Abstract

Rainfall and Streamflow Analysis of Depression Losses at the Rocky Flats National Wildlife Refuge

Anonymous — Wed, 10 Apr 2024 17:39:47 +0000

Rainfall and Streamflow Analysis of Depression Losses at the Rocky Flats National Wildlife Refuge Anonymous (not verified) Wed, 04/10/2024 - 11:39 Eric Balderrama

This study is centered around the analysis of rainfall and streamflow data collected from a watershed located within the Rocky Flats National Wildlife Refuge. The data was systematically filtered and cleaned to avoid skewness and potential error. Afterwards, a statistical analysis of the data was conducted which led to the creation of detailed relationships between rainfall and streamflow with the intention of updating historical depression loss values. Mile High Flood District (MHFD) gives up depression loss values of 0.2-0.6 in. for open fields, with a recommended value of 0.4 in. This means that we can expect 0.2-0.6 in. to get temporarily captured in depression storage, preventing it from becoming runoff. Now, when we look at the highest and lowest (non-zero) rainfall depths captured by the closest rain gage, in relative proximity to the watershed, which did not result in a flow event, we see these values are 2.48 in. and 0.04 in., respectively. This is significant because the largest value that did not result in a streamflow event is magnitudes larger than that of the recommended value of 0.4 in, indicating much of the captured rainfall must have been lost elsewhere. The relevance of this analysis is not to be underestimated, as it allows for the understanding of the threshold at which a flow event occurs. Additionally, there were 13 streamflow events in the 5-years’ worth of data that were captured with a delayed start time. Of the 13 events, the average delay time from the first instance of rainfall to the first detection of streamflow was 04:51 [hh:mm] with a standard deviation of 04:26 [hh:mm]. The data was further filtered and any time delay above 300 minutes was removed. This led to only 9 rainfall events that led to streamflow being analyzed. The time delay average and standard deviation of these events was 02:16 [hh:mm] and 01:21 [hh:mm], respectively. The investigation of depression losses in open fields presented a unique opportunity to examine the intricate relationship between rainfall depth and flow events. It was recognized that just before the threshold for flow events was reached, a significant quantity of rainfall was lost in depression storage. Therefore, the rainfall quantity was recorded for these 9 specific instances of delay time. The rainfall depth average and standard deviation are 0.64 in. and 0.50 in., respectively. These values allow for a much clearer comparison between the depression loss values given by MHFD and the data from the observed watershed.

Eric Balderrama · CEAE · BS Student

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Water Supply Prediction in Unmonitored Basins: Integrating Statistical Models and Remotely Sensed Snow Data

Anonymous — Tue, 09 Apr 2024 18:01:00 +0000

Water Supply Prediction in Unmonitored Basins: Integrating Statistical Models and Remotely Sensed Snow Data Anonymous (not verified) Tue, 04/09/2024 - 12:01 Kaitlyn Bishay

Accurate predictions of seasonal water supply are vital to all communities – regardless of their size, population, or location – as they are the basis for informed water resource decisions. Throughout the western U.S., predictions of total annual streamflow often rely upon spatially limited in situ snow measurements, which may not be available in all watersheds. However, previous work by the author team showed that these in situ measurements can be supplemented (or even replaced) by remotely sensed snow timing data. Initial findings for fifteen snow-dominated basins during the years 2001-2019 indicate the existence of a significant (p ≤ 0.05) predictive linear relationship between remotely sensed day of snow disappearance (DSD) and seasonal water supply, with mean DSD explaining roughly half of the variance in AMJJ total flow volume. This work expands on the spatial and temporal extents of previous research, describing the skill of these remotely sensed variables as predictors of water supply in over one hundred basins with varied watershed characteristics (elevation, SWE/P ratio, etc.) Further, we are particularly interested in the utility of remotely sensed snow disappearance in basins that lack in situ monitoring. By comparing the skill of watershed scale Monte Carlo linear regression models across monitored and unmonitored basins, this analysis provides new insight into the potential for remotely sensed data-driven models across the western U.S.

