Data Server with UC San Diego / San Diego Super Computer Center
The UC Center for Hydrologic Modeling (UCCHM) is partnering with the San Diego Super Computer Center (SDSC) and the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) to build a state-of-the-art, integrated computer model and data products for the state of California. The goal is to inform and advise state, regional, national and international leaders of our findings, projections and the future of water availability. Ultimately, it will be accessible to a broader group of stakeholders including local, state and federal agencies and academic and non-profit research groups. The hydrology-specific infrastructure will support integration of multiple datasets from distributed information sources, converting them into formats suitable for modeling and visualization needs. Also, it provides standardized methodology to access data in various formats and to link with models which have different interfaces.
The system will use unified services and interfaces with a goal towards compatibility with HIS infrastructure, CHyMP, CSDMS, LIS/ESMF and/or OpenMI model processing. The data services, model services, and other processing services will be registered in a UCCHM catalog to enable data discovery and data delivery to applications. CUAHSI ODM is the data model for storing observational data, and HIS server components to publish water observations data services; THREDDS for gridded data; GeoServer for spatial data. IRODS storage infrastructure is exploited to store and replicate large volumes of data, enable fast data exchange between UCCHM nodes and seamless extension of storage capacity when required by modeling needs. To the degree possible we will develop UCCHM models as regional prototypes for CHyMP, and Model processing services will take advantage of existing UCI and UCSD high performance computing resources.
Understanding factors that control outdoor residential water use
Outdoor water use applied to landscapes has become of concern in water-stressed areas such as Orange County, where it can more than double household water use. We are conducting a study in partnership with the Municipal Water District of Orange County (MWDOC) to understand the biophysical and socioeconomic variables that influence outdoor water use in Orange County. We are analyzing the effects of climate (humidity, temperature, precipitation, drought), lot characteristics (lot size, presence of a pool, management practice, vegetation type), and socioeconomic factors (income, size of household, ethnicity) on outdoor water use. Ultimately, the goal of this research is to couple a spatially-distributed integrated water balance model with biophysical and socioeconomic drivers to simulate urban outdoor water demand. This research will inform policies to promote more efficient and equitable water use. Results could help in the development of practices to conserve water in response to water scarcity predicted as a result of climate change and population growth.
Irrigation in California’s Central Valley Strengthens the North American Monsoon
Agricultural irrigation in the California's Central Valley has always depended on surface water reservoirs and groundwater pumping. This anthropogenic redistribution of water modifies the land hydrological cycle significantly, especially by increasing evapotranspiration. We use the global, NCAR Community Atmosphere Model, with realistic estimates of irrigation applied to the NCAR Community Land Model. Simulation results show that irrigation modifies the surface radiation budget by generally increasing latent heat, decreasing sensible heat and decreasing land surface temperature. Although atmospheric water vapor increases due to enhanced evapotranspiration, during the summer, the Central Valley underlies the descending branch of the large-scale circulation, which inhibits the occurrence of convection. Consequently, Central Valley irrigation has negligible effects on local precipitation. However, precipitation in the downwind region of California, i.e., in the southwestern United States, increases, enhancing the North American Monsoon, while forming a regional, anthropogenic recycling loop in the hydrologic cycle which returns water to California. This study has implications for the importance of human-driven impacts on the hydrological cycle and local and regional climate, and for water resources management in California and the Western United States.
Snowload Estimation using GRACE and GPS
Accurate estimation of the winter snowpack is crucial for prediction of available water supply, flooding, and climate feedbacks. Remote sensing of snow is currently limited to observations of the spatial extent of the snowpack. GPS observations of vertical land surface loading reveal seasonal responses of the land surface to the total weight of snow, providing information about the stored snow water equivalent. The seasonal signal in SOPAC GPS vertical land surface position time series is shown to be dominated by direct elastic loading of the crust by the snowpack and soil moisture in 4 locations in the Western United States. GPS observations of land surface deformation are then used to predict the water equivalent load as a function of time and compared to Snotel observations.
Managed water balance of California
California’s water resources have been in steady decline over the past seven years and at a high priority to local hydrologists, farmers and politicians. The Central Valley is the greatest producer of food in the United States and if farmers do not receive their water allocations, the entire nation will be affected. Hydrologists have used the Gravity Recovery and Climate Experiment (GRACE) to calculate a natural water balance for the Sacramento-San Joaquin River Basin, the main basin running north to south in California. Since 2005, there have been major implications of drought in the Central Valley with a steep decline in groundwater seen by the dual-satellite GRACE mission. However, since California is one of the most heavily water-managed states in the world, it is important to recognize the managed water balance to better understand where water is flowing, who is receiving water allocations and what the water is being used for. In our research, we propose to quantify the amount of water being diverting to the Central Valley via the Central Valley Project (CVP) as well as the water diverted to Southern California via the State Water Project (SWP) through the complex series of piping and pumping plants that serve as the basis for each project. We will also looks at the amount of Colorado River water being diverted to the Metropolitan Water District (MWD) in Southern California. We will quantify these amounts and determine how much water counties are using and determine the water use by working with individual water districts.
