Thaw-driven mass wasting couples slopes with downstream systems, and effects propagate through Arctic drainage networks

The intensification of thaw-driven mass wasting is transforming glacially conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Within the context of recent, rapidly evolving climate controls on the geomorphology of permafrost terrain, we (A) quantify three-dimensional retrogressive thaw slump enlargement and describe the processes and thresholds coupling slopes to downstream systems, (B) investigate catchment-scale patterns of slope thermokarst impacts and the geomorphic implications, and (C) map the propagation of effects through hydrological networks draining permafrost terrain of northwestern Canada. Power-law relationships between retrogressive thaw slump area and volume (R2=0.90), as well as the thickness of permafrost thawed (R2=0.63), combined with the multi-decadal (1986–2018) increase in the areal extent of thaw slump disturbance, show a 2 order of magnitude increase in catchment-scale geomorphic activity and the coupling of slope and hydrological systems. Predominant effects are to first- and second-order streams where sediment delivery, often indicated by formation of recent debris tongue deposits, commonly exceeds the transport capacity of headwater streams by orders of magnitude, signaling centennial- to millennial-scale perturbation of downstream systems. Assessment of hydrological networks indicates that thaw-driven mass wasting directly affects over 5538 km of stream segments, 889 km of coastline, and 1379 lakes in the 994 860 km2 study area. Downstream propagation of slope thermokarst indicates a potential increase in the number of affected lakes by at least a factor of 4 (n>5692) and impacted stream length by a factor of 8 (>44 343 km), and it defines several major impact zones on lakes, deltas, and coastal areas. Prince of Wales Strait is the receiving marine environment for greatly increased sediment and geochemical fluxes from numerous slump-impacted hydrological networks draining Banks Island and Victoria Island. The Peel and Mackenzie rivers are globally significant conveyors of the slope thermokarst cascade, delivering effects to North America's largest Arctic delta and the Beaufort Sea. Climate-driven erosion of ice-rich slopes in permafrost-preserved glaciated terrain has triggered a time-transient cascade of downstream effects that signal the rejuvenation of post-glacial landscape evolution. Glacial legacy, ground-ice conditions, and continental drainage patterns dictate that terrestrial, freshwater, coastal, and marine environments of western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia.

Investigation into Rain Attenuation Prediction Models at Locations in Lagos Using Remote Sensing

This paper investigated the performances of some rain attenuation prediction models at some GSM network locations in Lagos, Nigeria, using remote sensing at Ku band. Remote sensing is a collection and interpretation of information about an object without physical contact with the object being measured. Three popular terrestrial prediction models were considered in this work. These are ITU-R P.530-17, Lin and Silva Mello Models. Ten years (2010-2019) annual rainfall data with hourly integration time were sourced from the Nigerian Meteorological Agency (NIMET) and link budgets for three microwave links (Tarzan Yard, Kofo Abayomi and GLO Shop) in Victoria Island at 18 GHz were obtained from Global Communications Limited (GLO), Nigeria. Data analysis and comparison of the microwave links rainfall estimates were carried out to identify the most suitable of the three models at the selected locations of interest. Measurement data obtained from both NIMET and GLO were used to validate the predicted attenuation data from the three selected models. The ITU-R P.530-17 prediction model overestimated the measurement at Tarzan Yard; closely followed by Silva Mello, while Lin underestimated the measured data. Again, at Kofo Abayomi station, the ITU-R model overestimated the measurement, while both Silva Mello and Lin models underestimated the measurement. At the GLO Shop, the Silva Mello overestimated the measured value, while ITU-R and Lin underestimated the measurement. At 0.01% of time exceeded, NIMET measurement was higher (at 48.2 dB) than that of Tarzan Yard, Kofo Abayomi and GLO shop (43.1, 46.3 and 37.0 dB respectively). These results will provide useful information in mitigating signal outages due to rain for mobile communication systems. Keywords- Path attenuation, Prediction models, Rainfall rate, Terrestrial microwave links, Tropical region

The proposed Eko Atlantic City project, Victoria Island, Lagos: Preliminary impact assessment of land reclamation on the aquatic lives and climate change

