This is the PowerPoint prepared by Dawn Davies (Hill Country Alliance) for Texas Public Radio's Think Earth event held on October 7, 2022. The slide presentation focuses on light pollution, and matches with the audio on this page: https://www.tpr.org/tpr-events-initiatives/2022-09-28/think-earth-pollution
Lunar Surface Model Age Derivation: Comparisons Between Automatic and Human C...Sérgio Sacani
Dating young lunar surfaces, such as impact ejecta blankets and terrains associated with recent
volcanic activities, provides critical information on the recent events that shaped the surface of the Moon.
Model age derivation of young or small areas using a crater chronology is typically achieved through manual
counting, which requires a lot of small impact craters to be tediously mapped. In this study, we present the
use of a Crater Detection Algorithm (CDA) to extract crater populations on Lunar Reconnaissance Orbiter—
Narrow Angle Camera (LRO-NAC) and Kaguya Terrain Camera images. We applied our algorithm to images
covering the ejecta blankets of four Copernican impact craters and across four young mare terrains, where
manually derived model ages were already published. Across the eight areas, 10 model ages were derived. We
assessed the reproducibility of our model using two populations for each site: (a) an unprocessed population and
(b) a population adjusted to remove contaminations of secondary and buried craters. The results showed that
unprocessed detections led to overestimating crater densities by 12%–48%, but “adjusted” populations produced
consistent results within <20% of published values in 80% of cases. Regarding the discrepancies observed, we
found no significant error in our detections that could explain the differences with crater densities manually
measured. With careful processing, we conclude that a CDA can be used to determine model ages and crater
densities for the Moon. We also emphasize that automated crater datasets need to be processed, interpreted and
used carefully, in unity with geologic reasoning. The presented approach can offer a consistent and reproducible
way to derive model ages.
NISAR
Oil, Gas, and Water Underground Reservoirs
NASA
National Aeronautics and Space Administration
NASA-ISRO Synthetic Aperture Radar (NISAR)
By
Dr. Pankaj Dhussa
Lunar Surface Model Age Derivation: Comparisons Between Automatic and Human C...Sérgio Sacani
Dating young lunar surfaces, such as impact ejecta blankets and terrains associated with recent
volcanic activities, provides critical information on the recent events that shaped the surface of the Moon.
Model age derivation of young or small areas using a crater chronology is typically achieved through manual
counting, which requires a lot of small impact craters to be tediously mapped. In this study, we present the
use of a Crater Detection Algorithm (CDA) to extract crater populations on Lunar Reconnaissance Orbiter—
Narrow Angle Camera (LRO-NAC) and Kaguya Terrain Camera images. We applied our algorithm to images
covering the ejecta blankets of four Copernican impact craters and across four young mare terrains, where
manually derived model ages were already published. Across the eight areas, 10 model ages were derived. We
assessed the reproducibility of our model using two populations for each site: (a) an unprocessed population and
(b) a population adjusted to remove contaminations of secondary and buried craters. The results showed that
unprocessed detections led to overestimating crater densities by 12%–48%, but “adjusted” populations produced
consistent results within <20% of published values in 80% of cases. Regarding the discrepancies observed, we
found no significant error in our detections that could explain the differences with crater densities manually
measured. With careful processing, we conclude that a CDA can be used to determine model ages and crater
densities for the Moon. We also emphasize that automated crater datasets need to be processed, interpreted and
used carefully, in unity with geologic reasoning. The presented approach can offer a consistent and reproducible
way to derive model ages.
NISAR
Oil, Gas, and Water Underground Reservoirs
NASA
National Aeronautics and Space Administration
NASA-ISRO Synthetic Aperture Radar (NISAR)
By
Dr. Pankaj Dhussa
Using Remote Sensing Techniques For Monitoring Ecological Changes In Lakes: C...IJERA Editor
The ability to use remote sensing in studying lake ecology lies in the capability of satellite sensors to measure
the spectral reflectance of constituents in water bodies. This reflectance can be used to determine the
concentration of the constituents of the water column through mathematical relationships. This work identified a
simple linear equation for estimating suspended matter in Lake Naivasha with reflectance in Landsat7 ETM+
image. A R² = 0.94, n = 6 for suspended matter was obtained. Archive of Landsat imagery was used to
produce maps of suspended matter concentrations in the lake. The suspended matter concentrations at five
different locations in the lake over 30 year’s period were then estimated. It was therefore concluded that the
ecological changes Lake Naivasha is experiencing is the result of the high water abstraction and the effect of
climate change.
