Physical Sciences and Mathematics Commons^™

Understanding The Soil Water Dynamics During Excess And Deficit Rainfall Conditions Over The Core Monsoon Zone Of India, Mangesh M. Goswami, Milind Mujumdar1, Bhupendra Bahadur Singh, Madhusudan Ingale, Naresh Ganeshi, Manish Ranalkar, Trenton E. Franz, Prashant Srivastav, Dev Niyogi, R Krishnan, S N. Patil

School of Natural Resources: Faculty Publications

Observations of soil moisture (SM) during excess and deficit monsoon seasons between 2000 to 2021 present a unique opportunity to understand the soil water dynamics (SWD) over core monsoon zone (CMZ) of India. This study aims to analyse SWD by investigating the SM variability, SM memory (SMM), and the coupling between surface and subsurface SM levels. Particularly intriguing are instances of concurrent monsoonal extremes, which give rise to complex SWD patterns. Usually, it is noted that a depleted convective activity and persistence of higher temperatures during the pre-monsoon season leads to lower SM, while monsoon rains and post-monsoon showers support …

Development Of A Benchmark Eddy Flux Evapotranspiration Dataset For Evaluation Of Satellite-Driven Evapotranspiration Models Over The Conus, John M. Volk, Justin Huntington, Forrest S. Melton, Richard Allen, Martha C. Anderson, Joshua B. Fisher, Ayse Kilic, Gabriel Senay, Gregory Halverson, Kyla Knipper, Blake Minor, Christopher Pearson, Tianxin Wang, Yun Yang, Steven Evett, Andrew N. French, Richard Jasoni, William Kustas

School of Natural Resources: Faculty Publications

A large sample of ground-based evapotranspiration (ET) measurements made in the United States, primarily from eddy covariance systems, were post-processed to produce a benchmark ET dataset. The dataset was produced primarily to support the intercomparison and evaluation of the OpenET satellite-based remote sensing ET (RSET) models and could also be used to evaluate ET data from other models and approaches. OpenET is a web-based service that makes field-delineated and pixel-level ET estimates from well-established RSET models readily available to water managers, agricultural producers, and the public. The benchmark dataset is composed of flux and meteorological data from a variety of …

Calibration-Free Complementary Relationship Estimates Terrestrial Evapotranspiration Globally, N. Ma, J. Szilagyi, Y. Zhang

School of Natural Resources: Faculty Publications

No abstract provided.

Connections Between The Hydrological Cycle And Crop Yield In The Rainfed U.S. Corn Belt, Wang Zhou, Kaiyu Guan, Bin Peng, Jiancheng Shi, Chongya Jiang, Brian Wardlow, Ming Pan, John S. Kimball, Trenton Franz, Pierre Gentine, Mingzhu He, Jingwen Zhang

School of Natural Resources: Faculty Publications

No abstract provided.

Monitoring Residual Soil Moisture And Its Association To The Long-Term Variability Of Rainfall Over The Upper Blue Nile Basin In Ethiopia, Getachew Ayehu, Tsegaye Tadesse, Berhan Gessesse

Drought Mitigation Center: Faculty Publications

Monitoring soil moisture and its association with rainfall variability is important to comprehend the hydrological processes and to set proper agricultural water use management to maximize crop growth and productivity. In this study, the European Space Agency’s Climate Change Initiative (ESA CCI) soil moisture product was applied to assess the dynamics of residual soil moisture in autumn (September to November) and its response to the long-term variability of rainfall in the Upper Blue Nile Basin (UBNB) of Ethiopia from 1992 to 2017. The basin was found to have autumn soil moisture (ASM) ranging from 0.09–0.38 m³/m³, …

Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale

Daugherty Water for Food Global Institute: Faculty Publications

Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …

Water Balance Backward: Estimation Of Annual Watershed Precipitation And Its Long-Term Trend With The Help Of The Calibration-Free Generalized Complementary Relationship Of Evaporation, J. Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

Current Frameworks For Reference Et And Crop Coefficient Calculation, R G. Allen, Ayse Kilic, Clarence W. Robison

School of Natural Resources: Faculty Publications

Estimation of evapotranspiration is under continual development and evolution, with significant developments and standardizations made during the past three decades for both reference ET (ETref) and for crop coefficients (Kc). These standardizations provide consistency and reproducibility in estimating ETref and a consistent basis for determining and expressing Kc curves, especially at the local scale. The application of the dual Kc procedure is growing, and has strong potential for improving accuracy of ET estimates as compared to the single Kc approach. This article describes current structures for estimating crop coefficients including the standardized FAO-56 dual Kc approach, with example applications. Emphasis …