Kaitlyn Bishay · CEAE · PhD Student

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Mid-Century Alaskan hydrology in transition: how changing precipitation and evapotranspiration patterns are projected to reshape seasonal streamflow

Anonymous — Tue, 09 Apr 2024 18:00:40 +0000

Mid-Century Alaskan hydrology in transition: how changing precipitation and evapotranspiration patterns are projected to reshape seasonal streamflow Anonymous (not verified) Tue, 04/09/2024 - 12:00 Dylan Blaskey , Keith Musselman

Climate change is profoundly reshaping Arctic hydrology, necessitating a comprehensive understanding of evolving hydrological conditions for effective planning and resilience strategies. However, the majority of regional or global river models lack the necessary resolution to accurately project local conditions. In this study, we employ a series of high-resolution models to forecast river discharge trends by mid-century. Leveraging the mizuRoute river routing model, forced by output from a 4km resolution regional climate model, we compare results between historical (1990-2021) and mid-century (2034-2065) time frames across six future scenarios. These scenarios encompass two pseudo-global warming and four dynamically downscaled large ensemble models, under a "middle of the road" emission scenario. Our findings indicate a projected 6% increase in annual flow to the ocean, with the most significant increases anticipated during April and October. Notably, one-third of spring gauges exhibit escalating discharge across future scenarios, while half of all gauges show increased discharge in the fall. This increase is attributed to amplified rainfall including changing weather patterns and a transition from snow to rain in the spring and fall, coupled with heightened snowmelt. Rising evapotranspiration moderates the magnitude of discharge changes cause by changes in precipitation. Furthermore, the centroid of discharge is shifting earlier in the year at two-thirds of all gauges, despite peak discharge occurring later. Increasing discharge in fall, winter, and spring underscores the extensive alteration of hydrological fluxes in the Arctic.

Dylan Blaskey · CEAE · PhD Student

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Climate change impacts and its effect on cold weather storm water management

Anonymous — Tue, 09 Apr 2024 18:00:20 +0000

Climate change impacts and its effect on cold weather storm water management Anonymous (not verified) Tue, 04/09/2024 - 12:00 Maryam Buhamad

Climate change impacts have been causing noticeable changes in weather patterns which lead to a need to adapt wet weather management. Two components of this research were conducted: a climatology analysis and a literature review. The climatology data for each city was obtained from NOAA and processed using R Studio. Through this ongoing research it was found that daily weather patterns, specifically snowfall have changed from 1950-2021 resulting in a positive trend for the Mann Kendall Test. These cities were chosen based on population density and those that experience snowfall in the winter time. Based on those criteria, 19 cities were chosen throughout the contiguous United States. . From the literature review, it was found that increasing snowfall and cold climate storms has led to a need to adapt wet weather management and excess runoff. Increased road salt due to road deicing has led to higher lake salinity urging the need for alternative methods. Through the literature review, some BMPs have worked more efficiently than others in colder climates. This research revealed that many cities are facing colder weather due to climate change impacts, prompting the necessity to adapt wet weather management strategies to accommodate these changes. Future work will focus on developing a comprehensive guidance document tailored to stormwater utilities, offering insights into the most effective approaches for wet weather management in colder climates.

Maryam Buhamad · CEAE · MS Student

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Evaluating the Relationship between Streamflow and Hyporheic Active Layer Dynamics in Two McMurdo Dry Valley Streams

Anonymous — Tue, 09 Apr 2024 17:59:52 +0000

Evaluating the Relationship between Streamflow and Hyporheic Active Layer Dynamics in Two McMurdo Dry Valley Streams Anonymous (not verified) Tue, 04/09/2024 - 11:59 Jared Collins

The (MDVs) are an ice-free area of Antarctica characterized by a permafrost landscape with glacial meltwater streams that flow for 6-12 weeks during the austral summer. In the hyporheic zones beneath stream channels, the active layer can be extensive, ranging from a few centimeters from the surface to over half a meter in depth. The thaw and refreeze of the active layer under and adjacent to stream channels have important implications on hyporheic exchange and associated ecological and chemical properties of the stream ecosystems. This study aims to characterize the relationship between streamflow and hyporheic active layer dynamics by comparing long-term records of streamflow with soil sensor measurements (temperature, moisture, and salinity) in two streams in the MDVs. In addition to these records, field measurements of permafrost depth and channel morphology were collected to add context to sensor data. Here we analyze the controls on depth and duration of thaw in the hyporheic zones by comparing relationships among meteorological variables, streamflow, and subsurface conditions between hyporheic and dry subsurface locations. Preliminary results suggest that meltwater plays an important role in promoting and maintaining thaw. Further, the timing of active layer thaw and refreeze are at least partly correlated with the beginning and end of flow, respectively. These results point to the importance of liquid water in facilitating subsurface ecological processes in the MDVs and beyond, a major consideration for an increasingly warmer Antarctic climate.

