1999 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: R827448
Title: 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 - Berkeley
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, 1999 through June 30, 2000
Project Amount: $859,654
RFA: Integrated Assessment of the Consequences of Climate Change (1999) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Ecological Indicators/Assessment/Restoration , Water , Ecosystems , Climate Change


The objectives are to: (1) assess the vulnerability of water supply, water demand, water quality, ecosystem health, and socioeconomic welfare within the San Joaquin River Basin as a function of climate variability and extreme weather events; and (2) provide formulation guidance for management strategies that mitigate potential impacts due to climate variability and extreme weather.

Progress Summary:

To carry out these objectives, a decision support system (DSS) containing a suite of coupled environmental and economic models is being developed. DSS model components include: (1) region-to-basin climate downscaling, (2) rainfall-runoff (to key reservoirs), (3) water allocation, (4) agricultural production and agro-economics, (5) San Joaquin River water quality, (6) aquatic ecosystem and fisheries, and (7) socioeconomics. DSS model components have been assembled from federal and state water agencies, the University of California, and from private consultants.

The development status for each model component and the DSS framework is as follows:

Region-to-Basin Climate Downscaling:
Function?Generates basin-scale meteorology from a regional-scale climate scenario using both dynamic and statistical downscaling techniques. The basin area-averaged meteorological variables provide input forcing to the land-surface hydrological-streamflow model (Sacramento Model) for key twelve major watersheds including those representing the California State Department of Water Resources, Eight River Index (ERI) used for determining annual water allocation.

Development Progress?The dynamic simulations are being generated using three different Regional Climate Models (RCM) with the same large-scale input forcing. To date, we have completed a full analysis for two of the RCMs, the RegCM (National Center for Atmospheric Research) and the RCSM (Lawrence Berkeley National Laboratory) and generated basin area-averaged input forcing to the Sacramento Model. Statistical downscaling progress includes archiving daily data for the surface and upper-level atmospheric predictor variables. Daily data is being gathered for local meteorological observations (i.e., precipitation and temperature) in 6 of the 12 key watersheds; data for the remaining watersheds have been requested. A statistical model formulation is being initiated and will be compared with the dynamic model results. The advantage of the statistical approach for stationary conditions (i.e., daily to seasonal predictions) is the reduced computational demand. We expect the statistical forecasting model to be complete in Fall 2000.

Rainfall/Runoff Modeling:
Function?Generates streamflow data for the 12 key watersheds feeding reservoirs in the water allocation and agro-hydrology model component. We have been using both the National Weather Service-River Forecast Centers Sacramento Model and the modified version of the TOPography-based Model (TOPMODEL). The value of the Sacramento Model is its user base within NOAA and other federal agencies for streamflow forecasting. TOPMODEL has traditionally been a research model and has been used in a quasi-operational mode by our research team.

Development Progress?We have completed several simulations with the RCM dynamic input forcing to the Sacramento Model (for 12 basins). We are generating a statistical analysis for the determination of mean-monthly streamflow climatologies for climate change sensitivity. This result will be used for a set of change and no change streamflow scenarios that will be the input to the impacts models discussed below. TOPMODEL is being used in addition to the Sacramento Model for selected coastal basins at this time. Both the Sacramento Model and TOPMODEL will be implemented into the Modular Modeling System (MMS) framework developed by the U.S. Geological Survey (USGS). MMS integration into the DSS framework is discussed later in this section. Group orientation on MMS was completed in June 2000. Model development for the 12 key watersheds began in July 2000 and will be completed by December 2000.

Water Allocation:
Function?Generates reservoir storage states and release decisions based on: (1) inflow data provided by the rainfall-runoff modeling component, (2) water demand, water quality, and regulatory requirements, and (3) hydrologic assumptions downstream of reservoirs.

Development Progress?The model ECOSIM (Ecologically Cogent Operations Simulation Model) was selected to simulate water allocation and reservoir operations. ECOSIM was developed by D. Hilts at the U.S. Fish and Wildlife Service. It combines the reservoir operation models currently being used by the U.S. Bureau of Reclamation to manage the Central Valley Project (i.e., SANJASM and STANMOD) and the California State Department of Water Resources models used to manage the State Water Project (i.e., PROSIM). ECOSIM is developed and currently being integrated into the DSS framework.

