142 results on '"Al-Hamdan, Mohammad Z"'
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2. Application of 1D model for overland flow simulations on 2D complex domains
- Author
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Zhang, Yaoxin, Al-Hamdan, Mohammad Z., Bingner, Ronald L., Chao, Xiaobo, Langendoen, Eddy, O'Reilly, Andrew M., and Vieira, Dalmo A.N.
- Published
- 2024
- Full Text
- View/download PDF
3. A three-dimensional numerical model for variably saturated groundwater flow using meshless weak-strong form method
- Author
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Fang, Jiayu, Al-Hamdan, Mohammad Z., O'Reilly, Andrew M., Ozeren, Yavuz, and Rigby, James R.
- Published
- 2024
- Full Text
- View/download PDF
4. Generation of 1D channel networks for overland flow simulations on 2D complex domains
- Author
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Zhang, Yaoxin, Al-Hamdan, Mohammad Z., Bingner, Ronald L., Chao, Xiaobo, Langendoen, Eddy, and Vieira, Dalmo A.N.
- Published
- 2024
- Full Text
- View/download PDF
5. A novel floodwave response model for time-varying streambed conductivity using space-time collocation Trefftz method
- Author
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Fang, Jiayu, Al-Hamdan, Mohammad Z., O'Reilly, Andrew M., Ozeren, Yavuz, Rigby, James R., and Jia, Yafei
- Published
- 2023
- Full Text
- View/download PDF
6. Short-Term total and wildfire fine particulate matter exposure and work loss in California
- Author
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Meng, Ying-Ying, Yu, Yu, Al-Hamdan, Mohammad Z., Marlier, Miriam E., Wilkins, Joseph L., Garcia-Gonzales, Diane, Chen, Xiao, and Jerrett, Michael
- Published
- 2023
- Full Text
- View/download PDF
7. Association of diabetes and exposure to fine particulate matter (PM2.5) in the Southeastern United States
- Author
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Valdez, R. Burciaga, Tabatabai, Mohammad, Al-Hamdan, Mohammad Z., Wilus, Derek, Hood, Darryl B., Im, Wansoo, Nori-Sarma, Amruta, Ramesh, Aramandla, Donneyong, Macarius M., Langston, Michael A., Mouton, Charles P., and Juárez, Paul D.
- Published
- 2022
- Full Text
- View/download PDF
8. The effects of air pollution, meteorological parameters, and climate change on COVID-19 comorbidity and health disparities: A systematic review
- Author
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Juarez, Paul D., Ramesh, Aramandla, Hood, Darryl B., Alcendor, Donald J., Valdez, R. Burciaga, Aramandla, Mounika P., Tabatabai, Mohammad, Matthews-Juarez, Patricia, Langston, Michael A., Al-Hamdan, Mohammad Z., Nori-Sarma, Amruta, Im, Wansoo, and Mouton, Charles C.
- Published
- 2022
- Full Text
- View/download PDF
9. Validation of North American land data assimilation system Phase 2 (NLDAS-2) air temperature forcing and downscaled data with New York State station observations
- Author
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Estes, Maurice G., Jr., Insaf, Tabassum, Al-Hamdan, Mohammad Z., Adeyeye, Temilayo, and Crosson, William
- Published
- 2022
- Full Text
- View/download PDF
10. Parallel Implicit Solvers for 2D Numerical Models on Structured Meshes.
- Author
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Zhang, Yaoxin, Al-Hamdan, Mohammad Z., and Chao, Xiaobo
- Subjects
- *
NUMERICAL solutions to partial differential equations , *CENTRAL processing units , *COMPUTATIONAL fluid dynamics , *FLOW simulations , *SEDIMENT transport - Abstract
This paper presents the parallelization of two widely used implicit numerical solvers for the solution of partial differential equations on structured meshes, namely, the ADI (Alternating-Direction Implicit) solver for tridiagonal linear systems and the SIP (Strongly Implicit Procedure) solver for the penta-diagonal systems. Both solvers were parallelized using CUDA (Computer Unified Device Architecture) Fortran on GPGPUs (General-Purpose Graphics Processing Units). The parallel ADI solver (P-ADI) is based on the Parallel Cyclic Reduction (PCR) algorithm, while the parallel SIP solver (P-SIP) uses the wave front method (WF) following a diagonal line calculation strategy. To map the solution schemes onto the hierarchical block-threads framework of the CUDA on the GPU, the P-ADI solver adopted two mapping methods, one block thread with iterations (OBM-it) and multi-block threads (MBMs), while the P-SIP solver also used two mappings, one conventional mapping using effective WF lines (WF-e) with matrix coefficients and solution variables defined on original computational mesh, and a newly proposed mapping using all WF mesh (WF-all), on which matrix coefficients and solution variables are defined. Both the P-ADI and the P-SIP have been integrated into a two-dimensional (2D) hydrodynamic model, the CCHE2D (Center of Computational Hydroscience and Engineering) model, developed by the National Center for Computational Hydroscience and Engineering at the University of Mississippi. This study for the first time compared these two parallel solvers and their efficiency using examples and applications in complex geometries, which can provide valuable guidance for future uses of these two parallel implicit solvers in computational fluids dynamics (CFD). Both parallel solvers demonstrated higher efficiency than their serial counterparts on the CPU (Central Processing Unit): 3.73~4.98 speedup ratio for flow simulations, and 2.166~3.648 speedup ratio for sediment transport simulations. In general, the P-ADI solver is faster than but not as stable as the P-SIP solver; and for the P-SIP solver, the newly developed mapping method WF-all significantly improved the conventional mapping method WF-e. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Evaluating land cover changes in Eastern and Southern Africa from 2000 to 2010 using validated Landsat and MODIS data
- Author
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Al-Hamdan, Mohammad Z., Oduor, Phoebe, Flores, Africa I., Kotikot, Susan M., Mugo, Robinson, Ababu, Jaffer, and Farah, Hussein
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- 2017
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12. Investigating the effects of environmental factors on autism spectrum disorder in the USA using remotely sensed data
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Al-Hamdan, Ashraf Z., Preetha, Pooja P., Albashaireh, Reem N., Al-Hamdan, Mohammad Z., and Crosson, William L.
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- 2018
- Full Text
- View/download PDF
13. Estimating policy-relevant health effects of ambient heat exposures using spatially contiguous reanalysis data
- Author
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Adeyeye, Temilayo E., Insaf, Tabassum Z., Al-Hamdan, Mohammad Z., Nayak, Seema G., Stuart, Neil, DiRienzo, Stephen, and Crosson, William L.
