Portfolio

As part of an Advanced GIS course, I estimated land cover and land use change in four North Central Texas counties from 2001-2022 using the National Land Cover Database (NLCD). Over 21 years, 36% of the area changed in land cover and land use. Urbanization can be visualized as the developed areas (pink-red) sprawl across counties.

This furthered my understanding of the methods and data used to quantify land cover and land use changes as well as issues of human development, loss of natural land cover, and drought.

The Human Footprint Index represents cumulative human pressure on the environment from population density, built-up areas, roads/railways, crops/pastures, navigable water, and electric power infrastructure. As part of an Advanced GIS course, I used Zonal Statistics to analyze the average Human Footprint among states and within Texas and Michigan counties in 2009.

In TX, counties with a Footprint Index >60 contained Fort Worth, Dallas, Longview, and Houston, accounting for 17% of the total population.

In MI, 49% of the total population resides in the Metro Detroit Area. While 29% of land is the Upper Peninsula, it contains 3% of the total population and lowest human footprint.

Current corridor literature lacks a unified method to delineate landscape elements for spatial models. As part of my MS thesis research, Conservation, Connectivity, and Coexistence: Understanding Corridor Efficacy in Fragmented Landscapes, I standardized the digitization of forest and rangeland boundaries by integrating GPS coordinates of small mammal traps with satellite imagery and analyzing vegetation.

Delineations were used to quantify and analyze landscape connectivity between corridor complexes (patch-corridor-patch), intact reference areas, and isolated patches.

Understanding conservation corridor efficacy depends on identifying the start and end. For my MS thesis, Conservation, Connectivity, and Coexistence: Understanding Corridor Efficacy in Fragmented Landscapes, I used spatial and statistical analysis to identify transitional areas, where edge effects are expected to influence species movements, of 5 previously digitized corridor complexes. Patch one narrows into the corridor at 1 and 2 the corridor widens into patch two and 3 and 4.

This process raises the question, do we need to manage corridors distinctly from patches or extend management into patches to promote corridor efficacy?

Resistance-based connectivity models are frequently used to assess a species response to a landscape. As part of my MS thesis, Conservation, Connectivity, and Coexistence: Understanding Corridor Efficacy in Fragmented Landscapes, I used expert literature-based models to develop resistance rasters with environmental data layers known to influence small mammal movements and distribution: land cover, roads, distance to water, and elevation.

Resistance rasters were used for cost distance and current flow models to compare the resistance values for small mammal focal species to traverse patches connected by a corridor, through intact reference areas, and between isolates through a non-habitat matrix.

As part of my MS thesis, Conservation, Connectivity, and Coexistence: Understanding Corridor Efficacy in Fragmented Landscapes, I used cost distance and current flow models to quantify landscape connectivity for small mammal focal species between: (a) corridor start and end, (b) patches connected by a corridor, (c) intact reference area, and (d) isolates separated by a matrix. The least-cost path (LCP) identified the optimal path of the lowest cost between landscape configurations whereas the current flow identified a network of all potential paths.

High current flow indicates areas with a higher degree of landscape connectivity and lower resistance.