Month: October 2024

Estimation of Sentinel-1 derived soil moisture using modified Dubois model

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Abstract

Surface soil moisture plays a crucial role in various fields such as climate change, agronomy, water resources, and many other scientific and engineering domains. Accurately measuring soil moisture at both regional and global scales, with high spatial and temporal resolution, is essential for predicting and managing floods, droughts, and agricultural productivity to ensure food security. The launch of Sentinel operational satellites has significantly advanced remote sensing observations, enabling scientists to estimate soil moisture more accurately at improved spatial and temporal resolutions. This study aims to assess the potential of utilizing Sentinel-1A satellite images for soil moisture estimation in a semi-arid region using the Modified Dubois Model (MDM) semi-empirical model with Topp’s model. The soil moisture estimated is validated by comparing it with field measurements, which helps in understanding the spatial variability of soil moisture across various land use classes. Results concluded that the Sentinel 1 derived soil moisture on 3rd and 15th January 2022 in comparison with the soil moisture measured using soil moisture probe (R2 = 0.68 and 0.63) and laboratory measurement (R2 = 0.72 and 0.72) are found to be well correlated and can be adapted for monitoring drought and managing water resources. The study offers a robust accuracy assessment of Sentinel 1 derived soil moisture using soil moisture probe and laboratory analysis and suggests that the framework has the potential for operational monitoring of drought conditions and water resource management in semi-arid regions at a higher spatial and temporal resolution.

Visual MODFLOW, solute transport modeling, and remote sensing techniques for adapting aquifer potentiality under reclamation and climate change impacts in coastal aquifer

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Abstract

Global environmental changes, such as climate change and reclamation alterations, significantly influence hydrological processes, leading to hydrologic nonstationarity and challenges in managing water availability and distribution. This study introduces a conceptual underpinning for the rational development and sustainability of groundwater resources. As one of the areas intended for the development projects within the Egyptian national plan for the reclamation of one and a half million acres; hundreds of pumping wells were constructed in the Moghra area to fulfill the reclamation demand. This study investigates the long-term impacts of exploiting the drilled pumping wells under climate change. The approach is to monitor the groundwater levels and the salinity values in the Moghra aquifer with various operational strategies and present proposed sustainable development scenarios. The impact of global warming and climate change is estimated for a prediction period of 30 years by using satellite data, time series geographical analysis, and statistical modeling. Using MODFLOW and Solute Transport (MT3DMS) modules of Visual MODFLOW USGS 2005 software, a three-dimensional (3D) finite-difference model is created to simulate groundwater flow and salinity distribution in the Moghra aquifer with the input of forecast downscaling (2020–2050) of main climatic parameters (PPT, ET, and Temp). The optimal adaptation-integrated scenario to cope with long-term groundwater withdrawal and climate change impacts is achieved when the Ministry of Irrigation and Water Resources (MWRI) recommends that the maximum drawdown shouldn’t be more significant than 1.0 m/ year. In this scenario, 1,500 pumping wells are distributed with an equal space of 500 m, a pumping rate of 1,200 m3/day and input the forecast of the most significant climatic parameters after 30 years. The output results of this scenario revealed a drawdown level of 42 m and a groundwater salinity value of 16,000 mg/l. Climate change has an evident impact on groundwater quantity and quality, particularly in the unconfined coastal aquifer, which is vulnerable to saltwater intrusion and pollution of drinking water resources. The relationship between climate change and the hydrologic cycle is crucial for predicting future water availability and addressing water-related issues.

Evaluation and comparison of the performances of the CMIP5 and CMIP6 models in reproducing extreme rainfall in the Upper Blue Nile basin of Ethiopia

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Abstract

Understanding the characteristics of extreme rainfall is vital for planning effective adaptation and mitigation measures. Thus, this study aims to evaluate the performances of 16 general circulation models (GCMs) of the coupled model intercomparison project (8 CMIP5 and 8 CMIP6) in reproducing observed extreme rainfall indices (ERFIs) and monthly rainfall in the Upper Blue Nile (UBN) basin of Ethiopia (1981–2005). The observed ERFIs were computed based on rainfall estimates of the random forest merging (RF-MERGE) algorithm, which combines ground-based rainfall with three gridded rainfall products (GRFPs). The GCMs were evaluated using statistical performance measures such as the Pearson correlation coefficient (R), root mean square error (RMSE), and percent bias (PBIAS). Using the Technique for Order Preferences by Similarity to an Ideal Solution (TOPSIS), the GCMs were ranked from least skilled to most skilled. Accordingly, MIROC5 of the CMIP5 and MPI-ESM1-2-LR of the CMIP6 models were found to be the most suitable models. Furthermore, the top-ranked models were selected and bias corrected using quantile mapping (QM), and their ensembles (CMIP5-ensemble and CMIP6-ensemble) were used for projecting future extremes under representative concentration pathways (RCP4.5 and RCP8.5) and shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5), respectively, for the periods 2031–2055 and 2056–2080. Most of the ERFIs exhibited high variability and inconsistent trends for both the observations and future periods. The findings of this study provide valuable insights the the impacts of climate change on ERFIs, and the developed framework can serves as a useful reference for future research.

