Urgent need for protection of New Zealand’s coastal landscape

Alarm bells for protection of coastal landscape should be well and truly ringing! This is exemplified by the great rush toward “life-style block” subdivision of large coastal tracts (simply glance at the “NZ Herald” Real Estate section), and recent cases such as the University of Auckland’s hedonistic attempt to sell prime coastal land on the scenic Coromandel coastline for development. Coastal landscape protection is already embedded in the Resource Management Act, and most explicitly stated under S6 (“Matters of National Importance”). S6a refers to “preservation of the natural character of the coastal environment” – which implicitly includes landscape - and S6b “the protection of outstanding natural features and landscapes from inappropriate subdivision….”. Unfortunately landscape protection is rarely considered seriously as a major impediment to new sub-divisional developments along areas of largely undeveloped coast. There are compelling reasons for protection of coastal landscape. These include (i) reduction in long term economic return from tourism from ribbon development along the coast, (ii) huge increases in the cost of supplying infrastructure (roading, electricity, water supply, sewage disposal) to remote coastal wild and scenic locations – which the entire community contributes major cost for rather than the select few beneficiaries at the end of the line; and (iii) the improved infrastructure amenities, facilities and economic benefits possible from concentration of capital development into nucleated coastal settlements. But the major problem is the creeping ribbon development along the coast – leading to significant irreversible impact on the “vistas of nature” – especially along the scenic coasts of Northland, the Coromandel Peninsula, the central North Island and the Marlborough Sounds

Modelling of wave climate and sediment transport patterns at a tideless embayed beach, Pirita Beach, Estonia

Nearshore sand transport patterns along the tideless, embayed Pirita beach, Tallinn, Estonia, have been investigated utilizing high-resolution modelling of wave processes combined with bathymetric surveys and sediment textural analyses of the nearshore sea floor. Textural analysis showed the mean grain size is about 0.12 mm. Fine sand (0.063–0.125 mm) accounts for about 77% of the sediments. Coarser-grained sand (0.28 mm) dominates along the waterline. Based upon the spatial distribution of the mean grain size and basic features of the local wave activity, properties of the Dean Equilibrium Beach Profile were determined. Alongshore sediment transport was calculated based upon a long-term time series of wave properties along the beach, and the CERC formula applied to about 500 m long beach sectors. The time series of wave fields and the properties of the local wave climate were modelled using a triple nested WAM wave model with an extended spectral range for short waves. The model is forced by open sea wind data from Kalbådagrund for the years 1981–2002. Results indicate that typical closure depth at Pirita is 2.5 m. The width and mean slope of the equilibrium profile are 250 m and 1:100, respectively. Southward transport dominates in the northern sections of the beach whereas no prevailing transport direction exists in the southern sections. This pattern has several nontrivial implications for the planning of beach protection activities

Surf zone currents and influence on surfability

Surfing headlands are shallow and exposed coastal features that provide a specific form of breaking wave allowing a board-rider to ride on the unbroken wave face. The seabed shape and refraction of the waves in relation to depth contours provide the greatest influence on the quality of the surf break. The large scale and orientation of the Raglan headland allows only the low frequency swells to refract around the headland to create seven different surfing breaks. Each represents a compartmentalization of the shoreline along the headland. This creates variability in wave and current characteristics depending on the orientation and bathymetry at different locations. This provides not only potential access points through the surf-zone (ie: smaller currents), but greater surfability in a range of conditions that is not possible on small scale headlands. Headlands with surfing waves can be classified as mis-aligned sections of the coast, where the higher oblique angle of the breaking surf generates strong wave-driven currents. These currents are far greater than that found on coastlines in equilibrium with the dominant swell direction, where comparatively insignificant longshore drift is found. The strength and direction of wave-driven currents in the surf zone can influence the surfability of a break. At a surfing headland strong currents flowing downdrift along the shoreline make it difficult for a paddling surfer to get to the "take-off" location of the break, or maintain position in the line-up. In comparison currents flowing updrift along headlands makes getting "out the back" relatively easy, although surfers can be taken out to sea past the "take-off" point by a fast flowing current. Field experiments at Raglan, on the west coast of New Zealand have been conducted to measure current speed and direction during a large swell event. Observations of surfers attempting to paddle through the breaking-wave zone, confirms the strength of the wave-driven currents with surfers being swept rapidly down the headland. Results from the experiments at Raglan, have shown strong currents in the inshore breaking wave zone with burst-averaged velocities attaining 0.8 ms-1, and maximum bed orbital velocities of up to 2.0 ms-1. Interestingly, further offshore the currents have been found to flow in a re-circulating gyre back up the headland. Comparisons are made from observations of waves and currents found at other surfing headlands around the world. The effect that strong currents may have on the surfability of artificial surfing reefs needs to be considered in the design process, if the surfing amenity is to be maximised for large surf conditions

