the source, oxidation andatmospheric release of CH4. Monthly observations were made of CH4 in the water column over one year period as well as peeper incubations over one month during the stratification and mixing periods.Maximum rates of CH4 released from the sediment into water column were 0.4 mmol m-2 d-1 and corresponded to rapid enrichment of CH4 in the hypolimnion in a period of stable stratification.Atmospheric flux (from water column to atmosphere) was estimated to be around 0.1 mmol m-2 d-1 during stratification but immediately at the onset of destratification there was a very high pulse of CH4 (2.5 to 6.0 mmol m-2 d-1). Based on mass balance estimates, about 2.3 x 104 mol of CH4 is accumulated in the hypolimnion from the start of stratification until autumn overturn. Of the total hypolimnetic CH4 storage only about 11% escapes to the atmosphere during overturn. This indicates that CH4 oxidation in the water column has an important role in regulating CH4 fluxes from the lake. To complicate this analysis, however, large releases of CH4 to the atmosphere are suspected to occur via ebullition, when large bubblessuddenly occur and cannot easily be sampled.

DAPHNIA

Daphnia

Daphnia D. ‘pulex’ D. galeataDaphnia carinata

D. ‘pulex’ D. carinataD. ‘pulex’

D. carinata

D. ‘pulex’ D. carinata

D. carinata D. ‘pulex’ D. carinata D. galeata Daphnia

Daphnia

D. carinata D. ‘pulex’Gymnodinium

aGymnodinium

D. carinata D. galeataGymnodinium Anabaena Gymnodinium

DaphniaGymnodinium a

Anabaena

Daphnia in situ Daphnia

Daphnia

Biological Invasions

Soil Research

Proceedings of the New Zealand Grassland Association

Water Resources Research,

the replacement of abstractedgroundwater by flows from surface water bodies

the reduction of groundwater flows to surface water bodies

Galaxias maculatus

concentration–discharge relationships

y= 0.3242ln(x) + 1.5987R² = 0.3665

0.1 1 10 100

Cumulative

Discharge (m3 s 1)

y= 0.0435ln(x) + 0.0949R² = 0.3071

0.1 1 10 100

CumulativeFreq

Discharge (m3 s 1)

y= 5.0816ln(x) + 43.6979R² = 0.7864

0.1 1 10 100

Cumulative

Silica(mgL

Discharge (m3 s 1)

Flowdeciles

y= 1.663ln(x) + 15.318R² = 0.5983

0.1 1 10 100

CumulativeFreq

Discharge (m3 s 1)

Hydrol. Earth System Sci. Disc. 11

J. Hydrol. 505

0 5000 10000 15000 20000 25000 30000

MCIscore

straightline distance from national park (m)

inside NP

outside NP

0 5000 10000 15000 20000 25000 30000

ersample

straightline distance from national park (m)

inside NP

outside NP

Aedes albopictus.Ae. albopictus, Ae. aegypti Culex quinquefasciatus

Ae. albopictus Cu.quinquefasciatus Ae. aegypti Ae. tongae

Water Quality in New Zealand: Land use and nutrient pollution.Outspoken: Dairy Farming

Freshwater reform 2013 and beyond.Third Report of the Land & Water Forum

National Water Policy

Landscape and Urban Planning

F PF P

F P F P

Advances in Water Resources 34

Natural resources research 18

WCFM Technical Report 2012-0013.

Unpublished Master of Water Resource Managementthesis. University of Canterbury.

Groundwater level calibration at Riwaka Hall

Neochanna apoda

THE UK RIVER RESTORATION CENTRE: WHAT WE DO, HOW ANDWHY

Ground Water

PHORMIDIUM

Phormidium

PhormidiumPhormidium

Phormidium

DAPHNIA

D. CARINATA

Daphnia, D. carinataDaphnia

D.carinata”. D.

