Science Inventory

Sensitivity of Riparian Buffer Designs to Climate Change—Nutrient and Sediment Loading to Streams: A Case Study in the Albemarle-Pamlico River Basins (USA) Using HAWQS

Citation:

Ghimire, S., J. Corona, R. Parmar, G. Mahadwar, R. Srinivasan, K. Mendoza, AND J. Johnston. Sensitivity of Riparian Buffer Designs to Climate Change—Nutrient and Sediment Loading to Streams: A Case Study in the Albemarle-Pamlico River Basins (USA) Using HAWQS. Sustainability. MDPI, Basel, Switzerland, 13(22):12380, (2021). https://doi.org/10.3390/su132212380

Impact/Purpose:

In this study, we assessed sensitivity of watershed-specific riparian buffer zone (RBZ) designs to water quality indicator parameters in the contemporary climate and in future extreme climatic conditions. we summarized the RBZ design strategy and evaluated five water quality indicator (WQI) parameters: Dissolved Oxygen (DO), Total Phosphorous (TP), Total Nitrogen (TN), Sediment (SD), and Biochemical Oxygen Demand (BD) as component of watershed ecosystem services through sensitivity analyses of 135 simulation scenarios. The scenarios included the width variation of six baseline RBZs (Grass, Urban, Two-zone Forest, Three-zone Forest, Wildlife, and Naturalized) in three watersheds within the Albemarle-Pamlico river basin (USA). Analyses revealed optimal RBZ designs. The optimal Urban RBZ in contemporary climate (1983-2018) reduced SD from 61 to 96%, TN from 34 to 55%, TP from 9 to 48%, and BD from 53 to 99%; and raised DO from 4 to 10% with respect to No-RBZ in the three watersheds. The article will be of considerable interest to broader audience who study RBZ as best management practice (BMP), especially for the sustainability of watershed ecosystem services in terms of stream water quality in the face of projected climate change impacts.

Description:

Riparian buffer zones (RBZs) provide multiple benefits to watershed ecosystems. We aimed to conduct an extensive sensitivity analysis of the RBZ designs to climate change nutrient and sediment loadings to streams. We designed 135 simulation scenarios starting with the six baselines RBZs (grass, urban, two-zone forest, three-zone forest, wildlife, and naturalized) in three 12-digit Hydrologic Unit Code watersheds within the Albemarle-Pamlico river basin (USA). Using the hydrologic and water quality system (HAWQS), we assessed the sensitivity of the designs to five water quality indicator (WQI) parameters: dissolved oxygen (DO), total phosphorous (TP), total nitrogen (TN), sediment (SD), and biochemical oxygen demand (BD). To understand the climate mitigation potential of RBZs, we identified a subset of future climate change projection models of air temperature and precipitation using EPA’s Locating and Selecting Scenarios Online tool. Analyses revealed optimal RBZ designs for the three watersheds. In terms of watershed ecosystem services sustainability, the optimal Urban RBZ in contemporary climate (1983–2018) reduced SD from 61–96%, TN from 34–55%, TP from 9–48%, and BD from 53–99%, and raised DO from 4–10% with respect to No-RBZ in the three watersheds. The late century’s (2070–2099) extreme mean annual climate changes significantly increased the projected SD and BD; however, the addition of urban RBZs was projected to offset the climate change reducing SD from 28–94% and BD from 69–93% in the watersheds. All other types of RBZs are also projected to fully mitigate the climate change impacts on WQI parameters except three-zone RBZ.