Using Remote Sensing Techniques For Monitoring Ecological Changes In Lakes: C...IJERA Editor
The ability to use remote sensing in studying lake ecology lies in the capability of satellite sensors to measure
the spectral reflectance of constituents in water bodies. This reflectance can be used to determine the
concentration of the constituents of the water column through mathematical relationships. This work identified a
simple linear equation for estimating suspended matter in Lake Naivasha with reflectance in Landsat7 ETM+
image. A R² = 0.94, n = 6 for suspended matter was obtained. Archive of Landsat imagery was used to
produce maps of suspended matter concentrations in the lake. The suspended matter concentrations at five
different locations in the lake over 30 year’s period were then estimated. It was therefore concluded that the
ecological changes Lake Naivasha is experiencing is the result of the high water abstraction and the effect of
climate change.
Estimation of Global Solar Radiation in Ibadan, Nigeria using Angstrom - Pres...rahulmonikasharma
In this study, the data of mean daily bright sunshine hour for Ibadan was obtained from the International Institute of Tropical Agriculture (IITA) at Ibadan. It was used to estimate the monthly mean global solar radiation for Ibadan (latitude and longitude ). The data considered were for a period of 2008 to 2012. Angstrom-Prescott, and Glover & McCulloch’s Models were then used to estimate the mean monthly global solar radiation at Ibadan based on the monthly mean bright sunshine hour data of Ibadan. A new sunshine based model is also proposed to estimate global solar radiation at Ibadan for a period of five years (2008 – 2012). The performance of the models are evaluated by some statistical analysis like mean bias errors, root mean square error, mean percentage error, Nash- Sutcliffe error and coefficient of correlation in order to know the most suitable model. It was discovered that the month of August is the least amount of measured global solar radiation averaged for five years (2008 – 2012) at Ibadan is 9.77kW/m2. The most suitable model for Ibadan is Model 2 (Glover & McCulloch’s Model). The results obtained were validated with data of monthly mean global solar radiation data for Ibadan, obtained from the International Institute of Tropical Agriculture, Ibadan
Satellite based observations of the time-variation of urban pattern morpholog...Beniamino Murgante
Satellite based observations of the time-variation of urban pattern morphology using geospatial analysis
Gabriele Nolè, Rosa Lasaponara - Institute of Methodologies for Environmental Analysis, National Research Council, Italy
Minkowski’s foundations of spacetime physics and SDSS data motivate reassessm...Alexander F. Mayer
The objective, statistical nature of SDSS astrophysical datasets, which were not driven by any theoretical agenda, reveal false and misleading prior measurements (e.g., redshift-distance) driven by confirmation bias in the context of such agendas. SDSS data, including theta-z, redshift-magnitude (both photometric and spectroscopic pipelines), and galaxy population-density, are shown to conflict with the ΛCDM standard cosmological model. Moreover, all four of those distinct and independent data sets are similarly consistent with a new cosmological model that revives de Sitter’s 1917 exact solution to the field equations, long thought to entail an “empty universe.” Representing a paradigm shift in cosmology, that new model is entirely distinct from the textbook “de Sitter universe” model. It derives from considerations of symmetry and local proper time modeled as a geometric object, motivated by Minkowski’s metric characterization of relativity. All of the new predictive equations, which incorporate no free parameters, are confronted with corresponding SDSS data sets, thereby resolving the modern quandary of astrophysical observ-ables interpreted as accelerating cosmic expansion induced by ‘dark energy.’ The canonical idea of a non-relativistic universal time coordinate applicable to all of cosmological space and its energy content (i.e., ∼13.7 Gyr of ‘Cosmic Time’ from initial singularity) is supplanted by a relativistic, strictly-local time coordinate involving no such inscrutable space-time singularity.
