Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Publication
- Publication Type
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Century Wide Hydrologic Trends And Shifts In Colorado River Basin, Soumya Sagarika, Ajay Kalra, Sajjad Ahmad
Century Wide Hydrologic Trends And Shifts In Colorado River Basin, Soumya Sagarika, Ajay Kalra, Sajjad Ahmad
College of Engineering: Graduate Celebration Programs
To evaluate the long-term trends and step (abrupt change) changes in three hydrologic variables: temperature, precipitation, and streamflow over a century wide time frame in Colorado River Basin.
Changing Demands From Riparian Evapotranspiration And Free-Water Evaporation In The Lower Colorado River Basin Under Different Climate Scenarios, Daniel Bunk
UNLV Theses, Dissertations, Professional Papers, and Capstones
Observed and projected trends in riparian evapotranspiration (ET) and free-water evaporation are examined in this study to help improve water demand forecasting, particularly in modeling of lower Colorado River system reservoir operations. While most previous research in the Colorado River basin have focused on the impacts of climate change and climate variability on water supply, the impacts of changing climate on water demand have not been adequately addressed. Changes in temperature, precipitation, and wind patterns are expected to increase evaporative demands in the lower Colorado River mainstream, including free-water evaporation and ET from riparian vegetation, and may also impact infiltration …
Estimating Annual Precipitation For The Colorado River Basin Using Oceanic-Atmospheric Oscillations, Ajay Kalra, Sajjad Ahmad
Estimating Annual Precipitation For The Colorado River Basin Using Oceanic-Atmospheric Oscillations, Ajay Kalra, Sajjad Ahmad
Civil and Environmental Engineering and Construction Faculty Research
Estimating long-lead time precipitation under the stress of increased climatic variability is a challenging task in the field of hydrology. A modified Support Vector Machine (SVM) based framework is proposed to estimate annual precipitation using oceanic-atmospheric oscillations. Oceanic-atmospheric oscillations, consisting of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), and El Niño–Southern Oscillation (ENSO) for a period of 1900–2008, are used to generate annual precipitation estimates with a 1 year lead time. The SVM model is applied to 17 climate divisions encompassing the Colorado River Basin in the western United States. The overall results revealed that …
Changing Climatic Conditions In The Colorado River Basin: Implications For Water Resources Management In The Las Vegas Valley, Srijana Dawadi
Changing Climatic Conditions In The Colorado River Basin: Implications For Water Resources Management In The Las Vegas Valley, Srijana Dawadi
UNLV Theses, Dissertations, Professional Papers, and Capstones
Climate change affects the water available in a region. It also affects the water demand, because of the increase in temperature. A system dynamics model was developed for the Colorado River Basin (CRB), operating at a monthly time scale, to assess the potential impacts of climate change on streamflow in the Colorado River and its subsequent impact on the water resources management in the Las Vegas Valley (LVV). The effect of climate change on streamflow was evaluated using 16 global climate model outputs for 3 emission scenarios, also referenced in the Inter-Governmental Panel on Climate Change Fourth Assessment Report. Risk …
Evaluating Changes And Estimating Seasonal Precipitation For Colorado River Basin Using Stochastic Non-Parametric Disaggregation Technique, Ajay Kalra, Sajjad Ahmad
Evaluating Changes And Estimating Seasonal Precipitation For Colorado River Basin Using Stochastic Non-Parametric Disaggregation Technique, Ajay Kalra, Sajjad Ahmad
Civil and Environmental Engineering and Construction Faculty Research
Precipitation estimation is an important and challenging task in hydrology because of high variability and changing climate. This research involves (1) analyzing changes (trend and step) in seasonal precipitation and (2) estimating seasonal precipitation by disaggregating water year precipitation using a k-nearest neighbor (KNN) nonparametric technique for 29 climate divisions encompassing the Colorado River Basin. Water year precipitation data from 1900 to 2008 are subdivided into four seasons (i.e., autumn, winter, spring, and summer). Two statistical tests (Mann-Kendall and Spearman’s rho) are used to evaluate trend changes, and a rank sum test is used to identify the step change in …
Association Of Oceanic-Atmospheric Oscillations And Hydroclimatic Variables In The Colorado River Basin, Ajay Kalra
Association Of Oceanic-Atmospheric Oscillations And Hydroclimatic Variables In The Colorado River Basin, Ajay Kalra
UNLV Theses, Dissertations, Professional Papers, and Capstones
With increasing evidence of climatic variability, there is a need to improve forecast for hydroclimatic variables i.e., precipitation and streamflow preserving their spatial and temporal variability. Climatologists have identified different oceanic-atmospheric oscillations that seem to influence the behavior of these variables and in turn can be used to extend the forecast lead time. In the absence of a good physical understanding of the linkages between oceanic-atmospheric oscillations and hydrological processes, it is difficult to construct a physical model. An attractive alternative to physically based models are the Artificial Intelligence (AI) type models, also referred to as machine learning or data-driven …
Using Oceanic-Atmospheric Oscillations For Long Lead Time Streamflow Forecasting, Ajay Kalra, Sajjad Ahmad
Using Oceanic-Atmospheric Oscillations For Long Lead Time Streamflow Forecasting, Ajay Kalra, Sajjad Ahmad
Civil and Environmental Engineering and Construction Faculty Research
We present a data-driven model, Support Vector Machine (SVM), for long lead time streamflow forecasting using oceanic-atmospheric oscillations. The SVM is based on statistical learning theory that uses a hypothesis space of linear functions based on Kernel approach and has been used to predict a quantity forward in time on the basis of training from past data. The strength of SVM lies in minimizing the empirical classification error and maximizing the geometric margin by solving inverse problem. The SVM model is applied to three gages, i.e., Cisco, Green River, and Lees Ferry in the Upper Colorado River Basin in the …
Strategic Data Mining And Database Development For Research Projects At Lake Mead, Nevada-Arizona Usa, James Pollard, Gretchen M. Andrew
Strategic Data Mining And Database Development For Research Projects At Lake Mead, Nevada-Arizona Usa, James Pollard, Gretchen M. Andrew
Lake Mead Science Symposium
“Water 2025” is a Department of Interior initiative designed to guide the management of scarce water resources in the American West. As an important Colorado River reservoir, Lake Mead is a fundamental component of Water 2025. For Water 2025 to achieve its goals, comprehensive knowledge is needed of historic and current Lake Mead water quality data. A task agreement between the National Park Service and the University of Nevada, Las Vegas provides for a strategic data mining project to identify research and monitoring projects on Lake Mead that have been conducted in the past, prioritize relevant projects, and ensure data …