WALTHERThe Geography of Conflict in North and West Africa

Olivier Walther

Article first published online: 14 FEB 2020 OECD Report

DOI: 10.1787/02181039-en

ABSTRACT: African governments are increasingly confronted with new forms of political violence. The situation is particularly worrying in the Sahara-Sahel where violence is on the rise. This degrading security situation has prompted African countries and their partners to intervene militarily to stabilise the region and to prevent the spread of extremism and violence against civilians. However, these initiatives face many obstacles due to the transnational nature and geography of violence. Tensions regionalise across state borders when armed groups, defeated by counter-insurgency efforts, relocate to other countries. This study maps the evolution of violence across North and West Africa, with a particular focus on Mali, Lake Chad and Libya. In the regions experiencing the highest levels of political insecurity, it identifies whether and how conflicts tend to cluster or spread, potentially across national borders. The work is based on a new spatial indicator of political violence designed to assess the long-term evolution of conflicts and provide policy options.

Read the full publication at the OECD Report on The Geography of Conflict in North and West Africa 





CHILD, HERRERO, KHATAMI, SOUTHWORTH, WAYLEN, YANGA Healthy Park Needs Healthy Vegetation – The Story of Gorongosa National Park in the 21st Century

Hannah Herrero, Peter Waylen, Jane Southworth, Reza Khatami, Di Yang, Brian Child

Article first published online: 03 FEB 2020 Remote Sensing

DOI: 10.3390/rs12030476

ABSTRACT: Understanding trends or changes in biomass and biodiversity around conservation areas in Africa is important and has economic and societal impacts on the surrounding communities. Gorongosa National Park, Mozambique was established under unique conditions due to its complex history. In this study, we used a time-series of Normalized Difference Vegetation Index (NDVI) to explore seasonal trends in biomass between 2000 and 2016. In addition, vegetation directional persistence was created. This product is derived from the seasonal NDVI time series-based analysis and represents the accumulation of directional change in NDVI relative to a fixed benchmark (2000–2004). Trends in precipitation from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) was explored from 2000–2016. Different vegetation covers are also considered across various landscapes, including a comparison between the Lower Gorongosa (savanna), Mount Gorongosa (rainforest), and surrounding buffer zones. Important findings include a decline in precipitation over the time of study, which most likely drives the observed decrease in NDVI. In terms of vegetation persistence, Lower Gorongosa had stronger positive trends than the buffer zone, and Mount Gorongosa had higher negative persistence overall. Directional persistence also varied by vegetation type. These are valuable findings for park managers and conservationists across the world.

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GANSER, GLASS, KESSLERA Survey of Tick-Borne Bacterial Pathogens in Florida

Carrie E. De Jesus, Claudia Ganser, William H. Kessler, Zoe S. White, Chanakya R. Bhosale, Gregory E. Glass, and Samantha M. Wisely

Article first published online: 13 SEPT 2019 Insects

DOI: 10.3390/insects10090297

ABSTRACT: Within the past three decades, new bacterial etiological agents of tick-borne disease have been discovered in the southeastern U.S., and the number of reported tick-borne pathogen infections has increased. In Florida, few systematic studies have been conducted to determine the presence of tick-borne bacterial pathogens. This investigation examined the distribution and presence of tick-borne bacterial pathogens in Florida. Ticks were collected by flagging at 41 field sites, spanning the climatic regions of mainland Florida. DNA was extracted individually from 1608 ticks and screened for Anaplasma, Borrelia, Ehrlichia and Rickettsia using conventional PCR and primers that amplified multiple species for each genus. PCR positive samples were Sanger sequenced. Four species of ticks were collected: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. Within these ticks, six bacterial species were identified: Borrelia burgdorferi, Borrelia lonestari, Ehrlichia ewingii, Rickettsia amblyommatis, Rickettsia andeanae, Rickettsia parkeri, and Rickettsia endosymbionts. Pathogenic Borrelia, Ehrlichia, and Rickettsia species were all detected in the North and North-Central Florida counties; however, we found only moderate concordance between the distribution of ticks infected with pathogenic bacteria and human cases of tick-borne diseases in Florida. Given the diversity and numerous bacterial species detected in ticks in Florida, further investigations should be conducted to identify regional hotspots of tick-borne pathogens.

