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Locating Changes in Land Use from Long Term Remote Sensing Data in Morocco
Citation:
NASH, M. S., D. J. CHALOUD, AND W. G. KEPNER. Locating Changes in Land Use from Long Term Remote Sensing Data in Morocco. In Proceedings, 2009 Joint Statistical Meetings, Washington, DC, August 01 - 06, 2009. American Statistical Association, Alexandria, VA, 34-41, (2010).
Impact/Purpose:
This work is part of the NATO Environmental Security, and hence we chose Morocco as a case study and an approach to examine the entire region (Figure 1). Morocco was chosen because of moderate size, variation in topography and land cover types, it has had experienced landscape change over the last decades, it has increasing socioeconomic pressures in parts of the country, and primary and ancillary data for the country are available.
Description:
We present a method that allows mapping changes in vegetation cover over large areas quickly and inexpensively, thus providing policy makers with the capability to locate and assess areas undergoing environmental change, and improving their ability to positively respond or adapt to change. Using Morocco in the southern Mediterranean Region as an example, changes in vegetation cover were assessed over a 23-year period (1981-2003) using 8-km Normalized Difference Vegetation Index (NDVI) data derived from Advanced Very High Resolution Radiometer (AVHRR). A regression model of NDVI over time was developed to identify long-term trends in vegetation for each pixel in the study area. Results were mapped using ArcView for visualization of specific areas. Patches of decreasing or increasing vegetation cover were identified. A decreasing trend in vegetation cover is an indicator of stress, either natural (e.g., drought, fire) or anthropogenic (e.g., excessive grazing, urban growth) that affects the life-support function of the human environment. Our analyses offer results that can be mapped at different scales (locally and regionally) and can be used to assess trends over time and space; plus, the approach can easily be applied to other locations.