Geography and Geographic Informations SystemsBarry Wellar
This presentation at the University of Ottawa's GIS Day in 2006 was prepared as part of the Geography Awareness Week program, Canadian Association of Geographers.The objectives of the presentation were to illustrate to secondary school and university students the importance of geography in understanding the social, economic, planning, development, environmental, political, and other affairs of the world from the local to the international scales, and outline how geographrapic information systems (GIS) technology and applications contribute to mapping, anaysing, synthesizing, and understanding these geography-related situations and relationships, and then to designing geographic-based solutions to these problems.
Feature Extraction from the Satellite Image Gray Color and Knowledge Discove...IJMER
Satellite take images of the Earth in selected spectral bands that are in both the visible and
the infrared portions of the electromagnetic spectrum. Many Satellites provide three types of Satellite
Images. These Images are Visible Satellite Image, Infrared Satellite Image, and Water Vapor Satellite
Image. These images are important for different reasons, and, in some cases, all three are needed to
accurately interpret atmospheric conditions. These Satellite images contain different types of cloud. This
paper shows cloud feature extraction using Histogram. A table that shows cloud existence in different
image is created, called Association table in which Y represents cloud is exist and N represent not exist.
Association rule mining is applied to this table to make relations between different clouds and discover
the knowledge about cloud existence.
Monitoring and Landscape Quantification of Uncontrolled Urbanisation in Oasis Regions: The Case of Adrar City in Algeria
* 1 Dr. Assoule Dechaicha Image result for research orcid , 2 Assist. Prof. Adel Daikh Image result for research orcid , 3 Prof. Dr. Djamel Alkama Image result for research orcid
1, 2 and 3 Department of Architecture, Faculty of Sciences and Technology, 8 May 1945 University, Guelma, Algeria
E-mail 2: dechaicha.assoul@univ-guelma.dz , E-mail 1: alkama.djamel@univ-guelma.dz
E-mail 3: daikh.adel@univ-guelma.dz
ARTICLE INFO:
Article History:
Received 20 March 2021
Accepted 25 July 2021
Available online 12 August 2021
Keywords:
Uncontrolled Urbanisation,
Satellite Images,
Landscape Metrics,
Palm groves,
Oasis Ecosystem.
ABSTRACT
Nowadays, uncontrolled urbanisation is one of the major problems facing Algerian oasis regions. The monitoring and evaluation of its landscape transformations remain a key step for any oasis sustainability project. This study highlights the evolution of spatial growth in the city of Adrar in southern Algeria during the period 1986-2016 by establishing a Spatio-temporal mapping and landscape quantification. The methodological approach is based on a multi-temporal analysis of Landsat satellite images for 1986, 1996, 2006 and 2016, and the application of landscape metrics. The results show two opposite spatial trends: significant growth of built-up areas against an excessive loss of palm groves. The landscape metrics allowed the identification of a progressive fragmentation process characterising the palm groves. Thus, the findings of this study show the utility of satellite imagery and landscape metrics approach for monitoring urbanisation patterns and assessing their impacts on oasis ecosystems.
JOURNAL OF CONTEMPORARY URBAN AFFAIRS (2021), 5(2), 209-219.
Using Remote Sensing Techniques For Monitoring Ecological Changes In Lakes: C...IJERA Editor
The ability to use remote sensing in studying lake ecology lies in the capability of satellite sensors to measure
the spectral reflectance of constituents in water bodies. This reflectance can be used to determine the
concentration of the constituents of the water column through mathematical relationships. This work identified a
simple linear equation for estimating suspended matter in Lake Naivasha with reflectance in Landsat7 ETM+
image. A R² = 0.94, n = 6 for suspended matter was obtained. Archive of Landsat imagery was used to
produce maps of suspended matter concentrations in the lake. The suspended matter concentrations at five
different locations in the lake over 30 year’s period were then estimated. It was therefore concluded that the
ecological changes Lake Naivasha is experiencing is the result of the high water abstraction and the effect of
climate change.
