We used remote sensing imagery to characterize the hydrological dynamics of 8404 temporary freshwater wetlands (playas) in Texas (Landsat 5 TM WRS-2 P30/R36) from 2008 to 2011, comparing known wet and dry periods, and related these to land use within 100m. Hydroperiods were highly variable, and peak water availability occurred in different seasons in different years, varying by as much as two orders of magnitude with date. Land use affected the likelihood and duration of inundation, with playas in urban settings being modified in such a way as to extend hydroperiod, and playas surrounded by cropland experiencing shorter hydroperiods: 3726 playa basins never contained standing water during the four-year period, and many of these were surrounded by cotton, corn, wheat, or sorghum. In contrast, 25 playas never dried, and most of these were surrounded by urban development. Median hydroperiod was 17-109 days, being longer during the relatively wet year of 2010 compared to exceptional drought in 2011. Remote sensing was useful in monitoring playa surface water fluctuations as a function of land use, providing an alternative source of data in the absence of ground-based hydrological records, and granting a temporal perspective that may otherwise not exist for seasonal or ephemeral wetlands.
Bibliographical noteFunding Information:
This research was made possible by NSF -Macrosystems Biology collaborative grants 1065773 and 1065845 . NEM was supported in part by the Virginia and John Holtry Foundation at the Geographic Information Science Center of Excellence at South Dakota State University. Comments from two anonymous reviewers improved the manuscript.
Copyright 2014 Elsevier B.V., All rights reserved.
- Crop types
- Remote sensing