Open Access. Powered by Scholars. Published by Universities.®

Hydrology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Environmental Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 691 - 720 of 2534

Full-Text Articles in Hydrology

Analysis Of Gravity Recovery And Climate Experiment (Grace) Satellite-Derived Data As A Groundwater And Drought Monitoring Tool, Anthony James Mucia Jul 2018

Analysis Of Gravity Recovery And Climate Experiment (Grace) Satellite-Derived Data As A Groundwater And Drought Monitoring Tool, Anthony James Mucia

School of Natural Resources: Dissertations, Theses, and Student Research

This research compares Gravity Recovery and Climate Experiment (GRACE) groundwater storage (GWS) and root zone soil moisture (RZSM) percentiles to measured data, other drought indicators (DIs) and indices, and stakeholder observations for the purpose of assessing the feasibility and usefulness of these products to detect drought conditions. GRACE percentiles were directly compared to historic groundwater percentiles at 89 Nebraska well locations. Spatial time-series correlations over CONUS were performed between GRACE GWS and RZSM and the U.S. Drought Monitor (USDM), Standardized Precipitation Index (SPI), and soil moisture parameters from several North American Land Data Assimilation System (NLDAS) models. A survey of …


Tracking Drought Perspectives: A Rural Case Study Of Transformations Following An Invisible Hazard, Theresa Jedd, Deborah Bathke, Duane Gill, Bimal Paul, Nicole Wall, Tonya Bernadt, Jacob Peter, Anthony Mucia, Milan Wall Jun 2018

Tracking Drought Perspectives: A Rural Case Study Of Transformations Following An Invisible Hazard, Theresa Jedd, Deborah Bathke, Duane Gill, Bimal Paul, Nicole Wall, Tonya Bernadt, Jacob Peter, Anthony Mucia, Milan Wall

National Drought Mitigation Center: Faculty Publications

Rural towns are especially susceptible to the effects of drought because their economies are dependent on natural resources. However, they are also resilient in many ways to natural hazards because they are rich in civic engagement and social capital. Because of the diverse nature of drought’s impacts, understanding its complex dynamics and its effects requires a multidisciplinary approach. To study these dynamics, this research combines appreciative inquiry, the Community Capitals Framework, and a range of climatological monitoring data to assess the 2012–14 Great Plains drought’s effect on McCook, Nebraska. Community coping measures, such as water-use reduction and public health programs, …


Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, Rebecca Sally Haworth, Emma Rose Goodwin Jun 2018

Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, Rebecca Sally Haworth, Emma Rose Goodwin

Natural Resources Management and Environmental Sciences

Nitrate has become an increasingly ubiquitous pollutant in surface and groundwater, posing a threat to hu- man health and ecosystems. Nitrogen is a necessary nutrient for plant growth and is limiting in many soils. As a result, farmers often add nitrogen to soil in a usable form such as nitrate, nitrite, or ammonia through the addition of fertilizer.


Umphlett Qci June 2018, Natalie Umphlett Jun 2018

Umphlett Qci June 2018, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature Anomalies

Precipitation Anomalies

Water Resources

Agriculture

Temperature

Precipitation


Use Of Floodscape Mapping To Assess Changes In Inundation Frequency Of The Upper Mississippi River, Jeffrey L. Swanson May 2018

Use Of Floodscape Mapping To Assess Changes In Inundation Frequency Of The Upper Mississippi River, Jeffrey L. Swanson

Celebration of Learning

As an alternative to probability-based maps, DeJager (and others) reconceptualized floodplain mapping using the notion of “floodscapes” (DeJager et al., 2015). A floodscape map is developed using daily stage data and high-resolution topography to create maps that depict the average number of days of inundation (per year or growing season). Floodscape maps reveal intricate and continuous patterns of high-frequency flows that are critically important to floodplain ecological functioning. DeJager found significant correlations between floodscape inundation and riparian vegetation patterns but single floodscape maps only provide snapshots in time. This current research develops and utilizes multiple floodscape maps to quantify changes …


