Measuring and modeling event-based environmental flows: An assessment of HEC-RAS 2D rain-on-grid simulations.

There is an immediate need to use available modeling tools to quantify environmental flows targets where changing climate and human activity has altered hydroecologically important streamflow regimes. A model performance assessment was undertaken using observed data collected from five nested gauging sites in a mixed land use watershed of the central US. An integrated modeling approach was used to couple The Soil and Water Assessment Tool (SWAT version 2012), and The Hydrologic Engineering Center's River Analysis System (HEC-RAS version 5.

The occurrence and transport of microplastics: The state of the science.

Microplastic (MP) particles have been observed in most environments and concentrations are expected to increase over the coming decades given continued and increased production of synthetic polymer products. The expected increase in plastic pollution (including MPs) may elevate the risk posed by these synthetic particles to both environmental and human health. The purpose of this review is to provide a review of the state of knowledge regarding the occurrence and transport of MPs in and across three of the Earths subsystems, specifically, the lithosphere, atmosphere, and hydrosphere.

Quantifying relationships between urban land use and flow frequency of small Missouri streams.

Flow frequency is an important hydrologic statistic to consider in environmental flows assessment. However, there is a paucity of focused interdisciplinary hydrologic assessments that quantify human development influence on flow frequency of small streams (drainage area < 282 km). Relationships between urban land use and land cover (LULC) and flow frequency were assessed for general trends at current gauged watersheds (n = 32) of Missouri, USA.

Quantifying relationships between watershed characteristics and hydroecological indices of Missouri streams.

There is an ongoing need for multidisciplinary investigations that will lead to policy changes that target and reduce natural and anthropic alterations to hydroecological indices important for regional environmental flows management. The hydroecological indices assessed in this study were all deemed ecologically relevant due to causal linkages with hydrogeomorphology, physical habitat, water quality, and/or ecological processes. Watershed characteristics (i.

A method for advancing understanding of streamflow and geomorphological characteristics in mixed-land-use watersheds.

Methods are needed to quantify stream geomorphological response to land use and hydroclimatic variability. The method applied herein incorporated channel measurements from a physical habitat assessment (channel width, bankfull width, thalweg depth, and estimated cross-sectional area), and streamflow data collected via an experimental watershed study, to identify factors contributing to longitudinal variation in stream morphology in a mixed-land-use watershed of the central U.S.

Flow class analyses of suspended sediment concentration and particle size in a mixed-land-use watershed.

Knowledge gaps remain concerning fundamental suspended sediment physical processes/relationships, such as particle size class dynamics and hydroclimatic variability. Streamwater grab samples were collected four times per week (Oct. 2009-Feb.

An integrated modeling approach for estimating hydrologic responses to future urbanization and climate changes in a mixed-use midwestern watershed.

Future urban development and climatic changes are likely to affect hydrologic regimes in many watersheds. Quantifying potential water regime changes caused by these stressors is therefore crucial for enabling decision makers to develop viable environmental management strategies. This study presents an approach that integrates mid-21st century impervious surface growth estimates derived from the Imperviousness Change Analysis Tool with downscaled climate model projections and a hydrologic model Soil and Water Assessment Tool to characterize potential water regime changes in a mixed-use watershed in central Missouri, USA.

Spatiotemporal variability of suspended sediment particle size in a mixed-land-use watershed.

Given existing knowledge gaps, there is a need for research that quantitatively characterizes spatiotemporal variation of suspended sediment particle size distribution (PSD) in contemporary watersheds. A five-year study was conducted in a representative watershed of the central United States utilizing a nested-scale experimental watershed study design, comprising five gauging sites partitioning the catchment into five sub-watersheds. Streamwater grab samples were collected four times per week, at each gauging site, for the duration of the study period (Oct.

Improving understanding of mixed-land-use watershed suspended sediment regimes: Mechanistic progress through high-frequency sampling.

Given the importance of suspended sediment to biogeochemical functioning of aquatic ecosystems, and the increasing concern of mixed-land-use effects on pollutant loading, there is an urgent need for research that quantitatively characterizes spatiotemporal variation of suspended sediment dynamics in contemporary watersheds. A study was conducted in a representative watershed of the central United States utilizing a nested-scale experimental watershed design, including five gauging sites (n=5) partitioning the catchment into five sub-watersheds. Hydroclimate stations at gauging sites were used to monitor air temperature, precipitation, and stream stage at 30-min intervals during the study (Oct.

Quantifying loading, toxic concentrations, and systemic persistence of chloride in a contemporary mixed-land-use watershed using an experimental watershed approach.

A nested-scale experimental watershed study was implemented to quantify loading and persistence of chloride in an urbanizing, mixed-land-use watershed. A Midwest USA (Missouri) watershed was partitioned into five sub-basins with contrasting dominant land use. Streamwater was tested for chloride concentration four days per week from October 2009 through May 2014 at each site.

A SWAT model validation of nested-scale contemporaneous stream flow, suspended sediment and nutrients from a multiple-land-use watershed of the central USA.

There is an ongoing need to validate the accuracy of predictive model simulated pollutant yields, particularly from multiple-land-use (i.e. forested, agricultural, and urban) watersheds.

More than Drought: Precipitation Variance, Excessive Wetness, Pathogens and the Future of the Western Edge of the Eastern Deciduous Forest.

For many regions of the Earth, anthropogenic climate change is expected to result in increasingly divergent climate extremes. However, little is known about how increasing climate variance may affect ecosystem productivity. Forest ecosystems may be particularly susceptible to this problem considering the complex organizational structure of specialized species niche adaptations.

Continuous and event-based time series analysis of observed floodplain groundwater flow under contrasting land-use types.

There is an ongoing need to improve quantitative understanding of land-use impacts on floodplain groundwater flow regimes. A study was implemented in Hinkson Creek Watershed, Missouri, USA, including equidistant grids of nine piezometers, equipped with pressure transducers, which were installed at two floodplain study sites: a remnant bottomland hardwood forest (BHF) and a historical agricultural field (Ag). Data were logged at thirty minute intervals for the duration of the 2011, 2012, 2013, and 2014 water years (October 1, 2010-September 30, 2014).

Identification of the primary lesion of toxic aluminum in plant roots.

Despite the rhizotoxicity of aluminum (Al) being identified over 100 years ago, there is still no consensus regarding the mechanisms whereby root elongation rate is initially reduced in the approximately 40% of arable soils worldwide that are acidic. We used high-resolution kinematic analyses, molecular biology, rheology, and advanced imaging techniques to examine soybean (Glycine max) roots exposed to Al. Using this multidisciplinary approach, we have conclusively shown that the primary lesion of Al is apoplastic.

Temporal changes in endometrial gene expression and protein localization of members of the IGF family in cattle: effects of progesterone and pregnancy.

In the study presented, the hypothesis that ligands of the insulin-like growth factor (IGF) family, as well as their binding proteins (BPs), are temporally regulated and are altered by elevated progesterone (P4) and/or pregnancy was tested. Heifers detected in standing estrus following synchronization (n = 210, day 0), were artificially inseminated (n = 140) or left as noninseminated cyclic controls (n = 70). On day 3, half of each group were randomly assigned to receive a P4-releasing intravaginal device resulting in four treatment groups, pregnant and cyclic heifers with high and normal P4 concentrations on either day 5, 7, 13, or 16 of the estrous cycle/early pregnancy.