Population
Citation:
Monroy, E., A. Kuhn, AND M. Charpentier. Population. Chapter 4, State of Narragansett Bay and Its Watershed 2017 Technical Report. Narragansett Bay Estuary Program, PROVIDENCE, RI, , 90-107, (2017).
Impact/Purpose:
People are a fundamental driving force on the landscape. Human population growth increases the demand for larger or new infrastructure, which leads to land conversion (primarily from forest land to urban land), with construction of new roads, buildings, and other utilities and amenities. These changes in the landscape reshape the Narragansett Bay Watershed’s (NBW) functions by altering natural hydrological paths, strongly influencing the freshwater and estuarine ecosystems of the NBW and Narragansett Bay. The increase and spread of the human population in the NBW and the conversion of forest land to urban land has primarily altered the conveyance of rainfall as storm water and decreased the connectivity of natural habitats, diminishing the NBW's capacity to balance the effects of runoff and groundwater replenishment. The synergic impacts of these alterations include increasing flooding (or, conversely, worsening drought conditions), or exacerbating water quality issues through the transportation of contaminants, which, consequently, diminish the benefits of NBW’s natural resources to public health and aquatic life. Therefore, the shift of the population from crowded urban areas to more rural areas is an important driver of landscape changes, where less people are using more land to settle. Today, previously developed lands provide the infrastructure that a high-density population demand, whereas new development, without proper planning, can create new stressors to the surrounding landscape. In this chapter we developed an indicator to examine the total population and where people live across the Narragansett Bay Watershed, often referred to as “population distribution”. For this indicator, a dasymetric model was used to identify population density, which made it possible to quantify total population living in the Watershed and to calculate changes spatially, from 1990 through 2010.
Description:
Population growth influences many stressors on Narragansett Bay and its Watershed, including all landscape and chemical stressors discussed in other chapters of this report. In numerous ways, population growth affects the condition of the Bay ecosystem, Watershed ecosystem, and human health through loss of natural lands, increased pollutant loadings, declining water quality, changes in biotic communities, and other impacts. In 2014, an estimated 1.9 million people lived in the Narragansett Bay Watershed (NBW) with approximately half in Massachusetts and half in Rhode Island. Most of the population was concentrated in three urban areas: Providence, Rhode Island, and Worcester and Fall River, Massachusetts. Twenty percent of the NBW population resided in coastal lands that drain directly into Narragansett Bay. Between 1990 and 2010, the population increased by eight percent. This recent population growth was concentrated in the suburban and lesser-developed areas of the NBW, primarily in the watersheds of the Taunton River and Pawtuxet River; in contrast, coastal areas experienced a slight population decline of two percent. The amount of developed land per capita was much higher in rural and suburban areas than in urban areas and increased over time, showing intensifying sprawl. While 20 percent of the 1.9 million people in the NBW lived within the areas immediately draining the estuarine waters of the Bay, development patterns in the last 20 years or so show losses in these urban cores, especially Providence and Fall River, and gains in adjacent suburban areas. On average, 2,200 people moved from each of these coastal subwatersheds, and the percent decline ranged from three to fifteen percent of the 1990 population. In contrast, population growth was more evident in suburban areas, as people moved where there was more potential for new development, promoting sprawl across the NBW.
