Research Article

A System Dynamics Approach to Modeling Future Climate Scenarios: Quantifying and Projecting Patterns of Evapotranspiration and Precipitation in the Salton Sea Watershed

Table 2

Description of variables used for the statistical analyses. Note that event refers to days in which precipitation occurred, either as a one day occurrence or as multiple contiguous days.

NameDescriptionType of variableDescription of levels

PrcpDaily historic precipitationContinuous Daily values from 1982 to 2004

EToDaily historic evapotranspirationContinuous Daily values from 1982 to 2004

MonthMonth of yearDiscrete (12 levels)1 = January, 2 = Feb., …, 12 = Dec.

RainEventPresence or absence of Prcp eventDiscrete (binary)0 = absent, 1 = present

ETo ≤ 0.21′′Did ETo exceed 0.21′′?Discrete (binary)0 = true, 1 = false

CatEventNumber of consecutive days of precipitationDiscrete (7 levels)0 = no prcp, 1 = one day of prcp, …, 7 = seven consecutive days of prcp

CatVolComparison between volumes (v) of precipitation between subsequent time steps (i.e., comparing events at time to events at time ) Discrete (5 levels)0 = no prcp
1 = single event (a prcp event not followed by another)
2 =
3 =
4 =

PrcpAmtAmount of precipitation per eventDiscrete (5 levels)0 = no Prcp
1 = Prcp ≤ 0.1′′
2 = 0.1′′ < Prcp ≤ 0.2′′
3 = 0.2′′ < Prcp ≤ 0.5′′
4 = 0.5′′ < Prcp

PrcponafterDenotes first day of event or day after eventDiscrete (3 levels)1 = for first day of prcp event, 2 = day after event, 0 = all other days

PrcpbefafterDenotes day before event or day after event Discrete (3 levels)1 = for day preceding prcp event, 2 = day immediately after event, 0 = all other days

PrcpOn Denotes first day of eventDiscrete (binary)1 = first day in series of prcp event, 0 = all other days

EToAmtAmount of ETo per eventDiscrete (6 levels)0 = ETo ≤ 0.11
1 = 0.11 < ETo ≤ 0.21
2 = 0.21 < ETo ≤ 0.32
3 = 0.32 < ETo ≤ 0.41
4 = 0.41 < ETo ≤ 0.5
5 = 0.5 < ETo

EToPerChPercent change in ETo from one time step to nextContinuous

EToFirstCompares ETo on day before event to ETo on day of eventDiscrete (4 levels)0 = no prcp or a consecutive day
1 = ETo before prcp event < ETo on day of event
2 = ETo before prcp event = ETo on day of event
3 = ETo before prcp event > ETo on day of event

ETolev2 Compares ETo on day of event to ETo on day after event Discrete (4 levels)0 = no prcp
1 = ETo after prcp event < ETo on day of event
2 = ETo after prcp event = ETo on day of event
3 = ETo after prcp event > ETo on day of event

EToOne Compares ETo on day before an event to ETo on day after event Discrete (4 levels)0 = no prcp or a consecutive day
1 = ETo on day after event < ETo day before event
2 = ETo on day after event = ETo day before event
3 = ETo on day after event > ETo day before event

EToTwo Compares ETo of first day of an event to ETo on day after event Discrete (4 levels)0 = no prcp or a consecutive day
1 = ETo on day after event < ETo on first day of event
2 = ETo on day after event = ETo on first day of event
3 = ETo on day after event > ETo on first day of event