Using Remote Sensing Techniques For Monitoring Ecological Changes In Lakes: C...IJERA Editor
The ability to use remote sensing in studying lake ecology lies in the capability of satellite sensors to measure
the spectral reflectance of constituents in water bodies. This reflectance can be used to determine the
concentration of the constituents of the water column through mathematical relationships. This work identified a
simple linear equation for estimating suspended matter in Lake Naivasha with reflectance in Landsat7 ETM+
image. A R² = 0.94, n = 6 for suspended matter was obtained. Archive of Landsat imagery was used to
produce maps of suspended matter concentrations in the lake. The suspended matter concentrations at five
different locations in the lake over 30 year’s period were then estimated. It was therefore concluded that the
ecological changes Lake Naivasha is experiencing is the result of the high water abstraction and the effect of
climate change.
Estimation of Global Solar Radiation in Ibadan, Nigeria using Angstrom - Pres...rahulmonikasharma
In this study, the data of mean daily bright sunshine hour for Ibadan was obtained from the International Institute of Tropical Agriculture (IITA) at Ibadan. It was used to estimate the monthly mean global solar radiation for Ibadan (latitude and longitude ). The data considered were for a period of 2008 to 2012. Angstrom-Prescott, and Glover & McCulloch’s Models were then used to estimate the mean monthly global solar radiation at Ibadan based on the monthly mean bright sunshine hour data of Ibadan. A new sunshine based model is also proposed to estimate global solar radiation at Ibadan for a period of five years (2008 – 2012). The performance of the models are evaluated by some statistical analysis like mean bias errors, root mean square error, mean percentage error, Nash- Sutcliffe error and coefficient of correlation in order to know the most suitable model. It was discovered that the month of August is the least amount of measured global solar radiation averaged for five years (2008 – 2012) at Ibadan is 9.77kW/m2. The most suitable model for Ibadan is Model 2 (Glover & McCulloch’s Model). The results obtained were validated with data of monthly mean global solar radiation data for Ibadan, obtained from the International Institute of Tropical Agriculture, Ibadan
Satellite based observations of the time-variation of urban pattern morpholog...Beniamino Murgante
Satellite based observations of the time-variation of urban pattern morphology using geospatial analysis
Gabriele Nolè, Rosa Lasaponara - Institute of Methodologies for Environmental Analysis, National Research Council, Italy
Minkowski’s foundations of spacetime physics and SDSS data motivate reassessm...Alexander F. Mayer
The objective, statistical nature of SDSS astrophysical datasets, which were not driven by any theoretical agenda, reveal false and misleading prior measurements (e.g., redshift-distance) driven by confirmation bias in the context of such agendas. SDSS data, including theta-z, redshift-magnitude (both photometric and spectroscopic pipelines), and galaxy population-density, are shown to conflict with the ΛCDM standard cosmological model. Moreover, all four of those distinct and independent data sets are similarly consistent with a new cosmological model that revives de Sitter’s 1917 exact solution to the field equations, long thought to entail an “empty universe.” Representing a paradigm shift in cosmology, that new model is entirely distinct from the textbook “de Sitter universe” model. It derives from considerations of symmetry and local proper time modeled as a geometric object, motivated by Minkowski’s metric characterization of relativity. All of the new predictive equations, which incorporate no free parameters, are confronted with corresponding SDSS data sets, thereby resolving the modern quandary of astrophysical observ-ables interpreted as accelerating cosmic expansion induced by ‘dark energy.’ The canonical idea of a non-relativistic universal time coordinate applicable to all of cosmological space and its energy content (i.e., ∼13.7 Gyr of ‘Cosmic Time’ from initial singularity) is supplanted by a relativistic, strictly-local time coordinate involving no such inscrutable space-time singularity.