- Published
- 2019
- Full Text
- View/download PDF
14. Estimating ground-level PM2.5 concentrations in the Southeastern United States using MAIAC AOD retrievals and a two-stage model
- Author
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Hu, Xuefei, Waller, Lance A., Lyapustin, Alexei, Wang, Yujie, Al-Hamdan, Mohammad Z., Crosson, William L., Estes, Maurice G., Jr., Estes, Sue M., Quattrochi, Dale A., Puttaswamy, Sweta Jinnagara, and Liu, Yang
- Published
- 2014
- Full Text
- View/download PDF
15. Fine particulate matter and incident coronary heart disease in the REGARDS cohort
- Author
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Loop, Matthew Shane, McClure, Leslie A., Levitan, Emily B., Al-Hamdan, Mohammad Z., Crosson, William L., and Safford, Monika M.
- Published
- 2018
- Full Text
- View/download PDF
16. Heat Maps of Hypertension, Diabetes Mellitus, and Smoking in the Continental United States
- Author
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Loop, Matthew Shane, Howard, George, de los Campos, Gustavo, Al-Hamdan, Mohammad Z., Safford, Monika M., Levitan, Emily B., and McClure, Leslie A.
- Published
- 2017
- Full Text
- View/download PDF
17. Using Land Cover Data to Characterize Living Environments of Geocoded Addresses: Estes et al. Respond
- Author
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Estes,, Maurice G., Al-Hamdan, Mohammad Z., Crosson, William, Estes, Sue M., Quattrochi, Dale, Kent, Shia, and McClure, Leslie Ain
- Published
- 2010
- Full Text
- View/download PDF
18. Use of Remotely Sensed Data to Evaluate the Relationship between Living Environment and Blood Pressure
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Estes, Maurice G., Al-Hamdan, Mohammad Z., Crosson, William, Estes, Sue M., Quattrochi, Dale, Kent, Shia, and McClure, Leslie Ain
- Published
- 2009
- Full Text
- View/download PDF
19. The relationship between long-term sunlight radiation and cognitive decline in the REGARDS cohort study
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Kent, Shia T., Kabagambe, Edmond K., Wadley, Virginia G., Howard, Virginia J., Crosson, William L., Al-Hamdan, Mohammad Z., Judd, Suzanne E., Peace, Fredrick, and McClure, Leslie A.
- Published
- 2014
- Full Text
- View/download PDF
20. Using Landsat, MODIS, and a Biophysical Model to Evaluate LST in Urban Centers
- Author
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Al-Hamdan, Mohammad Z, Quattrochi, Dale A, Bounoua, Lahouari, Lachir, Asia, and Zhang, Ping
- Subjects
Earth Resources And Remote Sensing - Abstract
In this paper, we assessed and compared land surface temperature (LST) in urban centers using data from Landsat, MODIS, and the Simple Biosphere model (SiB2). We also evaluated the sensitivity of the models LST to different land cover types, fractions (percentages), and emissivities compared to reference points derived from Landsat thermal data. This was demonstrated in three climatologically- and morphologically-different cities of Atlanta, GA, New York, NY, and Washington, DC. Our results showed that in these cities SiB2 was sensitive to both the emissivity and the land cover type and fraction, but much more sensitive to the latter. The practical implications of these results are rather significant since they imply that the SiB2 model can be used to run different scenarios for evaluating urban heat island (UHI) mitigation strategies. This study also showed that using detailed emissivities per land cover type and fractions from Landsat-derived data caused a convergence of the model results towards the Landsat-derived LST for most of the studied cases. This study also showed that SiB2 LSTs are closer in magnitude to Landsat-derived LSTs than MODIS-derived LSTs. It is important, however, to emphasize that both Landsat and MODIS LSTs are not direct observations and, as such, do not represent a ground truth. More studies will be needed to compare these results to in situ LST data and provide further validation.
- Published
- 2016
- Full Text
- View/download PDF
21. Evaluation of NLDAS-2 and Downscaled Air Temperature data in Florida.
- Author
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Jung, Jihoon, Al-Hamdan, Mohammad Z., Crosson, William L., Uejio, Christopher K., Duclos, Chris, Kintziger, Kristina W., Reid, Keshia, Jordan, Melissa, Zierden, David, Spector, June T., and Insaf, Tabassum Z.
- Subjects
ATMOSPHERIC temperature ,LAND surface temperature ,URBAN heat islands ,CLIMATE extremes ,METEOROLOGICAL stations ,HURRICANE Irma, 2017 - Abstract
A broad spectrum of model-derived weather datasets are available in the US. Because each product integrates atmospheric conditions with different model processes, each produces different statistical biases. This study validated air temperature from NLDAS-2 and a novel statistically downscaled NLDAS-2 against observational weather station data for the state of Florida. We statistically downscaled NLDAS-2 to a 1-km grid product using MODIS land surface temperature. We investigated mean biases and Pearson correlation coefficients between daily observational data and the two model-derived datasets. We then calculated multiple Climate Extremes Indices to further scrutinize differences in capturing extreme temperatures. Finally, we quantified potential causes of systematic NLDAS-2 biases related to distance from the coast, urban heat island, land cover, and type of observational stations. Two model-derived datasets showed similar mean biases and correspondence with observational data, underestimating maximum temperature by 1°C and overestimating minimum temperature by 2°C. Extreme temperatures were well simulated in both datasets. However, we still found overestimated extreme minimum temperatures and underestimated extreme maximum temperatures. Systematic biases tended to be higher for coastal stations and grids having a high fraction of water. Our study suggests that including physical processes covering land surface and ocean interactions may improve the model accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Linking NASA Environmental Data with a National Public Health Cohort Study and a CDC on-line System to Enhance Public Health Decision Making
- Author
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Al-Hamdan, Mohammad Z, Crosson, William L, Estes, Maury, Estes, Sue, Hemmings, Sarah, Quattrochi, Dale, Wade, Gina, McClure, Leslie, Kent, Shia, Economou, Sigrid, and Puckett, Mark
- Subjects
Earth Resources And Remote Sensing ,Environment Pollution ,Life Sciences (General) - Published
- 2015
23. Health and Environment Linked for Information Exchange in Atlanta (HELIX-Atlanta)
- Author
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Al-Hamdan, Mohammad Z, Crosson, William L, Estes, Maury, Estes, Sue, Limaye, Ashutosh, Quattrochi, Dale, Rickman, Doug, Sinclair, Amber, Tolsma, Dennis, Qualters, Judy, Adeniyi, Kafayat, and Niskar, Amanda
- Subjects
Statistics And Probability ,Life Sciences (General) ,Documentation And Information Science ,Environment Pollution - Published
- 2015
24. Environmental Public Health Applications Using Remotely Sensed Data
- Author
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Al-Hamdan, Mohammad Z, Crosson, William L, Estes, Maury, Estes, Sue, Hemmings, Sarah, Limaye, Ashutosh, Luvall, Jeffrey, Quattrochi, Dale, Rickman, Douglas, and Wade, Gina
- Subjects
Life Sciences (General) ,Earth Resources And Remote Sensing ,Environment Pollution - Published
- 2015
25. Relationships Between Excessive Heat and Daily Mortality over the Coterminous U.S
- Author
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Crosson, William L, Al-Hamdan, Mohammad Z, Estes, Maury G., Jr, Estes, Sue M, and Quattrochi, Dale A
- Subjects
Life Sciences (General) ,Geosciences (General) - Abstract
In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. Using National Land Data Assimilation System (NLDAS) meteorological reanalysis data, we have developed several measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. These measures include daily maximum and minimum air temperatures, daily maximum heat indices and a new heat stress variable called Net Daily Heat Stress (NDHS) that gives an integrated measure of heat stress (and relief) over the course of a day. All output has been created on the NLDAS 1/8 degree (approximately 12 km) grid and aggregated to the county level, which is the preferred geographic scale of analysis for public health researchers. County-level statistics have been made available through the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. We have examined the relationship between excessive heat events, as defined in eight different ways from the various daily heat metrics, and heat-related and all-cause mortality defined in CDC's National Center for Health Statistics 'Multiple Causes of Death 1999-2010' dataset. To do this, we linked daily, county-level heat mortality counts with EHE occurrence based on each of the eight EHE definitions by region and nationally for the period 1999-2010. The objectives of this analysis are to determine (1) whether heat-related deaths can be clearly tied to excessive heat events, (2) what time lags are critical for predicting heat-related deaths, and (3) which of the heat metrics correlates best with mortality in each US region. Results show large regional differences in the correlations between heat and mortality. Also, the heat metric that provides the best indicator of mortality varied by region. Results from this research will potentially lead to improvements in our ability to anticipate and mitigate any significant impacts of extreme heat events on health.
