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Table 2

Contribution factor based on the trained ANN weights for the current and optimal rain gauge networks for 1-day-ahead streamflow forecasting

Sl. no.	Current rain gauge network (see Figure 1) (BoM's existing base network)					Optimal rain gauge network (see Figure 3) (additional fictitious stations are not considered in the network design)
	Input variables	Contribution factor^a (CFn) of the input variables (%)			Sum	Input variables	Contribution factor^a (CFn) of the input variables (%)			Sum
	Input variables	(t)	(t − 1)	(t − 2)	Sum	Input variables	(t)	(t − 1)	(t − 2)	Sum
1	R1	2.30	1.18	0.86	4.35	R1	2.82	1.41	1.64	5.88
2	R2	1.32	1.84	0.91	4.06	R2	2.60	1.38	0.82	4.80
3	R3	2.09	1.57	1.32	4.99	R3	1.93	1.68	1.42	5.03
4	R4	1.18	1.05	1.50	3.74	R4	1.04	1.24	0.83	3.12
5	R5	0.81	2.28	1.58	4.68	R5b^c	1.64	1.01	0.97	3.61
6	R6	0.89	0.86	0.53	2.28	R6	1.28	0.97	0.86	3.10
7	R7	2.15	0.71	1.42	4.29	R7	2.08	1.00	1.22	4.31
8	R8	1.79	2.52	1.55	5.86	R8	2.39	2.19	1.84	6.43
9	R9	1.61	1.42	1.51	4.54	R9	1.09	1.02	1.76	3.87
10	R10	2.49	1.15	1.79	5.42	R10	1.16	1.39	0.89	3.44
11	R11	0.96	0.86	1.22	3.04	R11	1.83	1.58	1.52	4.93
12	R12	1.34	0.69	0.61	2.63	R12	1.32	0.92	0.78	3.02
13	R13	1.90	1.44	0.73	4.06	R13	0.79	1.40	1.55	3.74
14	R14	1.28	2.22	1.27	4.76	R14	0.84	0.79	1.16	2.79
15	R15	2.05	1.44	0.90	4.39	R15	1.22	0.68	1.46	3.36
16	R16	1.56	0.65	1.09	3.30	R16	2.06	0.64	1.24	3.94
17	R17	1.86	0.70	1.21	3.76	R17	1.78	1.08	0.76	3.63
18	R18	1.34	1.98	0.98	4.30	R18a^b	2.10	1.62	0.63	4.35
19	R19	2.21	0.56	0.92	3.70	R19a^b	1.91	0.83	1.34	4.08
20	S1	1.76	2.53	1.58	5.88	S1	1.45	1.72	1.51	4.68
21	S2	2.68	2.83	1.76	7.27	S2	2.79	2.44	2.35	7.58
22	S3	2.91	1.06	1.23	5.19	S3	2.62	1.30	1.03	4.96
23	S4	1.37	1.11	1.03	3.51	S4	2.49	2.29	0.57	5.35
	Sum of contribution of all variables =				100	Sum of contribution of all variables =				100

Sl. no.	Current rain gauge network (see Figure 1) (BoM's existing base network)					Optimal rain gauge network (see Figure 3) (additional fictitious stations are not considered in the network design)
	Input variables	Contribution factor^a (CFn) of the input variables (%)			Sum	Input variables	Contribution factor^a (CFn) of the input variables (%)			Sum
	Input variables	(t)	(t − 1)	(t − 2)	Sum	Input variables	(t)	(t − 1)	(t − 2)	Sum
1	R1	2.30	1.18	0.86	4.35	R1	2.82	1.41	1.64	5.88
2	R2	1.32	1.84	0.91	4.06	R2	2.60	1.38	0.82	4.80
3	R3	2.09	1.57	1.32	4.99	R3	1.93	1.68	1.42	5.03
4	R4	1.18	1.05	1.50	3.74	R4	1.04	1.24	0.83	3.12
5	R5	0.81	2.28	1.58	4.68	R5b^c	1.64	1.01	0.97	3.61
6	R6	0.89	0.86	0.53	2.28	R6	1.28	0.97	0.86	3.10
7	R7	2.15	0.71	1.42	4.29	R7	2.08	1.00	1.22	4.31
8	R8	1.79	2.52	1.55	5.86	R8	2.39	2.19	1.84	6.43
9	R9	1.61	1.42	1.51	4.54	R9	1.09	1.02	1.76	3.87
10	R10	2.49	1.15	1.79	5.42	R10	1.16	1.39	0.89	3.44
11	R11	0.96	0.86	1.22	3.04	R11	1.83	1.58	1.52	4.93
12	R12	1.34	0.69	0.61	2.63	R12	1.32	0.92	0.78	3.02
13	R13	1.90	1.44	0.73	4.06	R13	0.79	1.40	1.55	3.74
14	R14	1.28	2.22	1.27	4.76	R14	0.84	0.79	1.16	2.79
15	R15	2.05	1.44	0.90	4.39	R15	1.22	0.68	1.46	3.36
16	R16	1.56	0.65	1.09	3.30	R16	2.06	0.64	1.24	3.94
17	R17	1.86	0.70	1.21	3.76	R17	1.78	1.08	0.76	3.63
18	R18	1.34	1.98	0.98	4.30	R18a^b	2.10	1.62	0.63	4.35
19	R19	2.21	0.56	0.92	3.70	R19a^b	1.91	0.83	1.34	4.08
20	S1	1.76	2.53	1.58	5.88	S1	1.45	1.72	1.51	4.68
21	S2	2.68	2.83	1.76	7.27	S2	2.79	2.44	2.35	7.58
22	S3	2.91	1.06	1.23	5.19	S3	2.62	1.30	1.03	4.96
23	S4	1.37	1.11	1.03	3.51	S4	2.49	2.29	0.57	5.35
	Sum of contribution of all variables =				100	Sum of contribution of all variables =				100

^aBold font shows variables having a contribution factor greater than 1/69 = 1.45%.

^bOptimal position of additional rain gauge stations (stations 18 and 19, see Figure 3) as identified by Adhikary et al. (2015).

^cOptimal re-located position of redundant rain gauge station (station 5, see Figure 3) as identified by Adhikary et al. (2015).