Using the Information Quantity Method to Assess the Regional Risk of Highway Slope to Improve the Level of Risk Management

Table 1

Table of risk assessment factors for natural slopes on the national and provincial highways in Quzhou City.

Evaluation factors		Factor classification	Classification coding	Number of grid cells				The amount of information	Corrected amount of information	Sorting
				Ni	N	Si	S
Geometric factors	The elevation F1	<150 m	1	227	65718	628	123746	−0.384731932		51
		150–250 m	2	234	42233	628	123746	0.087810121		29
		250–350 m	3	114	10482	628	123746	0.762229859		9
		350–450 m	4	27	2902	628	123746	0.606127623		14
		450–550 m	5	22	1803	628	123746	0.877281420		5
		>550 m	6	0	608	628	123746	—
	Topographic slope F2	0–20°	1	461	106812	628	123746	−0.161981326		41
		20–30°	2	120	11149	628	123746	0.751832846		10
		30–45°	3	39	5334	628	123746	0.365151132		18
		45–55°	4	4	435	628	123746	0.594394520		15
		>55°	5	0	16	628	123746	—
Internal factors	Distance from fault F3	<500 m	1	39	6476	628	123746	0.171149522		23
		500–1000 m	2	27	6545	628	123746	−0.207173622		42
		1000–2000 m	3	48	9786	628	123746	−0.034060871		33
		2000–3000 m	4	29	10415	628	123746	−0.600260334		52
		3000–4500 m	5	70	15287	628	123746	−0.102816641		40
		>4500 m	6	415	75237	628	123746	0.083326300	−0.08332630	37
	The types of rock and soil F4	Quaternary clay, argillaceous silt	1	5	3928	628	123746	−1.383001567	1.383001567	3
		Cretaceous purplish red conglomerate and calcareous mudstone	2	2	1880	628	123746	−1.562433685	1.562433685	2
		Cretaceous conglomerate and sandstone	3	28	12937	628	123746	−0.852196002	0.852196002	6
		Jurassic mudstone, mudstone with volcanic rock	4	61	11131	628	123746	0.076830767		31
		Jurassic conglomerate	5	3	1471	628	123746	−0.911639242	0.911639242	4
		Triassic conglomerate, sandstone, limestone, and dolomite	6	0	1	628	123746	—		—
		Permian limestone, mudstone, and siliceous rock	7	3	3128	628	123746	−1.666090623	1.666090623	1
		Carboniferous limestone, dolomitic limestone, and conglomerate	8	0	701	628	123746	—		—
		Devonian silty mudstone and quartz conglomerate	9	10	2283	628	123746	−0.147214363	0.147214363	25
		Silurian sandstone, silty mudstone, occasionally sandwiched tuff	10	15	3135	628	123746	−0.058888062	0.058888062	32
		Ordovician fine sandstone, siltstone interbedded, local limestone	11	114	19928	628	123746	0.119763582		26
		Ordovician mudstone and limestone	12	114	20170	628	123746	0.107693008		27
		Cambrian limestone, dolomite, and argillaceous limestone	13	62	16102	628	123746	−0.276118192	0.276118192	21
		Sinian dolomite, sandstone, and tuff	14	47	4848	628	123746	0.647272264		11
		Proterozoic intermediate-acid volcanic rocks interbedded with sandstone and mudstone	15	57	5109	628	123746	0.787738489		8
		Early Cretaceous granitic porphyry	16	0	0	628	123746	—		—
		Late Jurassic granite, monzogranite	17	17	2637	628	123746	0.239262348	−0.239262348	44
		Late Jurassic quartz syenite	18	45	12234	628	123746	−0.32186556		49
		Proterozoic rhyolite porphyry and granite porphyry	19	41	2139	628	123746	1.328924548	−1.328924548	53
	Relief degree F5	0–21	1	72	60209	628	123746	−1.445464813		54
		21–40	2	229	32428	628	123746	0.330390668		19
		40–63	3	205	17476	628	123746	0.837872379		7
		63–92	4	96	10254	628	123746	0.612371229		13
		92–209	5	23	3708	628	123746	0.200692479		22
External factors	Distance from the river F6	<50 m	1	81	9568	628	123746	0.511715869		16
		50–100 m	2	87	9192	628	123746	0.623265489		12
		100–200 m	3	76	16150	628	123746	−0.075495798		36
		200–500 m	4	98	24448	628	123746	−0.235890023		43
		500–1000 m	5	68	18918	628	123746	−0.344915233		50
		>1000 m	6	218	45470	628	123746	−0.056866794		35
	The average annual rainfall F7	<1600 mm	1	36	9643	628	123746	−0.307022414		48
		1600–1700 mm	2	128	16459	628	123746	0.426848735		17
		1700–1800 mm	3	400	86800	628	123746	−0.096451163		39
		>1800 mm	4	60	10940	628	123746	0.077609676		30
	Terrain slope F8	Flat (−1)	1	0	162	628	123746	—		—
		North (0–22.5°, 337.5–360°)	2	70	15017	628	123746	−0.084996739		38
		Northeast (22.5–67.5°)	3	59	14953	628	123746	−0.251683593		47
		East (67.5–112.5°)	4	64	16028	628	123746	−0.239763198		45
		Southeast (112.5–157.5°)	5	72	14755	628	123746	−0.039224978		34
		South (157.5–202.5°)	6	59	14791	628	123746	−0.240790533		46
		Southwest (202.5–247.5°)	7	94	15614	628	123746	0.170817746		24
		West (247.5-292.5°)	8	121	17145	628	123746	0.329774871		20
		Northwest (292.5–337.5°)	9	85	15281	628	123746	0.091731941		28