Fig. 1
Three different major climate zones in Indonesia based on Aldrian and Susanto (2013). Precipitation data were derived from TRMM 3B42.
Fig. 2
TRMM 3B42 composite seasonal rainfall and the corresponding NCEP reanalysis horizontal wind vectors from 1998–2010.
Fig. 3
Rain gauge stations used for the analysis, represented as red triangle. Shading color represent elevation. (Precipitation data are from BMKG; elevation data are based on ETOPO).
Table 1
Number of weather stations based on the elevation.
| Elevation (m a.s.l.) | Number of stations |
|---|---|
| 0–250 | 51 |
| 250–500 | 9 |
| 500–750 | 9 |
| 500–1,000 | 3 |
| >1,000 | 1 |
Fig. 4
Correlation-distance plot between weather stations with deleted station in cross red marks.
Fig. 5
a) An example of station with good consistency taken from Dracik Kramat Station, b) station with low consistency taken from Ngawen Station.
Fig. 6
Number of weather stations within each TRMM 0.25 sq. degree grid.
Fig. 7
Selection of interpolation techniques, a) Moving Average, b) Spline, c) IDW, d) Kriging, e) Nearest Neighbour, and f) Natural Neighbour.
Table 2
Correlation value, Mean Bias Error (MBE), and Root Mean Square Error (RMSE) for several interpolation method.
| Parameter | Interpolation | |||||
|---|---|---|---|---|---|---|
| Moving Average | Spline | IDW | Kriging | Nearest Neighbour | Natural Neighbour | |
| Correlation | 0.93 | 0.91 | 0.92 | 0.84 | 0.92 | 0.91 |
| MBE | 1.15 | −10.61 | 8.01 | 2.18 | 1.02 | 4.21 |
| RMSE | 81.51 | 88.17 | 83.37 | 118.94 | 89.82 | 92.06 |
Fig. 8
a) Correlation value, b) Mean Bias Error (MBE), and c) Root Mean Square Error (RMSE) of monthly precipitation between each weather stations and TRMM 3B42.
Fig. 9
a) Correlation value, b) Mean Bias Error (MBE), and c) Root Mean Square Error (RMSE) of monthly precipitation between weather stations (interpolated using Moving Average) and TRMM 3B42.
Fig. 10
Long term plot of precipitation from TRMM and interpolated weather station precipitation data.
Table 3
a) Correlation value, b) Mean Bias Error (MBE), and c) Root Mean Square Error (RMSE) for seasonal data.
| Season | Correlation | MBE | RMSE |
|---|---|---|---|
| DJF | 0.54 | −44 (−12.29%) | 149 (41.54%) |
| MAM | 0.68 | −17 (−7.16%) | 90 (37.56%) |
| JJA | 0.82 | 0.94 (0.16%) | 44 (64.25%) |
| SON | 0.81 | –16 (−9.09%) | 97 (54.07%) |
Fig. 11
a) Mean rainfall, b) correlation value, c) Mean Bias Error (MBE), and d) Root Mean Square Error (RMSE) for each station based on elevation rank from the lowest to the highest. Black-bold lines indicates average value for all season, while color lines indicate seasonal variation.
Fig. 12
Similar to previous figure, but for moving average interpolated rainfall data. The plot are based on grid elevation rank from the lowest to the highest.