A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum May 2018

A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum

Celebration of Learning

Urban expansion has had devastating impacts on forest ecosystems, especially within the past century. Human attempts to dominate nature have diminished natural disturbance regimes, which have maintained the biodiversity and historic composition of these ecosystems. Fires have been a prominent force in maintaining the structure of oak, hickory and other heliophytic (sun loving and fire-adapted) forest systems. Human induced fire suppression has led to mesophication across North America. Mesophication is the transition from drier conditions with open canopies to wetter conditions with closed canopies. These new conditions decrease the survival rates of these important species and begin to favor mesophytic …


Smap Soil Moisture Change As An Indicator Of Drought Conditions, Rajasekaran Eswar, Narendra N. Das, Calvin Christian Poulsen, Ali Behrangi, John Swigart, Mark D. Svoboda, Dara Entekhabi, Simon Yueh, Bradley Doorn, Jared Entin May 2018

Smap Soil Moisture Change As An Indicator Of Drought Conditions, Rajasekaran Eswar, Narendra N. Das, Calvin Christian Poulsen, Ali Behrangi, John Swigart, Mark D. Svoboda, Dara Entekhabi, Simon Yueh, Bradley Doorn, Jared Entin

National Drought Mitigation Center: Faculty Publications

Soil moisture is considered a key variable in drought analysis. The soil moisture dynamics given by the change in soil moisture between two time periods can provide information on the intensification or improvement of drought conditions. The aim of this work is to analyze how the soil moisture dynamics respond to changes in drought conditions over multiple time intervals. The change in soil moisture estimated from the Soil Moisture Active Passive (SMAP) satellite observations was compared with the United States Drought Monitor (USDM) and the Standardized Precipitation Index (SPI) over the contiguous United States (CONUS). The results indicated that the …


Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith May 2018

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …


Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords May 2018

Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords

Electronic Theses and Dissertations

Coal has a questionable future with the potential exhaustion of available coal. Alternate sources of energy production should be considered, such as hydropower dams, or the more environmentally friendly, Run of River (RoR) hydropower system. This study seeks to answer the question: What is the potential for RoR hydroelectric systems in Eastern Kentucky counties with significant decreases in coal production and employment? I hypothesize that GIS will identify suitable sites within Pike County for RoR systems. Site suitability for Eastern Kentucky was assessed and determined that Pike County did not have a suitable physical environment for RoR systems. The power …


A Comparative Study Of The Role Of Values In Reasoning About Socio-Hydrological Issues In Undergraduate Students From Developed And Developing Countries, Destini Petitt May 2018

A Comparative Study Of The Role Of Values In Reasoning About Socio-Hydrological Issues In Undergraduate Students From Developed And Developing Countries, Destini Petitt

School of Natural Resources: Dissertations, Theses, and Student Research

In a world that is becoming increasingly connected and exploited, it is essential to understand how students’ values influence socio-scientific reasoning, particularly when dealing with complex, multifaceted, ever-connected water-related issues. This research strives to better understand stakeholder reasoning to provide teachers and decision-makers with ways to implement those stakeholders’ ideals into choices about complex socio-hydrological issues. Moreover, with 96% of research behavioral research being conducted on peoples from developed countries – who only represent 17% of the world’s population – this study strives to understand how peoples from developing countries – who represent 83% of the world’s population – reason. …


Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier May 2018

Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier

School of Natural Resources: Dissertations, Theses, and Student Research

Even though wetlands provide a habitat for many plants and animals and numerous services for humans, they were not always treated as areas of value. Less than half of the United States’ pre-colonial wetlands have survived to the present day. Seeing a need to understand the remaining wetlands more fully, the Environmental Protection Agency developed the National Wetland Condition Assessment to monitor target wetlands throughout the country every five years.