- Published
- 2015
26. Relationship Between Watershed Land-Cover/Land-Use Change and Water Turbidity Status of Tampa Bay Major Tributaries, Florida, USA
- Author
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Moreno Madriñán, Max J., Al-Hamdan, Mohammad Z., Rickman, Douglas L., and Ye, Jun
- Published
- 2012
- Full Text
- View/download PDF
27. Methods for characterizing fine particulate matter using ground observations and remotely sensed data: potential use for environmental public health surveillance
- Author
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Al-Hamdan, Mohammad Z., Crosson, William L., Limaye, Ashutosh S., Rickman, Douglas L., Quattrochi, Dale A., Estes, Jr., Maurice G., Qualters, Judith R., Sinclair, Amber H., Tolsma, Dennis D., Adeniyi, Kafayat A., and Niskar, Amanda Sue
- Subjects
Air quality monitoring stations -- Usage -- Environmental aspects -- Measurement -- Methods ,Air quality -- Measurement -- Environmental aspects -- Methods -- Usage ,Environmental monitoring -- Methods -- Usage -- Measurement -- Environmental aspects ,Public health -- Environmental aspects -- Usage -- Measurement -- Methods ,Environmental services industry ,Environmental issues ,Science and technology - Abstract
ABSTRACT This study describes and demonstrates different techniques for surface fitting daily environmental hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 µm ([PM.sub.2.5]) for [...]
- Published
- 2009
28. Linking Excessive Heat with Daily Heat-Related Mortality over the Coterminous United States
- Author
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Quattrochi, Dale A, Crosson, William L, Al-Hamdan, Mohammad Z, and Estes, Maurice G., Jr
- Subjects
Meteorology And Climatology - Abstract
In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. This research seeks to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The focus of research is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM outputs, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons for 2040 and 2090 are compared to the recent past period of 1981- 2000. We characterize regional-scale temperature and humidity conditions using GCM outputs for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM outputs are analyzed to develop a 'heat stress climatology' based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km) much finer than that of GCMs, to create future climate realizations. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air temperatures, heat indices, and a new heat stress variable developed as part of this research that gives an integrated measure of heat stress (and relief) over the course of a day. Comparisons are made between projected (2040 and 2090) and past (1990) heat stress statistics. Outputs are aggregated to the county level, which is a popular scale of analysis for public health interests. County-level statistics are made available to public health researchers by the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. This addition of heat stress measures to CDC WONDER allows decision and policy makers to assess the impact of alternative approaches to optimize the public health response to EHEs. Through CDC WONDER, users are able to spatially and temporally query public health and heat-related data sets and create county-level maps and statistical charts of such data across the coterminous U.S.
- Published
- 2014
29. Estimating ground-level PM2.5 concentrations in the southeastern U.S. using geographically weighted regression☆
- Author
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Hu, Xuefei, Waller, Lance A., Al-Hamdan, Mohammad Z., Crosson, William L., Estes, Maurice G., Jr., Estes, Sue M., Quattrochi, Dale A., Sarnat, Jeremy A., and Liu, Yang
- Published
- 2013
- Full Text
- View/download PDF
30. Short- and long-term sunlight radiation and stroke incidence
- Author
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Kent, Shia T., McClure, Leslie A., Judd, Suzanne E., Howard, Virginia J., Crosson, William L., Al-Hamdan, Mohammad Z., Wadley, Virginia G., Peace, Fredrick, and Kabagambe, Edmond K.
- Published
- 2013
- Full Text
- View/download PDF
31. Three-Dimensional Numerical Modeling of Flow Hydrodynamics and Cohesive Sediment Transport in Enid Lake, Mississippi.
- Author
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Chao, Xiaobo, Hossain, A. K. M. Azad, Al-Hamdan, Mohammad Z., Jia, Yafei, and Cizdziel, James V.
- Subjects
SEDIMENT transport ,THREE-dimensional modeling ,LAKE sediments ,HYDRODYNAMICS ,FREE surfaces ,FLOCCULATION - Abstract
Enid Lake is one of the largest reservoirs located in Yazoo River Basin, the largest basin in the state of Mississippi. The lake was impounded by Enid Dam on the Yocona River in Yalobusha County and covers an area of 30 square kilometers. It provides significant natural and recreational resources. The soils in this region are highly erodible, resulting in a large amount of fine-grained cohesive sediment discharged into the lake. In this study, a 3D numerical model was developed to simulate the free surface hydrodynamics and transportation of cohesive sediment with a median diameter of 0.0025 to 0.003 mm in Enid Lake. Flow fields in the lake are generally induced by wind and upstream river inflow, and the sediment is also introduced from the inflow during storm events. The general processes of sediment flocculation and settling were considered in the model, and the erosion rate and deposition rate of cohesive sediment were calculated. In this model, the sediment simulation was coupled with flow simulation. In this research, remote sensing technology was applied to estimate the sediment concentration at the lake surface and provide validation data for numerical model simulation. The model results and remote sensing data help us to understand the transport, deposition and resuspension processes of cohesive sediment in large reservoirs due to wind-induced currents and upstream river flows. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
