Table 2 Cross-validation statistics from all interpolation methods and the appropriateness index (AI). AI-3 represents the first step of evaluation whereas AI-6 represents the second step of evaluation of the optimal interpolation technique. The values of cross-validation parameters are normalized using the minimum–maximum normalization method as discussed in section “Deterministic methods”.
From: Spatial–temporal characterization of rainfall in Pakistan during the past half-century (1961–2020)
Method | ME | RMSE | R2 | MSE | RMSSE | ASE | AI-3 | Rank AI-3 | AI-6 | Rank AI-6 |
|---|---|---|---|---|---|---|---|---|---|---|
IDW | 0.9428 | 0.9351 | 0.9494 | – | – | – | 0.9430 | 4 | – | – |
GPI | 0.9464 | 0.0000 | 0.0000 | – | – | – | 0.0000 | 26 | – | – |
RBF | 0.7973 | 1.0000 | 1.0000 | – | – | – | 0.9280 | 7 | – | – |
LPI | 0.4499 | 0.7589 | 0.8121 | 0.3564 | 0.9890 | 0.5263 | 0.6549 | 22 | 0.5524 | 15 |
EBK | 0.9280 | 0.9527 | 0.9628 | 1.0000 | 1.0000 | 0.8530 | 0.9482 | 3 | 0.9379 | 2 |
OK-c | 0.8314 | 0.9305 | 0.9456 | 0.8510 | 0.4728 | 0.6274 | 0.9020 | 10 | 0.7133 | 6 |
OK-s | 0.8157 | 0.9432 | 0.9561 | 0.8261 | 0.4652 | 0.6252 | 0.9036 | 9 | 0.7070 | 7 |
OK-e | 0.8716 | 0.9604 | 0.9691 | 0.8973 | 0.3678 | 0.5549 | 0.9333 | 6 | 0.6829 | 8 |
OK-g | 0.8789 | 0.9202 | 0.9375 | 0.8855 | 0.4717 | 0.6004 | 0.9127 | 8 | 0.7174 | 5 |
OK-h | 0.4922 | 0.9007 | 0.9253 | 0.4863 | 0.1819 | 0.3240 | 0.7452 | 17 | 0.4112 | 22 |
OK-k | 0.9204 | 0.9338 | 0.9476 | 0.9476 | 0.4845 | 0.6328 | 0.9345 | 5 | 0.7495 | 3 |
OK-j | 0.8387 | 0.9153 | 0.9343 | 0.8433 | 0.6094 | 0.6058 | 0.8961 | 11 | 0.7409 | 4 |
SK-c | 0.3122 | 0.8316 | 0.8649 | 0.3494 | 0.6906 | 0.6766 | 0.6108 | 23 | 0.5162 | 18 |
SK-s | 0.5312 | 0.8343 | 0.8661 | 0.5807 | 0.4865 | 0.5290 | 0.7291 | 18 | 0.5646 | 12 |
SK-e | 0.5135 | 0.8825 | 0.9066 | 0.5601 | 0.6091 | 0.6571 | 0.7456 | 16 | 0.6206 | 9 |
SK-g | 0.3140 | 0.8200 | 0.8552 | 0.3478 | 0.7249 | 0.6734 | 0.6069 | 24 | 0.5182 | 17 |
SK-h | 0.2878 | 0.7573 | 0.8004 | 0.3486 | 0.5651 | 0.4512 | 0.5620 | 25 | 0.4345 | 20 |
SK-k | 0.6010 | 0.8766 | 0.9013 | 0.6439 | 0.4888 | 0.5864 | 0.7821 | 14 | 0.6145 | 10 |
SK-j | 0.0000 | 0.7974 | 0.8376 | 0.0000 | 0.7438 | 0.6565 | 0.0000 | 26 | 0.0000 | 23 |
UK-c | 0.4652 | 0.8786 | 0.9071 | 0.5163 | 0.2183 | 0.3245 | 0.7208 | 19 | 0.4230 | 21 |
UK-s | 0.4502 | 0.8889 | 0.9136 | 0.5110 | 0.3055 | 0.4062 | 0.7174 | 20 | 0.4710 | 19 |
UK-e | 0.5655 | 0.9206 | 0.9379 | 0.6694 | 0.3469 | 0.4569 | 0.7893 | 13 | 0.5531 | 14 |
UK-g | 0.4380 | 0.8543 | 0.8832 | 0.5552 | 0.4937 | 0.4571 | 0.6939 | 21 | 0.5289 | 16 |
UK-h | 0.6553 | 0.8679 | 0.8943 | 0.9088 | 0.0000 | 0.0000 | 0.8000 | 12 | 0.0000 | 23 |
UK-k | 1.0000 | 0.9219 | 0.9429 | 0.9932 | 0.1674 | 0.3701 | 0.9548 | 2 | 0.5567 | 13 |
UK-j | 0.5679 | 0.8788 | 0.9032 | 0.6843 | 0.4948 | 0.4965 | 0.7688 | 15 | 0.5969 | 11 |
EBKRP | 0.9629 | 0.9558 | 0.9653 | 0.9150 | 0.9364 | 0.9774 | 0.9617 | 1 | 0.9425 | 1 |