Applying The Fao-56 Dual KC Method For Irrigation Water Requirements Over Large Areas Of The Western U.S., Richard Allen, Clarence W. Robison, Justin Huntington, James L. Wright, Ayse Kilic

School of Natural Resources: Faculty Publications

The FAO-56 dual crop coefficient procedure was used to determine evapotranspiration (ET) and net irrigation water requirements for all agricultural areas of the states of Idaho and Nevada and in a western U.S. study on effects of climate change on future irrigation water requirements. The products of the applications are for use by state governments for water rights management, irrigation system planning and design, wastewater application system design and review, hydrologic water balances, and groundwater modeling. The products have been used by the U.S. federal government for assessing impacts of current and future climate change on irrigation water demands. The …

A Review Of Landscape Water Requirements Using A Multicomponent Landscape Coefficient, R G. Allen, M. D. Dukes, R. L. Snyder, R. Kjelgren, Ayse Kilic

School of Natural Resources: Faculty Publications

Water requirements of landscapes are highly variable due to the heterogeneous natures of landscapes, vegetation types, influence of buildings, and nutrient and water management. Objectives for water management of landscapes are for general appearance and health rather than for maximum biomass production. A multi-component method developed for the Irrigation Association (IA) and extended from the California WUCOLS procedure is demonstrated in which the landscape coefficient (KL, equivalent to a crop coefficient) is broken down into four components: vegetation type, vegetation density, microclimate, and managed stress. Each of these components can be estimated using readily made descriptions of a landscaped area …

Global Production And Free Access To Landsat-Scale Evapotranspiration With Eeflux And Eemetric, Ayse Kilic, R G. Allen, Philip A. Blankenau, Peter Revelle, Doruk Ozturk, Justin L. Huntington

School of Natural Resources: Faculty Publications

EEFlux (Earth Engine Evapotranspiration Flux) is a version of the METRIC (mapping evapotranspiration at high resolution with internal calibration) application that operates on the Google Earth Engine (EE). EEFlux has a web-based interface and provides free public access to transform Landsat images into 30 m spatial evapotranspiration (ET) data for terrestrial land areas around the globe. EE holds the entire Landsat archive to power EEFlux along with NLDAS/CFSV2 gridded weather data for estimating reference ET. EEFlux is a part of the upcoming OpenET platform (https://openetdata.org/ ) that has leveraged nonprofit funding to provide ET information to all of the lower …

Metric-Gis: An Advanced Energy Balance Model For Computing Crop Evapotranspiration In A Gis Environment, J. M. Ramírez-Cuesta, R G. Allen, D. S. Intrigliolo, Ayse Kilic, Clarence W. Robison, Ricardo Trezza, C. Santos, I. J. Lorite

School of Natural Resources: Faculty Publications

A novel ArcGIS toolbox that applies the Mapping Evapotranspiration with Internalized Calibration model was developed and tested in a semi-arid environment. The tool, named METRIC-GIS, facilitates the pre-processing operations and the automatic identification of potential calibration and pixels review. The energy balance components obtained from METRIC-GIS were contrasted with those from the original METRIC version (R² = 1; RMSE = 0 W m^–2 or mm day^–1 for ET_c) Additionally, an irrigated scheme located at southern Spain was considered for assessing Kc variability in the maize fields with METRIC-GIS. The identified spatial variability was mainly due …

Effects Of Surface Heterogeneity Due To Drip Irrigation On Scintillometer Estimates Of Sensible, Latent Heat Fluxes And Evapotranspiration Over Vineyards, Hatim M. E. Geli, José González-Piqueras, Christopher M. U. Neale, Claudio Balbontín, Isidro Campos, Alfonso Calera

Daugherty Water for Food Global Institute: Faculty Publications

Accurate estimates of sensible (H) and latent (LE) heat fluxes and actual evapotranspiration (ET) are required for monitoring vegetation growth and improved agricultural water management. A large aperture scintillometer (LAS) was used to provide these estimates with the objective of quantifying the effects of surface heterogeneity due to soil moisture and vegetation growth variability. The study was conducted over drip-irrigated vineyards located in a semi-arid region in Albacete, Spain during summer 2007. Surface heterogeneity was characterized by integrating eddy covariance (EC) observations of H, LE and ET; land surface temperature (LST) and normalized difference vegetation index (NDVI) data from Landsat …

Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale

Daugherty Water for Food Global Institute: Faculty Publications

Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …

County-Wide Assessment Of Irrigation Expansion On Air Temperature, Humidity And Evapotranspiration Rates In Nebraska, 1979-2015, Jozsef Szilagyi

