Role of Human Activities: Introduction
There is increasing evidence that recent accelerated land losses in many coastal regions are largely anthropogenic and attributable to human alteration of the littoral system and wetland environment. Land losses indirectly related to human activities are difficult to quantify because they promote alterations and imbalances in the primary factors causing land loss such as sediment budget, coastal processes, and relative sea level (Fig. 2). Coastal construction, land excavation, and extraction of hydrocarbons and groundwater now account for the greatest losses of wetlands and barrier islands where these natural resources have undergone intensive economic development for more than 50 years.
Human activities causing land loss are discussed according to their impacts on the physical agents (Fig. 1). The linkage between human activities and the physical agents is as follows: transportation networks tend to increase erosion, coastal construction projects typically increase deficits in the sediment budget, subsurface fluid extraction and climate alterations accelerate submergence, and excavation causes direct losses of land.
U.S. Department of the Interior, U.S. Geological Survey
Maintained by Publishing Services
Last modified: 23:13:06 Sat 12 Jan 2013
Privacy statement | General disclaimer | Accessibility