Historical and contemporary perspectives on the sediments of Lake Rotorua

Lake Rotorua is probably the oldest continuously inundated lake in New Zealand, occupying a caldera formed by or closely associated with the eruption of the Mamaku ignimbrite and the collapse of the Rotorua caldera (Healy, 1975; Lowe and Green, 1991). The lake has undergone drastic changes in size and depth as a result of tectonics, volcanic activity and erosion. Since the Rotoehu eruption, (~60 kyr), the lake level has fluctuated between 120 m above present (280 m asl) and 10 m below present level. The modern lake covers an area of 79 km2 and has a mean depth of 10 m. Despite its long history of sedimentation, Lake Rotorua has an irregular bathymetry with features including faulted blocks, slumps, hydrothermal explosion craters, springs and large methane discharge pock marks

Comparison of a self-processed EM3000 multibeam echosounder dataset with a QTC view habitat mapping and a sidescan sonar imagery, Tamaki Strait, New Zealand

A methodology for automatically processing the data files from an EM3000 multibeam echosounder (Kongsberg Maritime, 300 kHz) is presented. Written in MatLab, it includes data extraction, bathymetry processing, computation of seafloor local slope, and a simple correction of the backscatter along-track banding effect. The success of the latter is dependent on operational restrictions, which are also detailed. This processing is applied to a dataset acquired in 2007 in the Tamaki Strait, New Zealand. The resulting maps are compared with a habitat classification obtained with the acoustic ground-discrimination software QTC View linked to a 200-kHz single-beam echosounder and to the imagery from a 100-kHz sidescan sonar survey, both performed in 2002. The multibeam backscatter map was found to be very similar to the sidescan imagery, quite correlated to the QTC View map on one site but mainly uncorrelated on another site. Hypotheses to explain these results are formulated and discussed. The maps and the comparison to prior surveys are used to draw conclusions on the quality of the code for further research on multibeam benthic habitat mapping

