A method for small-area estimation of population mortality in settings affected by crises

Background Populations affected by crises (armed conflict, food insecurity, natural disasters) are poorly covered by demographic surveillance. As such, crisis-wide estimation of population mortality is extremely challenging, resulting in a lack of evidence to inform humanitarian response and conflict resolution. Methods We describe here a ‘small-area estimation’ method to circumvent these data gaps and quantify both total and excess (i.e. crisis-attributable) death rates and tolls, both overall and for granular geographic (e.g. district) and time (e.g. month) strata. The method is based on analysis of data previously collected by national and humanitarian actors, including ground survey observations of mortality, displacement-adjusted population denominators and datasets of variables that may predict the death rate. We describe the six sequential steps required for the method’s implementation and illustrate its recent application in Somalia, South Sudan and northeast Nigeria, based on a generic set of analysis scripts. Results Descriptive analysis of ground survey data reveals informative patterns, e.g. concerning the contribution of injuries to overall mortality, or household net migration. Despite some data sparsity, for each crisis that we have applied the method to thus far, available predictor data allow the specification of reasonably predictive mixed effects models of crude and under 5 years death rate, validated using cross-validation. Assumptions about values of the predictors in the absence of a crisis provide counterfactual and excess mortality estimates. Conclusions The method enables retrospective estimation of crisis-attributable mortality with considerable geographic and period stratification, and can therefore contribute to better understanding and historical memorialisation of the public health effects of crises. We discuss key limitations and areas for further development.

Main drivers of plant diversity patterns of rubber plantations in the Greater Mekong Sub-region

The Greater Mekong Sub-region (GMS) is one the global biodiversity hotspots. However, the diversity has been seriously threatened due to environmental degradation and deforestation, especially by expansion of rubber plantations. Yet, little is known about the impact of rubber plantations on plant diversity. In this study, we analyzed plant diversity patterns of rubber plantations in the GMS based on a ground survey of a large number of samples. We found that diversity varied across countries due to varying agricultural intensities. Laos had the highest diversity, then followed China, Myanmar, Cambodia. Thailand and Vietnam were the lowest among them. Plant species richness of Laos was about 1.5 times that of Vietnam. We uncovered latitudinal and longitudinal gradients in plant diversity across these artificial forests of rubber plantations. These gradients could be explained by the traditional ecological theories. Furthermore, null deviation of observed community to the randomly assembled communities were larger than zero indicating deterministic process were more important for structuring the community. Meanwhile, the results also showed that higher dominance of some exotic species (such as Chromolaena odorata and Mimosa pudica) were associated with a loss of plant diversity within rubber plantations. In conclusion, not only environmental factors (such as elevation and latitude), but also exotic species were the main factors affecting diversity of these artificial stands. Much more effort should be made to balance agricultural production with conservation goals in this region, particularly to minimize the diversity loss in Vietnam and Cambodia.

From Coastal to Montane Forest Ecosystems, Using Drones for Multi-Species Research in the Tropics

Biodiversity monitoring is crucial in tackling defaunation in the Anthropocene, particularly in tropical ecosystems. However, field surveys are often limited by habitat complexity, logistical constraints, financing and detectability. Hence, leveraging drones technology for species monitoring is required to overcome the caveats of conventional surveys. We investigated prospective methods for wildlife monitoring using drones in four ecosystems. We surveyed waterbird populations in Pulau Rambut, a community of ungulates in Baluran and endemic non-human primates in Gunung Halimun-Salak, Indonesia in 2021 using a DJI Matrice 300 RTK and DJI Mavic 2 Enterprise Dual with additional thermal sensors. We then, consecutively, implemented two survey methods at three sites to compare the efficacy of drones against traditional ground survey methods for each species. The results show that drone surveys provide advantages over ground surveys, including precise size estimation, less disturbance and broader area coverage. Moreover, heat signatures helped to detect species which were not easily spotted in the radiometric imagery, while the detailed radiometric imagery allowed for species identification. Our research also demonstrates that machine learning approaches show a relatively high performance in species detection. Our approaches prove promising for wildlife surveys using drones in different ecosystems in tropical forests.

