A5058519822- Hydrology and Watershed Management Studies
- Soil erosion and sediment transport
- Groundwater and Isotope Geochemistry
- Hydrology and Sediment Transport Processes
- Groundwater flow and contamination studies
- Soil and Unsaturated Flow
- Soil and Water Nutrient Dynamics
- Water resources management and optimization
- Climate variability and models
- Water-Energy-Food Nexus Studies
- Landslides and related hazards
- Rangeland and Wildlife Management
- Cryospheric studies and observations
- Soil Moisture and Remote Sensing
- Tropical and Extratropical Cyclones Research
- Plant Water Relations and Carbon Dynamics
- Irrigation Practices and Water Management
- Geology and Paleoclimatology Research
- Fire effects on ecosystems
- Flood Risk Assessment and Management
- Water Quality and Resources Studies
- Interdisciplinary Research and Collaboration
- Geophysical Methods and Applications
- Isotope Analysis in Ecology
- Aeolian processes and effects
Washington State University
2016-2025
University of Washington
2023
University of Idaho
2008-2018
Waters (United States)
2011-2015
Washington State University Spokane
2015
Social Science Research Council
2010
University of Nebraska–Lincoln
2010
Oregon Department of Environmental Quality
2006
Rocky Mountain Research Station
2006
Russian State Agrarian University - Moscow Timiryazev Agricultural Academy
2004
Abstract Ecuador has the highest deforestation rate in South America, causing large‐scale soil erosion. Inter‐Andean watersheds are especially affected by a rapid increase of population leading to conversion large areas montane forest into pasture and cropland. In this study, we estimate erosion risk small mixed land‐use watershed southern Andes Ecuador. Soil loss was estimated at spatial resolution 30 m, using Revised Universal Loss Equation (RUSLE) where RUSLE factors were on basis limited...
Current physically based overland flow erosion models for rangeland application do not separate disturbed and undisturbed conditions in modeling concentrated erosion. In this study, simulations on rangelands were used to estimate the erodibility evaluate performance of linear power law equations that describe relationship between rate several hydraulic parameters. None parameters consistently predicted detachment capacity well all sites, however, stream performed better than most other Using...
One of the most challenging parameters in hillslope‐ and watershed‐scale, distributed, hydrologic models is lateral saturated hydraulic conductivity ( K s ). In this paper, we present a methodology to determine hillslope‐scale above moderately deep sloping restrictive layer an 18 × 35 m hillslope plot using perched water level measurements drain tile outflow data. The was compared small‐scale measured with small soil cores Guelph permeameter. Our results show that underestimate actual . were...
Abstract Sampling solute concentrations in the vadose zone provides an early‐warning system for groundwater pollution. Various sampling devices are available. This study evaluates functionality of fiberglass wicks a soil solution sampler. Fiberglass act as hanging water column, drawing from undisturbed field without external application suction. Flow characteristics were observed laboratory by miscible‐displacement tests using Br and organic dye. The matric potential wick function flow rate...
The transport of pesticides and other chemicals through macropores has been widely observed predicting it is a challenge. This article considers simplified two-layer model, similar to overland flow models in which the processes adsorption desorption are separated. For layer near surface, or mixing layer, solute concentration equal that percolating water (including preferentially moving water). In lower profile, partitioned between matrix preferential flow. characterized by soil condition...
Hydrologic response to rainfall on fragmented or burnt hillslopes is strongly influenced by the ensuing connectivity of runoff and erosion processes. Yet cross-scale process seldom evaluated in field studies owing scale limitations experimental design. This study quantified surface susceptibility hydrologic across point hillslope scales at two degraded unburnt woodland sites using simulation modelling. High (31–47 mm) (154–1893 g m–2) measured patch (13 m2) were associated with accumulation...
The last 2014-16 El Niño event was among the three strongest episodes on record. considerably changes annual and seasonal precipitation across tropics. Here, we present a unique stable isotope data set of daily collected in Costa Rica prior to, during, after 2014-16, combination with Lagrangian moisture source anomaly diagnostics. δ2H composition ranged from -129.4 to +18.1 (‰) while δ18O -17.3 +1.0 (‰). No significant difference observed (P=0.186) (P=0.664) mean compositions. However,...
Abstract High‐elevation tropical grassland systems, called Páramo, provide essential ecosystem services such as water storage and supply for surrounding lowland areas. Páramo systems are threatened by climate land use changes. Rainfall generation processes moisture transport pathways influencing precipitation in the poorly understood but needed to estimate impact of these changes, particularly during El Niño conditions, which largely affect hydrometeorological conditions regions. To fill...
The rapid growth of demand in agricultural production has created water scarcity issues worldwide. Simultaneously, climate change scenarios have projected that more frequent and severe droughts are likely to occur. Adaptive resources management been suggested as one strategy better coordinate surface groundwater (i.e., conjunctive use) address droughts. In this study, we enhanced an aggregated resource tool represents integrated agriculture, water, energy, social systems. We applied the...
Artificial capillary barriers are being used to divert water away from sensitive underground regions. Conversely, funneled flow over natural may increase the danger of groundwater contamination by decreasing travel time and contact area. There have been relatively few experimental studies barrier patterns. In this study, was applied uniformly across top surface a backlit tilting chamber, 1 cm thick, 110 high, 180 long, in which coarse sand layer imbedded fine sand. Bedding slope application...
The complexity of explaining highly scientific information and juggling a plethora social values is leading agencies communities such as those in the Palouse Basin to explore use participatory modeling processes using system dynamics. Participatory dynamics methodology creates transparent nexus science, policy options, concerns local knowledge that enhances discussion issues surrounding natural resources. process developing systems model uses tenets theory, hypothesis testing clear...
The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from Caribbean Sea and Pacific Ocean. In Rica, stable isotope monitoring was conducted by International Atomic Energy Agency World Meteorological Association as part worldwide effort entitled Global Network Isotopes in Precipitation. Sampling campaigns were mainly comprised monthly-integrated samples during intermittent years 1990 to 2005. main goal this study...
Abstract Serpentinization is a planetary process that has important consequences on geochemical cycles, supporting microbial activity through the formation of H 2 and CH 4 having potential to sequester atmospheric CO . We present evidence active serpentinization in Santa Elena Ophiolite, Costa Rica which sustained by peridotites with degree less than 50% no an internal heat source. Average spring water temperatures are 29.1°C. Two hyperalkaline systems were discovered, fluid pH up 11.18. The...
The purpose of this paper is to recommend a framework and methodology for incorporating hydrologic data ecohydrologic relationships in Ecological Site Descriptions (ESDs) thereby enhance the utility ESDs assessing rangelands guiding resilience-based management strategies. Resilience-based strategies assess manage ecological state dynamics that affect vulnerability and, therefore, provide opportunities adapt management. Many are spatially heterogeneous or sparsely vegetated where vegetation...