Willem Pieter de Lange

Willem Pieter de Lange
The University of Waikato · Division of Health Engineering Computing and Science

DPhil

About

277
Publications
62,275
Reads
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1,723
Citations
Citations since 2017
28 Research Items
564 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Current projects include: • Monitoring and predicting the impacts of port and other developments within Tauranga Harbour • Assessing the rates of Holocene sedimentation within estuaries in the Bay of Plenty and Coromandel Peninsula, including anthropic sediment pulses • Effects of Earth tides • Identifying and characterising "hidden" faults in urban areas
Additional affiliations
November 1984 - May 2016
The University of Waikato
Position
  • Professor (Associate)
November 1984 - present
The University of Waikato
Position
  • Professor (Associate)
Education
July 1983 - May 1988
The University of Waikato
Field of study
  • Earth Science
March 1981 - December 1982
The University of Waikato
Field of study
  • Earth Science and Computer Science
March 1978 - December 1980
The University of Waikato
Field of study
  • Earth Science and Computer Science

Publications

Publications (277)
Article
Full-text available
The Makassar Strait region has had the highest frequency of historical tsunamievents for Indonesia. The strait has a seismic activity due to the convergenceof four tectonic plates that produces a complex mixture of structures. The maintsunamigenic features in the Makassar Strait are the Palu-Koro and Pasternostertransform fault zones, which form th...
Article
Full-text available
Toheroa (Paphies ventricosa) were formerly abundant on west and south-facing New Zealand surf beaches. Harvesting of this surf clam was intense during the early to mid-1900s, and populations declined to levels where harvesting was no longer viable. Despite having now been protected for 35–45 years, toheroa have failed to recover. This paper reviews...
Article
Full-text available
Based on the analysis of 14 short sediment cores, we present new insights into the distribution of surficial sediments in the central Hauraki Gulf, a semi-enclosed coastal embayment on the northeast coast of New Zealand’s North Island. We identify and discuss the effects of interaction of modern wind-generated waves and currents with regard to depo...
Article
Full-text available
Rainfall is one of the most important triggers of slope failure. Weathered pyroclastic (tephra) deposits are especially vulnerable to slope failure because they commonly form slopes of high porosity and high clay content. Empirically derived thresholds for the triggering of landslides are commonly based on rainfall conditions and have been widely a...
Conference Paper
There has been a long-identified need in New Zealand for a community-developed, three- dimensional (3D) model of active faults that is publicly accessible and available to all practitioners. Over the past year, work has progressed on building and parameterising such a model – the New Zealand Community Fault Model (NZ CFM). The NZ CFM will serve as...
Presentation
Full-text available
Presentation to Omokoroa Residents and Ratepayers Association
Article
Full-text available
The Helgoland Mud Area (HMA) in the German Bight, covering an area of approximately 500 km², is one of a few depocentres for finer sediments in the North Sea. Radiocarbon and ²¹⁰Pb analyses revealed continuous sedimentation over the last several centuries. Zinc (Zn) and lead (Pb) contents in the sediments show a distinct increase towards the younge...
Article
Full-text available
Under stable sea level conditions, estuaries tend to accumulate sediment resulting in changes that can be conceptualised as a progression from a juvenile system to maturity. Sea level rise results in an increase in accommodation space within the estuary that can effectively reverse the progression towards maturity. This effect was investigated for...
Article
Full-text available
The underwater light regime is fundamental to the ecological health of aquatic systems because it is a limiting factor for photosynthesis in marine plants such as seagrasses. Although seagrass meadows are a key component of coastal systems, their survival has been threatened by increased turbidity levels, both from resuspension of marine sediments...
Technical Report
Full-text available
The Port of Tauranga is considering port developments that would require capital dredging of a section of the southern Stella Passage to achieve depths comparable to the northern Stella Passage. Seismic profiles, core samples, and CPT data were collected by the University of Waikato and OPUS for the area impacted by proposed development. The core s...