Javan langur responses to the repeated exposure of ground survey and novel stimulus, unmanned aerial vehicles

The use of small Unmanned Aerial Vehicles (UAVs; a.k.a “drones”) for ecological monitoring, conservation campaign, and management is increasing enormously. UAVs operate at low altitudes (<150 m) and in any terrain; thus, they are susceptible to interact with local fauna, generating a new type of anthropogenic disturbance that has not been systematically evaluated. Both policy-makers and practitioners require data about the potential impacts of UAVs on natural biota, but few studies exist. The research aims to compare behavioral responses from ground-based surveys vs. UAVs flights. Moreover, we conducted two experiments of UAVs overflights, specifically aiming to assess the responses of Trachypithecus auratus. Between January and March 2021, we conducted 24 UAVs flight approaches and 12 ground surveys at Mount Halimun-Salak National Park, Indonesia. We applied generalized linear mixed-effects models and Kruskal-Wallis tests to 364 behavioral scores obtained from two independent observers. When directly compared, the detection time was higher using UAVs (χ2 = 38.50; df= 1; p < 0.050), and behavioral responses by Javan langur to UAVs overflights at > 30 m were different from responses to ground surveys were more intense. Finally, we suggest data-driven best practices for UAVs use and the design of future UAVs-wildlife response studies.

A new technique for remote location of unknown caves and deep-seated faults by unmanned aerial systems (UAS)

Here, for the first time in Bulgaria, we demonstrate that aerial survey of the terrain with a coaxial thermal and visible camera mounted on an UAS can detect much larger number of entrances to underground cavities and deep seated faults than a detailed systematic ground survey by experienced personnel. Thus geophysical problems are solved with these remote sensing methods. It is extremely promising and reveals great opportunities for improving techniques for location of unknown caves and deep seated faults to a much higher level. Obtained results are a significant step forward in the state-of-the art.

Monitoring and Quantitative Human Risk Assessment of Municipal Solid Waste Landfill Using Integrated Satellite–UAV–Ground Survey Approach

Landfills are the dominant method of municipal solid waste (MSW) disposal in many developing countries, which are extremely susceptible to failure under circumstances of high pore water pressure and insufficient compaction. Catastrophic landfill failures have occurred worldwide, causing large numbers of fatalities. Tianziling landfill, one of the largest engineered sanitary landfills in China, has experienced massive deformation since January 2020, making early identification and monitoring of great significance for the purpose of risk management. The human risk posed by potential landfill failures also needs to be quantitatively evaluated. The interferometric synthetic aperture radar (InSAR) technique, unmanned aerial vehicle (UAV) photogrammetry, and ground measurements were combined to obtain landfill deformation data in this study. The integrated satellite–UAV–ground survey (ISUGS) approach ensures a comprehensive understanding of landfill deformation and evolution. The deformation characteristics obtained using the InSAR technique and UAV photogrammetry were analyzed and compared. A close relationship between the most severe mobility events, precipitation episodes, and was observed. Based on early hazard identification using ISUGS, a quantitative risk assessment (QRA) method and F-N curves were proposed, which can be applied to landfills. The comparison showed that ISUGS allowed a better understanding of the spatial and temporal evolution of the landfill and more accurate QRA results, which could be as references for local governments to take effective precautions.