Conservation and Survey Division

Total irrigated land area has been expanding in Nebraska over the last 40 years, propelling the state into a leading position within the US in terms of irrigated acreages. Typically, those counties which display the largest degree of irrigation development had a significant portion of their land area already irrigated in 1978. Large-scale irrigation in Nebraska affects its atmospheric environment. During the typical irrigation season of May to August, counties with the largest rate of irrigation expansion have cooled by about 0.2 – 0.3 °F per decade in the summer months of June, July and August, while counties with the …

Annual, Seasonal, And Diel Surface Energy Partitioning In The Semiarid Sand Hills Of Nebraska, Usa, Nathan C. Healey, Timothy J. Arkebauer, David P. Billesbach, John D. Lenters

School of Natural Resources: Faculty Publications

Study Region: The Nebraska Sand Hills consisting of four major land cover types: (1) lakes and wetlands (∼5% for both), (2) subirrigated meadows (∼10%), (3) dry valleys (∼20%), and (4) upland dunes (∼65%).

Study Focus: Examination of surface energy and water balances on multiple temporal scales with primary focus on latent heat flux (λE), and evapotranspiration (ET), to gain a better understanding of the annual, seasonal, and diel properties of surface energy partitioning among different Sand Hills ecosystems to improve regional water resource management. New Hydrological Insights for the Region: Based on surface energy and water balance measurements using Bowen …

Evaluation Of A Hybrid Reflectance-Based Crop Coefficient And Energy Balance Evapotranspiration Model For Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren, Andrew E. Suyker

Biological Systems Engineering: Papers and Publications

Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (K_cbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the …

Evapotranspiration Trends (1979-2015) In The Central Valley Of California, Usa: Contrasting Tendencies During 1981-2007, Jozsef Szilagyi, Janos Jozsa

School of Natural Resources: Faculty Publications

No abstract provided.

The Future Of Evapotranspiration: Global Requirements For Ecosystem Functioning, Carbon And Climate Feedbacks, Agricultural Management, And Water Resources, Joshua B. Fisher, Forrest S. Melton, Elizabeth M. Middleton, Christopher Hain, Martha C. Anderson, Richard G. Allen, Matthew Mccabe, Simon Hook, Dennis Baldocchi, Philip A. Townsend, Ayse Kilic, Kevin Tu, Diego Miralles, Johan Perret, Jean-Pierre Lagouarde, Duane Waliser, Adam J. Purdy, Andrew French, David Schimel, James S. Famiglietti, Graeme Stephens, Eric F. Wood

Department of Earth and Atmospheric Sciences: Faculty Publications

The fate of the terrestrial biosphere is highly uncertain given recent and projected changes in climate. This is especially acute for impacts associated with changes in drought frequency and intensity on the distribution and timing of water availability. The development of effective adaptation strategies for these emerging threats to food and water security are compromised by limitations in our understanding of how natural and managed ecosystems are responding to changing hydrological and climatological regimes. This information gap is exacerbated by insufficient monitoring capabilities from local to global scales. Here, we describe how evapotranspiration (ET) represents the key variable in linking …

Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi

Conservation and Survey Division

No abstract provided.

A Calibration-Free, Robust Estimation Of Monthly Land Surface Evapotranspiration Rates For Continental-Scale Hydrology, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Tiejun Wang, Justin Gibson, Ayse Kilic, Richard Allen, Andrew Suyker

School of Natural Resources: Faculty Publications

No abstract provided.

Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The purpose of this study was to understand how a large-scale representation of agroecosystems and ecosystems respond to extreme hydrometeorological and climate extreme events (EHCE) within the Platte River Basin. The ability for agroecosystems and ecosystems to adapt to a changing and variable climate is vital for global water, energy, and food security. Two model experiments were performed, the first with a time span from 2000 to 2013 in which a dynamic leaf area index (LAI) MODIS15A2 product was implemented. The second experiment ran from 1950 through 2013 used a climatological fixed seasonal cycle calculated as the average from the …

Estimation Of Energy Balance Components Over A Drip-Irrigated Olive Orchard Using Thermal And Multispectral Cameras Placed On A Helicopter-Based Unmanned Aerial Vehicle (Uav), Samuel Ortega-Farias, Samuel Ortega-Salazar, Tomas Poblete, Ayse Kilic, Richard Allen, Carlos Poblete-Echeverria, Luis Ahumada-Orellana, Mauricio Zuniga, Daniel Sepulveda