Presentation
Full-text available
A summary of sea level changes and their impacts over geological and historical times, with particular focus on Auckland, and a discussion of future sea level change and potential impacts
Technical Report
Full-text available
We report results of an examination of the effects of proposed dredge-channel and wharf extensions in the Port of Tauranga. Comparisons between Base Run and Future Development Model simulations predict that changes in sediment transport due to development are minimal and highly localised. The simulations represent a worst-case situation as they hav...
Article
Benthic plants such as seagrasses rely on light availability, which is controlled by light attenuation in the water column. Elevated suspended sediment within estuaries strongly influences light attenuation and is governed by the recent history of natural events and human activities. To determine the constituents controlling light penetration (quan...
Article
Groundwater seeping from the beach face can induce erosion and so may play a role in controlling the development of beach morphology. A study at Muriwai Beach, New Zealand, was conducted to measure the relationship between surf zone morphology, groundwater, and intertidal beachface volume. Time exposure images from a video camera were used to study...
Conference Paper
Full-text available
The Universities of Waikato and Bremen have examined sedimentation in the Hauraki Gulf, focussing on the sediment discharges from the Coromandel Peninsula and the Waihou/Ohinemuri river systems, to assess whether anthropic land-use changes over the last millennium have resulted in increased sedimentation rates. Previous studies identified increased...
Conference Paper
Full-text available
A series of complex fault systems have recently been discovered within the Hamilton Basin, New Zealand. Though the first zone was unexpectedly exposed during construction excavations, other zones have been discovered due to their influences on the local geomorphology. In this paper we present evidence for tectonic geomorphic features that were firs...
Technical Report
Full-text available
The impact of the Stella Development Plan, specifically proposed wharf, reclamation and channel extensions, on the hydrodynamics of Tauranga Harbour were investigated using a depth-averaged barotropic numerical model, Delft3D. The model was calibrated and validated using field observations collected in March 2017 after the completion of capital dre...
Conference Paper
Full-text available
Sensitive soils derived from weathered rhyolitic pyroclastic materials are associated with many landslides in the Bay of Plenty. Undrained, consolidated static triaxial tests show contractive p'-q' plots, strain-softening stress-strain behaviour coupled with rising pore water pressures, shear band formation after peak strength, and considerable str...
Conference Paper
Full-text available
Geological and geomorphological mapping provide evidence for three complex fault zones in the Hamilton Basin, an area with no previously mapped surface fault traces. Rectangular drainage patterns, stream knickpoints, and linear ridge and drainage systems all point to structural control on the path of the Waikato River and its tributary gullies. Exp...
Conference Paper
Full-text available
Diurnal ground movement may contribute to slope failure at Omokoroa due to cyclic loading of a sensitive layer within volcaniclastic deposits. Inclinometer measurements indicate that differential movement of the main stratigraphic units (Te Puna Ignimbrite, Pahoia Tephras, Hamilton Ashes, and Rotoehu and younger tephras) occurs in response to the E...
Presentation
Full-text available
Background information about recent capital dredging at the Port of Tauranga for the NZ Coastal Society 25th Annual Conference field trip
Conference Paper
Full-text available
Within the Bay of Plenty, Tauranga and Ohiwa Harbours are unusual in that their hypsometry indicates that they are less mature estuaries than the rest of the estuaries in the region, which is not consistent with the assumption that the Tauranga Harbour is being impacted by increased sedimentation due to changing land use over the last 200 years. Th...
Technical Report
Full-text available
The Gisborne District Council (GDC) is seeking resource consent to replace an existing protection structure and ongoing beach scraping on Wainui Beach, and a retrospective consent for an emergency structure at 21 Wairere Rd. The work is intended to be consistent with the Wainui Beach Erosion Management Strategy (WBEMS) established in 2014. This rep...
Article
Tauranga Harbour is a major economic centre and home to New Zealand’s largest port. Despite the importance of the harbour basin, and especially of the shipping channel, the subsurface stratigraphy of this area has not been studied in detail. We use sediment cores retrieved in support of a recent dredging campaign to characterise the subsurface stra...