Agricultural Production and Agro-Economics:
Function?ECOSIM will provide water allocations to agriculture, urban and environmental uses based on reservoir inflow in each of the major San Joaquin Basin tributaries. The SJADE (San Joaquin Ag Production Drainage Economics) model uses these allocation decisions to agriculture in the San Joaquin Basin, together with current water quality constraints along the main stem of the San Joaquin River, to determine future agricultural production in the San Joaquin Basin. Shifts in water availability and constraints on agricultural drainage salt loads to the river cause changes in crop production and in the long-term viability of agriculture on the west side of the San Joaquin Valley. Changes in crop production affect agricultural income and hence the local economy of local communities in the San Joaquin Basin. The IMPLAN model uses economic multipliers to estimate the dollar impact of any changes in agricultural production estimated by the SJADE model.

Development Progress?This model is currently under development using: WADE (Westside Agriculture Drainage and Economics, developed at the USBR), IRDROP (Irrigation and Drainage Operations, developed at the USBR) and SWAP (Statewide Agricultural Production, developed at the University of California, Davis). Model development will begin in November 2000 and is expected to be completed in April 2001.

San Joaquin River Water Quality:
Function?The DSM-2 model provides the means of evaluating the impact of changes on reservoir release patterns and river hydrology as well as return flows from agriculture on the east and west sides of the San Joaquin Valley on San Joaquin River water quality. Water quality in the San Joaquin River is highly regulated for multiple purposes including South Delta agricultural diversions, fish populations and urban drinking water concerns. Exceedence of water quality objectives can lead to increased releases from New Melones reservoir, which is operated for water quality, leading to reductions in water supply to east-side agriculture and riparian diverters. The model is essential for resolving some of the feedback loops that make the San Joaquin River Basin one of the most complex from a management perspective in the US.

Development Progress?Training in the use of a new version of the model, which has been under development by the California State Department of Water Resources, has commenced. This training should be complete by February 1, 2001.

Modeling for both the Aquatic Ecosystem and Fisheries is occurring in two parts. The first part is underway and involves computing the change in frequency of instream flow violations under climate-altered conditions relative to current conditions. This impact is being modeled using ECOSIM, our reservoir operations and water allocation model. ECOSIM includes constraints on reservoir releases that represent existing regulations for maintaining environmental flow conditions that support fisheries and aquatic ecosystems. The second part involves modeling changes in reservoir and stream-water temperature, and will begin September 2001.

Decision Support System (DSS):
The DSS framework includes: (1) aforementioned model components linked in a loosely coupled manner, (2) database, (3) graphic user interface (GUI), and (4) Geographic Information System (GIS) tool.

Function?Manage data for the model components and for GIS visualization.

Development Progress?Database will be generated using Microsoft Access. Database design began in summer 2000 and will be completed by January 2001.

Graphic User Interface (GUI):
Function?Provide user-friendly environment for executing modeling system, managing data, and visualizing results.

Development Progress?The MMS-Object User Interface (MMS-OUI) is developed by the USGS and will be used for this project. It provides a DSS framework suitable for a suite of loosely coupled model components. It features a GUI, integrates well with Arc/Info GIS, and supports several database types, including Microsoft Access. MMS-OUI contains an embedded version of MMS that supports TOPMODEL. The USGS will complete MMS-OUI development in late Summer 2000. Group orientation with a beta version of MMS-OUI was completed in June 2000. A working version for the project group should be received by Fall 2000.

Geographic Information System (GIS):
Function?Allow spatial visualization and analysis of model data and results.

Development Progress?Licenses for Arc/Info 8.0 have been obtained. Arc/Info will readily integrate with MMS-OUI once it is obtained.

Future Activities:

Work is progressing simultaneously on all of the modeling tasks listed above. We expect that the system will be assembled and ready for inputs of climate scenarios by June 2001.

Journal Articles:

No journal articles submitted with this report: View all 21 publications for this project

Supplemental Keywords:

media, 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, Hydrology, Ecology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, climate change, State, Economics, Ecological Risk Assessment, environmental monitoring, risk assessment, water resources, 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 variability

Relevant Websites:

A Web site currently is under construction and will be completed during the second year of this project.

Progress and Final Reports:

Original Abstract
  • 2000
  • 2001
  • 2002 Progress Report
  • Final Report