Land Use and Land Cover Changes

The conversion of natural landscapes to agricultural or urban uses eliminates the ecosystem services they provided. Reduced infiltration of rainwater, water purification, and primary production, along with habitat fragmentation and loss, increased stormwater runoff, stream bank erosion and sedimentation are all consequences of land use changes.

Mobile Bay is a critical ecologic and economic region in the Gulf of Mexico and to the entire country. Mobile Bay was designated as an estuary of “national significance” in 1996. This estuary receives the fourth largest freshwater inflow in the United States. It provides vital nursery habitat for commercially and recreationally important fish species. It has exceptional aquatic and terrestrial biodiversity; however, its estuary health is influenced by changing LULC patterns, such as urbanization. Mobile and Baldwin counties have experienced a population growth of 1.1% and 20.5%, respectfully, from 2000‐2006.

Land‐use and land‐cover change can negatively impact Gulf coast water quality and ecological resources. The conversion of forest to urban cover types impacts the carbon cycle and increases the freshwater and sediment in coastal waters. Increased freshwater runoff decreases salinity and increases the turbidity of coastal waters, thus impacting the growth potential of submerged aquatic vegetation (SAV), which is critical nursing ground for many Gulf fish species. A survey of Mobile Bay SAV showed widespread decreases since the 1940s. Prior to our project, coastal environmental managers in Baldwin and Mobile counties needed more understanding of the historical LULC, and therefore to properly assess the impacts of increasing urbanization. In particular, more information on the location and extent of changing urbanization LULC patterns was needed to aid LULC planning and to assess predictions of future LULC patterns.

These videos courtesy of NASA Stennis Space Center displays land‐use and land‐cover (LULC) changes in the coastal counties of Mobile and Baldwin, AL between 1974 and 2008.

Land Use and Land Cover Changes (1974-2008)
Funded by
NASA (Grant # NNX10AC57G)