Read the full publication at Insects.

BUNTING, WAYLENInterannual Hydroclimatic Variability of the Lake Mweru Basin, Zambia

Peter Waylen, Christopher Annear, and Erin Bunting

Article first published online: 29 AUG 2019 Water

DOI: 10.3390/w11091801

ABSTRACT: Annual precipitation inputs to the Lake Mweru basin, Zambia, were computed from historic data and recent gridded data sets to determine historic (1925–2013) changes in lake level and their potential impacts on the important fisheries of the lake. The results highlight a period from the early 1940s to the mid-1960s when interannual variability of inputs doubled. Existing lake level data did not capture this period but they did indicate that levels were positively correlated with precipitation one to three years previously, reflecting the hydrologic storage of the lake, the inflowing Luapula River and the upstream Bangweulu wetland complex. Lag cross-correlations of rainfall to El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole were weak and spatially and temporally discontinuous. The two drivers were generally positively correlated and induced opposing effects upon annual precipitation and lagged lake levels. This correlation became non-significant during the time of high observed interannual variability and basin inputs were prone to the vagaries of either driver independently or reinforcing drought/excess conditions. During times of high flows and persistent elevated lake levels, breeding habitat for fish increased markedly, as did nutrition supplied from the upstream wetlands. High hydrologic storage ensures that lake levels change slowly, despite contemporary precipitation totals. Therefore, good conditions for the growth of fish populations persisted for several years and populations boomed. Statistical models of biological populations indicated that such temporally autocorrelated conditions, combined with abundant habitat and nutrition can lead the “boom and bust” of fish populations witnessed historically in Lake Mweru.

Read the full publication at Water





WAYLENSocializing the rain: human adaptation to ecological variability in a fishery, Mweru-Luapula, Zambia

Christopher M. Annear, Peter R. Waylen

Article first published online: 23 AUG 2019 Journal of Political Ecology

DOI: 10.2458/v26i1.23246

ABSTRACT: Rainfall drives fishery fertility in Mweru-Luapula, thus rainfall variability contributes to frequent changes in fishing catches. Fishers and traders have adapted their institutions to this variable ecology in a variety of ways, including learning to read the fishery for productive periods and practicing multiple modes of income procurement. By accurately identifying inter-annual, inter-decadal, and longer spans of rainfall trends, future high and low yields can be forecast. This article presents and analyzes annual rainfall in the fishery from 1916-1992 and quantitative fish market data comprised of observed fish catch numbers by species in three markets from September 2004 to September 2005. It uses political ecology to better understand fish production, trade, and subsistence in this South-Central African freshwater fishery. We combine qualitative analysis of fisher and marketer perceptions of the fishery and knowledge of rainfall patterns to show how human behavior is not “tragically” driven, but instead based on the state of the ecological, sociocultural, and socioeconomic environment at a given time.

Read the full publication at Journal of Political Ecology

Image courtesy Sensors

BUNTING, CHILD, HERRERO, SOUTHWORTHIntegrating Surface-Based Temperature and Vegetation Abundance Estimates into Land Cover Classifications for Conservation Efforts in Savanna Landscapes

Hannah Victoria Herrero, Jane Southworth, Erin Bunting, Romer Ryan Kohlhaas, and Brian Child

Article first published online: 07 AUG 2019 Sensors

DOI: 10.3390/s19163456

ABSTRACT: Southern African savannas are an important dryland ecosystem, as they account for up to 54% of the landscape, support a rich variety of biodiversity, and are areas of key landscape change. This paper aims to address the challenges of studying this highly gradient landscape with a grass–shrub–tree continuum. This study takes place in South Luangwa National Park (SLNP) in eastern Zambia. Discretely classifying land cover in savannas is notoriously difficult because vegetation species and structural groups may be very similar, giving off nearly indistinguishable spectral signatures. A support vector machine classification was tested and it produced an accuracy of only 34.48%. Therefore, we took a novel continuous approach in evaluating this change by coupling in situ data with Landsat-level normalized difference vegetation index data (NDVI, as a proxy for vegetation abundance) and blackbody surface temperature (BBST) data into a rule-based classification for November 2015 (wet season) that was 79.31% accurate. The resultant rule-based classification was used to extract mean Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI values by season over time from 2000 to 2016. This showed a distinct separation between each of the classes consistently over time, with woodland having the highest NDVI, followed by shrubland and then grassland, but an overall decrease in NDVI over time in all three classes. These changes may be due to a combination of precipitation, herbivory, fire, and humans. This study highlights the usefulness of a continuous time-series-based approach, which specifically integrates surface temperature and vegetation abundance-based NDVI data into a study of land cover and vegetation health for savanna landscapes, which will be useful for park managers and conservationists globally.

