Remote Monitoring of Vegetation Managed for Dust Control on the Dry Owens Lakebed, California

David P Groeneveld,David D Barz

doi:10.4236/ojmh.2013.34029

Abstract

A monitoring program was developed to assess the cover of saltgrass managed for dust control on the saline dry Owens Lake. Although the original intent was to manage the vegetation as total cover that included green and senesced leaf and stem material, aged leaves that make up a large proportion of total cover were not differentiable spectrally from the background salt and lakebed. Hence, greenness-based indices were explored for detection of plant recruitment. Since all plant cover begins as green and growing, greenness indices provide a measure of all future cover whether living or senesced. The criteria for judging compliance were changed so that spatially variable vegetation cover measured as a milestone will need to be met in the future. A derivative of NDVI, NDVIx, calculated using scene statistics, proved highly accurate, to about 0.001 of this index and with an average signal to noise ratio of 64. This high level of accuracy allowed detection of small changes in vegetation growth and vigor. Performance according to the benchmark-as-par standard was determined through combined use of cumulative distribution functions and derivative maps.

Highlights

Prior to dust control efforts that began during the first decade of this millennium, the Owens Dry Lake, located in Eastern Central California (Figure 1) was the single largest source of anthropogenic PM10 in the western hemisphere (GBUAPCD 2003)
This paper describes development and application of an operational remote sensing program to evaluate Managed Vegetation Area (MVA) vegetation
An earth observation satellite data (EOS) index, NDVIoffset first described by Baugh and Groeneveld [10] was selected as the basis for monitoring vegetation on the managed vegetation area

Summary

Introduction

Prior to dust control efforts that began during the first decade of this millennium, the Owens Dry Lake, located in Eastern Central California (Figure 1) was the single largest source of anthropogenic PM10 in the western hemisphere (GBUAPCD 2003). PM10 is particulate matter less than 10 μm in aerodynamic diameter that has been implicated in reducing respiratory health [1]. This dust was caused by hydrologic changes due to diversion of water from the 280 km lake. Owens Dry Lake was filled with water but was declining due to irrigation diversion. The lake desiccated completely by 1927 after complete diversion to Los Angeles [2]

Methods

Results

Conclusion