Hydrologic Characteristics of Streamflow in the Southeast Atlantic and Gulf Coast Hydrologic Region during 1939–2016 and Conceptual Map of Potential Impacts

Abstract

Streamflow is one the most important variables controlling and maintaining aquatic ecosystem integrity, diversity, and sustainability. This study identified and quantified changes in 34 hydrologic characteristics and parameters at 30 long term discharge stations in the Southeast Atlantic and Gulf Coast Hydrologic Region (Region 3) using Indicators of Hydrologic Alteration (IHA) variables. The southeastern United States (SEUS) is a biodiversity hotspot, and the region has experienced a number of rapid land use/land cover changes with multiple primary drivers. Studies in the SEUS have been mostly localized on specific rivers, reservoir catchments and/or species, but the overall region has not been assessed for the long-term period of 1939-2016 for multiple hydrologic characteristic parameters. The objectives of the study were to provide an overview of multiple river basins and 31 hydrologic characteristic parameters of streamflow in Region 3 for a longer period and to develop a conceptual map of impacts of selected stressors and changes in hydrology and climate in the SEUS. A seven step procedure was used to accomplish these objectively:Step 1: Download data from the 30 USGS gauging stations. Steps 2 and 3: Select and analyze the 31 IHA parameters using boxplots, scatter plots, and PDFs. Steps 4 and 5: Synthesize the drivers of changes and alterations and the various change points in streamflow in the literature.Step 6: Synthesize the climate of the SEUS in terms of temperature and precipitation changes.Step 7: Develop a conceptual map of impacts of selected stressors on hydrology using Driver-Pressure-State-Impact-Response (DPSIR) framework and IHA parameters. The 31 IHA parameters were analyzed. The meta-analysis of literature in the SEUS revealed the precipitation changes observed ranged from −30% to +35% and temperature changes from −2 • C to 6 • C by 2099. The fiftieth percentile of the Global Climate Models (GCM) predict no precipitation change and an increase in the temperature of 2.5 • C in the region by 2099. Among the GCMs, the 5th and 95th percentile of precipitation changes range between −40% and 110% and temperature changes between −2 • C and 6 • C by 2099. Meta-analysis of land use/land cover show the region has experienced changes. A number of rapid land use/land cover changes in 1957, 1970, and 1998 are some of the change points documented in the literature for precipitation and streamflow in the region. A conceptual map was developed to represent the impacts of selected drivers and the changes in hydrology and climate in the study region for three land use/land cover categories in three different periods.

Sustainable Development Tool Using Meta‐Analysis and DPSIR Framework — Application to Savannah River Basin, U.S.

“…Urbanization, increased agricultural use and forest management are the major land use change in the SRB (Zurqani et al 2018). However, a few other studies were found that focused on larger regions (e.g., Southeastern U.S., Georgia‐North Carolina‐South Carolina) encompassing SRB (Anandhi and Bentley 2018; Anandhi et al 2018a). For example, it was observed that Southeastern U.S. region is particularly vulnerable to a number of climate‐driven events and has been affected by more than billion‐dollar disasters than any other region in the country (Anandhi and Bentley 2018).…”

“…Similarly, many basins throughout Georgia, North Carolina, and South Carolina have been undergoing considerable urbanization trends over decades, which is expected to continue (Wrona et al 2007). The Southeastern U.S. has experienced rapid land use/land cover change during the 19th and early 20th Centuries due to conversion of forests to agriculture (lowest around 1920s), then conversion of agriculture back to forest after the Great Depression (during 1930s), followed by forest fragmentation during the economic boom (1980s to 2000s) and, recently, the conversion of agricultural land use to urban/suburban development (Anandhi et al 2018a).…”

“…However, the meta‐analysis showed few studies focused on these six common units for the entire SRB even when new search terms were included (Step 6 in methodology). Furthermore, a few other studies were found that focused on larger regions (e.g., Southeastern U.S.) encompassing SRB (Anandhi and Bentley 2018; Anandhi et al 2018a). Anandhi and Bentley (2018)’s study showed precipitation changes from meta‐analysis and data analysis of 19 global climate models ranged from −30% to +35% and −40% to 110% (5th and 95th; 50th percentile no change), respectively, by 2099 for Southeastern U.S.…”

“…(4) The decommissioned Savannah River Nuclear Plant is located on the SRB (Cormier et al 2013). (5) Increasing population (Cormier et al 2013), changing climate (Anandhi and Bentley 2018), variable hydrology (Anandhi et al 2018a), and changing sea levels significantly affect the SRB (Conrads et al 2010). (6) Finally, the environmental changes on the SRB are exacerbated by other biophysical limits such as declining per‐capita land and water, and rising demand for food, water, and energy (Zhu et al 2012).…”

DPSIR-ESA Vulnerability Assessment (DEVA) Framework: Synthesis, Foundational Overview, and Expert Case Studies

“…This case study is based on three studies in several states in the southeastern U.S. (Anandhi and Bentley, 2018;Anandhi et al, 2018aAnandhi et al, , 2018b. Together, these studies used a broad definition of the land-resource system (multiple elements including land use, water resources, other natural resources, climate, biological systems) and stressors (multiple elements including precipitation and temperature change, land-use change, changes in other natural resources).…”