32. Future Extreme Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health over the Coterminous U.S.
- Author
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Quattrochi, Dale A, Crosson, William L, Al-Hamdan, Mohammad Z, and Estes, Maurice G., Jr
- Subjects
Meteorology And Climatology ,Life Sciences (General) - Abstract
In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. This research seeks to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The focus of research is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM outputs, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons for 2040 and 2090 are compared to the recent past period of 1981- 2000. We characterize regional-scale temperature and humidity conditions using GCM outputs for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM outputs are analyzed to develop a 'heat stress climatology' based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km), to create future climate realizations. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air temperatures, heat indices and a new heat stress variable developed as part of this research that gives an integrated measure of heat stress (and relief) over the course of a day. Comparisons are made between projected (2040 and 2090) and past (1990) heat stress statistics. Outputs are aggregated to the county level, which is a popular scale of analysis for public health interests. County-level statistics are made available to public health researchers by the Centers for Disease Control and Prevention (CDC) via the Wideranging Online Data for Epidemiologic Research (WONDER) system. This addition of heat stress measures to CDC WONDER allows decision and policy makers to assess the impact of alternative approaches to optimize the public health response to EHEs. Through CDC WONDER, users are able to spatially and temporally query public health and heat-related data sets and create county-level maps and statistical charts of such data across the coterminous U.S
- Published
- 2013
33. Development of National Future Extreme Heat Scenario to Enable the Assessment of Climate Impacts on Public Health
- Author
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Quattrochi, Dale A, Cresson, William L, Al-Hamdan, Mohammad Z, and Estes, Maurice G
- Subjects
Meteorology And Climatology - Abstract
The project's emphasis is on providing assessments of the magnitude, frequency and geographic distribution of EHEs to facilitate public health studies. We focus on the daily to weekly time scales on which EHEs occur, not on decadal-scale climate changes. There is, however, a very strong connection between air temperature patterns at the two time scales and long-term climatic changes will certainly alter the frequency of EHEs.
- Published
- 2013
34. Estimating Ground-Level PM(sub 2.5) Concentrations in the Southeastern United States Using MAIAC AOD Retrievals and a Two-Stage Model
- Author
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Hu, Xuefei, Waller, Lance A, Lyapustin, Alexei, Wang, Yujie, Al-Hamdan, Mohammad Z, Crosson, William L, Estes, Maurice G., Jr, Estes, Sue M, Quattrochi, Dale A, Puttaswamy, Sweta Jinnagara, and Liu, Yang
- Subjects
Environment Pollution ,Earth Resources And Remote Sensing - Abstract
Previous studies showed that fine particulate matter (PM(sub 2.5), particles smaller than 2.5 micrometers in aerodynamic diameter) is associated with various health outcomes. Ground in situ measurements of PM(sub 2.5) concentrations are considered to be the gold standard, but are time-consuming and costly. Satellite-retrieved aerosol optical depth (AOD) products have the potential to supplement the ground monitoring networks to provide spatiotemporally-resolved PM(sub 2.5) exposure estimates. However, the coarse resolutions (e.g., 10 km) of the satellite AOD products used in previous studies make it very difficult to estimate urban-scale PM(sub 2.5) characteristics that are crucial to population-based PM(sub 2.5) health effects research. In this paper, a new aerosol product with 1 km spatial resolution derived by the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm was examined using a two-stage spatial statistical model with meteorological fields (e.g., wind speed) and land use parameters (e.g., forest cover, road length, elevation, and point emissions) as ancillary variables to estimate daily mean PM(sub 2.5) concentrations. The study area is the southeastern U.S., and data for 2003 were collected from various sources. A cross validation approach was implemented for model validation. We obtained R(sup 2) of 0.83, mean prediction error (MPE) of 1.89 micrograms/cu m, and square root of the mean squared prediction errors (RMSPE) of 2.73 micrograms/cu m in model fitting, and R(sup 2) of 0.67, MPE of 2.54 micrograms/cu m, and RMSPE of 3.88 micrograms/cu m in cross validation. Both model fitting and cross validation indicate a good fit between the dependent variable and predictor variables. The results showed that 1 km spatial resolution MAIAC AOD can be used to estimate PM(sub 2.5) concentrations.
- Published
- 2013
- Full Text
- View/download PDF
35. It's the Heat AND the Humidity -- Assessment of Extreme Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health
- Author
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Crosson, William L, Al-Hamdan, Mohammad Z, Economou, Sigrid, A, Estes, Maurice G, Estes, Sue M, Puckett, Mark, and Quattrochi, Dale A
- Subjects
Meteorology And Climatology - Abstract
In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. In a NASA-funded project supporting the National Climate Assessment, we are providing historical and future measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The project s emphasis is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM output, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons, 2040 and 2090, are the focus of future assessments; these are compared to the recent past period of 1981-2000. We are characterizing regional-scale temperature and humidity conditions using GCM output for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM output have been analyzed to develop a heat stress climatology based on statistics of extreme heat indicators. Differences between the two future and past periods have been used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes, combined with hourly historical meteorological data at a spatial scale (12 km) much finer than that of GCMs, enable us to create future climate realizations, from which we compute the daily heat stress measures and related spatially-specific climatological fields. These include the mean annual number of days above certain thresholds of maximum and minimum air temperatures, heat indices and a new heat stress variable that gives an integrated measure of heat stress (and relief) over the course of a day. Comparisons are made between projected (2040 and 2090) and past (1990) heat stress statistics. All output is being provided at the 12 km spatial scale and will also be aggregated to the county level, which is a popular scale of analysis for public health researchers. County-level statistics will be made available by our collaborators at the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. CDC WONDER makes the information resources of the CDC available to public health professionals and the general public. This addition of heat stress measures to CDC WONDER will allow decision and policy makers to assess the impact of alternative approaches to optimize the public health response to EHEs. It will also allow public health researchers and policy makers to better include such heat stress measures in the context of national health data available in the CDC WONDER system. The users will be able to spatially and temporally query public health and heat-related data sets and create county-level maps and statistical charts of such data across the coterminous U.S.
- Published
- 2013
36. Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL
- Author
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Al-Hamdan, Mohammad Z, Estes, Maurice G., Jr, Judd, Chaeli, Thom, Ron, Woodruff, Dana, Ellis, Jean T, Quattrochi, Dale, Watson, Brian, Rodriquez, Hugo, and Johnson, Hoyt
- Subjects
Environment Pollution - Abstract
Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for dissemination to coastal resource managers and stakeholders.