Geography and Geographic Informations SystemsBarry Wellar
This presentation at the University of Ottawa's GIS Day in 2006 was prepared as part of the Geography Awareness Week program, Canadian Association of Geographers.The objectives of the presentation were to illustrate to secondary school and university students the importance of geography in understanding the social, economic, planning, development, environmental, political, and other affairs of the world from the local to the international scales, and outline how geographrapic information systems (GIS) technology and applications contribute to mapping, anaysing, synthesizing, and understanding these geography-related situations and relationships, and then to designing geographic-based solutions to these problems.
Feature Extraction from the Satellite Image Gray Color and Knowledge Discove...IJMER
Satellite take images of the Earth in selected spectral bands that are in both the visible and
the infrared portions of the electromagnetic spectrum. Many Satellites provide three types of Satellite
Images. These Images are Visible Satellite Image, Infrared Satellite Image, and Water Vapor Satellite
Image. These images are important for different reasons, and, in some cases, all three are needed to
accurately interpret atmospheric conditions. These Satellite images contain different types of cloud. This
paper shows cloud feature extraction using Histogram. A table that shows cloud existence in different
image is created, called Association table in which Y represents cloud is exist and N represent not exist.
Association rule mining is applied to this table to make relations between different clouds and discover
the knowledge about cloud existence.
Monitoring and Landscape Quantification of Uncontrolled Urbanisation in Oasis Regions: The Case of Adrar City in Algeria
* 1 Dr. Assoule Dechaicha Image result for research orcid , 2 Assist. Prof. Adel Daikh Image result for research orcid , 3 Prof. Dr. Djamel Alkama Image result for research orcid
1, 2 and 3 Department of Architecture, Faculty of Sciences and Technology, 8 May 1945 University, Guelma, Algeria
E-mail 2: dechaicha.assoul@univ-guelma.dz , E-mail 1: alkama.djamel@univ-guelma.dz
E-mail 3: daikh.adel@univ-guelma.dz
ARTICLE INFO:
Article History:
Received 20 March 2021
Accepted 25 July 2021
Available online 12 August 2021
Keywords:
Uncontrolled Urbanisation,
Satellite Images,
Landscape Metrics,
Palm groves,
Oasis Ecosystem.
ABSTRACT
Nowadays, uncontrolled urbanisation is one of the major problems facing Algerian oasis regions. The monitoring and evaluation of its landscape transformations remain a key step for any oasis sustainability project. This study highlights the evolution of spatial growth in the city of Adrar in southern Algeria during the period 1986-2016 by establishing a Spatio-temporal mapping and landscape quantification. The methodological approach is based on a multi-temporal analysis of Landsat satellite images for 1986, 1996, 2006 and 2016, and the application of landscape metrics. The results show two opposite spatial trends: significant growth of built-up areas against an excessive loss of palm groves. The landscape metrics allowed the identification of a progressive fragmentation process characterising the palm groves. Thus, the findings of this study show the utility of satellite imagery and landscape metrics approach for monitoring urbanisation patterns and assessing their impacts on oasis ecosystems.
JOURNAL OF CONTEMPORARY URBAN AFFAIRS (2021), 5(2), 209-219.
Think Earth: Water Pollution, by Saugata DattaNathan Cone
This is the PowerPoint prepared by Dr. Saugata Datta (UTSA) for Texas Public Radio's Think Earth event held on October 7, 2022. The slide presentation focuses on water pollution, and matches with the audio on this page: https://www.tpr.org/tpr-events-initiatives/2022-09-28/think-earth-pollution
This is the PowerPoint prepared by Diane Rath (AACOG) for Texas Public Radio's Think Earth event held on October 7, 2022. The slide presentation focuses on air pollution, and matches with the audio on this page: https://www.tpr.org/tpr-events-initiatives/2022-09-28/think-earth-pollution
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
Follow us on: Pinterest
Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Alert-driven Community-based Forest monitoring: A case of the Peruvian Amazon
Think Earth: Light Pollution
1. Dawn Davies, Night Sky Program Manager
7 October 2022
Texas Public Radio
Think Earth: Light Pollution
2. The Hill Country Alliance (HCA) is a
nonprofit organization working to bring
together a diverse coalition of partners
to preserve the open spaces, starry
night skies, clean and abundant waters,
and unique character of the Texas Hill
Country.
