Remote sensing of the decrease of juniper woodlands in the mountains of Southwestern Saudi Arabia—reasons and consequences

Abstract

Urban sprawl is a typical land use change in developed countries, which converts agricultural land or vegetated areas to built-up areas or other consolidated land cover types, like roads. In southwestern Saudi Arabia, urban sprawl and establishment of recreation areas decreases the area of juniper woodlands, which are important for carbon sequestration, biodiversity maintenance, erosion control, and atmospheric moisture harvest and water storage. The change detection study applying land cover classification for Landsat TM and ETM+ data from 1984, 1999, and 2014 in the Al Bahah governorate demonstrated a 10 % loss of juniper woodlands from 1984 to 2014, mainly caused by establishment of recreation sites in the mountains. At the same time, built-up area expanded 24 % mostly on the cost of barren lands, but also on the cost of woodlands. The juniper woodlands are also declining in quality as throughout the southwestern mountains a dieback is reported and visible also in the study area. Knowing the scarcity of woodlands in the Arabian Peninsula and the importance of the unique woodlands for water resources, it is of utmost importance to use the results for raising awareness and protecting the juniper woodlands. Further research is required to study the loss of the juniper forests and rate of dieback in the whole study area.