Jared Collins · CEAE · PhD Student

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Exploring Spatiotemporal Urban Flood Drivers Using Multisource Data Integration

Anonymous — Tue, 09 Apr 2024 17:59:28 +0000

Exploring Spatiotemporal Urban Flood Drivers Using Multisource Data Integration Anonymous (not verified) Tue, 04/09/2024 - 11:59 Stacie DeSousa

·Urban flooding is an increasing threat to city and resident well-being. The Federal Emergency Management Agency (FEMA) typically reports losses attributed to flooding that results from a stream overtopping its banks, discounting impacts of flooding that occurs when precipitation intensity exceeds the capacity of a drainage system. This study uses municipal service requests reporting on street flooding in Denver, Colorado from 2000-2019 in coordination with Mile High Flood District rain gauge data and Census tract information to understand spatiotemporal drivers of urban flooding. A threshold analysis was conducted on storm characteristics with performance of best thresholds being close to random chance, indicating single storm characteristics were not able to effectively predict where and when flooding reports occurred, leading us to a combined spatial and temporal analysis. Topographic Wetness Index of locations of flooding reports were found higher than randomly selected points. A logistic regression describing the probability of a storm leading to a flood report showed the strongest predictors of urban flooding were, in descending order, maximum five-minute intensity, population density, storm depth, storm duration, median tract income, and stormwater pipe length per area. Maximum five-minute intensity and population density are nearly identical in prediction power for urban flood reports. The logistic regression revealed information about the comparative influence of spatial and temporal variables on flood reporting. A linear regression describing amounts of reports per area showed percent impervious as the only predictor. Our methodologies can be used to better inform urban flood awareness, response, and mitigation.

Stacie DeSousa · CEAE · MS Student

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Comparative Analysis of Snow-Water Equivalent Measurements: Insights from Niwot Ridge

Anonymous — Tue, 09 Apr 2024 17:59:10 +0000

Comparative Analysis of Snow-Water Equivalent Measurements: Insights from Niwot Ridge Anonymous (not verified) Tue, 04/09/2024 - 11:59 Samuel Fitterman , Drake Stasyshyn , Eva Ramm , Jennifer Frances Morse

This study investigates the correlation between snow: depth, water equivalent and density measurements taken by the SNOTEL 663 site and those obtained through the Federal Snow Sampler at C1 on Niwot Ridge from 2016 - 2023. Utilizing linear regression analysis, we examined the relationship between the two measurement techniques to assess their comparability and reliability. Our study identified moderate positive correlations between SNOTEL and Federal Sampler measurements for snow depth and snow water equivalent (SWE) on Niwot Ridge, demonstrating that SNOTEL data can partially explain the variability in Federal Sampler readings. The regression analysis yielded a correction equation for Federal Sampler density measurements based on SNOTEL data, facilitating further insight into achieving accurate water availability forecasting. Niwot Ridge is located in the Front Range of the Colorado Rockies and is a designated United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve. The C1 site is characterized by its relative shelter within a subalpine forest on a ridge with an elevation of 3022 meters. The SNOTEL site is approx. 262 meters to the WNW of the C1 pit site. By analyzing the correlations between these methodologies and employing linear regression to establish a correction equation, this research aims to enhance data comparability and reliability, thereby improving water resource management and predictive modeling in snow hydrology within the subalpine ecosystems of the Colorado Rockies.

Samuel Fitterman, Drake Stasyshyn, Eva Ramm, · GEOG · BA Students

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Circulation in Beaufort Sea lagoons with varying river and shelf influence: a numerical modeling study

Anonymous — Tue, 09 Apr 2024 17:59:00 +0000

Circulation in Beaufort Sea lagoons with varying river and shelf influence: a numerical modeling study Anonymous (not verified) Tue, 04/09/2024 - 11:59 Tina Geller