- Published
- 2012
37. Use of Remote Sensing/Geographical Information Systems (RS/GIS) to Identify Environmental Limits of Soil Transmitted Helminthes (STHs) Infection in Boaco, Nicaragua
- Author
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Moreno Madrinan, Max J, Parajon, David G, Al-Hamdan, Mohammad Z, Martinez, Roberto, Rickman, Douglas L, Parajon, Laura, and Estes, Sue
- Subjects
Life Sciences (General) - Published
- 2011
38. Use of Remote Sensing/Geographical Information Systems (RS/GIS) to Identify the Distributional Limits of Soil-Transmitted Helminths (STHs) and Their Association to Prevalence of Intestinal Infection in School-Age Children in Four Rural Communities in Boaco, Nicaragua
- Author
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Moreno, Max J, Al-Hamdan, Mohammad Z, Parajon, David G, Rickman, Douglas L, Luvall, Jeffrey, Parajon, Laura C, Martinez, Roberto A, and Estes, Sue
- Subjects
Earth Resources And Remote Sensing - Abstract
STHs can infect all members of a population but school-age children living in poverty are at greater risk. Infection can be controlled with drug treatment, health education and sanitation. Helminth control programs often lack resources and reliable information to identify areas of highest risk to guide interventions and to monitor progress. Objectives: To use RS/GIS to identify the environmental variables that correlate with the ecology of STHs and with the prevalence of STH infections. Methods: Geo-referenced in situ prevalence data will be overlaid over an ecological map derived from the RS environmental data using ESRI s ArcGIS 9.3. Prevalence data and RS environmental data matching at the same geographical location will be analyzed for correlation and those RS environmental variables that better correlate with prevalence data will be included in a multivariate regression model. Temperature, vegetation, and distance to bodies of water will be inferred using data from the Moderate-Resolution Imaging Spectroradiometer (MODIS) onboard the Terra and Aqua satellites, and Thematic Mapper (TM) and Enhance Thematic Mapper Plus (ETM+) satellite sensors onboard Landsat 5 and Landsat 7 respectively. Elevation will be estimated with data from The Shuttle Radar Topography Mission (SRTM). Prevalence and intensity of infections will be determined by parasitological survey (Kato Katz) of children enrolled in rural schools in Boaco, Nicaragua, in the communities of El Roblar, Cumaica Norte, Malacatoya 1, and Malacatoya 2). Expected Results: Associations between RS environmental data and prevalence in situ data will be determined and their applications to public health will be discussed. Discussion/Conclusions: The use of RS/GIS data to predict the prevalence of STH infections could be useful for helminth control programs, providing improved geographical guidance of interventions while increasing cost-effectiveness. Learning Objectives: (1) To identify the RS environmental variables that can help predict the prevalence of STH infections. (2) To understand potential applications of RS/GIS to national helminth control programs. (3) To asses the applicability of RS/GIS to control STH infections.
- Published
- 2011
39. Analysis of Association Between Remotely Sensed (RS) Data and Soil Transmitted Helminthes Infection Using Geographical Information Systems (GIS): Boaco, Nicaragua
- Author
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MorenoMadrinan, Max J, Al-Hamdan, Mohammad Z, Parajon, David G, Rickman, Douglas L, Luvall, Jeffrey, Podest, Erika, Parajon, Laura C, Martinez, Roberto A, and Estes, Sue
- Subjects
Earth Resources And Remote Sensing - Abstract
Soil-transmitted helminths are intestinal nematodes that can infect all members of a population but specially school-age children living in poverty. Infection can be significantly reversed with anthelmintic drug treatments and sanitation improvement. Implementation of effective public health programs requires reliable and updated information to identify areas at higher risk and to calculate amount of drug required. Geo-referenced in situ prevalence data will be overlaid over an ecological map derived from RS data using ARC Map 9.3 (ESRI). Prevalence data and RS data matching at the same geographical location will be analyzed for correlation and those variables from RS data that better correlate with prevalence will be included in a multivariate regression model. Temperature, vegetation, and distance to bodies of water will be inferred using data from Moderate-Resolution Imaging Spectroradiometer (MODIS) and Landsat TM and ETM+. Elevation will be estimated with data from The Shuttle Radar Topography Mission (SRTM). Prevalence and intensity of infections are determined by parasitological survey (Kato Katz) of children enrolled in rural schools in Boaco, Nicaragua, in the communities of El Roblar, Cumaica Norte, Malacatoya 1, and Malacatoya 2). This study will demonstrate the importance of an integrated GIS/RS approach to define sampling clusters without the need for any ground-based survey. Such information is invaluable to identify areas of high risk and to geographically target control programs that maximize cost-effectiveness and sanitation efforts.
- Published
- 2011
40. Identifying Geographic Areas at Risk of Soil-Transmitted Helminthes Infection Using MODIS Products: Boaco, Nicaragua as a Case Study
- Author
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MorenoMadrinan, Max J, Al-Hamdan, Mohammad Z, Parajon, David J, Rickman, Douglas L, Luvall, Jeffrey, Estes, Sue, and Podest, Erika
- Subjects
Earth Resources And Remote Sensing - Published
- 2011
41. Identifying Geographic Areas at Risk of Soil-transmitted Helminthes Infection Using Remote Sensing and Geographical Information Systems: Boaco, Nicaragua as a Case Study
- Author
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Moreno, Max J, Al-Hamdan, Mohammad Z, Parajon, David G, Rickman, Douglas L, Luvall, Jeffrey, Estes, Sue, and Podest, Erika
- Subjects
Earth Resources And Remote Sensing - Abstract
Several types of intestinal nematodes, that can infect humans and specially school-age children living in poverty, develop part of their life cycle in soil. Presence and survival of these parasites in the soil depend on given environmental characteristics like temperature and moisture that can be inferred with remote sensing (RS) technology. Prevalence of diseases caused by these parasitic worms can be controlled and even eradicated with anthelmintic drug treatments and sanitation improvement. Reliable and updated identification of geographic areas at risk is required to implement effective public health programs; to calculate amount of drug required and to distribute funding for sanitation projects. RS technology and geographical information systems (GIS) will be used to analyze for associations between in situ prevalence and remotely sensed data in order to establish RS proxies of environmental parameters that indicate the presence of these parasits. In situ data on helminthisasis will be overlaid over an ecological map derived from RS data using ARC Map 9.3 (ESRI). Temperature, vegetation, and distance to bodies of water will be inferred using data from Moderate-Resolution Imaging Spectroradiometer (MODIS) and Landsat TM and ETM+. Elevation will be estimated with data from The Shuttle Radar Topography Mission (SRTM). Prevalence and intensity of infections are determined by parasitological survey (Kato Katz) of children enrolled in rural schools in Boaco, Nicaragua, in the communities of El Roblar, Cumaica Norte, Malacatoya 1, and Malacatoya 2). This study will demonstrate the importance of an integrated GIS/RS approach to define clusters and areas at risk. Such information will help to the implementation of time and cost efficient control programs and sanitation efforts.
