Flood Monitoring Using Enhanced Resolution Passive Microwave Data: A Test Case over Bangladesh

Monitoring floods is a major issue in water resources management and risk mitigation, especially in the Global South. Optical and radar observations, even providing a fine spatial resolution, are still limited by cloud cover interaction or insufficient temporal resolution. On the other hand, passive microwave (PMW) sensors collect information on a daily frequency with minor cloud cover interaction, but they have been historically limited in terms of spatial resolution. Here, we evaluate the capability of an enhanced spatial resolution PMW dataset (3.125 km) in monitoring spatio-temporal evolution of flood events, focusing on a major flood event that occurred in October 2005 in Bangladesh. We apply an algorithm aimed to remove the seasonal variability of surface temperature from the PMW timeseries, exploiting the difference in emissivity between dry and water-covered pixels. We assess the capability of the algorithm in capturing flood evolution and extension through the comparison with quantities obtained from optical data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and water level measurements. We also compare the enhanced product with the historical coarser resolution dataset by means of a variogram-based analysis to evaluate the improvements in terms of spatial representation. Finally, we evaluate the possibility to extract the water fraction within a single pixel by using an Advanced Microwave Scanning Radiometer—Earth Observing System (AMSR-E) emissivity dataset and compare the estimates with MODIS-derived water fractions. Our results show that the enhanced PMW product outperforms the coarser one when compared to flood mapped from optical data based on information content, indicating that it is possible to integrate such a product into the mapping of floods at a global scale on a daily basis. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Narcotrafficking and Land Control in Guatemala and Honduras

On frontiers dominated by illicit activities such as narcotrafficking, criminal organizations’ usurpation of land and resources is profoundly changing rural livelihoods and prospects for biodiversity conservation. Prior work has demonstrated how drug trafficking catalyzes forest loss and smallholder dispossession but does not make clear the extent to which the long-term control of land is moved from state, Indigenous, or smallholders to criminal or other actors. This study attempts to describe those shifts. Specifically: we develop a typology of land control, and use it to track how drug trafficking initiates shifts from public lands and Indigenous territories to private large holdings. We examine an array of secondary sources indicating shifts in land control related to narcotrafficking, including illegal land seizure documents, news media, and surveys of land managers. In absence of formal land registries, frontier actors may signal their control over land through land use change. After establishing where changes in land control have taken place, we analyzed land use and resulting changes in spatial patterns of forest loss. We found that large scale sustained forest losses (over 713,244 ha and 417,329 ha), in Guatemala and Honduras, respectively, from 2000–2019) corresponds with areas undergoing shifts in control towards large landowners, often related to narcotrafficking. Incomplete empirical data on land control prevent comprehensive attribution of all sustained forest loss related to narcotrafficking. Yet the limited evidence gathered here indicates drug trafficking activities initiate widespread and sustained shifts and consolidation of who controls land and resources at the frontier. Our work suggests that in Central America and likely elsewhere, control over land—quite separate from property rights—is the key factor in understanding social and eco-logical change. © 2021 The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The post-conflict expansion of coca farming and illicit cattle ranching in Colombia

Abstract Illicit cattle ranching and coca farming have serious negative consequences on the Colombian Amazon’s land systems. The underlying causes of these land activities include historical processes of colonization, armed conflict, and narco-trafficking. We aim to examine how illicit cattle ranching and coca farming are driving forest cover change over the last 34 years (1985–2019). To achieve this aim, we combine two pixel-based approaches to differentiate between coca farming and cattle ranching using hypothetical observed patterns of illicit activities and a deep learning algorithm. We found evidence that cattle ranching, not coca, is the main driver of forest loss outside the legal agricultural frontier. There is evidence of a recent, explosive conversion of forests to cattle ranching outside the agricultural frontier and within protected areas since the negotiation phase of the peace agreement. In contrast, coca is remarkably persistent, suggesting that crop substitution programs have been ineffective at stopping the expansion of coca farming deeper into protected areas. Countering common narratives, we found very little evidence that coca farming precedes cattle ranching. The spatiotemporal dynamics of the expansion of illicit land uses reflect the cumulative outcome of agrarian policies, Colombia’s War on Drugs, and the 2016 peace accord. Our study enables the differentiation of illicit land activities, which can be transferred to other regions where these activities have been documented but poorly distinguished spatiotemporally. We provide an applied framework that could be used elsewhere to disentangle other illicit land uses, track their causes, and develop management options for forested land systems and people who depend on them

