@article{rice_emanuel_2019, title={Ecohydrology of Interannual Changes in Watershed Storage}, volume={55}, ISSN={["1944-7973"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85074610023&partnerID=MN8TOARS}, DOI={10.1029/2019WR025164}, abstractNote={AbstractWatershed studies often rely on the assumption that interannual storage changes are negligible in the hydrologic balance of a watershed. The assumption can be useful and is sometimes necessary, but it is widely acknowledged as unrealistic. Identifying and understanding systematic deviations from hydrologic steady state has important implications for both hydrologic research and water management. To that end, we evaluated the magnitude of interannual changes in storage for nearly 1000 watersheds in the conterminous United States for the 10‐year period 2002 to 2011 using ground‐based and remotely sensed data. We evaluated relationships between changes in storage (i.e., deviations from hydrologic steady state), vegetation cover, and hydroclimatic variables. Analysis of results using a Budyko framework revealed that, in general, greater evaporative partitioning led to smaller deviations from hydrologic steady state. Additional analysis using gradient boosted regression tree modeling identified an inverse relationship between forest cover and the magnitude of deviations from hydrologic steady state. In fact, modeling showed forest cover to be a stronger driver of variability in deviations from steady state than any hydroclimatic variable. We discuss ecohydrological feedbacks capable of contributing to steady‐state conditions in forested watersheds, and we discuss implications of these results for the coevolution of watersheds, vegetation, and climate.}, number={10}, journal={WATER RESOURCES RESEARCH}, author={Rice, Joshua S. and Emanuel, Ryan E.}, year={2019}, month={Oct}, pages={8238–8251} }
 @article{rice_emanuel_2017, title={How are streamflow responses to the El Nino Southern Oscillation affected by watershed characteristics?}, volume={53}, ISSN={["1944-7973"]}, url={http://dx.doi.org/10.1002/2016wr020097}, DOI={10.1002/2016wr020097}, abstractNote={AbstractUnderstanding the factors that influence how global climate phenomena, such as the El‐Nino Southern Oscillation (ENSO), affect streamflow behavior is an important area of research in the hydrologic sciences. While large‐scale patterns in ENSO‐streamflow relationships have been thoroughly studied, and are relatively well‐understood, information is scarce concerning factors that affect variation in ENSO responses from one watershed to another. To this end, we examined relationships between variability in ENSO activity and streamflow for 2731 watersheds across the conterminous U.S. from 1970 to 2014 using a novel approach to account for the intermediary role of precipitation. We applied an ensemble of regression techniques to describe relationships between variability in ENSO activity and streamflow as a function of watershed characteristics including: hydroclimate, topography, geomorphology, geographic location, land cover, soil characteristics, bedrock geology, and anthropogenic influences. We found that variability in watershed scale ENSO‐streamflow relationships was strongly related to factors including: precipitation timing and phase, forest cover, and interactions between watershed topography and geomorphology. These, and other influential factors, share in common the ability to affect the partitioning and movement of water within watersheds. Our results demonstrate that the conceptualization of watersheds as signal filters for hydroclimate inputs, commonly applied to short‐term rainfall‐runoff responses, also applies to long‐term hydrologic responses to sources of recurrent climate variability. These results also show that watershed processes, which are typically studied at relatively fine spatial scales, are also critical for understanding continental scale hydrologic responses to global climate.}, number={5}, journal={WATER RESOURCES RESEARCH}, author={Rice, Joshua S. and Emanuel, Ryan E.}, year={2017}, month={May}, pages={4393–4406} }
 @article{rice_emanuel_vose_2016, title={The influence of watershed characteristics on spatial patterns of trends in annual scale streamflow variability in the continental US}, volume={540}, ISSN={["1879-2707"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000382269500066&KeyUID=WOS:000382269500066}, DOI={10.1016/j.jhydrol.2016.07.006}, abstractNote={As human activity and climate variability alter the movement of water through the environment the need to better understand hydrologic cycle responses to these changes has grown. A reasonable starting point for gaining such insight is studying changes in streamflow given the importance of streamflow as a source of renewable freshwater. Using a wavelet assisted method we analyzed trends in the magnitude of annual scale streamflow variability from 967 watersheds in the continental U.S. (CONUS) over a 70 year period (1940–2009). Decreased annual variability was the dominant pattern at the CONUS scale. Ecoregion scale results agreed with the CONUS pattern with the exception of two ecoregions closely divided between increases and decreases and one where increases dominated. A comparison of trends in reference and non-reference watersheds indicated that trend magnitudes in non-reference watersheds were significantly larger than those in reference watersheds. Boosted regression tree (BRT) models were used to study the relationship between watershed characteristics and the magnitude of trends in streamflow. At the CONUS scale, the balance between precipitation and evaporative demand, and measures of geographic location were of high relative importance. Relationships between the magnitude of trends and watershed characteristics at the ecoregion scale exhibited differences from the CONUS results and substantial variability was observed among ecoregions. Additionally, the methodology used here has the potential to serve as a robust framework for top-down, data driven analyses of the relationships between changes in the hydrologic cycle and the spatial context within which those changes occur.}, journal={JOURNAL OF HYDROLOGY}, author={Rice, Joshua S. and Emanuel, Ryan E. and Vose, James M.}, year={2016}, month={Sep}, pages={850–860} }
 @article{rice_emanuel_vose_nelson_2015, title={Continental U.S. streamflow trends from 1940 to 2009 and their relationships with watershed spatial characteristics}, volume={51}, ISSN={0043-1397}, url={http://dx.doi.org/10.1002/2014WR016367}, DOI={10.1002/2014wr016367}, abstractNote={AbstractChanges in streamflow are an important area of ongoing research in the hydrologic sciences. To better understand spatial patterns in past changes in streamflow, we examined relationships between watershed‐scale spatial characteristics and trends in streamflow. Trends in streamflow were identified by analyzing mean daily flow observations between 1940 and 2009 from 967 U.S. Geological Survey stream gages. Results indicated that streamflow across the continental U.S., as a whole, increased while becoming less extreme between 1940 and 2009. However, substantial departures from the continental U.S. (CONUS) scale pattern occurred at the regional scale, including increased annual maxima, decreased annual minima, overall drying trends, and changes in streamflow variability. A subset of watersheds belonging to a reference data set exhibited significantly smaller trend magnitudes than those observed in nonreference watersheds. Boosted regression tree models were applied to examine the influence of watershed characteristics on streamflow trend magnitudes at both the CONUS and regional scale. Geographic location was found to be of particular importance at the CONUS scale while local variability in hydroclimate and topography tended to have a strong influence on regional‐scale patterns in streamflow trends. This methodology facilitates detailed, data‐driven analyses of how the characteristics of individual watersheds interact with large‐scale hydroclimate forces to influence how changes in streamflow manifest.}, number={8}, journal={Water Resources Research}, publisher={American Geophysical Union (AGU)}, author={Rice, Joshua S. and Emanuel, Ryan E. and Vose, James M. and Nelson, Stacy A. C.}, year={2015}, month={Aug}, pages={6262–6275} }
 @article{rice_emanuel_2014, title={Landscape position and spatial patterns in the distribution of land use within the southern Appalachian Mountains}, volume={35}, ISSN={["1930-0557"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000341138200005&KeyUID=WOS:000341138200005}, DOI={10.1080/02723646.2014.909218}, abstractNote={Understanding the forces that influence the distribution of land use and land-use change (LUC) is an essential step in developing effective strategies for managing these issues. We examined the influence of landscape position on spatial patterns in land-use distribution within the Little Tennessee River Basin (LTRB) of the southern Appalachian Mountains. We show that landscape position, defined with respect to both natural and anthropogenic spatial variables, provides for the identification of statistically significant differences in the distribution of common forms of land use in the study region. Using the same variables, significant differences in the landscape positions subject to land-use change in the LTRB are also examined. These results suggest landscape position exerts a strong influence on the distribution of different forms of land use and the likeliness of given area undergoing LUC. The approach presented here, of considering land use as a function of landscape position that responds to both natural and anthropogenic forces, may prove useful in aiding the development of future strategies to address the consequences of land use in many regions.}, number={5}, journal={PHYSICAL GEOGRAPHY}, author={Rice, Joshua S. and Emanuel, Ryan E.}, year={2014}, pages={443–457} }