C&EE HWR  

Margulis Research Group

Department of Civil and Environmental Engineering

UCLA
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Group Research Activities

The overarching research theme in our group focuses on improving our fundamental understanding of the terrestrial and atmospheric branches of the hydrologic cycle. We seek to understand the mean states and fluxes between terrestrial and atmospheric reservoirs as well as the spatial and temporal variability in these processes. Our studies span a range of space and time scales to allow for improved understanding of historical climate patterns, real-time diagnosis of hydrologic processes, and extension to understanding and predicting future climate change and its connection to water resources. A primary objective of this work is to ultimately improve our ability to manage water resources and mitigate the effects of environmental hazards.

To address these topics, the tools we use include: multi-spectral remote sensing, distributed hydrologic modeling, coupled land-atmosphere modeling, atmospheric modeling, radiative transfer modeling, data assimilation techniques, and high-performance parallel computing

Current research activities in our group fall under the following general areas:

Snow hydrology

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Mountain snowpacks plays an important water resource role in many semi-arid regions of the globe. Through albedo effects, snow can also have significant impact on regional and global climate. We aim to better characterize seasonal snow water equivalent in mountainous watersheds and how it varies in space/time. Work in this area includes:

  • Distributed snowpack modeling
  • Microwave/visible remote sensing of mountain snowpacks
  • Radiative transfer modeling of snowpacks
  • Snow data assimilation

Selected group papers/presentations on this topic:

Soil moisture/evapotranspiration

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Soil moisture is a key land surface state due to its role in partitioning both the water and energy fluxes at the surface. Estimates of soil moisture and the resulting evapotranspiration are also needed in irrigated agriculture management. We aim to better characterize space/time patterns in soil moisture and its impact on watershed-scale fluxes. Work in this area includes:

  • Distributed watershed modeling
  • Unsaturated/saturated flow processes
  • Microwave remote sensing of soil moisture
  • Visible/Near-infrared remote sensing of vegetation canopies
  • Radiative transfer modeling of soil and vegetation

Selected group papers/presentations on this topic:

 

Land-atmosphere interaction

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The water/energy fluxes between the land and atmosphere greatly impact regional weather and climate patterns. The fluxes result from the tightly coupled system made up of the land surface and the overlying atmospheric boundary layer (ABL). We aim to better understand the coupled system (including pathways of interaction and feedbacks) and how heterogeneity of the land surface impacts the regional fluxes. Work in this area includes:

  • Bulk land-ABL models
  • Large-eddy simulations of the ABL
  • Regional climate modeling

Selected Group papers/presentations on this topic:

 

Clouds, Radiation, and Precipitation

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The primary forcing of land surface processes are precipitation and incoming short- and lonwave radiation. Clouds play a significant role in the controlling the primary modes of variability in these fluxes. We aim to better understand the couple nature of water and energy flux inputs at the surface and develop better methods for estimating these fluxes (and their associated variability and uncertainty) for land surface modeling applications. Work in this area includes:

  • Visible/near-infrared/thermal remote sensing of clouds
  • Remote sensing of surface radiation and precipitation
  • Development of simple coupled models of radiation and precipitation processes
  • Assessing impact of forcing variability and uncertainty on land surface response

 

Selected group papers/presentations on this topic: