Grantee Research Project Results
2002 Progress Report: Vulnerability Assessment of San Joaquin Basin Water Supply, Ecological Resources, and Rural Economy Due to Climate Variability and Extreme Weather Events
EPA Grant Number: R827448Title: Vulnerability Assessment of San Joaquin Basin Water Supply, Ecological Resources, and Rural Economy Due to Climate Variability and Extreme Weather Events
Investigators: Dracup, John A.
Current Investigators: Dracup, John A. , Grober, Leslie , Howitt, Richard , Brekke, L. D. , Bashford, K. E. , Hidalgo, H. G. , Miller, N. L. , Hatchett, Stephen P , Quinn, Nigel
Institution: University of California - Los Angeles
Current Institution: University of California - Berkeley , California EPA Central Valley Regional Water Quality Control Board , University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: July 1, 1999 through June 30, 2002 (Extended to June 30, 2003)
Project Period Covered by this Report: July 1, 2002 through June 30, 2003
Project Amount: $859,654
RFA: Integrated Assessment of the Consequences of Climate Change (1999) RFA Text | Recipients Lists
Research Category: Climate Change , Ecological Indicators/Assessment/Restoration , Water , Aquatic Ecosystems
Objective:
The objectives of this research project are to: (1) assess the vulnerability of water supply, water demand, water quality, ecosystem health, and socioeconomic welfare within the San Joaquin River Basin (see Figure 1) as a function of climate variability and extreme weather events; and (2) deliver a decision support system (DSS) to project stakeholders that guides the formulation of management strategies that mitigate potential impacts due to climate variability and extreme weather conditions.
Progress Summary:
To carry out these objectives, a suite of coupled environmental and economic models are being used to conduct several impact assessments. Model components include: (1) global- to basin-scale climate downscaling, (2) rainfall-runoff in major study area reservoirs, (3) water allocation, (4) agricultural production and agroeconomics, (5) San Joaquin River water quality, (6) aquatic ecosystem and fisheries, and (7) socioeconomics. Model components have been assembled from federal and state water agencies, the University of California, and private consultants. The development status for each model component and the DSS framework is as follows:
Global- to Basin-Scale Climate Downscaling
Function. The global-to basin-scale climate downscaling generates basin-scale meteorology (i.e., 10 km spatial resolution) from a general circulation model (GCM) climate scenario using historically derived regression equations based on the Parameterelevation Regressions on Independant Slopes Model (PRISM) technique (Daly, et al., 1999). The basin area-averaged meteorological variables provide input forcing to the hydrological-streamflow model (Sacramento Model) for five major key basins tributaries to the joint Sacramento River and San Joaquin River Basin: Sacramento (above Lake Shasta), Feather (above Lake Oroville), American (above Folsom Lake), Merced (above Lake McClure), and Kings (hydrologically connected to the San Joaquin River Basin during wet years).
Development Progress. This work has been completed (Miller, et al., 2002) using a warm wet GCM climate projection based on the Hadley Centre's HadCM2 run 1 (i.e., HCM) and a cool dry climate projection based on the National Center for Atmospheric Research (NCAR) Parallel
Major SJRB Water Resource Systems
Central Valley Project (AG)
State Water Project (M&I)
Figure 1. San Joaquin River Basin (SJRB), California
Climate Model (PCM) run B06.06 (i.e., PCM), relative to the mean of the Intergovernmental Panel on Climate Change (IPCC) GCM projections for California; each selected as end-member climate scenarios. From these coupled atmosphere-ocean GCM simulations, two 30-year periods (2010 to 2039, 2050 to 2079) and one 20-year period (2080-2099) were used. The GCM data were statistically downscaled and interpolated based on the PRISM technique (Daly, et al., 1999). Monthly temperature shifts and precipitation ratios were then derived for each basin relative to historical climatologies. Results of this downscaling work have been submitted for peer-review (Miller, et al., 2002).
Rainfall/Runoff Modeling
Function. Downscaled meteorological data from the GCM-based scenarios are used to simulate rainfall-runoff in the Sierra Nevada and southern Cascade Mountains. The data also are used to generate streamflow data for five watersheds feeding major reservoirs serving California's Central Valley.
Development Progress. This work has been completed (Miller, et al., 2002) using the National Weather Service-River Forecast Center's Sacramento Soil Moisture Accounting Model (Burnash, et al., 1973). Basin runoff data from hydrologic simulations based on the HCM and PCM climate scenarios for each of the projection periods (i.e., 2010-2039, 2050-2079, and 2080-2099) were compared to streamflow data from a 1963-1992 verification period to produce monthly sensitivity functions for each climate change scenario and projection period relative to present climate. Each sensitivity function is made up of 12 monthly ratios (October through September) of mean climatological runoff under climate change relative to present climate. These functions were used to develop climate change reservoir inflow for the water allocation model component.