Read the full publication at Sensors






MOSSA and WUDecadal-Scale Variations of Thalweg Morphology and Riffle–Pool Sequences in Response to Flow Regulation in the Lowermost Mississippi River

Chia-Yu Wu and Joann Mossa

Article first published online: 5 JUN 2019 Water

DOI: 10.3390/w11061175

ABSTRACT: The lowermost Mississippi River (LMR) is one of the largest deltaic systems in North America and one of the heavily human-manipulated fluvial river systems. Historic hydrographic surveys from the mid-1900s to the early 2010s were used to document the thalweg morphology adjustments, as well as the riffle–pool sequences. Extensive aggradation was observed during 1950s to 1960s, as the Atchafalaya River was enlarging before the completion of the Old River Control Structure (ORCS). Following the completion of the ORCS, reductions in sediment input to the LMR resulted in net degradation of the thalweg profile patterns since the mid-1960s except for the 1992–2004 period. Different flood events that supplied sediment might be the cause of upstream aggradation from 1963–1975 and net aggradation along the entire reach from 1992–2004. Furthermore, the change pattern of thalweg profiles appear to be controlled by backwater effects, as well as the Bonnet Carré spillway opening. Results from riffle–pool sequences reveal that the averaging Ws ratios (length to channel width) are 6–7, similar to numerous previous studies. Temporal variations of the same riffles and pools reveal that aggradation and degradation might be heavily controlled by similar factors to the thalweg variations (i.e., sediment supply, backwater effects). In sum, this study examines decadal-scale geomorphic responses in a low-lying large river system subject to different human interventions, as well as natural flood events. Future management strategies of this and similar river systems should consider recent riverbed changes in dredging, sediment management, and river engineering.

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GOLANTWomen Caring for Our Aging in Place Seniors Will Lose Out because of U.S. Immigration Policies

Stephen M. Golant

Article first published online: 15 Apr 2019 Journal of Aging & Social Policy

DOI: 10.1080/08959420.2019.1603535

ABSTRACT: Most older people experiencing chronic health problems, physical disabilities, and memory losses are still able to age in place in their own homes. However, they often need help from others to enjoy healthy, active, and independent lives. They turn mostly to family members, mainly women and usually their daughters, daughters-in-law or wives. But caring for frail elders has become more demanding and complex, and these family members often feel physically and emotionally overwhelmed and burnt out. They concede that they cannot do it alone. Others find it more difficult to hold full-or even part-time jobs. Hiring home (direct) care workers to assist their loved ones can be an effective solution to ease their caregiving responsibilities. However, these personal care aides, home health aides, and nursing assistants are already in short supply. Moreover, going forward the aging of the baby boomer population will result in an even greater demand for their services even as these jobs are often unattractive to American-born workers and turnover is high. This country’s immigration policies will make it even more difficult for women caring for older persons to hire these workers. Over 25 percent of home care workers are low-skilled immigrants or foreign-born. However, the Trump administration’s policies reduce the number of immigrants entering the U.S. and specifically choke off the various pathways that enable low-skilled persons to be hirable in the home care sector. Female caregivers seeking relief from their caregiving responsibilities will lose out unless we remove these immigration barriers.

Read the full publication at Journal of Aging & Social Policy






SCHAPER – Habitat mapping of giant kelp (Macrocystis pyrifera) and devil weed (Sargassum horneri) off the coast of Santa Catalina Island, California

Michael Espriella, Tyler Schaper, Alison Atchia, Katherine Rose, Vincent Lecours

Article first published online: APR 2019 McGill Science Undergraduate Research Journal


Background: Macrocystis pyrifera, commonly known as giant kelp, is a fast-growing brown alga that typically inhabits temperate waters. In southern California, M. pyrifera provides many ecologically and economically significant ecosystem services. Sargassum horneri, a non-native brown macroalga commonly known as devil weed, often outcompetes M. pyrifera while providing fewer ecological or economical benefits. Examining potential areas of species overlap is key to understanding the invasion potential of S. horneri and essential to the implementation of removal efforts. This study aims to map the suitable habitat of M. pyrifera and invasive S. horneri in the coastal waters of Santa Catalina Island, California, and to quantify any overlapping habitat between the two macroalgae.