D. carinataD. carinata D. thomsoni

Groundwater 44International

Association of Scientific Hydrology Commission of Subterranean Waters 52

E. coli

Hymenolaimus malacorhynchos

GALAXIAS MACULATUS

Galaxias maculatus

G. maculatusG. maculatus

“the purposeful recharge of water to aquifers for subsequent recovery or environmental benefit”

Managed aquifer recharge: An Introduction. Waterlines Report Series No. 13,

The State of Our Environment – Gisborne 2009 and 2010 – Fresh Water Resources

Groundwaters of New Zealand

Groundwater in the Poverty Bay Flats

Determination of Radon in Drinking Water by Liquid Scintillation Counting Method 913

Environmental Tracers In Subsurface Hydrology

PHORMIDIUM

Phormidium

Phormidium Phormidium

Phormidium

Sigara sp Microvelia macgregori Kokiria miharo, Xanthocnemis sp Oecetis sp Antiporus strigolus and

Actinella

European Journal of Phycology

Gobiomorphus cotidianus Eleotridae

GobiidaeEleotridae

Evolution

Galaxias argenteus

ENGELAND, K. & GOTTSCHALK, L. 2002. Bayesian estimation of parameters in a regional hydrologicalmodel. Hydrology and Earth System Sciences Discussions, 6, 883 898.

Galaxias maculatusDeleatidium .

Deleatidium

Oncorhynchus mykiss Gobiomorphus cotidianus

Paranephrops planifrons) Potamopyrgus antipodarum

Sphaerium novaezelandiae

UPDATE ON THE HYDROLOGICAL MODEL OF NEW ZEALAND – VERSION 2

Zammit, C.1, Singh, S.K. 1, McMillan, H.K. 1 Henderson, R.D. 1

1 National Institute of Water and Atmospheric Research, Christchurch

This presentation summarises NIWA’s current capability in hydrological modelling using the TopNet model to predict flows and other hydrological variables at National level. We describe our recent improvement, testing and applications of National TopNet for flow and water resource applications.

The National Hydrological model of New Zealand is a long-term hydrological modelling project whose goal is to make reliable estimates of all water fluxes and storages of New Zealand, and reliable estimates of potential changes in those water resources. This is an extremely ambitious scientific project, with many practical implications for water use and water planning.

Twelve years ago, the first version of this model was presented to the 2002 Society Symposium in Blenheim, and it has since been used for several updates of New Zealand’s national water accounts (SNZ 2011), which are developed at regional spatial scales, and annual timescales; and Water stock take of the regional water resources. The major limitations of that model from 10 years ago were (i) an ad hoc approach to estimation of model parameters which lead in some cases to poor simulations at sub-annual timescales (ii) a very limited sub-model for surface-groundwater exchange and groundwater flows and storages (iii) no sub-model for water use. In this presentation we address the first limitation. The second is the subject of current research in the MBIE Waterscape research programme (CO1X1006), and the third is being addressed by NIWA Cumulative Hydrological Simulator (CHES) tool.

The National hydrological model is uncalibrated, but uses information on land use, soils, geology and recession analysis to provide a priori parameter estimation based on the national dataset and physical catchment characteristics. Climate information is provided by the Virtual Climate Station network (VCSN), which provides daily climate information on a 0.05 degrees grid across New Zealand since 1972, associated with regional council climate information.

The presentation will focus on current work to test the model results against more than 900 flow records around New Zealand across several spatial and temporal scales, as well as other hydrological variables such as soil moisture or snow depth. National TopNet model results are made freely available to end users via NIWA TopDesk application (GUI based). TopDesk allows users to view modelled river flows for every river in a region, for the period 1972-2014, under current and potential climate change weather scenarios. National TopNet results are also used as baseline data for the Cumulative Hydrological Effects Simulator (CHES) that enables scenario analysis of the impact of on and off-line water storage, and irrigation schemes, on river flow rates

NZFSS Lim Soc 2014

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