Table 1 Conditions used in the deterioration test

1

Clean wind for 5 min at:

12 m s⁻¹

A

Threshold in wind tunnel studies

2

17 m s⁻¹

B

Maximum wind speed in storm at Suoyang (14th–15th Aug 2018)

3

25 m s⁻¹

C

Highest wind speed recorded at Suoyang in 2015–2016

4

Sediment-laden wind 80 g min⁻¹ for 5 min at:

12 m s⁻¹

A

Threshold in wind tunnel studies

5

15 m s⁻¹

C

Intermediate wind speed as 17 m s⁻¹ caused visible damage

6

17 m s⁻¹

B

Maximum wind speed in storm at Suoyang (14th–15th Aug 2018)

7

Rainfall at 0.2 L/min for:

20 s

C

The time at which visible deterioration occurred

8

1 min

B

Volume of water is equivalent to the 2nd highest maximum daily rainfall in 2018 at Suoyang

9

2 min

A

Volume of water is equivalent to the maximum daily rainfall in 2018 at Suoyang