[p

m = 0.:

(b) Soil moisture and snow water equivalent in the snowpack (time clip: 01.05.1976) 1

(b) Soil moisture and snow water equivalent in the snowpack (time clip: 01.05.1976) 1

for SN

Figure 10.6 Fuzzy membership functions of model input (precipitation P and potential évapotranspiration Ep), parameters (profile water holding capacities Ctp and Cfc) and system state variables (soil moisture S and snow water equivalent SN) on the 1st of May 1976

for SN

Figure 10.6 Fuzzy membership functions of model input (precipitation P and potential évapotranspiration Ep), parameters (profile water holding capacities Ctp and Cfc) and system state variables (soil moisture S and snow water equivalent SN) on the 1st of May 1976

a parsimonious model, with just eight parameters, gives good predictions of the signature plots and streamflow hydrographs at the monthly and annual time scales, which was anticipated because of satisfactory results obtained in the previous study (Eder et al. 2003). The crisp graph visualizes model results for / of 1.0, equivalent to the model results from the deterministic water balance model of the previous study (Eder etal. 2003) based on crisp input data and parameter values. These predictions could be improved with further calibration of the parameter values, but this is not the purpose of this exercise. Rather, we use the model to understand the contributions of the various parameters and inputs to the resulting fuzziness of the model predictions.

The results show that simulated high flows exhibit high fuzziness, whereas low flows are less fuzzy (Figure 10.7c and 10.7d). Monthly results have been aggregated to annual estimates that were presented in Figure 10.7(a) and 10.7(b) also foralevel of presumption of 0.8. At this stage, one has to accept that the fuzzy results are a direct product of the transformation of fuzzy parameters and input data through the water balance model (Table 10.2). Next, the relative sensitivity of parameter estimates and the set of input data on the overall fuzziness of simulated discharges is investigated.

0 0

Post a comment