MS Geography Portfolio

Texas State University Department of Geography and Environmental Studies

My name is Amy Paredes Jackson. My research is focused on dark sky conservation in Texas.

Welcome to my Texas State University GIS portfolio. The maps you see below are the result of coursework, side projects I participated in and my thesis project while I was a graduate student from 2019-2023.

This map shows sky brightness values by ALR ratio metric which is the ratio of natural background sky brightness to artificial sky brightness. The natural background sky brightness reference condition value is 21.60 magnitudes per squared arcsecond or 250 microcandela per square meter. This is the metric associated with a naturall dark night sky. For instance, a value of 0.02 is 2 % above the natural reference condition of a dark sky. The visual graphic below helps to understand what the night sky looks like for a range of sky brightness values. In 2022, Big Bend National Park is the only area with a sky brightness close to this naturally dark reference condition.

There are many night sky quality metrics researchers and astronomers use to describe sky brightness caused by light pollution. The top metric is MPSAS, or magnitudes per squared arcsecond. Bortle Scale is another commonly used metric. ALR is the metric used by the National Park Service and shows the ratio of natural to artificial sky brightness.

This .gif shows trends in sky brightness in Texas over 10 years. I created this imagery using VIIRS DNB annual composites as input for the National Park Service All Sky Light Pollution Ratio model. The rasters created here were used to analyze sky brightness change over time for a comparative study between Dark Sky International dark sky places and control communities in Texas.

Digging through my data, I noticed an outlier for sky brightness values in 2019 for communities near the Greater Big Bend International Dark Sky Reserve. Swipe and see how oil and gas flaring increased sky brightness from 2018-2019 and how that impacted sky brightness far distances from the flaring locations. The circles are gas flaring point locations.

Dr. Li's Wind River Range Glacier Project

Working on this project, I learned a lot about the Wind River Range glacier topography. For Dr. Li's study, I digitized USGS historic topographic maps in preparation for analysis of glacier volume over time.

Using the Farsite Model to model movement of a fire.

Dr. Chow's Environmental Modeling class explored different types of environmental issues that ranged from modeling fires to floods, wildlife habitat to air pollution. The advanced geoprocessing techniques we used in this course helped me understand how modeling and GIS work together to create meaning and to analyze complicated environmental phenomena.

Modeling potential flood damage along Onion Creek

This project modeled potential flood damage to homes along Onion Creek.

This project modeled the direction and volume of air pollutants.

This project modeled habitat suitability using weighted linear combination, a method used for multi-attribute decision making.

We collected GPS data using the transect method to create a digital elevation model for this land parcel in Austin, TX.

This map shows sky brightness values by ALR ratio metric which is the ratio of natural background sky brightness to artificial sky brightness. The natural background sky brightness reference condition value is 21.60 magnitudes per squared arcsecond or 250 microcandela per square meter. This is the metric associated with a naturall dark night sky. For instance, a value of 0.02 is 2 % above the natural reference condition of a dark sky. The visual graphic below helps to understand what the night sky looks like for a range of sky brightness values. In 2022, Big Bend National Park is the only area with a sky brightness close to this naturally dark reference condition.

There are many night sky quality metrics researchers and astronomers use to describe sky brightness caused by light pollution. The top metric is MPSAS, or magnitudes per squared arcsecond. Bortle Scale is another commonly used metric. ALR is the metric used by the National Park Service and shows the ratio of natural to artificial sky brightness.

This .gif shows trends in sky brightness in Texas over 10 years. I created this imagery using VIIRS DNB annual composites as input for the National Park Service All Sky Light Pollution Ratio model. The rasters created here were used to analyze sky brightness change over time for a comparative study between Dark Sky International dark sky places and control communities in Texas.

Dr. Li's Wind River Range Glacier Project

Using the Farsite Model to model movement of a fire.

Modeling potential flood damage along Onion Creek

Digging through my data, I noticed an outlier for sky brightness values in 2019 for communities near the Greater Big Bend International Dark Sky Reserve. Swipe and see how oil and gas flaring increased sky brightness from 2018-2019 and how that impacted sky brightness far distances from the flaring locations. The circles are gas flaring point locations.