Oceanography and Atmospheric Sciences and Meteorology Commons^™

Analyses Of Streamflow Change Patterns And Correlation Of These Changes With Sea-Surface Temperature Fluctuations, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents a comprehensive statistical analysis that determines the direction, rate, and interval of significant streamflow change patterns in the continental U.S. and correlates these changes with sea-surface temperature fluctuations. First, by using two non-parametric tests, namely, the Mann-Kendall trend test and the Pettitt’s test, the presence of long-term trends and abrupt shifts were determined at 10% significance level over continuously adjustable periods that stretched from 1903 to 2012. Modified versions of the tests were applied to account for the presence of persistence (autocorrelation) in data. Theil-Sen slope was determined to evaluate the rate of change across multiple temporal …

Identification Of Long Term Changes And Evaluation Of The Relationships Among Streamflow Variability And Oceanic-Atmospheric Indices, Soumya Sagarika

UNLV Theses, Dissertations, Professional Papers, and Capstones

To examine the effects of climate variability on streamflow, this thesis presents a comprehensive analysis of the streamflow variability of the continental United States and its association with oceanic-atmospheric indices. First, the presence of trends with consideration of short term and long term persistence followed by shifts over the past years in the continental U.S. streamflow were analyzed by using the non-parametric tests: Mann Kendall and Pettitt. Second, the spatio-temporal relationships between seasonal streamflow variability of continental U.S. and sea surface temperatures (SST) and 500 mbar geopotential height (Z500) of the Pacific and Atlantic were established using the singular valued …

Impacts Of Climate Changes On The Spatiotemporal Distribution Of Precipitation In The Western United States, Peng Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Precipitation in the Intermountain West is characterized by its great variability in both spatial and temporal distributions. Moreover, the spatiotemporal distribution of the precipitation is changing due to the climate changes. In this dissertation, three studies are conducted to investigate the multi-scale temporal variability of precipitation, the performance of current climate models on this variability, the influence of large-scale ocean oscillations on heavy precipitation, and the impact of human induced global warming on storm properties.

The first study is to examine the performance of current climate models on the simulation of the multi-scale temporal variability determined from the observed station …

Hydroclimatic Forecasting In The Western United States Using Paleoclimate Reconstructions And Data-Driven Models, Christopher Allen Carrier

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis investigated climate variability and their associated hydrologic responses in the western United States. The western United States faces the problem of water scarcity, where the management and mitigation of available water supplies are further complicated by climate variability. Climate variability associated with the phases of oceanic-atmospheric oscillations has been shown to influence streamflow and precipitation, where predictive relationships have led to the possibility of producing long-range forecasts. Based on literature review, four oceanic-atmospheric oscillation indices were identified in having the most prominent influence over the western United States including the El Niño - Southern Oscillation (ENSO), Pacific Decadal …

Groundwater Contamination Potential In Northern Nevada From Mining, Associated Communities, And Agriculture As Forecasted By Two Vulnerability Methods, John L. Swatzell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two methodologies, DRASTIC and the NDEP method, were used to compare the groundwater vulnerability of mining, associated towns, and agricultural areas in northern Nevada. The DRASTIC and NDEP methods were compared to determine which method produces a more accurate depiction of vulnerability. Vulnerability maps were created using the United States Environmental Protection Agency's (USEPA) DRASTIC and Nevada Department of Environmental Protection (NDEP) methodologies. The DRASTIC map uses seven aspect layers of geologic and hydrologic information with assigned values and weights that are applied to a mathematical equation. The NDEP method uses field data collection for potential contaminant sources and well …

Impacts Of Climate Change And Weather Modification On Hydrologic Characteristics Of Watersheds In The Western United States, Anil Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research quantifies the impacts of climate change and weather modification (WM) on hydrologic characteristics of watersheds in the arid regions of the western United States. This research performs a long-term simulation of streamflow for present and future climate conditions in the North Platte (NP) Watershed, Wyoming; a shorter duration simulation is then performed to observe the likely impacts of event based changes in an urban watershed in Las Vegas, Nevada.

First, a study is carried out in Chapter 3 that evaluates the impacts of WM on water supply by developing a hydrologic model for the NP Watershed. The variable …

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 …

Improving Ensemble Streamflow Prediction Using Interdecadal/Interannual Climate Variability, Kenneth W. Lamb

UNLV Theses, Dissertations, Professional Papers, and Capstones

The National Weather Service’s (NWS) river forecast centers provide long-term water resource forecasts for the main river basins in the U.S. The NWS creates seasonal streamflow forecasts using an ensemble prediction model called the Extended Streamflow Prediction (ESP) software. ESP creates runoff volume forecasts by taking the current observed soil moisture and snowpack conditions in the basin and applying them to historical temperature and precipitation scenarios. The ESP treats every historic input year as a likely scenario of future basin conditions. Therefore improving the knowledge about how long-term climate cycles impact streamflow can extend the forecast lead time and improve …

Wind Flow Modeling For Wind Energy Analysis Of The Nellis Dunes Area In Nevada, Upendra Rangegowda

UNLV Theses, Dissertations, Professional Papers, and Capstones

A wind energy analysis of the Nellis Dunes area in Nevada was conducted. A DEM file which contains the elevation data was used to generate the surface model and to create a 3-D mesh of the region. Local meteorological tower data collected for a period of one year was used to generate the diagnostic initial wind fields. Upper level wind fields were created using a surface boundary layer technique along with linear interpolation of the tower level wind fields. The vertical components of the velocities were adjusted using the equation of continuity. Mass consistent 3-D wind fields were then calculated …

Assessment Of Impacts To Hydroclimatology And River Operations Due To Climate Change Over The Colorado River Basin, William Paul Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigated the impacts of climate change to the hydroclimatology and river and reservoir management operations within the Colorado River Basin. Preliminary research indicated observed warming trends throughout the Colorado River Basin and corresponding seasonal trends to the magnitude and timing of runoff in the Colorado River Basin. Subsequent research investigated the changing character of precipitation and corresponding impacts to streamflow over the Colorado River Basin. Analysis of snowpack telemetry (SNOTEL) stations over the American West and Colorado River Basin indicated decreasing trends in annual snowpack, often at least at the 95% confidence interval. A shorter snowpack season was …

Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

In south-western United States, soil moisture data is important for drought studies in the region which is experiencing a drought for many years, whereas in South Florida, water stage data is required by hydrologists to monitor the hydrological flow in wetlands. Soil moisture data and water stage data are not sufficiently available due to sparse monitoring stations. Installation of dense measuring stations over an extended area is costly and labor intensive. Therefore, there is a need to develop an alternative method of measuring soil moisture and water stage. Microwave remote sensing has proven to be a useful tool in the …