Water Allocation
Function. Generates reservoir storage states and release decisions for the joint Central Valley Project (CVP) and State Water Project (SWP) systems, located inside and outside the San Joaquin River Basin, and based on: (1) climate scenario-dependent inflow data developed using the monthly sensitivity functions and historical inflow data included with the California Water Allocation and Reservoir Operations (CALSIM II) model; (2) water demand, water quality, and regulatory requirements; and (3) hydrologic assumptions downstream of reservoirs.
Development Progress. Using the CALSIM II G-Model with year 2000 land-use assumption, this work has been completed. CALSIM is a general water resources planning software developed by the California Department of Water Resources (CDWR) 2002. CALSIM II, developed through a collaborative effort by CDWR and the U.S. Bureau of Reclamation, represents a comprehensive simulation of the joint CVP/SWP system. CALSIM II produces water allocation data for each climate change scenario that will be used to force the agricultural production and agroeconomics model component.
Agricultural Production Salinity Irrigation and Drainage Economics
Function. Models, such as CALSIM II, determine optimal water allocations based on basin hydrology, reservoir inflow, and system rules that simulate policies to address fishery, water quality, and other institutional constraints. CALSIM II focuses on water supply and assumes no change in water demand. New levels of demand for water are introduced into CALSIM II by changing the "level of development," which extrapolates current trends in population growth and development of reservoir storage to achieve the most accurate estimation of future conditions. The disadvantage of this procedure is that it is not dynamic and is insensitive to factors, such as a changing regulatory environment and agricultural salinization of soil, which can change the water demand trend line.
Model Description. Agricultural Production Salinity Irrigation Drainage Economics (APSIDE) is the impact assessment model developed for the project. This model will be used by project stakeholders for other planning efforts. Agricultural demand for water is directly proportional to crop production, however, different crops have different water requirements and cultural practices. Cultural practices affect irrigation efficiency. The type of irrigation technology employed also affects irrigation efficiency and management practices that influence how these technologies are deployed in the field.
The APSIDE model can be thought of as three interacting models that are updated monthly. First, an agricultural production submodel is used to project cropping decisions and estimate the total crop production for a given year based on the economics of production and yield response to soil salinity. The economics of crop production include the costs of farm labor, equipment, seeds, fertilizer, and the other fixed and variable costs for each crop type. The economics of crop production also include the market price of these commodities; more of one crop will be grown if the net returns to production (revenue minus cost) are greater. The crop production model solves and distributes the demand for water over the 12 months of the year. Second, a water balance submodel is used to compute and estimate the balance for each drainage zone within each subarea, and for each of the four vertical layers that the groundwater aquifer underlying each subarea is subdivided. Third, a salinity mass balance submodel is used to determine mass transport of salts between all four vertical layers in each APSIDE model subarea. Salts introduced in imported irrigation water supply can evapoconcentrate in the soil root zone unless leached by downward-moving percolating water. Salts transported vertically in the aquifer eventually reach deep layers where they can be returned to the surface through groundwater pumpage. Salinity related yield impacts reduces revenue, which provides feedback to the agricultural production submodel.
Development Progress. The APSIDE model coding is complete. An initial model was formulated for just five subareas to assist with model calibration. Results from this model show a significant long-term increase in drainage salinity for each of the five water districts (subareas) during summer months under an assumed climate-change scenario that might induce a 50 percent reduction in water supply availability.
Current activity focuses on data development, both for the model and for the model calibration. APSIDE model data development should be complete by early August 2002, and model calibration will commence at this time. Model data interfaces to move data between CALSIM-II, APSIDE, and DSM2-SJR should be complete by early September 2002.
San Joaquin River Water Quality
Function. The DSM2-SJR is a hydrodynamic model that simulates mass transport using continuity equation. It has been used in this study to produce a distribution of the water quality along a reach of the San Joaquin River, from its confluence with Bear Creek, to just beyond its confluence with the Stanislaus River, where the Vernalis monitoring station is located.
Development Progress. The Delta Simulation Model for the San Joaquin River (DSM2-SJR) model has been calibrated with the baseline scenario from CALSIM II (1922-1994). The climate change scenarios will be transferred automatically once APSIDE is in operation. The linkage between APSIDE and DSM2-SJR will be completed following final development of APSIDE.