This study is an intensification of the National Wetland Condition Assessment for Nebraska wetlands that allowed us to sample more areas of the state and gather additional information. During the …


Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer May 2018

Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer

School of Natural Resources: Dissertations, Theses, and Student Research

Streambed hydraulic conductivity (K) is known to be spatially and temporally heterogeneous, but few attempts to understand the controls on temporal variability have been made. This study documents temporal K transience and demonstrates how hydraulic, geophysical, and sedimentological methods can be combined to understand the processes that give rise to changes in streambed K. Falling head permeameter tests and slug tests were conducted to determine vertical K (Kv) and K (slug test K), respectively. These tests were repeated three times over a twelve-week period on the same grid at a depth of 0.5 …


Assessment Of Water Quality Variation In Rivers Through Comparative Index Technique And Its Reliability For Decision Making, Aldo Kitalika, Revocatus Machunda, Hans Komakech, Karoli N Njau Apr 2018

Assessment Of Water Quality Variation In Rivers Through Comparative Index Technique And Its Reliability For Decision Making, Aldo Kitalika, Revocatus Machunda, Hans Komakech, Karoli N Njau

Tanzania Journal of Science

The National Sanitation Foundation (NSF) and Weighed Arithmetic Index (WAI) methods for water quality index (WQI) have been studied to evaluate their reliability in water quality assessment in rivers. Water samples were collected in various GPS predetermined points in Temi, Nduruma, Tengeru and Maji ya Chai rivers-Tanzania during wet and dry seasons and were analyzed for several water quality parameters using standard methods as per APHA. Medium to excellent water qualities were observed for pristine environment in three rivers except Maji ya Chai under NSF and WIA methods, respectively. Excellent water quality was observed in the pristine environment of Temi …


The Impact Of Land Use On Nitrate-N Movement And Storage In The Vadose Zone Of The Hastings’ Whpa, Craig Adams Apr 2018

The Impact Of Land Use On Nitrate-N Movement And Storage In The Vadose Zone Of The Hastings’ Whpa, Craig Adams

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska has one of the largest agricultural economies in the United States and relies heavily on irrigation and fertilizer application to maintain crop yields. Over-irrigation and continuous application of nitrogen (N) in many areas has led to accumulation of nitrate-N in soils and sediments throughout the state’s vadose zone. Because nitrate-N is both persistent and mobile, groundwater concentrations in many areas of Nebraska and other agriculturally intensive states are increasing. Nitrate-N contamination of public and private drinking water supplies that utilize groundwater are of particular concern. Vadose zone sampling is an important method for rapidly assessing the effect of changing …


Downscaling Africa’S Drought Forecasts Through Integration Of Indigenous And Scientific Drought Forecasts Using Fuzzy Cognitive Maps, Muthoni Masinde, Mwanjele Mwagha, Tsegaye Tadesse Apr 2018

Downscaling Africa’S Drought Forecasts Through Integration Of Indigenous And Scientific Drought Forecasts Using Fuzzy Cognitive Maps, Muthoni Masinde, Mwanjele Mwagha, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

In the wake of increased drought occurrences being witnessed in Sub-Saharan Africa, more localized and contextualized drought mitigation strategies are on the agendas of many researchers and policy makers in the region. The integration of indigenous knowledge on droughts with seasonal climate forecasts is one such strategy. The main challenge facing this integration, however, is the formal representation of highly-structured and holistic indigenous knowledge. In this paper, we demonstrate how the use of fuzzy cognitive mapping can address this challenge. Indigenous knowledge on droughts from five communities was modeled and represented using fuzzy cognitive maps. Maps from one of these …


Imidacloprid Sorption And Transport In Cropland, Grass Buffer, And Riparian Buffer Soils, Laura E. Satkowski, Keith W. Goyne, Stephen H. Anderson, Robert N. Lerch, Elisabeth B. Webb, Daniel D. Snow Apr 2018

Imidacloprid Sorption And Transport In Cropland, Grass Buffer, And Riparian Buffer Soils, Laura E. Satkowski, Keith W. Goyne, Stephen H. Anderson, Robert N. Lerch, Elisabeth B. Webb, Daniel D. Snow

