CHAPTER II. AGROCLIMATIC MONITORING PROGRAM 



As stated In Chapter I, the objective of the agrocllmatlc 

 monitoring program is to collect and analyze climatological data 

 throughout the various agricultural water service areas within the 

 State. The analyses of these data will accomplish two purposes. 

 First, they will enable segregation and delineation of zones or 

 areas with similar evaporation potentials. Secondly, these data 

 will provide a basis for estimating evapotranspiration rates of 

 various crops within those zones. This can be accomplished by 

 utilizing coefficients which relate measured crop evapotranspira- 

 tion (to be discussed in Chapter III) to agrocllmatlc data. The 

 program of correlating measured evapotranspiration to various 

 evaporative indices, such as evaporation pans and atmometers, is 

 discussed in Chapter IV. 



To date, agrocllmatlc stations have been established at 

 typical locations within certain of the major inland agricultural 

 areas in the central and northern portions of the State. The data 

 collected and summarized in this report comprise weekly measure- 

 ments of evaporation from U, S. Weather Bureau Standard Class A 

 pans, and differences of evaporation between Livingston black and 

 white atmometers. Measurement of solar radiation, air temperature, 

 and humidity was made at a few locations. These data, however, 

 are not included in this report, as research regarding their re- 

 lationships to evapotranspiration and methods of analysis are still 

 in the process of development. 



As of i960, the program Included 52 stations, although 

 a total of 112 stations have been operated for various periods of 