School of Natural Resources: Faculty Publications

A field experiment was carried out to implement a remote sensing energy balance (RSEB) algorithm for estimating the incoming solar radiation (Rsi), net radiation (Rn), sensible heat flux (H), soil heat flux (G) and latent heat flux (LE) over a drip-irrigated olive (cv. Arbequina) orchard located in the Pencahue Valley, Maule Region, Chile (35^◦25'S; 71^◦44'W; 90 m above sea level). For this study, a helicopter-based unmanned aerial vehicle (UAV) was equipped with multispectral and infrared thermal cameras to obtain simultaneously the normalized difference vegetation index (NDVI) and surface temperature (Tsurface) at very high resolution (6 cm …

Assessing The Evolution Of Soil Moisture And Vegetation Conditions During The 2012 United States Flash Drought, Jason A. Otkin, Martha C. Anderson, Christopher R. Hain, Mark D. Svoboda, David K. Johnson, Richard Mueller, Tsegaye Tadesse, Brian D. Wardlow, Jesslyn Brown

Drought Mitigation Center: Faculty Publications

This study examines the evolution of several model-based and satellite-derived drought metrics sensitive to soil moisture and vegetation conditions during the extreme flash drought event that impacted major agricultural areas across the central U.S. during 2012. Standardized anomalies from the remote sensing based Evaporative Stress Index (ESI) and Vegetation Drought Response Index (VegDRI) and soil moisture anomalies from the North American Land Data Assimilation System (NLDAS) are compared to the United States Drought Monitor (USDM), surface meteorological conditions, and crop and soil moisture data compiled by the National Agricultural Statistics Service (NASS).

Overall, the results show that rapid decreases in …

The Spatial Sensitivity Analysis Of Evapotranspiration Using Penman-Monteith Method At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

The need to allocate the existing water in a sustainable manner, even with the projected population growth, has made to assess the consumptive use or evapotranspiration (ET), which determines the irrigation demand. As underscored in the literature, Penman-Monteith method which is a combination of aerodynamic and energy balance method is widely used and accepted as the method of estimation of ET. However, the application of Penman-Monteith relies on many climate parameters such as relative humidity, solar radiation, temperature, and wind speed. Therefore, there exists a need to determine the parameters that are most sensitive and correlated with dependent variable ( …

A Spatial Evapotranspiration Tool At Grid Scale, Sivarajah Mylevaganam, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

The drastic decline in groundwater table and many other detrimental effects in meeting irrigation demand, and the projected population growth have force to evaluate consumptive use or evapotranspiration (ET), the rate of liquid water transformation to vapor from open water, bare soil, and vegetation, which determines the irrigation demand. As underscored in the literature, Penman- Monteith method which is based on aerodynamic and energy balance method is widely used and accepted as the method of estimation of ET. However, the estimation of ET is oftentimes carried out using meteorological data from climate stations. Therefore, such estimation of ET may vary …

Evaluation Of Regional Climate Models With Remotely Sensed Evapotranspiration Data, Doruk Ozturk

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Water is one of the most precious resources on Earth. Managing water resources is a complex discipline that requires accurate data, which in turn means that the management of water resources is limited by the availability and quality of these datasets. Evapotranspiration (ET) is one of these key datasets, but is also one that is lacking in large-scale spatial distribution with traditional methods such as weighing lysimeters or Bowen ratio. This is a quantity that needs to be evaluated in regional and global climate models since it is a substantial component of the land surface-atmosphere interaction. In order to overcome …

Green Roof Energy Balances For Native Grasses And Sedum, Chris Schwarz

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

Green roofs offer a possible solution to reduce urban heat island effects caused by urbanization. Conventional green roofs use sedum for plant cover but growing evidence suggests native species offer better results for harsher environments. However, more information is needed to understand the potential of native species for green roof use in terms of survivability and cooling potential. This study was conducted from July 2013 through October 2013 to quantify the energy balance components for native grasses and sedum on a Midwestern green roof. The semi-intensive green roof located on the Larson Building parking garage in Lincoln, NE was used …

Identifying And Evaluating A Suitable Index For Agricultural Drought Monitoring In The Texas High Plains, Jerry E. Moorhead, Prasanna H. Gowda, Vijay P. Singh, Dana O. Porter, Thomas H. Marek, Terry A. Howell, B A. Stewart

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Drought is a complex and highly destructive natural phenomenon that affects portions of the United States almost every year, and severe water deficiencies can often become catastrophic for agricultural production. Evapotranspiration (ET) by crops is an important component in the agricultural water budget; thus, it is advantageous to include ET in agricultural drought monitoring. The main objectives of this study were to (1) conduct a literature review of drought indices with a focus to identify a simple but simultaneously adequate drought index for monitoring agricultural drought in a semiarid region and (2) using the identified drought index method, develop and …