Hydrodynamic modelling of tsunami inundation in Whitianga

In 2006, Waikato Regional Council (WRC) provided research funding for the Coastal Marine Group, Department of Earth and Ocean Sciences, University of Waikato, to undertake research on the impacts of tsunami inundation on Whitianga town and harbour. The main aims of the study are to: ● Identify potential tsunami sources; ● Establish an understanding of tsunami inundation impacts in Whitianga township and harbour – including the hydrodynamic processes and responses of Mercury Bay, Buffalo Bay, Whitianga Harbour and adjacent land to tsunami wave action; ● Develop tsunami inundation maps, showing depth and velocity (speed) of tsunami waves; and ● Provide sound evidence upon which to base community risk mitigation measures – including recommendations for evacuation planning, public education and awareness, protection of infrastructure, management of impacts to marine vessels and future land use planning. The numerical model used in this study is the 3DD Suite-Computational Marine and Freshwater Laboratory model (Black, 2001). The model has demonstrated the ability to accurately reproduce tsunami hydrodynamics during propagation and run up on both laboratory and real-world scales. There are three primary tsunami sources that could potentially affect Whitianga from the Kermadec Trench, and beyond the New Zealand continental shelf, being: 1. Mt Healy undersea volcano eruptions (15th Century event); 2. Large earthquakes along segments 1 and 2 of the Kermadec Trench subduction zone; and 3. A 1960 Chilean-type earthquake event. Each source is modelled, and the results that show the greatest risk and impacts to Whitianga are used as the basis for the hazard maps and hazard zones. Modelling results indicate that: • The Mt Healy type of eruption produced a minimal impact on Whitianga. The tsunami waves generated from this event did not inundate Whitianga. Despite this, strong currents of up to 2.5 m/s were generated inside Buffalo Bay and at the Whitianga Harbour inlet. •The Kermadec Trench earthquake scenarios with both positive and negative leading waves, as a result of a subduction fault dislocation along segments 1 and 2, have a significant impact on Whitianga. The waves inundate the coastal area up to 2.5 and 3 km inland for the subduction thrust fault and normal fault events respectively, and affect the entire area of Whitianga Harbour. The normal fault event that produces positive leading waves has more impact than the thrust fault event that produces negative leading waves. • The 1960 Chilean-type earthquake event produced tsunami waves that inundated Buffalo Beach Road and houses in Whitianga, as observed by eyewitnesses. Strong currents of up to 5 m/s are generated inside Buffalo Bay and the Whitianga Harbour inlet. The modelling indicates that: • Whitianga would be inundated five times by a Kermadec Trench earthquake scenario, and three times by a 1960 Chilean-type of tsunami • For the Kermadec Trench scenario (normal fault), the first waves penetrate Mercury Bay within 75–98 minutes after the fault rupture • Regardless of the tsunami source, it takes 11–18 minutes for waves to arrive at the Whitianga foreshore once they have entered Mercury Bay. The modelling indicates that the period between waves is 40 – 60 minutes, which is consistent with the 1960 Chilean event. The geometry of Buffalo Bay and Mercury Bay amplify the incoming tsunami waves, and the sea level inside the bay continues to oscillate, even after the sea level outside of Mercury Bay returns to normal. This situation is consistent with eyewitness accounts of the 1960 Chilean tsunami. Modelling also shows that strong currents are produced within Buffalo Bay and Whitianga Harbour, as well as during the overland flows - especially in areas adjacent to the Taputapuatea Stream and in the foreshore area between Albert Street and the wharf. The flow speed ranged from 1.5 m/s to 8 m/s for overland flows, and above 8 m/s within the entrance of Whitianga Harbour and in the middle of Buffalo Bay. For the first time in New Zealand, a combination of non-ground striking and ground striking LIDAR data was used in modelling tsunami inundation, which increased the accuracy of the modelling results considerably. Inundation flow behaviour and the effect of topography, as well as land use, can be analysed more accurately, and a more precise hazard map can be produced accordingly. Mitigation measures suggested to protect the Whitianga waterfront include a combination of enhanced coastal sand dunes and planted forest belts, which could be done along both sides of the Taputapuatea Stream. A stop gate could also be constructed at the entrance of the Taputapuatea Stream to minimise the impact of the tsunami flows upstream. With respect to evacuation, it is concluded that due to the lag time between a local event from the Kermadec Trench and wave arrival at the Whitianga foreshore, there is enough time for residents to be evacuated to shelter sites using major roads. Three locations are identified as evacuation shelter sites. These are the marina parking area and Buffalo Beach scenic reserve (both of which are located on high ground adjacent to the high-risk zone), and further inland at the airfield. Vertical evacuation sites are needed inside the high-risk zone, and recommendations on potential locations are provided. It is important that vertical evacuation measures are integrated into community response plans, and that they be reviewed and revised regularly. Overland flow information derived from modelling using the ground-striking and non-ground striking LIDAR data provides a basis to influence new development that occurs within tsunami hazard risk zones. Overland flow information also indicates the areas of existing development that need protection from future tsunami events. Risk mitigation may be accomplished through redevelopment, retrofit, coastal defence measures, safety planning for ships and boats, land reuse plans, and also via public education and awareness programmes. A major challenge of risk mitigation is to maintain emergency preparedness programmes and procedures when the threat of tsunami is perceived as remote. Periodic exercises are essential to maintain awareness, and regular information should be provided for those occupying tsunami hazard areas. Tsunami are rare events, but their impacts on coastal communities can be devastating. It is quite dangerous to believe that the impacts of a tsunami can be completely prevented by man-made structures (Horikawa and Shuto, 1983). However, possible impacts may be minimised through careful design of solutions based on systematic research. An important consideration for risk mitigation works is that they may affect the quality of daily life, and risk mitigation involves choices and trade-offs between risk management and other uses. Video animations of each scenario are provided at regional, intermediate and local scales. The animations cover tsunami wave behaviour during generation, propagation, run up, and overland flows, and may be used to inform land use planning and public education and awareness programmes

Physical activity, sedentary behaviours, and the prevention of endometrial cancer

Physical activity has been hypothesised to reduce endometrial cancer risk, but this relationship has been difficult to confirm because of a limited number of prospective studies. However, recent publications from five cohort studies, which together comprise 2663 out of 3463 cases in the published literature for analyses of recreational physical activity, may help resolve this question. To synthesise these new data, we conducted a meta-analysis of prospective studies published through to December 2009. We found that physical activity was clearly associated with reduced risk of endometrial cancer, with active women having an approximately 30% lower risk than inactive women. Owing to recent interest in sedentary behaviour, we further investigated sitting time in relation to endometrial cancer risk using data from the NIH-AARP Diet and Health Study. We found that, independent of the level of moderate–vigorous physical activity, greater sitting time was associated with increased endometrial cancer risk. Thus, limiting time in sedentary behaviours may complement increasing level of moderate–vigorous physical activity as a means of reducing endometrial cancer risk. Taken together with the established biological plausibility of this relation, the totality of evidence now convincingly indicates that physical activity prevents or reduces risk of endometrial cancer

Melanocortin-1 Receptor, Skin Cancer and Phenotypic Characteristics (M-SKIP) Project: Study Design and Methods for Pooling Results of Genetic Epidemiological Studies

Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods: Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion: Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council