Utilization of High Resolution Integrated Indirect Inspection Survey Technologies as Part of the Direct Assessment Methodology of Ageing Non-Cathodically Protected Pipeline Network

There is an old adage “if it is not broken, do not fix it” and this could be applicable for our day-to-day menial activities, but could prove fatally disastrous if followed by any pipeline owners globally. Although, pipelines are statistically the safest means of transporting hydrocarbon — the consequence to an event could be exponential, even if the probability of the event to occur is low. The magnitude of consequence only goes higher with the ever-burgeoning population. To this effect, Oil India Limited (OIL) owns an intensive network of spider-webbed carbon steel pipelines in Upper Assam, India geographical area with varying vintage. Understanding the associated risks of operating such critical pipeline systems, it was decided for the pipelines to undergo code-compliant integrity assessment. It is well known that non-CP protected pipelines are electrically continuous conductors without any insulation (isolation) joints to separate the above-ground station piping to the cross-country underground pipeline sections. With respect to this, OIL deployed a state-of-the-art integrated indirect inspection survey tool to assist in conducting Direct Assessment based integrity assessment. This paper provides an insight into such a scenario where the operator proactively employed the use of advanced high-resolution integrated survey technology to their non-cathodically protected, but coated pipeline assets. Due to the age and design of these “temporary” pipeline systems, there were no prior readily available records in terms of construction, drawings, maps, alignment sheets, operational or historical maintenance data for these pipelines. The advanced Integrated survey played a vital role in decluttering these extensively jumbled network of non-CP pipelines. Firstly, by actually locating the pipeline based on sub meter accuracy and secondly performing simultaneous above ground survey for coating assessment and susceptibility for corrosion. The adaptability of integrated survey as per given situation helped overcome the difficult pipeline route conditions and customize the assessment for these highly challenging pipelines and make ECDA feasible as per NACE SP0502 Standard Practice for this very complex spider web network of pipelines.

Humans as geomorphic agents: Lidar detection of the past, present and future of the Teotihuacan Valley, Mexico

As humans are the primary geomorphic agents on the landscape, it is essential to assess the magnitude, chronological span, and future effects of artificial ground that is expanding under modern urbanization at an alarming rate. We argue humans have been primary geomorphic agents of landscapes since the rise of early urbanism that continue to structure our everyday lives. Past and present anthropogenic actions mold a dynamic “taskscape” (not just a landscape) onto the physical environment. For example, one of the largest Pre-Columbian metropolitan centers of the New World, the UNESCO world heritage site of Teotihuacan, demonstrates how past anthropogenic actions continue to inform the modern taskscape, including modern street and land alignments. This paper applies a multi-scalar, long durée approach to urban landscapes utilizing the first lidar map of the Teotihuacan Valley to create a geospatial database that links modern and topographic features visible on the lidar map with ground survey, historic survey, and excavation data. Already, we have recorded not only new features previously unrecognized by historic surveys, but also the complete erasure of archaeological features due to modern (post-2015) mining operations. The lidar map database will continue to evolve with the dynamic landscape, able to assess continuity and changes on the Teotihuacan Valley, which can benefit decision makers contemplating the stewardship, transformation, or destruction of this heritage landscape.

Utilization of Unmanned Aerial Vehicle (UAV) Technology for Mapping Mangrove Ecosystem

Technological developments, especially in remote sensing in mangrove mapping are growing. One of them is the use of Unmanned Aerial Vehicle (UAV) as a vehicle for capturing aerial photo data. This study aims to map the mangrove ecosystem in order to find out spatial information with UAV technology and to identify mangrove species, distribution, and associations. The ground survey was conducted on 02 until 04 May 2019 in North of Lancang Island, Seribu Islands, DKI Jakarta Province. The mangrove data collection was carried out in four stations with marking, tracking the mangrove area and drone flights for taking aerial photo data. Based on the research, it was found that the mangroves were in good condition with an area of around 4 hectares, consisting of Rhizophora mucronata. However, there is a lot of waste around the mangrove ecosystem, especially inorganic waste in the form of plastic. Where the presence of garbage can cover the roots of the mangrove so that it can affect respiration and cause death in mangroves. The application of UAV technology that is integrated with GIS in mangrove ecosystem mapping is expected to be an alternative in extracting mangrove databases for future coastal ecosystem management.