3. Night Sky
• Education
⚬ Light Pollution
⚬ Night Sky Friendly Lighting
⚬ Night Sky Month
• Friends of the Night Sky
• Ordinances and Resolutions
• Projects & Mapping
Working with community partners to reduce light
pollution, establish better practices, and celebrate the
dark night sky
4. Supporting regional
water quality and
quantity through
water conservation
and infrastructure
alternatives, sound
decision-making,
and long-term
planning
COMMUNITY NETWORK
NIGHT SKY
LAND
WATER
Working with
community
partners to reduce
light pollution,
establish better
practices, and
celebrate the dark
night sky
Educating
landowners,
elected officials,
and residents on
stewardship best
practices while
facilitating large-
scale landscape
conservation
Maximizing
protection of the
Hill Country’s
natural resources
through enhanced
collaboration
Supporting vibrant
communities and
wise planning in
both urban
corridors and rural
areas
6. Lubbock
Amarillo
Dallas
Austin
El Paso
Houston
San Antonio
56% Excellent
34% Good
10% Poor
Austin
Llano
Junction
Kerrville
Fredericksburg
Uvalde
San Antonio
62% Excellent 24% Good 14% Poor
Dark Sky Quality % by County
Central Texas Overall Dark Sky Quality
Bandera 68% 32% 0%
Bexar 0 3.5 96
Blanco 45 55 0
Burnet 28 71 1
Comal 0 61 39
Edwards 99.97 0.03 0
Gillespie 87.08 12.5 0.36
Hays 0 67 33
Kendall 26 69 5
Kerr 66 32 2
Kimble 98.98 1.02 0
Llano 86 14 0
Mason 99.31 0.69 0
Medina 34 60 5
Real 99.6 0.44 0
San Saba97.9 2.1 0
Travis 0 25 75
Uvalde 91 8.7 1
County ExcellentGoodPoor County ExcellentGoodPoor
0 10 20 30 40
5
Miles
0 30 60 90 120
15
Miles
Introduction:
The practice of lighting up our night sky decreases the visibility of our stars and our
own galaxy, the Milky way. Light pollution not only affects dark sky quality, but also
has a large impact on the health of humans, plants and wildlife and wastes billions of
dollars every year. The picture below shows the World Atlas of Artificial Night Sky
Brightness.
Fig. 1 World Atlas of Artificial Sky Brightness
Most of our planet’s population live in urban areas and so are inundated by light
pollution. Effort is underway between the City of Austin, Travis County, the Texas
chapter of the International Dark Sky Association and local interest groups, such as
the Hill Country Alliance, to eradicate light pollution for surrounding communities and
Austin, TX. Understanding the impact of light pollution for the state of Texas will
help to bring about awareness which will inspire collective action. This collective
action, in time, will increase the need for night sky lighting ordinances and change
laws and practices for cities and communities throughout the state.
The Hill Country Alliance is a non-profit organization focused on conservation of the
Texas Hill Country. One of their main focus areas for conservation is dark skies. In
collaboration with the Hill Country Alliance Dark Sky team, this project is focused on
answering two questions, “What is the dark sky quality of the state of Texas and the
Texas Hill Country 18 county region?” The results of this analysis will aid in the Hill
Country Alliance’s assessment of dark sky quality in order to communicate the need
for change in current practices and focus conservation efforts for this 18 county
region
Methodology:
This project used two main datasets to analyze dark sky quality for Texas and the
hill country 18 county region. 1) Floating point data used to make the World Atlas of
Artificial Night Sky Brightness, produced by the Light Pollution Science and
Technology Institute (ISTIL), and described in the paper "The New World Atlas of
Artificial Night Sky Brightness" (Falchi et al. 2016) and 2) Texas Political Boundaries
data. The end goal was a Texas Overall Dark Sky Quality map and a Texas Hill
Country Dark Sky Quality map of the 18 country region specified by the Hill Country
Alliance.