Daugherty Water for Food Global Institute: Faculty Publications

An understanding of neonicotinoid sorption and transport in soil is critical for determining and mitigating environmental risk associated with the most widely used class of insecticides. The objective of this study was to evaluate mobility and transport of the neonicotinoid imidacloprid (ICD) in soils collected from cropland, grass vegetative buffer strip (VBS), and riparian VBS soils. Soils were collected at six randomly chosen sites within grids that encompassed all three land uses. Single-point equilibrium batch sorption experiments were conducted using radio-labeled (14C) ICD to determine solid–solution partition coefficients (Kd). Column experiments were conducted using soils collected …


Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael Apr 2018

Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael

Research and Creative Activities Poster Day

Persistent scatterer interferometric analyses were conducted on a stack of 84 Envisat ASAR scenes spanning 7 years (2004 to 2010) over the entire Nile Delta of Egypt and surroundings to monitor the ongoing spatial and temporal land deformation, identify the factors controlling the deformation, and model the interplay between sea level rise and land subsidence to identify areas and populations threatened by sea encroachment by the end of the 21st century. Findings include: (1) general patterns of subsidence in the northern delta, near-steady (none) subsidence in the southern delta, separated by a previously mapped flexure zone undergoing uplift; (2) high …


Documentation Of Particle-Size Analyzer Time Series, And Discrete Suspended-Sediment And Bed-Sediment Sample Data Collection, Niobrara River Near Spencer, Nebraska, October 2014, Nathaniel J. Schaepe, Anthony M. Coleman, Ronald B. Zelt Apr 2018

Documentation Of Particle-Size Analyzer Time Series, And Discrete Suspended-Sediment And Bed-Sediment Sample Data Collection, Niobrara River Near Spencer, Nebraska, October 2014, Nathaniel J. Schaepe, Anthony M. Coleman, Ronald B. Zelt

United States Geological Survey: Water Reports and Publications

Document abstract

The Ubited States Geological Survey (USGS), in cooperation with the United States Army Corps of Engineers, monitored a sediment release by Nebraska Public Power District from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. The accumulated sediment behind Spencer Dam ordinarily is released semiannually; however, the spring 2014 release was postponed until the fall. Because of the postponement, the scheduled fall sediment release would consist of a larger volume of sediment. The larger than normal sediment release expected in fall 2014 provided an opportunity for the USGS and US Army Corps …


Validation Of New Satellite Rainfall Products Over The Upper Blue Nile Basin, Ethiopia, Getachew Tesfaye Ayehu, Tsegaye Tadesse, Berhan Gessesse, Tufa Dinku Apr 2018

Validation Of New Satellite Rainfall Products Over The Upper Blue Nile Basin, Ethiopia, Getachew Tesfaye Ayehu, Tsegaye Tadesse, Berhan Gessesse, Tufa Dinku

National Drought Mitigation Center: Faculty Publications

Accurate measurement of rainfall is vital to analyze the spatial and temporal patterns of precipitation at various scales. However, the conventional rain gauge observations in many parts of the world such as Ethiopia are sparse and unevenly distributed. An alternative to traditional rain gauge observations could be satellite-based rainfall estimates. Satellite rainfall estimates could be used as a sole product (e.g., in areas with no (or poor) ground observations) or through integrating with rain gauge measurements. In this study, the potential of a newly available Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) rainfall product has been evaluated in comparison …


Management Of An Urban Stormwater System Using Projected Future Scenarios Of Climate Models: A Watershed-Based Modeling Approach, Ranjeet Thakali, Ajay Kalra, Sajjad Ahmad, Kamal Qaiser Apr 2018

Management Of An Urban Stormwater System Using Projected Future Scenarios Of Climate Models: A Watershed-Based Modeling Approach, Ranjeet Thakali, Ajay Kalra, Sajjad Ahmad, Kamal Qaiser

Civil and Environmental Engineering and Construction Faculty Research

Anticipating a proper management needs for urban stormwater due to climate change is becoming a critical concern to water resources managers. In an effort to identify best management practices and understand the probable future climate scenarios, this study used high-resolution climate model data in conjunction with advanced statistical methods and computer simulation. Climate model data from the North American Regional Climate Change Assessment Program (NARCCAP) were used to calculate the design storm depths for the Gowan Watershed of Las Vegas Valley, Nevada. The Storm Water Management Model (SWMM), developed by the Environmental Protection Agency (EPA), was used for hydrological modeling. …


