Did  El Nino Impact San Joaquin County Agriculture?
A GIS/ArcView Project
by
Gene Pearson
Department of Geology and Geography
University of the Pacific
Stockton, California
 
 
 

PROJECT GOALS:

Students will:
  • evaluate the impact, if any, of the 1998 El Nino on San Joaquin County agriculture
  • be introduced to data analysis using ArcView software
  • become familiar with the names and topography of San Joaquin and adjacent counties
  • be introduced to the relationship between topography and agricultural production in California
  • be introduced to regional rainfall patterns in the central valley of California
  • become aware of the economic importance of agricultural production in San Joaquin County

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    METHODS:

  • Analysis of maps obtained from internet websites
  • Analysis of data obtained from internet websites
  • Analysis of data displayed utilizing ArcView software

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    STEP 1: Geographic Framework

    Obtain a  county map of California and download a copy to your computer.  Locate San Joaquin County
    and study the counties adjacent to San Joaquin County.  How many could you name before looking at the map key?  Save the county map and then view a  relief map of California .  Describe the relief in San Joaquin County.  What is the relief in the adjacent counties?  Look at the map and decide in which counties agricultural production would be a major component of the economy.
     


    STEP 2: Agricultural Production in California

    Obtain the statistics on agricultural production in California for 1996 from the  California Department of Food and Agriculture .  The listing is in rank order.  What is San Joaquin County's 1996 rank?  What was the dollar amount of agricultural production in San Joaquin County in 1996?  From the statistics, is it easy to determine the level of agricultural production in the counties surrounding San Joaquin County?  Open the project file in ArcView and activate the 1996prod view.  Notice the concentration of agriculture in the San Joaquin Valley (San Joaquin, Stanislaus, Merced, Tulare, Fresno, and Kern Counties.)  Notice also the agricultural production in the Salinas Valley of Monterey County and the high productivity in San Diego and Riverside Counties in southern California. What are the advantages and disadvantages of using the ArcView map?  What the advantages and disadvantages of using the ranking list?
     
     


     STEP 3: 1998 Estimated Crop Losses
     
    Obtain the crop damage estimates for the 1998 calendar year from  California Department of Food and Agriculture .  Notice the Statistical Table includes total damage and a breakdown of damage to crops, animals and facilities.  Activate the agricultural losses theme in the ArcView project. Notice the concentration of losses in San Joaquin and Stanislaus Counties.  Activate the crop damage theme in the ArcView project.  Again notice the concentration of losses in San Joaquin and Stanislaus Counties. What counties experienced the greatest losses in livestock and bird production? What county experienced the greatest loss of facilities? What county experienced the greatest percent in of its total production?


     
     STEP 4: El Nino and regional precipitation patterns

    Although there was a lot of precipitation there was no major flooding in San Joaquin and Stanislaus counties in the Spring of 1998.  By analyzing precipitation data from selected National Weather Service stations from the  California Data Exchange Commision .  Activate the Weather Stations theme on the ArcView Project.  Click on the individual stations to see the data recorded for each station.  Activate the ArcView Chart produced using the data from the weather stations. Notice the pattern of precipitation as you go from Weather Stations in the north to Weather Stations in the south.  Can you reach any tentative conclusions from analyzing this chart?
     


    STEP 5: Explanation of 1998 losses in San Joaquin County

    From the chart you viewed in Step 4 you were able to see the difference in precipitation between 1997 and 1998.  But why did this increase in precipitation result in crop loss when there was no significant flooding in San Joaquin County?  One possible explanation could be the monthly rainfall pattern.  Activate the May ArcView Chart produced using the data from the weather stations.  Notice the dramatic increase in May rainfall during 1998.  The rain and cool weather in May of 1998 likely impacted pollination and maturation of crops.
     



     

    This project was produced during a 1998 Woodrow Wilson TORCH Institute held at the University of the Pacific in Stockton, California.  It was completed thanks to the support and guidance provided by the instructors, Institute Director Dick Filson, and my fellow participants.