Preprint
Full-text available
Draft final report for EQC project locating potential faults within the Hamilton Basin. Submitted in July 2017 and under review
Conference Paper
The Port of Tauranga have proposed extending the berthage of both the Sulphur Point and Maunganui wharves southward to provide a combined length of 1,303 m. The dredged channel (Stella Passage) will also be extended south into Town Reach, with the dredged sediment used to reclaim 4.7 ha behind the wharf extensions and along the Sulphur Point shorel...
Technical Report
Full-text available
Surveys of the mean high water mark before and after the capital dredging of 2015/16 indicate minor shoreline fluctuations on the open coast of Matakana Island that are consistent with normal variations. The largest change has occurred at the Panepane Point spit tip, which eroded by ˜20 m between August 2015 and October 2016. This is most likely du...
Conference Paper
Full-text available
The collapse of toheroa (Paphies ventricosa), and endemic surf clam of cultural, recreational and economic importance, is attributed to the intensification of human harvesting in the early to mid 1900's leading to population decline and ultimately closure of the fishery in the 1970s. Despite 40+ years of protection, toheroa have failed to recover,...
Article
Magnetic susceptibility and electric conductivity within the uppermost meter of the seafloor were measured with high resolution along 33 coast-normal profiles in the Bay of Plenty (New Zealand), using the recently developed electromagnetic benthic profiler MARUM NERIDIS III. These parameters are used to determine magnetic mineral concentration and...
Technical Report
Full-text available
This review reports findings from the peer review panel (‘the Panel’) assessment of the Tonkin & Taylor Ltd (2015) report: Coastal Hazard Assessment – Stage Two (‘the Report’). The Panel were asked to address four overarching questions in this review (‘the Review’), covering both the science and legal context of the report. These were (i) Does the...
Article
Full-text available
The Port of Tauranga plays a key role in New Zealand's export import industry, and capital dredging commenced in October 2015 to extend the shipping channels to accommodate larger container vessels. This study investigated two-dimensional and three-dimensional subsurface estuarine sediment stratigraphy to predict the sedimentological conditions enc...
Conference Paper
Full-text available
The collapse of toheroa (Paphies ventricosa), an endemic surf clam of cultural, recreational and economic importance, is attributed to the intensification of human harvesting in the early to mid-1900’s leading to population decline and ultimately closure of the fishery in the 1970s. Despite 40+ years of protection, toheroa have failed to recover, w...
Presentation
Full-text available
Mangrove and seagrass occupy different environments within an estuary, and both potentially respond to environmental stressors such as, nutrient loading, sedimentation, turbidity and climate change. Therefore, they could be useful indicators of the health of the estuary. However, there are common misunderstandings about the function of flowering pl...
Technical Report
Full-text available
Surveys of the mean high-water mark since 2015 indicate a continuing trend for erosion affecting the southeastern ~1 km of Matakana Island, and extending ~400 m into the harbour. The video camera installed by the Port of Tauranga Ltd is providing useful qualitative data, allowing identification of the processes contributing to erosion and accretion...
Article
Oil spill forecast modelling is typically used immediately after a spill to predict oil dispersal and promote mobilisation of more effective response operations. The aim of this work was to map oil dispersal after the grounding of the MV Rena on Astrolabe Reef and to verify the results against observations. Model predictions were broadly consistent...
Article
During the Rena oil spill, no data existed for New Zealand conditions on the likely depth of burial and the expected degradation of oil deposited on sandy beaches. Sediment cores were taken from 12 locations along the Bay of Plenty coastline c. 1 year after the Rena oil spill. No visible oil was detected in cores and trenches dug within the beaches...
Article
Sediment dynamics on a storm-dominated shelf (western Bay of Plenty, New Zealand) were mapped and analyzed using the newly developed multi-sensor benthic profiler MARUM NERIDIS III. An area of 60 km × 7 km between 2 and 35 m water depth was surveyed with this bottom-towed sled equipped with a high-resolution camera for continuous close-up seafloor...
Data
Sediment dynamics on a storm-dominated shelf (western Bay of Plenty, New Zealand) were mapped and analyzed using the newly developed multi-sensor benthic profiler MARUM NERIDIS III. An area of 60 km × 7 km between 2 and 35 m water depth was surveyed with this bottom-towed sled equipped with a high-resolution camera for continuous close-up seafloor...