Methods: Broadly defined potential habitats were characterized around Santa Catalina Island using an unsupervised approach to habitat mapping based on a series of abiotic surrogates mapped at a 2 m spatialresolution. In situ substrate data were then overlaid onto the unsupervised classification to identify spatial associations between substrate type and potential habitats, and to interpret the classes. To predict the distribution of M. pyrifera and S. horneri around Santa Catalina Island based on their respective association with the environment, maximum entropy (MaxEnt) was used to produce species distribution models. The resulting models for M. pyrifera and S. horneri were overlaid to identify potential areas of conflict based on suitable habitat overlap.

Results: The unsupervised approach to habitat mapping resulted in a map of four potential habitats around Santa Catalina Island based on substrate cover. Sand was the most dominant type of substrate. The supervised approach using MaxEnt identified 10.27% of the study area as suitable habitat for M. pyrifera and 7.37% as suitable habitat for S. horneri. A total of 33.56% of the suitable habitat for M. pyrifera was found to also be suitable for S. horneri.

Limitations: The characterization of habitats and the species distribution modeling were limited to the study of benthic terrain characteristics due to the unavailability of other high-resolution environmental data (e.g., hydrodynamics and chemical data) around Santa Catalina Island. In addition, data were not available for the very shallow waters near the coast, where giant kelp is often found. Given the complexity of this ecosystem, the addition of other variables and data coverage closer to the coast would potentially make the maps and models more representative of the actual distribution of M. pyrifera and S. horneri and provide a more complete understanding of their environmental preferences.

Conclusion: This study provides insight into the kelp forest ecosystems found in California’s Channel Islands; it is a vital first step in order to understand the potential areas for invasion of M. pyrifera by S. horneri, thus supporting decision making and efforts to control S. horneri abundance.

Read the full publication at McGill Science Undergraduate Research Journal



ALENEZI, GOODMEHEDYSpatial pattern analysis of manufacturing industries in Keraniganj, Dhaka, Bangladesh

Mohammad Mehedy Hassan, Meshari S. Alenezi, Ryan Z. Good

Article first published online: 01 JAN 2019 GeoJournal

DOI: 10.1007/s10708-018-9961-5

ABSTRACT: Understanding industrial clustering and its patterns of development are important steps in linking regional policy development, strategic decision making, business site management, and fostering a country’s economic growth. A considerable variety of common location-based cluster measures are available in practice, including area-based measures and a variety of indicators based on analyses of point data. This study uses the geostatistical approaches kernel density, multi-distance Reply’s-K, and spatial autocorrelation, both global Moran’s-I and local Moran’s-I, to assess the degree of spatial clustering of manufacturing locations in Keranignaj, located at the southern periphery of the urban region of Dhaka, Bangladesh. Results indicated a non-random pattern for all manufacturing locations in the study region. Small-scale industries such as garment manufacturing, metal, and brick making have a strong presence in Keranignaj. Expansion of such industries were highly associated with proximity to a river, while food processing, rubber and plastics manufacturing industries were clustered in relation to road proximity. The spatial association Global Moran’s-I with higher positive coefficient value indicates homogeneity, or spatial auto-correlation, exist in the industrial locations studied here. Local Moran’s-I, which documents regional clustering, has yielded a statistically significant manufacturing cluster (0.05 level) for the manufacturing areas of Zinjira, Kaliganj, Mirerbagh, and Chunkutia. Since cluster-based economic development has recently been an area of increasing interest for both developed and developing nations, the outcomes from this study provide an insight into spatial processes of industrial development in Bangladesh, and the Dhaka area in particular, enabling planners and policymakers to make rational, informed decisions and strengthening the economic growth and capacity for development of micro-industries clusters for the area studied here and the region beyond.

Read the full publication at GeoJournal