Abstract

Playa wetlands are some of the most important natural features of the High Plains of the central United States. Playas provide a range of ecosystem services such as groundwater recharge, surface water storage, and wetland habitat. However, playa functions are declining due to land cover change, climate change, and playa and watershed modifications. There are only a few studies that have examined the variability and controls on playa water storage. This project aims to determine how playa and watershed morphology, watershed land cover, and precipitation patterns affect timing and duration of water storage in 92 playas distributed throughout a 10-county region in western Kansas. Playa and watershed morphology were calculated in a GIS environment and classified into quartiles based on playa surface area and watershed area. Watershed tilled index was determined using 2016, 2017, 2018, and 2019 Cropland Data Layers available from the National Agricultural Statistics Service and classified as either cropland (>75% cropland), grassland (>75% grassland), or mixed. Monthly precipitation data for 2016-2019 were compiled from the Oakley 22S High Plains Regional Climate Center weather station. Playa water status for 2016-2019 was classified monthly as dry/moist soil or standing water by visually examining 4-band satellite imagery with 3.7 m resolution and pre-defined image enhancements available from Planet Explorer (www.planet.com). Playa water status is only moderately influenced by playa and watershed morphology and watershed land cover, with playas in the largest size class and cropland TI class having slightly greater standing water observations. However, standing water within playas is most strongly correlated with monthly precipitation. Playas in all size classes, TI classes, and counties have similar responses to precipitation patterns. Dry/moist observations increase during periods of drought, and standing water observations increase with wetter periods. Playas are critical resources for the High Plains, providing a range of ecosystem services dependent upon the playa's ability to store water. Playa functions are under continued threat from cropland expansion, climate change, and playa and watershed modifications. More research is required to understand better the spatial and temporal variability in playa water status driven by precipitation patterns.

Advisor

Mark Bowen

Committee Member

Fei Yuan

Committee Member

Ryan Wersal

Date of Degree

2021

Language

english

Document Type

Thesis

Degree

Master of Science (MS)

Department

Geography

College

Social and Behavioral Sciences

Share

COinS
 

Rights Statement

In Copyright