Conference Paper
Full-text available
Tauranga Harbour is one of the largest estuaries in New Zealand, formed during the most recent post-glacial marine transgression. It is part of Tauranga Basin, a tensional graben, which is infilled with significant thicknesses of volcaniclastic sediments. The basin is in a tectonically active coastal marine setting, which typically have rapid deliv...
Conference Paper
Full-text available
Coromandel Harbour is one of the largest estuaries on the Coromandel Peninsula and is of significant economic importance in the region. However, its sedimentary structure remains relatively underexplored compared to its smaller regional estuarine counterparts. A previous study based on limited data found that recent sedimentation rates are much gre...
Conference Paper
Full-text available
The National Seismic Hazard Model (NSHM) has evaluated a relatively low seismic hazard for the Hamilton Basin, based on an absence of active faults and low levels of historic seismicity. However, it was recognised that Quaternary sediments may obscure the presence of active faults. A range of different lines of evidence indicate the presence of at...
Conference Paper
Full-text available
At least four hidden faults occur in the Hamilton Basin, three within Hamilton (see de Lange et al. “Hidden faults in the Hamilton Basin”). Injection structures (dykes) associated with seismic liquefaction within Late-Pleistocene volcanogenic alluvium (Hinuera Formation) have been identified at two locations within the Hamilton Basin (one at Endeav...
Conference Paper
Full-text available
Sensitive soil failures in the Tauranga area commonly occur after heavy rainfall events, causing considerable infrastructure damage. Notable landslides include a large failure at Bramley Drive, Omokoroa in 1979, the Ruahihi Canal collapse in 1981, and landslides at Otumoetai in May 2005; recently the Bramley Drive scarp was reactivated in 2011 and...
Conference Paper
Full-text available
Rapid emplacement of a mass via pyroclastic flows, or edifice failure, generates volcanic tsunamis. Physical modelling demonstrates that the efficiency of tsunami generation is influenced by the angle the mass enters the ocean. Efficiency decreases with increasing slope angle from 20° to 60°, before increasing to a maximum at 90°, which corresponds...
Conference Paper
Full-text available
Sensitive soils in the Bay of Plenty in North Island occur within weathered, rhyolitic pyroclastic and volcaniclastic deposits, with hydrated halloysite (not allophane) as the principal clay mineral. We evaluate the development of sensitivity and characteristic geomechnical behaviours for sequences of the silt-rich, halloysitic soils. Morphological...
Conference Paper
Full-text available
The short-and long-term impacts of dredging on the Matakana Banks ebb-tidal delta was investigated by numerical modelling using Delft3D. The model covered dredging locations inside Tauranga Harbour and the offshore areas around the Matakana Banks ebb-tidal delta, and was calibrated by an extensive field programme to measure hydrodynamic processes a...
Conference Paper
Full-text available
Water quality standards associated with dredging have become more stringent, requiring better monitoring and prediction. Here, we describe the dynamics and development of plumes generated during two dredging cycles and how they vary with respect to time and distance from the dredging activity. Backscatter signals were measured using a boat-mounted...
Conference Paper
Full-text available
The eastern entrance to Tauranga Harbour has been modified by capital and maintenance dredging since 1968, raising concerns that there have been, or will be, adverse impacts. This paper reviews the effects that extreme events, such as tsunami, and the influence that the underlying geological structures have had on the evolution of the present day e...
Data
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Research
Full-text available
Considering the sea level projections adopted by the DCCS, the key points are: a) Due to vertical land movements, the magnitude of relative sea level changes around the coast of the Wellington region varies significantly, and at centennial scales the effects of a major earthquake and the cumulative effect of slow-slip events are likely to dominate...
Article
Piezovibrocones have been developed to evaluate the liquefaction potential of onshore soils, but have not yet been utilized to evaluate the in-situ liquefaction behavior of offshore marine and volcanoclastic sediments. Two static and vibratory CPTu (Cone Penetration Tests) were performed at Tauranga Harbor, New Zealand. The lithology is known from...
Conference Paper
Full-text available