- Published
- 2011
42. Use of MODIS Terra Imagery to Estimate Surface Water Quality Standards, Using Lake Thonotosassa, Florida, as a Case Study
- Author
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Moreno, Max J, Al-Hamdan, Mohammad Z, Estes, Maurice G., Jr, and Rickman, Douglas L
- Subjects
Earth Resources And Remote Sensing - Abstract
Lake Thonotosassa is a highly eutrophied lake located in an area with rapidly growing population in the Tampa Bay watershed, Florida. The Florida Administrative Code has designated its use for "recreation, propagation and maintenance of a healthy, well-balanced population of fish and wildlife." Although this lake has been the subject of efforts to improve water quality since 1970, overall water quality has remained below the acceptable state standards, and has a high concentration of nutrients. This condition is of great concern to public health since it has favored episodic blooms of Cyanobacteria. Some Cyanobacterial species release toxins that can reach humans through drinking water, fish consumption, and direct contact with contaminated water. The lake has been historically popular for fishing and water sports, and its overflow water drains into the Hillsborough River, the main supply of municipal water for the City of Tampa, this explains why it has being constantly monitored in situ for water quality by the Environmental Protection Commission of Hillsborough County (EPC). Advances in remote sensing technology, however, open the possibility of facilitating similar types of monitoring in this and similar lakes, further contributing to the implementation of surveillance systems that would benefit not just public health, but also tourism and ecosystems. Although traditional application of this technology to water quality has been focused on much larger coastal water bodies like bays and estuaries, this study evaluates the feasibility of its application on a 46.6 km2 freshwater lake. Using surface reflectance products from Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra, this study evaluates associations between remotely sensed data and in situ data from the EPC. The parameters analyzed are the surface water quality standards used by the State of Florida and general indicators of trophic status.
- Published
- 2010
43. Exploiting Satellite Remote-Sensing Data in Fine Particulate Matter Characterization for Serving the Environmental Public Health Tracking Network (EPHTN): The HELIX-Atlanta Experience and NPOESS Implications
- Author
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Al-Hamdan, Mohammad Z, Crosson, William L, Limaye, Ashutosh S, Rickman, Douglas L, Quattrochi, Dale A, Estes, Maurice G, Qualters, Judith R, Sinclair, Amber H, Tolsma, Dennis D, and Adeniyi, Kafayat A
- Subjects
Earth Resources And Remote Sensing - Abstract
As part of the U.S. National Environmental Public Health Tracking Network (EPHTN), the National Center for Environmental Health (NCEH) at the U.S. Centers for Disease Control and Prevention (CDC) led a project in collaboration with the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC) called Health and Environment Linked for Information Exchange (HELIX-Atlanta). Under HELIX-Atlanta, pilot projects were conducted to develop methods to better characterize exposure; link health and environmental datasets; and analyze spatial/temporal relationships. This paper describes and demonstrates different techniques for surfacing daily environmental hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM(sub 2.5) for the purpose of integrating respiratory health and environmental data for the CDC's pilot study of HELIX-Atlanta. It describes a methodology for estimating ground-level continuous PM(sub 2.5) concentrations using spatial surfacing techniques and leveraging NASA Moderate Resolution Imaging Spectrometer (MODIS) data to complement the U.S. Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM(sub 2.5) from the EPA database for the year 2003 as well as PM(sub 2.5) estimates derived from NASA's MODIS data. Hazard data have been processed to derive the surrogate exposure PM(sub 2.5) estimates. The paper has shown that merging MODIS remote sensing data with surface observations of PM(sub 2.5), may provide a more complete daily representation of PM(sub 2.5), than either data set alone would allow, and can reduce the errors in the PM(sub 2.5) estimated surfaces. Future work in this area should focus on combining MODIS column measurements with profile information provided by satellites like the National Polar-orbiting Operational Environmental Satellite System (NPOESS). The Visible Infrared Imager/Radiometer Suite (VIIRS) and the Aerosol Polarimeter Sensor (APS) NPOESS sensors will provide first-order information on aerosol particle size and are anticipated to provide information on aerosol products at higher resolution and accuracy than MODIS. Use of the NPOESS remote sensing data should result in more robust remotely sensed data that can be coupled with the methods discussed in this paper to generate surface concentrations of PM(2.5) for linkage with health data in Environmental Public Health Tracking.
- Published
- 2008
44. The Use of GIS and Remotely Sensed Data in Environmental Public Health Tracking (EPHT): The HELIX-Atlanta Experience
- Author
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Al-Hamdan, Mohammad Z, Crosson, William L, Limaye, Ashutosh S, Estes, Maurice G., Jr, Watts, Carol, Rickman, Douglas L, Quattrochi, Dale A, Qualters, Judith R, Sinclair, Amber H, Tolsma, Dennis D, and Adeniyi, Kafayat A
- Subjects
Earth Resources And Remote Sensing - Abstract
As part of the National Environmental Public Health Tracking Network (EPHTN), the National Center for Environmental Health (NCEH) at the Centers for Disease Control and Prevention (CDC) is leading a project in collaboration with the NASA Marshall Space Flight Center (NASA/MSFC) called Health and Environment Linked for Information Exchange (HELIX-Atlanta). HELIX-Atlanta's goal is to examine the feasibility of building an integrated electronic health and environmental data network in five counties of metropolitan Atlanta, GA. Under HELIX-Atlanta, pilot projects are being conducted to develop methods to characterize exposure; link health and environmental data; analyze the relationship between health and environmental factors; and communicate findings. There is evidence in the research literature that asthmatic persons are at increased risk of developing asthma exacerbations with exposure to environmental factors, including PM(sub 2.5). Thus, HELIX-Atlanta is focusing on methods for characterizing population exposure to PM(sub 2.5) for the Atlanta metropolitan area that could be used in ongoing surveillance. NASA/MSFC is working with CDC to combine NASA earth science satellite observations related to air quality and environmental monitoring data to model surface estimates of fine particulate matter (PM(sub 2.5)) concentrations in a Geographic Information System (GIS) that can be linked with clinic visits for asthma on the aggregated grid level as well as the individual level at the geographic locations of the patients' residences.