It was necessary to determine criteria for dark sky quality rating. We based dark sky
quality criteria using: 1) the World Atlas of Artificial Sky Brightness shown in Fig.1 2)
the Sky Brightness Nomogram, shown in Fig. 2, from the International Dark Skies
Task Group of the National Optical Astronomical Observatory,
Fig. 2 National Optical Astronomy Observatory Fig 3. IDA
3) the Bortle Scale, shown in Fig. 3 and 4) our knowledge of the night sky quality in
given areas.
The following table summarizes the dark sky quality criteria we determined for
symbolizing and reclassifying pixel values from the World Atlas of Artificial Sky
Brightness floating point data.
Fig. 4 Dark Sky Quality Table
skies correspond to some of the darkest skies in Texas. At this level of
dark sky quality, you can see the summer Milky Way and the winter Milky Way
which is fainter than in summer. These skies are dark with minimal domes of light on
the horizon. Fainter stars are visible.
skies correspond to seeing the winter and the summer Milky Way, yet
the structure of the Milky Way will not be as brilliant as in an ‘Excellent’ dark sky
quality area. A lesser amount of faint stars are visible on the horizon. The summer
Milky Way is slightly visible when overhead but lacks in any detailed structure. As
you get closer to the boundary between ‘Good’ and ‘Poor’, light domes are visible on
the horizon if you are viewing from an area near urban centers which are areas of
high light pollution
skies correspond to a lack of visibility for the winter and summer Milky
Way. Close to city centers where light pollution is high, the sky is glowing with light
and so people living in these areas may never experience a ‘true night’ since the sky
is in a state of ‘artificial twilight’.
The World Atlas raster layer was symbolized using manual intervals based on the
Dark Sky Quality Criteria Table shown in Fig. 4. I then made a reclassified raster
based on this symbology and used the ‘raster to polygon’ geoprocessing tool to
make polygon feature classes from the raster. I conducted an overlay analysis by
using the ‘intersect’ geoprocessing tool to overlay the the state of Texas polygonal
feature class and the Central Texas 18 county region of interest feature classes to
determine Dark Sky Quality based on the criteria table in Fig. 4.
After joining data tables for the state of Texas and Central Texas, I determined
percentages of each category of dark sky quality, ‘excellent’ , ‘good’ and ‘poor’.
It looks like Texas is doing pretty well maintaining dark skies, however, by looking at
the map, you can see that most of the light polluted areas with poor dark sky
quality occurs in urban centers. Most people all over the world live in urban centers,
so even though dark sky quality may be mostly excellent, who gets to see these
night skies and how far will people have to travel to see a truly excellent, dark night
sky? Growth in Texas, especially central Texas, in particular Austin, is increasing
dramatically. Will this map look different in 3 years? It depends on how we value our
night sky and what we do to change our lighting practices in our urban centers and
beyond.
Created by Amy Jackson, Starry Sky Austin for ACC GIS Capstone Project in Collaboration with the Hill Country Alliance. May 18, 2019.
34% Good
10% Poor
56% Excellent
7.
8. Light pollution is quantified using the
Bortle Scale, a numeric range from 1 to 9
measuring sky brightness from a specific
location.
Bortle 1 night-skies are akin to those
found in Big Bend National Park.
Bortle 9 night-skies are typically seen at
the center of metropolitan areas, such as
Manhattan.
Measurements at San Antonio’s city
center range from Bortle 8 - 9, and Bortle
6 – 7 at the city limits.
Lightpollutionmap.info
10. Night Sky: Heritage, culture, wonder
Wildlife: Insects, birds, mammals,
ecosystems
Human Health: Sleep disorders,
metabolism, cancer
Crime: Leads criminals to targets, decreases
visibility
Traffic: Decreases visibility
Finance: Wasted electricity, lost tourism
opportunity
Four out of five North Americans have lost
the view of the Milky Way where they live.
(The New World Atlas of artificial night sky brightness,
Science Advances, 10 June 2016: Vol.2, no. 6)