PREFACE

This year the event of the Joint Geospatial Asia-Europe 2021 and GeoAdvances 2021 was held virtually from Casablanca, Morocco from 5 to 6th October. Sixty-two papers were received and 46 papers were accepted for the ISPRS International Archives. These papers could be categorized into three sub-disciplines – GIS, Geomatics, and Geo-computation (machine learning and applications). All accepted papers as revealed in this proceedings and presented at the conference. Several renowned researchers presented their works as keynotes, they are Prof Dr Peter van Oosterom (from TU Delft, the Netherlands), Prof Dr Volker Coors (from HfT Stuttgart, Germany), Dr Filip Biljecli (from National University of Singapore), Prof Dr Hassan Rhinane (from Hassan II University Casablanca, Morocco), Prof Dr Umit Isikdag (from Mimar Sinan Fine Arts University, Turkey), Assoc Prof Dr Gurcan Buyuksalih (Istanbul, Turkey), Prof Dr Sisi Zlatanova (from University of New South Wales, Sydney, Australia), Assoc Prof Dr Lars Bodum (Aalborg University, Denmark), Prof Dr Andreas Buerkert (from University of Kassel, Germany). Presentations from Invited Speakers from various universities and research institutes from Philippines, Malaysia, Poland, Switzerland, Qatar, Indonesia, and Germany enhanced the conference academic standing.We would like to thank all reviewers for their diligent works on the feedbacks and comments on the assigned papers.Last, but not least, gratitude to all the volunteers mainly our research students for making sure all the online system runs smoothly.Enjoy!

The impact of the COVID-19 pandemic on hospital-treated self-harm in Sydney (Australia)

Objectives: This study investigated trends in hospital-treated self-harm and hospital presenting suicidal ideation in the period before and after COVID-19 public health responses by key socio-demographic groups among those presenting to hospitals in the Western Sydney (Australia) population catchment. Methods: Emergency department presentations for the period January 2016 to June 2021 were used to specify a series of interrupted time-series models to compare the observed and expected event rates of (1) hospital-treated self-harm and (2) hospital presenting suicidal ideation in the period following the onset of COVID-19 public health measures in March 2020. Rate differences between observed and expected rates in the post-implementation period were also estimated in models stratified by sex, age group, country of birth and socio-economic status. Results: There was no significant increase in hospital-treated self-harm in the period post-implementation of public health orders (March 2020) compared to the previous period, although there were lower than expected rates of emergency department presentations among non-Australian-born males, males aged 0–14 years and 25–44 years, and females aged 45–64 years. In contrast, there was a significant increase in hospital presenting suicidal ideation, particularly among women (rate difference per 100,000 = 3.91, 95% confidence interval = [1.35, 6.48]) and those aged 15–24 years (both males and females, rate differences ranging from 8.91 to 19.04), and among those residing in lower socio-economic status areas (both males and females, rate differences ranging from 0.90 to 2.33). Conclusion: There was no increase in hospital-treated self-harm rates in the 15 months post-implementation of COVID-19 public health orders in Western Sydney; however, there was a significant increase in hospital presenting suicidal ideation. The limited change in suicidal behaviour may reflect the success of social and economic supports during this period, the benefits of which may have been different for young people, and those of lower socio-economic status.

Lockout, Lockdown and Land Use: Exploring the Spatio-Temporal Evolution Patterns of Licensed Venues in Sydney, Australia between 2012 and 2021 in the Context of NSW Public Policy

The hospitality industry in Sydney, Australia, has been subject to several regulatory interventions in the last decade, including lockout laws, COVID-19 lockdowns and land use planning restrictions. This study has sought to explore the spatial implications of these policies in Inner Sydney between 2012 to 2021. Methods based in spatial analysis were applied to a database of over 40,000 licensed venues. Point pattern analysis and spatial autocorrelation methods were used to identify spatially significant venue clusters. Space-time cube and emerging-hot-spot methods were used to explore clusters over time. The results indicate that most venues are located in the Sydney CBD on business-zoned land and show a high degree of spatial clustering. Spatio-temporal analysis reveals this clustering to be consistent over time, with variations between venue types. Venue numbers declined following the introduction of the lockout laws, with numbers steadily recovering in the following years. There was no discernible change in the number of venues following the COVID-19 lockdowns; however, economic data suggest that there has been a decline in revenue. Some venues were identified as having temporarily ceased trading, with these clustered in the Sydney CBD. The findings of this study provide a data-driven approach to assist policymakers and industry bodies in better understanding the spatial implications of policies targeting the hospitality sector and will assist with recovery following the COVID-19 pandemic. Further research utilising similar methods could assess the impacts of further COVID-19 lockdowns as experienced in Sydney in 2021.

