Contribution of environmental forcings to US runoff changes for the period 1950–2010

Abstract

Runoff in the United States is changing, and this study finds that the measured change is dependent on the geographic region and varies seasonally. Specifically, observed annual total runoff had an insignificant increasing trend in the US between 1950 and 2010, but this insignificance was due to regional heterogeneity with both significant and insignificant increases in the eastern, northern, and southern US, and a greater significant decrease in the western US. Trends for seasonal mean runoff also differed across regions. By region, the season with the largest observed trend was autumn for the east (positive), spring for the north (positive), winter for the south (positive), winter for the west (negative), and autumn for the US as a whole (positive). Based on the detection and attribution analysis using gridded WaterWatch runoff observations along with semi-factorial land surface model simulations from the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), we found that while the roles of CO 2 concentration, nitrogen deposition, and land use and land cover were inconsistent regionally and seasonally, the effect of climatic variations was detected for all regions and seasons, and the change in runoff could be attributed to climate change in summer © 2018 The Author(s). Published by IOP Publishing Ltd Environ. Res. Lett. 13 (2018) 054023 and autumn in the south and in autumn in the west. We also found that the climate-only and historical transient simulations consistently underestimated the runoff trends, possibly due to precipitation bias in the MsTMIP driver or within the models themselves.

The Compensatory CO2 Fertilization and Stomatal Closure Effects on Runoff Projection From 2016–2099 in the Western United States

“…Besides, restoration of endangered riparian ecosystems related to depleted water resources, which has recently received an increasing attention, requires more water in the episodes of droughts (Anderson & Woosley, 2006). In addition to substantial water demands, significant reductions in annual runoff yield have been observed across the western US due to climate change (Forbes et al., 2018), with earlier snowmelt runoff and reduced summer flows (Clow, 2010; Hamlet et al., 2007). It is crucial to discern the controlling factors of runoff for reducing the uncertainties in future runoff and water resource projections.…”

Streamflow in the Columbia River Basin: Quantifying Changes Over the Period 1951‐2008 and Determining the Drivers of Those Changes

“…To isolate the net effect of NDEP, we used the difference of ALL and the fourth simulation (named NDEP). Since the radiative and physiological effects of CO2 on climate change cannot be separated by using offline ELM simulations and are included in the transient climate drivers, CO2, NDEP, and LULCC thus represent the direct effects of CO 2 physiology, NDEP, and LULCC, respectively (Forbes et al, ; Gedney et al, ; Mao et al, ; Zhu et al, ).…”

Publishing Environmental Assessment and Management Science: Crossing the Hurdles

“…For example, Hutchins and colleagues (2017) summarized commonalities and sources of differences among several carbon dioxide emission inventories for the United States. High-profile articles integrate or compare modeling results and large data sets—for example, Earth system model results and US runoff data (Forbes et al 2018 ). The publication challenges relate to how scientists engaged in archiving large or small data sets can publish journal articles themselves and how environmental management scientists can use extensive data sets while giving appropriate credit to the collectors.…”