Lagoons along the Alaskan Beaufort Sea coast are seasonally productive during ice-free months (i.e., the open water season) and support diverse food webs that include or sustain fish, migratory birds, polar bears, and whales. Nutrients are the base of these food webs, and their transport at the coast is modulated by highly variable lagoon circulation and inlet fluxes. To characterize open-water circulation in Beaufort Sea lagoons, a numerical model was implemented for a connected system of five lagoons that vary in river input and shelf connectivity. Specifically, the Regional Ocean Modeling System (ROMS) was implemented for July to October of 2019 for Arey, Kaktovik, Jago, Tapkaurak, and Oruktalik Lagoons. The model accounts for winds, rivers, shelf circulation, and tides. Preliminary results show that transport within the lagoons and lagoon-shelf fluxes vary in magnitude and direction, corresponding to shifts in winds and shelf currents. Additionally, from early to late summer, as river discharge decreases, the delay between freshwater entry and exit increases. The response of circulation to different forcings varies among the lagoons, however. Kaktovik Lagoon, with no direct shelf connection, has the smallest inlet fluxes and is shielded from large swings in salinity and temperature with river discharge. Jago, Tapkaurak, and Oruktalik Lagons, located on the east side of the chain, have no physical barriers separating them, and therefore function as one lagoon that becomes fresher and warmer with river discharge but is quickly flushed with shelf water during a strong wind or current event. Arey Lagoon, on the west side of the chain, has the largest river influence and the largest inlet fluxes. These preliminary results suggest that nutrients will remain longer in more protected Beaufort Sea lagoons and will be exported to the shelf in greater amounts during time periods with high wind and strong offshore currents.

Tina Geller · ATOC · PhD Student

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Groundwater Depletion in Santa Clara Valley Over the Most Recent Drought in California inferred from Sentinel-1 InSAR Deformation

Anonymous — Tue, 09 Apr 2024 17:56:00 +0000

Groundwater Depletion in Santa Clara Valley Over the Most Recent Drought in California inferred from Sentinel-1 InSAR Deformation Anonymous (not verified) Tue, 04/09/2024 - 11:56 Khosro Ghobadi-Far , Susanna Werth , Manoochehr Shirzaei , Roland Bürgmann

Groundwater resources play a crucial role in the Santa Clara Valley (SCV) where almost half of the water used is pumped from aquifers. This reliance on groundwater is expected to increase in the future with climate change increasing the frequency and intensity of droughts, and thus, reducing the surface water resources. As such, any tool that helps to better manage the groundwater resources in the SCV can be extremely beneficial. In this presentation, we demonstrate InSAR as a viable tool which can help with better management of groundwater extraction, storage, and recharge assessing the success of managed aquifer recharge. We first demonstrate that groundwater dynamics in deep aquifer layers below 120 m mainly drive vertical deformation in the SCV. We then build on this strong correlation to calibrate the aquifer’s mechanical properties using InSAR data. The calibrated aquifer mechanical properties, along with the InSAR data, can then be used to quantify the impact of droughts on groundwater depletion in the SCV at a high spatial and temporal resolution (i.e., 100 m and weekly). We also examine the impact of the most recent California droughts on groundwater depletion and subsidence in the SCV. We show that, from 2019 to 2021, Santa Clara County subsided up to 30 mm, and groundwater levels dropped by as much as 18 m. We show that the subsidence caused by groundwater depletion during the drought remained elastic (recoverable) thanks to the managed aquifer recharge by the SCV Water District. Our results demonstrate how InSAR data can provide helpful information for the operational management of groundwater resources and ensure recoverable land subsidence, particularly during severe drought.

Khosro Ghobadi-Far · ASEN · CIRES Faculty

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Urban Water Dynamics: Outdoor Consumption Patterns in the Colorado River Basin

Anonymous — Tue, 09 Apr 2024 17:55:33 +0000

Urban Water Dynamics: Outdoor Consumption Patterns in the Colorado River Basin Anonymous (not verified) Tue, 04/09/2024 - 11:55 Nicholas Guthro , Aditi Bhaskar

Water from the Colorado River Basin is a major water source for residents of the American Southwest, serving nearly 40 million people. In these urban areas, residential usage is one of the major uses of water, with outdoor water usage regularly representing over fifty percent of each household’s total usage. Outdoor usage is often identified as a target for reduction, as many cities using basin water are facing growing water scarcity concerns. This study compiled the water use of over thirty urban areas using Colorado River Basin water and separated the indoor and outdoor water usage using a combination of the minimum method and smart metering data. Results show a large variability in outdoor water usage per capita between cities with different population sizes and locations. Still, there has been an overall downward trend of outdoor water usage in most large urban areas over the past decade. The outdoor water usage total was then examined for trends with explanatory variables (population, climate, water rates). Initial results showed correlations between higher outdoor usage with higher temperatures and lower precipitation. Our future work will include examining the effectiveness of water conservation policies in the river basin and modeling the effect of past changes in policy, climate, population, and water rates. This work can help quantify the amount of outdoor water usage for municipalities within the Colorado River Basin Service area the effects of various water use reduction efforts such as watering restrictions and turfgrass replacement programs.

Nicholas Guthro · CEAE · PhD Student

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