Primary Atmospheric Drivers Of Pluvial Years In The United States Great Plains, Paul Flanagan, Jeffrey B. Basara, Jason C. Furtado, Xiangming Xiao Apr 2018

Primary Atmospheric Drivers Of Pluvial Years In The United States Great Plains, Paul Flanagan, Jeffrey B. Basara, Jason C. Furtado, Xiangming Xiao

High Plains Regional Climate Center: Staff Publications

Precipitation variability has increased in recent decades across the Great Plains (GP) of the United States. Drought and its associated drivers have been studied in the GP region; however, periods of excessive precipitation (pluvials) at seasonal to interannual scales have received less attention. This study narrows this knowledge gap with the overall goal of understanding GP precipitation variability during pluvial periods. Through composites of relevant atmospheric variables from the ECMWF twentieth-century reanalysis (ERA-20C), key differences between southern Great Plains (SGP) and northern Great Plains (NGP) pluvial periods are highlighted. The SGP pluvial pattern shows an area of negative height anomalies …


Daugherty Water For Food Global Institute Strategic Plan Fy18 – Fy23 Apr 2018

Daugherty Water For Food Global Institute Strategic Plan Fy18 – Fy23

Daugherty Water for Food Global Institute: Administrative Materials

Through research and policy development, education and communication, the institute is enhancing knowledge, fostering future water and food security leaders and developing effective techniques to sustainably manage water and increase food security. DWFI focuses its efforts in five areas of expertise and has identified key outcomes in each area to drive impact and measure success in the next five years, FY2018 to FY2023:

Closing Water & Agricultural Productivity Gaps: • Develop and deploy global satellite-based decision support and monitoring tools based on daily evapotranspiration estimates in key agricultural areas in the US and selected countries. • Improve knowledge of best …


Droughtscape, Spring 2018, National Drought Mitigation Center Apr 2018

Droughtscape, Spring 2018, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Drought shifts to south in beginning of 2018

Ag records impacts; strong fire season forecast

Drought maps show regional and river forecast areas

Greenness indicator could save lives in Africa

NDMC on a global playing field

Visitors from Korea tap drought resources, experts

Svoboda named to United Nations advisory group

Responding to drought in the Southern Plains

Crops, cattle and climatology in the Upper Niobrara

Connecting locally for global change


High-Resolution Water Footprints Of Production Of The United States Mar 2018

High-Resolution Water Footprints Of Production Of The United States

Daugherty Water for Food Global Institute: Faculty Publications

The United States is the largest producer of goods and services in the world. Rainfall, surface water supplies, and groundwater aquifers represent a fundamental input to economic production. Despite the importance of water resources to economic activity, we do not have consistent information on water use for specific locations and economic sectors. A national, spatially detailed database of water use by sector would provide insight into U.S. utilization and dependence on water resources for economic production. To this end, we calculate the water footprint of over 500 food, energy, mining, services, and manufacturing industries and goods produced in the United …


Precipitation Extremes In Dynamically Downscaled Climate Scenarios Over The Greater Horn Of Africa, Andualem Shiferaw, Tsegaye Tadesse, Clinton M. Rowe, Robert Oglesby Mar 2018

Precipitation Extremes In Dynamically Downscaled Climate Scenarios Over The Greater Horn Of Africa, Andualem Shiferaw, Tsegaye Tadesse, Clinton M. Rowe, Robert Oglesby

National Drought Mitigation Center: Faculty Publications

This study first assesses the performance of regional climate models in the Coordinated Regional Climate Downscaling Experiment (CORDEX) in reproducing observed extreme precipitation indices over the Greater Horn of Africa (GHA) region during 1989–2005. The study then assesses projected changes in these extremes during 2069–2098 compared to 1976–2005. The Regional Climate Model (RCM) simulations are made using two RCMs, with large-scale forcing from four CMIP5 Global limate Models(GCMs) under two Representative Concentration Pathways (RCP4.5 and RCP8.5). We found that RCM simulations have reasonably captured observed patterns of moderate precipitation extreme indices (MPEI). Pattern correlation coefficients between simulated and observed MPEI …