The spectre of the thing: The construction of the Sydney Gay and Lesbian Holocaust memorial

The Sydney Gay and Lesbian Holocaust Memorial is situated on the western side of Green Park in Darlinghurst, in Sydney, Australia. Darlinghurst is considered the heart of Sydney's gay and lesbian population, having been the site of demonstrations, public meetings, Gay Fair Days, and the starting point for the AIDS Memorial Candlelight Rally. It is also very close to both the Sydney Jewish Museum and the Jewish War Memorial. The planning and construction of the Memorial between 1991 and 2001 was a process framed by two competing imperatives. Balancing the commemoration of a subset of victims of the Holocaust with a positioning of the event as a universal symbol of the continuing persecution of gays and lesbians was a challenge that came to define the ten year struggle to have the memorial built.

An Object-based Climatology of Precipitation Systems in Sydney, Australia

The climate is warming and this is changing some aspects of storms, but we have relatively little knowledge of storm characteristics beyond intensity, which limits our understanding of storms overall. In this study, we apply a cell-tracking algorithm to 20 years of radar data at a mid-latitude coastal-site (Sydney, Australia), to establish a regional precipitation system climatology. The results show that extreme storms in terms of translation-speed, size and rainfall intensity usually occur in the warm season, and are slower and more intense over land between ~10am and ~8pm (AEST), peaking in the afternoon. Precipitation systems are more frequent in the cold season and often initiate over the ocean and move northward, leading to precipitation mostly over the ocean. Using clustering algorithms, we have found five precipitation system types with distinct properties, occurring throughout the year but peaking in different seasons. While overall rainfall statistics don't show any link to climate modes, links do appear for some system types using a multivariate approach. This climatology for a variety of precipitation system characteristics will allow future study of any changes in these characteristics due to climate change.

Are we planning blue-green infrastructure opportunistically or strategically? Insights from Sydney, Australia

Strategic placement of water-sensitive urban design (WSUD) is essential in optimising its performance and maximising co-benefits. However, little is known about the current placement and interconnectedness between WSUD assets and the performance of current planning strategies. We evaluated the placement of existing WSUDs in a highly urbanised catchment in Sydney, Australia. We used a three-step process: (1) compiling a comprehensive spatial asset database, (2) performing spatial correlation analysis between asset locations and biophysical, urban form and socioeconomic variables and (3) using a novel approach to facilitate holistic understanding through analysing asset locations compared with the outcome of the spatial suitability analysis tool (SSANTO). WSUD coverage was generally low, with clustering in some municipalities. Placement was constrained by physical variables, such as slope, limited space and varying land uses. However, placement was not detectably influenced by most socioeconomic variables. SSANTO's suitability score at asset locations was only slightly higher than average, suggesting that the placement of existing WSUD was opportunistic, rather than strategically planned. Further development and implementation of tools able to account for spatial constraints will help guide future WSUD placement as a component of green urban stormwater management.

Challenges in the control of COVID-19 outbreaks caused by the delta variant during periods of low humidity: an observational study in Sydney, Australia

Background Since the appearance of severe acute respiratory coronavirus 2 (SARS-CoV-2) and the coronavirus disease 2019 (COVID-19) pandemic, a growing body of evidence has suggested that weather factors, particularly temperature and humidity, influence transmission. This relationship might differ for the recently emerged B.1.617.2 (delta) variant of SARS-CoV-2. Here we use data from an outbreak in Sydney, Australia that commenced in winter and time-series analysis to investigate the association between reported cases and temperature and relative humidity. Methods Between 16 June and 10 September 2021, the peak of the outbreak, there were 31,662 locally-acquired cases reported in five local health districts of Sydney, Australia. The associations between daily 9:00 am and 3:00 pm temperature (°C), relative humidity (%) and their difference, and a time series of reported daily cases were assessed using univariable and multivariable generalized additive models and a 14-day exponential moving average. Akaike information criterion (AIC) and the likelihood ratio statistic were used to compare different models and determine the best fitting model. A sensitivity analysis was performed by modifying the exponential moving average. Results During the 87-day time-series, relative humidity ranged widely (< 30–98%) and temperatures were mild (approximately 11–17 °C). The best-fitting (AIC: 1,119.64) generalized additive model included 14-day exponential moving averages of 9:00 am temperature (P < 0.001) and 9:00 am relative humidity (P < 0.001), and the interaction between these two weather variables (P < 0.001). Humidity was negatively associated with cases no matter whether temperature was high or low. The effect of lower relative humidity on increased cases was more pronounced below relative humidity of about 70%; below this threshold, not only were the effects of humidity pronounced but also the relationship between temperature and cases of the delta variant becomes apparent. Conclusions We suggest that the control of COVID-19 outbreaks, specifically those due to the delta variant, is particularly challenging during periods of the year with lower relative humidity and warmer temperatures. In addition to vaccination, stronger implementation of other interventions such as mask-wearing and social distancing might need to be considered during these higher risk periods. Graphical Abstract