- Published
- 2007
45. Characterization of Forested Landscapes From Remotely Sensed Data Using Fractals and Spatial Autocorrelation
- Author
-
Al-Hamdan, Mohammad Z, Cruise, James F, Rickman, Douglas L, and Quattrochi, Dale A
- Subjects
Earth Resources And Remote Sensing - Abstract
The characterization of forested areas is frequently required in resource management practice. Passive remotely sensed data, which are much more accessible and cost effective than are active data, have rarely, if ever, been used to characterize forest structure directly, but rather they usually focus on the estimation of indirect measurement of biomass or canopy coverage. In this study, some spatial analysis techniques are presented that might be employed with Landsat TM data to analyze forest structure characteristics. A case study is presented wherein fractal dimensions, along with a simple spatial autocorrelation technique (Moran s I), were related to stand density parameters of the Oakmulgee National Forest located in the southeastern United States (Alabama). The results of the case study presented herein have shown that as the percentage of smaller diameter trees becomes greater, and particularly if it exceeds 50%, then the canopy image obtained from Landsat TM data becomes sufficiently homogeneous so that the spatial indices reach their lower limits and thus are no longer determinative. It also appears, at least for the Oakmulgee forest, that the relationships between the spatial indices and forest class percentages within the boundaries can reasonably be considered linear. The linear relationship is much more pronounced in the sawtimber and saplings cases than in samples dominated by medium sized trees (poletimber). In addition, it also appears that, at least for the Oakmulgee forest, the relationships between the spatial indices and forest species groups (Hardwood and Softwood) percentages can reasonably be considered linear. The linear relationship is more pronounced in the forest species groups cases than in the forest classes cases. These results appear to indicate that both fractal dimensions and spatial autocorrelation indices hold promise as means of estimating forest stand characteristics from remotely sensed images. However, additional work is needed to confirm that the boundaries identified for Oakmulgee forest and the linear nature of the relationship between image complexity indices and forest characteristics are generally evident in other forests. In addition, the effects of other parameters such ,as topographic relief and image distortion due to sun angle and cloud cover, for example, need to be examined.
- Published
- 2007
46. Methods for Characterizing Fine Particulate Matter Using Satellite Remote-Sensing Data and Ground Observations: Potential Use for Environmental Public Health Surveillance
- Author
-
Al-Hamdan, Mohammad Z, Crosson, William L, Limaye, Ashutosh S, Rickman, Douglas L, Quattrochi, Dale A, Estes, Maurice G, Qualters, Judith R, Niskar, Amanda S, Sinclair, Amber H, Tolsma, Dennis D, and Adeniyi, Kafayat A
- Subjects
Earth Resources And Remote Sensing - Abstract
This study describes and demonstrates different techniques for surfacing daily environmental / hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5) for the purpose of integrating respiratory health and environmental data for the Centers for Disease Control and Prevention (CDC s) pilot study of Health and Environment Linked for Information Exchange (HELIX)-Atlanta. It described a methodology for estimating ground-level continuous PM2.5 concentrations using B-Spline and inverse distance weighting (IDW) surfacing techniques and leveraging National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectrometer (MODIS) data to complement The Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM2.5 from the EPA database for the year 2003 as well as PM2.5 estimates derived from NASA s satellite data. Hazard data have been processed to derive the surrogate exposure PM2.5 estimates. The paper has shown that merging MODIS remote sensing data with surface observations of PM2.5 not only provides a more complete daily representation of PM2.5 than either data set alone would allow, but it also reduces the errors in the PM2.5 estimated surfaces. The results of this paper have shown that the daily IDW PM2.5 surfaces had smaller errors, with respect to observations, than those of the B-Spline surfaces in the year studied. However the IDW mean annual composite surface had more numerical artifacts, which could be due to the interpolating nature of the IDW that assumes that the maxima and minima can occur only at the observation points. Finally, the methods discussed in this paper improve temporal and spatial resolutions and establish a foundation for environmental public health linkage and association studies for which determining the concentrations of an environmental hazard such as PM2.5 with good accuracy levels is critical.
- Published
- 2007
47. Downscaling NLDAS-2 daily maximum air temperatures using MODIS land surface temperatures.
- Author
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Crosson, William L., Al-Hamdan, Mohammad Z., and Insaf, Tabassum Z.
- Subjects
- *
LAND surface temperature , *ATMOSPHERIC temperature , *WATER temperature , *LAND use , *DOWNSCALING (Climatology) , *MAXIMA & minima , *URBAN heat islands - Abstract
We have developed and applied a relatively simple disaggregation scheme that uses spatial patterns of Land Surface Temperature (LST) from MODIS warm-season composites to improve the spatial characterization of daily maximum and minimum air temperatures. This down-scaling model produces qualitatively reasonable 1 km daily maximum and minimum air temperature estimates that reflect urban and coastal features. In a 5-city validation, the model was shown to provide improved daily maximum air temperature estimates in the three coastal cities, compared to 12 km NLDAS-2 (North American Land Data Assimilation System). Down-scaled maximum temperature estimates for the other two (non-coastal) cities were marginally worse than the original NLDAS-2 temperatures. For daily minimum temperatures, the scheme produces spatial fields that qualitatively capture geographic features, but quantitative validation shows the down-scaling model performance to be very similar to the original NLDAS-2 minimum temperatures. Thus, we limit the discussion in this paper to daily maximum temperatures. Overall, errors in the down-scaled maximum air temperatures are comparable to errors in down-scaled LST obtained in previous studies. The advantage of this approach is that it produces estimates of daily maximum air temperatures, which is more relevant than LST in applications such as public health. The resulting 1 km daily maximum air temperatures have great potential utility for applications such as public health, energy demand, and surface energy balance analyses. The method may not perform as well in conditions of strong temperature advection. Application of the model also may be problematic in areas having extreme changes in elevation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Methods, availability, and applications of PM2.5 exposure estimates derived from ground measurements, satellite, and atmospheric models.