The effects of climate change in the face of land reclamation among other anthropogenic activities are of great concern to aquatic genetic resources and biodiversity. This study was designed to assess the preliminary impact of the proposed Eko Atlantic City (EAC) project on the aquatic lives and/or biodiversity, and the level of development and challenges that have implications on climate change in Victoria Island and its environs in Lagos State, Nigeria. The selected areas such as Lamgbasa, Badore, Ajah and Victoria Island were evaluated using the snowball sampling approach, whereby 111 respondents were assessed. Results showed that land reclamation and construction activities had impacted on the aquatic lives and the primitive fishing occupation (5.5%). Respondents (44.4%) agreed that the on-going EAC had contributed to the development of Lagos State, however, negative impacts of climate change such as ocean surge, sea level rise, flooding among others were high but with low level of adaptive capacity agreement (41.7%). Furthermore, analysis showed varying degrees in the extent of severity of problems encountered from climate change effects such as rainfall, flooding, temperature, health issues among others. The study revealed that these communities were susceptible or vulnerable to the impacts of climate change such as coastal erosion, flooding, storm/ocean surge, sea level rise etc and importantly loss of non- renewable aquatic genetic resources. The government is hereby advised to have sound policies for adaptation and mitigation strategies to protect these non-renewable genetic resources and effect of climate change activities. Les effets du changement climatique face à la mise en valeur des terres, entre autres activités anthropiques, sont très préoccupants pour les ressources génétiques aquatiques et la biodiversité. Cette étude a été conçue pour évaluer l'impact préliminaire du projet proposé Eko Atlantic City (EAC) sur la vie aquatique et / ou la biodiversité, ainsi que le niveau de développement et les défis qui ont des implications sur le changement climatique dans l'île Victoria et ses environs dans l'État de Lagos, Nigeria. Les zones sélectionnées telles que Lamgbasa, Badore, Ajah et Victoria Island ont été évaluées à l'aide de la méthode d'échantillonnage en boule de neige, qui a permis d'évaluer 111 répondants. Les résultats ont montré que la remise en état des terres et les activités de construction avaient eu un impact sur la vie aquatique et l'occupation de la pêche primitive (5.5%). Les répondants (44.4%) ont convenu que l'EAC en cours avait contribué au développement de l'État de Lagos, cependant, les impacts négatifs du changement climatique tels que la montée des océans, l'élévation du niveau de la mer, les inondations, entre autres, étaient élevés mais avec un faible niveau d'accord de capacité d'adaptation (41.7%). En outre, l'analyse a montré des degrés divers dans l'étendue de la gravité des problèmes liés aux effets du changement climatique tels que les précipitations, les inondations, la température, les problèmes de santé, entre autres. L'étude a révélé que ces communautés étaient sensibles ou vulnérables aux impacts du changement climatique tels que l'érosion côtière, les inondations, les tempêtes / ondes océaniques, l'élévation du niveau de la mer, etc. et surtout la perte de ressources génétiques aquatiques non renouvelables. Il est conseillé au gouvernement de se doter de politiques solides pour les stratégies d'adaptation et d'atténuation afin de protéger ces ressources génétiques non renouvelables et les effets des activités liées aux changements climatiques.

Forecasting Performance of Commercial Property Investments in Lagos Metropolis

Investors rely on statistical forecasts to guide their investment decisions. Given the relative opportunity cost associated with these decisions, and the huge financial implication of commercial property investments, such insights are invaluable; because investors can choose investments from an informed position. Despite this recognised benefit of forecasting, there has been little focus on forecasting the performance (total returns) of commercial property investments in Lagos Metropolis. This paper, therefore, aims to forecast the total returns of two commercial property investment types (shops and offices) in five sub-markets (Yaba, Ikeja, Ikoyi, Victoria Island and Lagos Island) within the Lagos property market. In doing so, the study uses longitudinal data for the capital and rental values of commercial property investments in Lagos between 2006 to 2018 alongside a simple regression model for 2019-2021 predicted total returns. Autocorrelation was used in testing the predictive validity of this data set. Furthermore, multiple-forecasts were evaluated simultaneously for accuracy and, together, they illustrate the difficulty of compiling a robust dataset in the absence of a central database. This paper suggests that the sampled total returns for the five sub-markets fluctuate and tend to decline as seen in the Ordinary Least Square Regression technique for 2019 to 2021. The results also suggest a low autocorrelation in most of the sub-markets, which indicates that the observed pattern of returns may not continue. This paper recommends that investors be wary of commercial property investment in Lagos Metropolis, due to the observed poor performance (low and fluctuating total returns). It is also recommended that a property database be constructed to improve property data reliability and allow for the application of complex quantitative forecasting techniques.