Aquatic Ecosystem and Fisheries
Function. The effects of climate change and/or extreme hydrologic effects upon the health of aquatic ecosystems in the San Joaquin Basin are being assessed using fisheries populations as a proxy for the health of aquatic ecosystems. The San Joaquin Basin is the southernmost native habitat of chinook salmon (Oncorhynchus tschawytscha), the largest among the world's seven species of Pacific salmon (Healey 1991). Historical spawning runs of chinook salmon in the Sacramento-San Joaquin Basin were on the order of one million fish, but major habitat alterations have limited current San Joaquin populations to four major tributaries draining the east side of the basin: the Merced, Tuolumne, Stanislaus, and Mokelumne Rivers (Healey 1991). The diminishment of the chinook runs is caused by impassable dams, diminished streamflow, and concomitant elevated water temperatures (Kjelson, et al., 1982). Due to the inherent difficulties in physically modeling ecosystems, this study is using chinook salmon populations as a proxy for the vitality of riverine habitats.
Development Progress. To address the formidable nonlinearities in biological systems, salmon population models are being developed using an Artificial Neural Network (ANN) approach. ANNs have been employed in a wide variety of research and practical applications because of their ability to discern complex numerical patterns within data, including contributions that presently are not understood. Consequently, an ANN model is well suited to the complex task of describing the time-dependent response of chinook salmon populations to the degradation of their natural habitat, which is superimposed upon natural population variability.
Annual salmon escapements (i.e., counts of spawning salmon) are being used with water temperature and streamflow discharge data to develop salmon population models for three San Joaquin Tributaries: the Merced, Tuolumne, and Stanislaus Rivers. The models are undergoing calibration, which includes estimation of boundary-condition water temperatures from the most downstream reservoirs on each of the three tributaries considered. Upon suitable representation of observed data, input data from climate change, and/or severe weather simulations will be used to predict future impacts to chinook salmon populations.
Socioeconomics
Function. Socioeconomic impacts of climate change in the San Joaquin Valley mostly derive from changes in agricultural production and agricultural profitability in the San Joaquin Basin. Salinization of agricultural land leads to poorer crop yields and a reduction in farm profit. A multiplier effect typically is assumed, whereby a dollar of production at the farm gate stimulates economic activity worth several dollars in the local community. The IMPLAN software often is used to estimate economic multipliers for different sectors of the economy for various regions around the U.S. With these multipliers, it also is possible to estimate impacts of reduction in agricultural production due to root zone salt buildup on the local economy.
Development Progress. The IMPLAN software has been ordered and will likely be installed by mid July 2002. Data management interfaces will be developed between APSIDE and IMPLAN.
Decision Support System (DSS)
We are developing an interactive map-based Web site that will distribute climate change impacts assessment data, analysis descriptions, and reports over the Internet to project stakeholders (e.g., DWR, U.S. Bureau of Reclamation, California Department of Fish and Game, U.S. Fish and Wildlife Service, Central Valley Regional Water Quality Control Board, San Joaquin River Basin irrigation districts, and environmental interest groups). This mode of information distribution will not require any special software, hardware, or training beyond familiarity of working within a Web browser. Moreover, this use of Internet-based information transfer will allow for centralized and immediate control of data distribution, which will allow for better quality control and assurance that project stakeholders are operating with the most up-to-date information produced from our impact assessment modeling system.
The Web site will allow users to explore, retrieve, and display information such as geo-referenced maps, three-dimensional images, and spreadsheet data. An interactive mapping tool similar to other map-based Internet information resources used by the stakeholders will be a part of our Web site and will be connected to a geo-database, allowing for the query and display of results. Our Web site also will include a graphical visualization tool that will aid in the display and analysis of time-series data.
Future Activities:
Work is progressing simultaneously on all of the impact assessment tasks listed above. We expect all assessments will be completed by January 2003. We have been approved for a no-cost extension until June 30, 2003.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 21 publications | 5 publications in selected types | All 4 journal articles |
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Type | Citation | ||
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Quinn NWT, Miller NL, Dracup JA, Brekke L, Croben LF. An integrated modeling system for environmental impact analysis of climate variability and extreme weather events in the San Joaquin Basin, California. Advances In Environmental Research 2001;5(4):309-317. |
R827448 (2002) R827448 (Final) |
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Supplemental Keywords:
water, drinking water, watersheds, groundwater, land, soil, sediments, global climate, precipitation, ecological effects, ecosystem, scaling, terrestrial, aquatic, habitat, integrated assessment, socioeconomic, engineering, hydrology, modeling, analytical, climate models, Pacific coast, EPA Region 9, agriculture, business, industry, service industry, food processing., RFA, Scientific Discipline, Air, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Hydrology, Ecosystem/Assessment/Indicators, Ecosystem Protection, Environmental Chemistry, climate change, State, Economics, Ecological Risk Assessment, risk assessment, water resources, environmental monitoring, fish habitat, extreme weather events, San Joaguin Basin, economic models, hydrologic models, socioeconomic indicators, climate models, San Joaquin, agriculture, environmental stressors, vulnerability assessment, water quality, California (CA), climate variabilityRelevant Websites:
http://www.ce.berkeley.edu/~dracup/epastar/index.htm Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.