- Author
-
Diao, Minghui, Holloway, Tracey, Choi, Seohyun, O'Neill, Susan M., Al-Hamdan, Mohammad Z., Van Donkelaar, Aaron, Martin, Randall V., Jin, Xiaomeng, Fiore, Arlene M., Henze, Daven K., Lacey, Forrest, Kinney, Patrick L., Freedman, Frank, Larkin, Narasimhan K., Zou, Yufei, Kelly, James T., and Vaidyanathan, Ambarish
- Subjects
ATMOSPHERIC models ,HEALTH risk assessment ,PARTICULATE matter ,ATMOSPHERIC chemistry ,MORTALITY ,CULTURAL landscapes - Abstract
Fine particulate matter (PM
2.5 ) is a well-established risk factor for public health. To support both health risk assessment and epidemiological studies, data are needed on spatial and temporal patterns of PM2.5 exposures. This review article surveys publicly available exposure datasets for surface PM2.5 mass concentrations over the contiguous U.S., summarizes their applications and limitations, and provides suggestions on future research needs. The complex landscape of satellite instruments, model capabilities, monitor networks, and data synthesis methods offers opportunities for research development, but would benefit from guidance for new users. Guidance is provided to access publicly available PM2.5 datasets, to explain and compare different approaches for dataset generation, and to identify sources of uncertainties associated with various types of datasets. Three main sources used to create PM2.5 exposure data are ground-based measurements (especially regulatory monitoring), satellite retrievals (especially aerosol optical depth, AOD), and atmospheric chemistry models. We find inconsistencies among several publicly available PM2.5 estimates, highlighting uncertainties in the exposure datasets that are often overlooked in health effects analyses. Major differences among PM2.5 estimates emerge from the choice of data (ground-based, satellite, and/or model), the spatiotemporal resolutions, and the algorithms used to fuse data sources. Implications: Fine particulate matter (PM2.5 ) has large impacts on human morbidity and mortality. Even though the methods for generating the PM2.5 exposure estimates have been significantly improved in recent years, there is a lack of review articles that document PM2.5 exposure datasets that are publicly available and easily accessible by the health and air quality communities. In this article, we discuss the main methods that generate PM2.5 data, compare several publicly available datasets, and show the applications of various data fusion approaches. Guidance to access and critique these datasets are provided for stakeholders in public health sectors. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
49. Compilation and spatio-temporal analysis of publicly available total solar and UV irradiance data in the contiguous United States.
- Author
-
Zhou, Ying, Meng, Xia, Belle, Jessica Hartmann, Zhang, Huanxin, Kennedy, Caitlin, Al-Hamdan, Mohammad Z., Wang, Jun, and Liu, Yang
- Subjects
ALTITUDES ,SOLAR spectra ,SOLAR radiation ,SOLAR ultraviolet radiation ,SKIN cancer ,U.S. states ,ENVIRONMENTAL health ,DATABASES - Abstract
Skin cancer is the most common type of cancer in the United States, the majority of which is caused by overexposure to ultraviolet (UV) irradiance, which is one component of sunlight. National Environmental Public Health Tracking Program at CDC has collaborated with partners to develop and disseminate county-level daily UV irradiance (2005–2015) and total solar irradiance (1991–2012) data for the contiguous United States. UV irradiance dataset was derived from the Ozone Monitoring Instrument (OMI), and solar irradiance was extracted from National Solar Radiation Data Base (NSRDB) and SolarAnywhere data. Firstly, we produced daily population-weighted UV and solar irradiance datasets at the county level. Then the spatial distributions and long-term trends of UV irradiance, solar irradiance and the ratio of UV irradiance to solar irradiance were analyzed. The national average values across all years are 4300 Wh/m
2 , 2700 J/m2 and 130 mW/m2 for global horizontal irradiance (GHI), erythemally weighted daily dose of UV irradiance (EDD) and erythemally weighted UV irradiance at local solar noon time (EDR), respectively. Solar, UV irradiances and the ratio of UV to solar irradiance all increased toward the South and in some areas with high altitude, suggesting that using solar irradiance as indicator of UV irradiance in studies covering large geographic regions may bias the true pattern of UV exposure. National annual average daily solar and UV irradiances increased significantly over the years by about 0.3% and 0.5% per year, respectively. Both datasets are available to the public through CDC's Tracking network. The UV irradiance dataset is currently the only publicly-available, spatially-resolved, and long-term UV irradiance dataset covering the contiguous United States. These datasets help us understand the spatial distributions and temporal trends of solar and UV irradiances, and allow for improved characterization of UV and sunlight exposure in future studies. Image 1 • The first UV irradiance dataset for all counties in contiguous US for public access. • National solar and UV irradiances increased significantly over study periods. • UV and solar irradiances, and the ratio increased towards the South and with altitude. • Using solar irradiance as indicator in large geographic regions may bias UV exposure. • These new datasets can improve UV exposure estimates in future epidemiology studies. The UV irradiance dataset is currently the only publicly-available, spatially-resolved, and long-term UV irradiance dataset covering the contiguous United States. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
50. Reconnoitering the linkage between cardiovascular disease mortality and long-term exposures to outdoor environmental factors in the USA using remotely-sensed data.
- Author
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Al-Hamdan, Ashraf Z., Preetha, Pooja P., Al-Hamdan, Mohammad Z., Crosson, William L., and Albashaireh, Reem N.
- Subjects
CARDIOVASCULAR disease related mortality ,REMOTE sensing ,HEAT index ,PARTICULATE matter ,SEDENTARY behavior ,SOCIOECONOMIC factors - Abstract
This ecological study aimed to assess the association between long-term exposures to outdoor environmental factors and mortality rate from cardiovascular disease (CVD) in a diverse and spatially distributed population from 3,094 counties within the U.S. (n > 3,780,000 CVD deaths) using satellite-derived data of PM
2.5 concentrations, sunlight, and maximum heat index. Multivariable logistic regression analyses were conducted to determine whether PM2.5 , sunlight and maximum heat index were related to the odds of the total CVD death rate based on gender, race, and age taking into consideration the confounding risk factors of diabetes, obesity, leisure- time physical inactivity, smoking and socioeconomic status. The study has shown that elevated levels of PM2.5 , sunlight and heat long-term exposures are significantly associated with an increase in the odds ratio of the total CVD mortality. The results suggest a 9.8% (95% CI = 6.3% - 13.4%), 0.9% (95% CI = 0.5% - 1.2%), and 0.7% (95% CI = 0.5% - 11.2%) increase in total CVD mortality associated with 10 μg/m3 increase in PM2.5 concentrations, 1,000 kJ/m2 increases in sunlight, and 1o F increase in heat index, respectively. The odds ratios for the CVD death rate due to long-term exposures of PM2.5 , sunlight, and heat index were significantly greater than 1.0 for all categories except for Asians, Hispanics, and American Indians, indicating that the effect of long-term exposures to particulate matter, sunlight radiation, and maximum heat on CVD mortality is trivial for Asians, Hispanics, and American Indians. Among the categories of age, the group of 65 years and older had the highest odds ratios, suggesting that the age group of 65 years and older are the most vulnerable group to the environmental exposures of PM2.5 (OR = 1.179, 95% CI = 1.124 - 1.237), sunlight (OR = 1.047, 95% CI = 1.041 - 1.053), and maximum heat (OR = 1.014, 95% CI = 1.011 - 1.016). The odds ratios of CVD mortality due to the environmental exposures were higher for Blacks than those for Whites. The odds ratios for all categories were attenuated with the inclusion of diabetes, obesity, leisure-time physical inactivity, smoking, and income covariates, reflecting the effect of other medical conditions, lifestyle, behavioral and socioeconomic factors on the CVD death rate besides the environmental factors. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
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