People and Pixels 20 years later:the current data landscape and research trends blending population and environmental data

In 1998, the National Research Council published People and Pixels: Linking Remote Sensing and Social Science. The volume focused on emerging research linking changes in human populations and land use/land cover to shed light on issues of sustainability, human livelihoods, and conservation, and led to practical innovations in agricultural planning, hazard impact analysis, and drought monitoring. Since then, new research opportunities have emerged thanks to the growing variety of remotely sensed data sources, an increasing array of georeferenced social science data, including data from mobile devices, and access to powerful computation cyberinfrastructure. In this article, we outline the key extensions of the People and Pixels foundation since 1998 and highlight several breakthroughs in research on human–environment interactions. We also identify pressing research problems—disaster, famine, drought, war, poverty, climate change—and explore how interdisciplinary approaches integrating people and pixels are being used to address them

Gabapentin Disrupts Binding of Perlecan to the α2δ1 Voltage Sensitive Calcium Channel Subunit and Impairs Skeletal Mechanosensation

Our understanding of how osteocytes, the principal mechanosensors within bone, sense and perceive force remains unclear. Previous work identified “tethering elements” (TEs) spanning the pericellular space of osteocytes and transmitting mechanical information into biochemical signals. While we identified the heparan sulfate proteoglycan perlecan (PLN) as a component of these TEs, PLN must attach to the cell surface to induce biochemical responses. As voltage-sensitive calcium channels (VSCCs) are critical for bone mechanotransduction, we hypothesized that PLN binds the extracellular α2δ1 subunit of VSCCs to couple the bone matrix to the osteocyte membrane. Here, we showed co-localization of PLN and α2δ1 along osteocyte dendritic processes. Additionally, we quantified the molecular interactions between α2δ1 and PLN domains and demonstrated for the first time that α2δ1 strongly associates with PLN via its domain III. Furthermore, α2δ1 is the binding site for the commonly used pain drug, gabapentin (GBP), which is associated with adverse skeletal effects when used chronically. We found that GBP disrupts PLN::α2δ1 binding in vitro, and GBP treatment in vivo results in impaired bone mechanosensation. Our work identified a novel mechanosensory complex within osteocytes composed of PLN and α2δ1, necessary for bone force transmission and sensitive to the drug GBP

Pillars of Cloud‐Based Earth Observation Science Education

Abstract Earth observation (EO) is undergoing a paradigm shift with the development of cloud‐based analytical platforms supporting EO data collection and access, parallel processing, easier communication of results, and expanded accessibility. As the global community of users and the diversity of applications grow, there is a clear need for expanded educational capacity to leverage these developments and increase the impact of EO research and teaching. Drawing upon extensive conversations between educators, practitioners, and researchers, we propose three pillars that must be prioritized to prepare students, researchers, and professionals to take full advantage of the cloud‐based EO paradigm and guide future growth

On the milieu of security: situating the emergence of new spaces of public action

Copyright © 2015 SAGE PublicationsCritical analysis of security presents processes of securitization as sinister threats to public values such as accountability, inclusion and transparency. By questioning some of the theoretical premises of this view of the milieu of security, it is argued that practices of securitization might be understood less as an assertive medium for the constitution of the social field and more as a responsive mode of problematization of the temporalities of concerted public action. The argument proceeds in stages. First, two ways in which publicness is figured in the critique of security are identified and the spatiality of securitization associated with them elaborated. Second, this view of the spatiality of securitization is then linked to two modes of temporality that apparently define the historical novelty of contemporary security practices. It is argued that uncovering the pernicious politics of security depends on identifying putative subject effects sought and achieved by programmes of rule. In contrast to this approach, an alternative inflection of the genealogical perspective on security is identified. This inflection seeks to diagnose problematizations to which security initiatives are a response, suggesting a reorientation of critical attention to investigating the reconfiguration of public life around various temporal registers of uncertainty, adjustment and repair. The article closes by arguing that the specific public values at stake in securitization should be given more credence