Other products considered include the USGS WRSI
for crops and rangelands (Senay and Verdin 2003; Verdin and Klaver 2002), NDVI (J.
The study consisted in the following steps: i--analysis of meteorological data and WRSI calculation for the stations; ii--fit of the semivariograms and data interpolation; and iii --classification of the maps and sum of unsuitable, restricted and suitable areas for each period.
The maps were generated by spatializing the mean values of WRSI that varied from zero to one and indicate the ratio between the actual crop evapotranspiration (ETr) and the potential crop evapotranspiration (ETp), representing the relationship between the amount of water available and the demand to guarantee maximum yield using the following aptitude classes: suitable (WRSI > 0.65); b) restricted (0.55 < WRSI < 0.65) and c) unsuitable (WRSI < 0.55) (Farias et al., 2001).
The WRSI values were calculated through the relationship between the actual crop evapotranspiration and the potential evapotranspiration of reference, in an EXCEL[TM] worksheet (Rolim et al., 1998), which were compared with the critical stage of the crop (15 days before flowering until grain filling) (Andrade et al., 2006).
The WRSI values were calculated for 12 sowing periods (Table 1) for the three levels of Available Water Capacity (AWC) of the soil (30, 50 and 75 mm) according to the classification proposed by Sans et al.
Pretests of the WRSI that had no missing data, refusals, or respondent queries indicated that the global concepts of teaching, scholarship, and service--the same global measures used in earlier research of tenure and promotion--were applicable and understood at all of the contemporary schools of social work sampled.
Each of the responses to the WRSI is mutually exclusive and represents one of four models of work role priority for each rank.
The WRSI was pilot tested through use of a convenience sample of 79 graduate faculty members, deans, and directors.
Table 1 summarizes responses to each of the four WRSI items for three groups of deans or directors: (a) those representing all graduate schools and departments (n=130); (b) those from academic units with MSW and doctoral programs (n=61); and (c) those from MSW degree programs only (n=69).
Because tenure and promotion standards contained in faculty handbooks and other documents are sometimes vague about the importance of scholarship and other faculty roles in tenure and promotion (Seipel, 2003), the WRSI was developed to strengthen existing self-report methods of soliciting this information from deans.
Because the researchers believed that the priorities of tenure and promotion policies at the various schools actually shape and focus the priorities of faculty work, a moderately strong positive correlation between WRSI scores and the number of articles produced by each faculty was expected.
Multiple Regression of Total Articles Published in Professional Journals: 2000-2004 Predictor Variable r [beta] p WRSI (number of academic ranks for which scholarship is preeminent expectation) .31 .082 .98 Date graduate program established -.27 .055 .54 Number of full-time faculty .43 .135 .13 USNWR 2004 rating of educational quality of MSW program .84 .784 <.001 Note.