Teacher Professional Development
In February and August 2010, the American Museum of Natural History (AMNH) sponsored the GRACE Educational Workshop and Professional Development course for High School and Middle School teachers in the greater New York area. The goal was to relate remote sensing hydrologic data from GRACE to the teachers in a format they could take back to their classrooms. AMNH asked the UC Center for Hydrologic Modeling (UCCHM) to help develop and present the material to the teachers. With the development of a short GRACE based film, a dynamic data interface, and access to actual scientific data, the teachers learned the material and created their own lesson plans to take back to their students. The AMNH Workshop is centered on the basic knowledge of the hydrologic cycle, GRACE fundamentals and three case studies (California, India and the Ice Sheets). UCCHM gave PowerPoint presentations to introduce these items and provided Excel spreadsheets with assignments for hands on experience with the data. Once the teachers manipulated the data to produce the same results they recognized in scientific journals, we discussed the socioeconomic and political implications of the data. The UCCHM still has contact with certain high school teachers to continue to bring new information into the classroom. The interaction between high school teachers, UCCHM scientists and the AMNH proved to be a success by introducing present day science challenges to the attention of high school students who will have the biggest impact on future environmental conditions.
Central Valley groundwater and outreach
On August 2, 2010, the UC Center for Hydrologic Modeling (UCCHM) sponsored an event entitled, “Working Toward Sustainable Water Solutions to Support Central Valley Farmers,” at the UC Merced Center in Fresno, California. The high rates of groundwater depletion we have seen from GRACE led us to this event. The goal of the event was to better understand the water supply issues in California by promoting dialogue between the academic, agricultural, and citizen stakeholders of the Central Valley. We, as scientists, wanted to gain an on-the-ground perspective of the circumstances in the Central Valley, how water-use decisions are made from an agricultural perspective, and how we can focus our research to improve water management practices. The Central Valley stakeholders wanted to describe what it is like to live and work in the Central Valley in a water-limited state, providing a “human” context to our research. Some of the attendees included Central Valley farmers; county farm bureau groups including Tulare, San Joaquin, Merced, and Fresno counties; farmer representative groups including the California Latino Water Coalition, the California Farm Bureau Federation, the California Grape & Tree Fruit League, and the California Farm Water Coalition; policy makers; and Center scientists.
We learned that the farmers’ water allocations from the California Department of Water Resources are often received after crops have to be planted, which results in an increased dependence on groundwater in below-average allocation years. As a result, UCCHM and California’s academic community is presented with the challenge of working with state decision-makers to improve the forecasting and modeling systems that are used to make allocation decisions, in order to better match the farmers’ needs. Another opportunity presented by the agricultural community was for the scientific community to provide farms with improved soil moisture monitoring for more efficient irrigation, in exchange for water use and groundwater level data. The next step for UCCHM is to establish collaboration with the California Department of Water Resources, while continuing communication with the agricultural stakeholders.
ARkStorm: Extreme flooding in California
An ARkStorm (for Atmospheric River 1000 Storm) is a hypothetical but scientifically realistic "extreme storm" scenario developed and documented by the USGS. It is required to prevent extreme flood disasters and establish flood inundation map as non-structural measures against a plausible ARkStrom in California. The accurate numerical model such as BreZo can be a useful tool for flood control against extreme flooding in California.
BreZo is a 2D flood inundation model and being optimized for wetting and drying applications involving natural topography and runs on an unstructured grid of hybrid cells, making it possible to efficiently represent and simulate arbitrary topography in California. Flood extents, water depths, velocities, and durations by ARkStorm scenarios in California will be issued on Google Earth KMZ files based on the results of BreZo and ArcGIS.
Statewide ET mapping
Evapotranspiration (ET) is a key component of the water cycle; changes in ET directly impact runoff and water availability for urban, agricultural, and environmental uses. ET may change significantly regionally with anticipated climate change. Timely observations of ET and understanding of mechanisms controlling ET are needed to predict water availability for human and environmental uses. Unfortunately, ET is the most uncertain and poorly measured component of the hydrologic cycle. Recent advances in satellite remote sensing and surface meteorological measurements have enabled near-realtime spatial ET products to be developed, which could improve assessments of current and future water availability. California’s competing demands for water and hydrologic variability make these types of products especially important. However, California’s vegetation types and topographic variation confound the biophysical relationships that underpin these products.
My collaborative role with UCCHM is twofold. First, I am comparing an ensemble of ET products against a well-constrained water budget in the Central Valley that is one of the richest agricultural regions in the world and which has been undergoing well documented groundwater depletion. I implemented a surface energy balance ET model to create one of the products. I integrated the ET products with gravimetric estimates of groundwater depletion to assess surface water consumption by irrigated agriculture. My second role is a statewide implementation and comparison of ET methods. I implemented four ET methods on a common grid statewide. Currently I’m comparing the performance of these approaches across California’s ten hydrologic regions. I will assess what approach works best in each region and controls (e.g. vegetation cover, vegetation seasonality, topography, and elevation) on ET in each region.