Impacts of Climate Change on Hydroclimatic Conditions of U.S. National Forests and Grasslands

Abstract

The conterminous United States includes national forests and grasslands that provide ecological, social, economic, recreational, and aesthetic services. Future climate change can alter long-term hydroclimatic conditions of national forests and grasslands and lead to negative consequences. This study characterizes shifts in hydroclimatology and basin characteristics of US National Forests (NFs) and National Grasslands (NGs) in response to climate change over the 21st century under the DRY, MIDDLE, and WET climate models with the representative concentration pathway (RCP) 8.5 emission scenario. Climatic projections for three climate models ranging from the driest to wettest conditions were obtained from the Multivariate Adaptive Constructed Analogs (MACA) dataset. Then, the variable infiltration capacity (VIC) model was used to model hydrological responses of the selected future climates. Changes in regional hydroclimatic conditions of NFs and NGs were assessed by the magnitude and direction of movements in the Budyko space. The Fu’s equation was applied to estimate changes in basin characteristics. The results indicate that NFs and NGs are likely to experience larger changes in basin characteristics compared to the average of the United States. In general, across the conterminous US, the NFs in mountainous regions are likely to have larger changes in hydroclimatic variables than NFs with lower elevation and NGs. Comparing Forest Service regions, Pacific Northwest, Intermountain, and Northern regions may have a less arid climate with lower freshwater availability. The Southwestern, Northern, Intermountain, and Rocky Mountain regions are likely to experience higher shifts in their basin characteristics. This study can help environmental scientists, and land and water managers improve future land management plans.

Climate Change and Changes in Compound Coastal‐Riverine Flooding Hazard Along the U.S. Coasts

“…Several studies based on modeling and observations show that climate change is also influencing extreme hydrological events regionally (Ahn & Palmer 2016; Peterson et al., 2008). For example, while some areas have experienced an increase in the frequency of heavy precipitation and extreme streamflow events (e.g., the central U.S.: Pryor et al., 2009, and the eastern U.S.: Groisman et al., 2001, 2005), some other regions have experienced prolonged droughts (e.g., the Southwest U.S.: Cook et al., 2015; Heidari, Arabi, Ghanbari, et al., 2020; Heidari, Arabi, Warziniack, et al., 2020; Heidari et al., 2021). Such changes in hydrological conditions have an immediate impact on the risks of urban and riverine flooding.…”

Effects of Climate Change on Natural-Caused Fire Activity in Western U.S. National Forests

“…Wildfires have increased in size and frequency throughout western United States national forests between 1980-2015 [1][2][3][4][5][6]. Increased wildfire activity already posed severe economic, social, ecological, and environmental damage such as the destruction of homes, adverse air and water quality, extra costs, and loss of life that are likely to accelerate with climate change [4,7,8]. Changes in high-severity fire activity may lead to the loss of forest ecosystem resilience and the conversion of the forest structure, dominant species, life forms, or functions [9][10][11].…”

“…This number is on the rise as fire events become more frequent and their damage becomes more catastrophic [13]. Wildfire losses in developed areas could substantially increase in the western United States due to the expanding wildland-urban interface [12] in which the buildup of forest fuels coupled with increasing aridification, drought, and urbanization [8,14,15] are likely to catalyze plume-driven fires spreading to developed areas. As wildfire losses continue to grow and the WUI problems gain more attention, the enhanced understanding of changes in future forest fires is vital and further study is needed to develop community mitigation and planning strategies to adapt to the increasing incidence of natural-caused forest fires [12].…”

“…Interactions between climate and natural wildfires are known as the most important drivers of national forest ecosystem responses to future climate change. The increase in forest fires is associated with warmer temperatures and decreasing summer precipitation [1,3,7,[21][22][23][24], both of which are projected to continue under plausible future climate scenarios throughout the 21st century [8,[25][26][27][28]. An improved understanding of linkages between climate variables and natural wildfires is required to forecast future fire activity [10].…”

Effects of Urban Development Patterns on Municipal Water Shortage

“…Municipal water shortage can be defined as the lack of sufficient water supply to meet demand in urban areas (Foti et al, 2014;Zhao et al, 2019;Heidari et al, 2020a). Although water supply may be significantly affected in the future by climate change as a result of varying precipitation and increasing temperature (Heidari et al, 2020b(Heidari et al, , 2021b, water demand may increase over time due to rapid urbanization (Liu et al, 2020). Rapid urbanization can intensify imbalance between water supply and demand and lead to higher likelihood of water shortage conditions in developed areas in the future (Foti et al, 2012;Brown et al, 2019).…”