Components of antenatal care received by women in fishing communities on Lake Victoria, Uganda; a cross sectional survey

Background Uganda has one of the highest maternal deaths at a ratio of 336 per 100,000 live births. As Uganda strives to achieve sustainable development goals, appropriate antenatal care is key to reduction of maternal mortality. We explored women’s reported receipt of seven of the Uganda guidelines components of antenatal care, and associated factors in hard to reach Lake Victoria island fishing communities of Kalangala district. Methods A cross sectional survey among 486 consenting women aged 15–49 years, who were pregnant at any time in the past 6 months was conducted in 6 island fishing communities of Kalangala district, Uganda, during January–May 2018. Interviewer administered questionnaires, were used to collect data on socio-demographics and receipt of seven of the Uganda guidelines components of antenatal care. Regression modeling was used to determine factors associated with receipt of all seven components. Results Over three fifths (65.0%) had at least one ANC visit during current or most recent pregnancy. Fewer than a quarter of women who reported attending care at least four times received all seven ANC components [(23.6%), P < 0.05]. Women who reported receipt of ANC from the mainland were twice as likely to have received all seven components as those who received care from islands (aOR = 1.8; 95% CI:0.9–3.7). Receipt of care from a doctor was associated with thrice likelihood of receiving all components relative to ANC by a midwife or nurse (aOR = 3.2; 95% CI:1.1–9.1). Conclusions We observed that the delivery of antenatal care components per Ugandan guidelines is poor in these communities. Cost effective endeavors to improve components of antenatal care received by women are urgently needed. Task shifting some components of ANC to community health workers may improve care in these island communities. Trial registration PACTR201903906459874 (Retrospectively registered).

Components of antenatal care received by women in fishing communities on Lake Victoria, Uganda; a cross sectional survey

Background: Uganda has one of the highest maternal deaths at a ratio of 336 per 100,000 live births. As Uganda strives to achieve sustainable development goals, appropriate antenatal care is key to reduction of maternal mortality. We explored women’s reported receipt of seven of the Uganda guidelines components of antenatal care, and associated factors in hard to reach Lake Victoria island fishing communities of Kalangala district.Methods: A cross sectional survey among 486 consenting women aged 15-49 years, who were pregnant at any time in the past 6 months was conducted in 6 island fishing communities of Kalangala district, Uganda, during January-May 2018. Interviewer administered questionnaires, were used to collect data on socio-demographics and receipt of seven of the Uganda guidelines components of antenatal care. Regression modeling was used to determine factors associated with receipt of all seven components. Results: Over three fifths (65.0%) had at least one ANC visit during current or most recent pregnancy. Fewer than a quarter of women who reported attending care at least four times received all seven ANC components [(23.6%), P<0.05]. Women who reported receipt of ANC from the mainland were twice as likely to have received all seven components as those who received care from islands (aOR=1.8; 95% CI:0.9-3.7). Receipt of care from a doctor was associated with thrice likelihood of receiving all components relative to ANC by a midwife or nurse (aOR=3.2; 95% CI:1.1-9.1). Conclusions: We observed that the delivery of antenatal care components per Ugandan guidelines is poor in these communities. Cost effective endeavors to improve components of antenatal care received by women are urgently needed. Task shifting some components of ANC to community health workers may improve care in these island communities.Trial Registration: PACTR201903906459874 (Retrospectively registered).