Implementation Science for HIV Prevention and Treatment in Indigenous Communities: a Systematic Review and Commentary

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Abstract

Purpose of Review

We systematically reviewed implementation research conducted in Indigenous communities in the Americas and the Pacific that focused on improving delivery of HIV preventive or treatment services. We highlight strengths and opportunities in the literature and outline principles for Indigenous-led, HIV-related implementation science.

Recent Findings

We identified 31 studies, revealing a consistent emphasis on cultural tailoring of services to Indigenous communities. Common barriers to implementation included stigma, geographic limitations, confidentiality concerns, language barriers, and mistrust. Community involvement in intervention development and delivery emerged as a key facilitator, and nearly half of the studies used community-based participatory research methods. While behavioral HIV prevention, especially among Indigenous youth, was a major focus, there was limited research on biomedical HIV prevention and treatment. No randomized implementation trials were identified.

Summary

The findings underscore the importance of community engagement, the need for interventions developed within Indigenous communities rather than merely adapted, and the value of addressing the social determinants of implementation success. Aligned to these principles, an indigenized implementation science could enhance the acceptability and reach of critical HIV preventive and treatment services in Indigenous communities while also honoring their knowledge, wisdom, and strength.

System Design, Automatic Data Collection Framework and Embedded Software Development of Internet of Things (IoT) for Air Pollution Monitoring of Nagpur Metropolis

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Abstract

In the era of smart computing, edge computing, and machine intelligence, the Internet of Things (IoT) is playing a greater role in establishing hyper connective, cost-effective infrastructure for monitoring the environment. With the increase in the level of urbanization and population density in very fast-growing cities like Nagpur, the increase in air pollution needs to be monitored. This requires a network of Pollution monitoring systems for carrying out spatio-temporal analysis of pollution in the city on a real-time basis. Such established networks can be a key to understand the sources of pollution under various city conditions. To monitor and manage air pollutants, it is essential to put in place monitoring stations at multiple places. Although commercial pollution monitoring stations exist, they are limited in number. In this study, an attempt has been made to develop and implement a network of IoT devices using cost effective Metal Oxide Semiconductor based gas sensors integrated with ATMEGA 328P Microcontroller. Commercial systems are found to be space, energy and cost expensive. The developed pollution monitoring system can be replicated easily since they are compact in size, cost-effective, network and energy independent. This study discusses the development and implementation of a network of 10 smart IoT sensors in the Nagpur metropolis. The developed smart air pollution monitoring system combines IoT technology with real-time pollution monitoring systems. It measures and monitors temperature, humidity and pollutant concentration of Carbon Monoxide, Ozone, Carbon Dioxide, Sulphur Dioxide and PM2.5 and Nitrous oxides simultaneously. The study envisages to support Sustainable Development Goals – SDG11 which aims to reduce the environmental impact of cities by improving air quality.

Childhood-Onset Systemic Lupus Erythematosus (cSLE): An International Perspective

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Abstract

Purpose of Review

Childhood-onset systemic lupus erythematosus (cSLE) is a severe and potentially life-threatening chronic autoimmune disease. cSLE is more aggressive and has poorer outcomes than adult-onset disease. The global burden of cSLE is poorly understood, with most publications on cSLE originating from high-resourced settings. The reports from less resourced settings indicate high morbidity and mortality in these populations.

Recent Findings

In this article, we review the disparities in global access to rheumatology care and research for patients with cSLE. We highlight recent cSLE advances from all regions of the globe. We describe current obstacles to cSLE clinical care and research in all settings. Finally, we propose a path forward for high quality, equitable and accessible care to individuals with cSLE everywhere.

Summary

Individuals with cSLE are at risk for morbidity and death, yet patients worldwide face challenges to adequate access to care and research. Sustained, collaborative efforts are needed to create pathways to improve care and outcomes for these patients.