Preliminary investigation of emerging suburban landsliding in Gisborne, New Zealand

Recently uplifted, soft Pleistocene sediments in northern New Zealand are particularly vulnerable to landsliding because they are often underlain by less permeable, clay-rich Neogene mudstone/siltstone rocks. Typically, instability is rainfall-induced, often due to a high intensity rainfall event from extra-tropical cyclones, following wetter months when antecedent soil moisture has increased. Using remote sensing, field surveys and laboratory testing, we report on some emerging slope instability hazards in the eastern suburbs of the coastal city of Gisborne, on the North Island. Retrogressive failure of the main landslide (at Wallis Road) is ongoing and has already led to the abandonment of one home, while an adjacent landslide (at Titirangi Drive) appears to be in an incipient phase of failure. The Wallis Road landslide has been particularly active from mid-2017, with slumping of the headscarp area transitioning to a constrained mudflow downslope, which then descends a cliff before terminating on the beach. In contrast, the incipient Titirangi Drive landslide at present displays much more subtle effects of deformation. While activity at both landslides appears to be linked to rainfall-induced increases in soil moisture, this is due to the effects of prolonged periods of rainfall rather than the passage of high intensity cyclonic storms.

Exploration of the atmospheric chemistry of nitrous acid in a coastal city of southeastern China: results from measurements across four seasons

Because nitrous acid (HONO) photolysis is a key source of hydroxyl (OH) radicals, identifying the atmospheric sources of HONO is essential to enhance the understanding of atmospheric chemistry processes and improve the accuracy of simulation models. We performed seasonal field observations of HONO in a coastal city of southeastern China, along with measurements of trace gases, aerosol compositions, photolysis rate constants (J), and meteorological parameters. The results showed that the average observed concentration of HONO was 0.54 ± 0.47 ppb. Vehicle exhaust emissions contributed an average of 1.45 % to HONO, higher than the values found in most other studies, suggesting an influence from diesel vehicle emissions. The mean conversion frequency of NO2 to HONO in the nighttime was the highest in summer due to water droplets evaporating under high-temperature conditions. Based on a budget analysis, the rate of emission from unknown sources (Runknown) was highest around midday, with values of 4.51 ppb h−1 in summer, 3.51 ppb h−1 in spring, 3.28 ppb h−1 in autumn, and 2.08 ppb h−1 in winter. Unknown sources made up the largest proportion of all sources in summer (81.25 %), autumn (73.99 %), spring (70.87 %), and winter (59.28 %). The photolysis of particulate nitrate was probably a source in spring and summer while the conversion from NO2 to HONO on BC enhanced by light was perhaps a source in autumn and winter. The variation of HONO at night can be exactly simulated based on the HONO / NOx ratio, while the J(NO3-_R) × pNO3- should be considered for daytime simulations in summer and autumn, or 1/4× (J(NO3-_R) × pNO3-) in spring and winter. Compared with O3 photolysis, HONO photolysis has long been an important source of OH except for summer afternoons. Observation of HONO across four seasons with various auxiliary parameters improves the comprehension of HONO chemistry in southeastern coastal China.

Bearing Capacity Analysis of Transmission Tower Structure Considering Corrosion Damage

As an important part of power grid equipment, transmission towers are in direct contact with the external environment for a long time. As a coastal city in China, Fujian has been affected by marine environment and industrial pollution for a long time, which directly affects the safety of transmission towers in long-term service. In order to explore the changes of the ultimate bearing capacity of the tower structure after corrosion, this paper uses finite element software to analyse the mechanical properties of the tower structure during long-term service, and finds that the 45° wind direction is the control condition, and the overall stiffness of the tower decreases with the growth of corrosion time, and the increment of tower top displacement reaches 7% at 12 years of corrosion. The corrosion-sensitive members of the tower were clearly identified, and their stress ratios increased from 0.78, 0.79, and 0.83 to 0.97, 0.98, and 0.99, respectively, at 12 years of corrosion.

Connectivity Benefits of Small Zero-Emission Autonomous Ferries in Urban Mobility—Case of the Coastal City of Gdańsk (Poland)

An increase in energy-efficient transportation is one way that cities try to mitigate climate change. In coastal cities, public water transit is also undergoing transitions. A small zero-emission autonomous ferry seems to be a cutting-edge technology in this field. This study aims to decrease the knowledge gap in research on the impacts of autonomous passenger ferry development on urban mobility. In particular, the central theme regards the extent to which the new transport solution can help improve sustainable mobility patterns. This study explores the local spatial context of ferry development, land-use patterns, and transport network structure, and moderates the shift in urban mobility practices. Regarding land use patterns, the case of the coastal city of Gdańsk has been documented in secondary qualitative and quantitative data, including in a large body of policy documents, accompanying expert opinions, and scholarly literature. This study strongly emphasises that a typical short river crossing, due to autonomous vessels, can regain a competitive position, which was partially lost due to linear routes along the river. The research identified crucial benefits of autonomous ferry shipping on urban mobility by increasing public transport network connectivity, reducing travel distance, and creating modal shifts towards foot travel and bike riding. It appears as an exciting scalable solution for cities where limited or dispersed demand prevents achievement of economies of scale, therefore diminishing the necessary expenditures.

Planning in Times of Uncertainty

Coastal city-regions are dealing with new wicked problems due to climate change. Therefore, there is a demand for alternative paradigms and methodologies beyond the neoconservative perspective, demanding a transformative planning practice based on a territory-landscape plan as a catalyst for change. Landscape approaches are not ‘new,’ but they have become a driving paradigm in the international realm during the last decades. This paper explores the differences in taking a landscape approach on the Global North and South and discusses how a landscape approach can add value to coastal planning theory, especially when looking for the territories of the 21st metropolis. Conclusions have shown that landscape approaches from both Global North and South can strongly lead to a transformative and adaptive response.