Extreme Precipitation Events, Impacts, Trends And Projections For Indiana, Sam Lashley Mar 2018

Extreme Precipitation Events, Impacts, Trends And Projections For Indiana, Sam Lashley

Purdue Road School

The National Weather Service is working with core partners to build a Weather Ready Nation for present and future generations by taking advanced action against the devastating impacts of extreme weather events, including extreme precipitation and flooding. One way in which this can be accomplished is by studying trends in historical weather data and applying what we learn to future mitigation efforts. The goal is to gain a better understanding of the magnitude and impacts that future extreme precipitation events may have on local infrastructure.

This presentation will review extreme rainfall and flooding events that have occurred across Indiana along …


Umphlett Qci March 2018, Natalie Umphlett Mar 2018

Umphlett Qci March 2018, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Mountain Snowpack

Enhanced Fire Activity During Winter

Utilities Impacted by Extreme Cold

3-Month Precipitation and Temperature Outlooks

Winter Drought Conditions and Outlook


Fossils On The Floor In The Nebraska State Capitol: A Coloring And Activities Book, Robert F. Diffendal Jr. Mar 2018

Fossils On The Floor In The Nebraska State Capitol: A Coloring And Activities Book, Robert F. Diffendal Jr.

Conservation and Survey Division: Faculty and Staff Publications

The Nebraska State Capitol is a wonderful place. This building is home to great treasures of art owned by the people of Nebraska. The floor of the Capitol Rotunda has beautiful works of art. Maybe you have seen this art. Small pieces of two kinds of rocks make pictures of people, their tools, the natural resources they used, and pictures of fossil animals and plants. These kinds of pictures are called mosaics [moe ZAY icks]. The animals and plants follow one another in a curved ribbon around the floor. In that ribbon of pictures are many kinds of fossil animals …


Comparison Of The Performance Of Six Drought Indices In Characterizing Historical Drought For The Upper Blue Nile Basin, Ethiopia, Yared Bayissa, Shreedhar Maskey, Tsegaye Tadesse, Schalk Jan Van Andel, Semu Moges, Ann Van Griensven, Dimitri Solomatine Feb 2018

Comparison Of The Performance Of Six Drought Indices In Characterizing Historical Drought For The Upper Blue Nile Basin, Ethiopia, Yared Bayissa, Shreedhar Maskey, Tsegaye Tadesse, Schalk Jan Van Andel, Semu Moges, Ann Van Griensven, Dimitri Solomatine

National Drought Mitigation Center: Faculty Publications

The Upper Blue Nile (UBN) basin is less-explored in terms of drought studies as compared to other parts of Ethiopia and lacks a basin-specific drought monitoring system. This study compares six drought indices: Standardized Precipitation Index (SPI), Standardized Precipitation Evaporation Index (SPEI), Evapotranspiration Deficit Index (ETDI), Soil Moisture Deficit Index (SMDI), Aggregate Drought Index (ADI), and Standardized Runoff-discharge Index (SRI), and evaluates their performance with respect to identifying historic drought events in the UBN basin. The indices were calculated using monthly time series of observed precipitation, average temperature, river discharge, and modeled evapotranspiration and soil moisture from 1970 to 2010. …


Expanding The "Active Layer", Peter Ashmore, Sarah Peirce, Pauline Leduc Feb 2018

Expanding The "Active Layer", Peter Ashmore, Sarah Peirce, Pauline Leduc

Geography & Environment Publications

Church and Haschenburger (2017) make helpful distinctions around the issue of defining the active layer, with which we agree. We propose expanding discussion and definition of the ”active layer” in fluvial bedload transport to include the concept of the “morphological active layer”. This is particularly applicable to laterally unstable rivers (such as braided rivers) in which progressive morphological change over short time periods is the process by which much of the bedload transport occurs. The morphological active layer is also distinguished by variable lateral and longitudinal extent continuity over a range of flows and transport intensity. We suggest that the …