बोफर्ट मापक्रम

फोर्स १२ पर समुद्र की दशा

बोफर्ट मापक्रम (Beaufort scale) पवनवेग और समुद्र तथा स्थल की दशाओं के बीच सम्बन्ध बताने वाला एक आनुभविक (इम्पिरिकल) तालिका है। इसका पूरा नाम 'बोफर्ट पवनवेग मापक्रम' (Beaufort wind force scale) है। यह मापक्रम 1805 में फ्रांसिस बोफर्ट (Francis Beaufort) द्वारा सुझाया गया था। वे जो आयरिश रॉयल नेवी में अफसर थे।

आधुनिक स्केल

बोफर्ट संख्या	विवरण	पवन वेग	तरंग ऊँचाई	समुद्र की दशा	स्थल की दशा	समुद्र की दशा का फोटो	संबन्धित चेतावनी ध्वज
0	प्रशान्त (Calm)	< 1 km/h	0 m	समतल	धुआँ सीधा उठता है।
		< 1 mph
		< 1 knot	0 ft
		< 0.3 m/s
1	हल्की वायु (Light air)	1.1–5.5 km/h	0–0.2 m	Ripples without crests.	धुएँ में हलचल होती है और वह हवा की दिशा दिखाता है। Leaves and wind vanes are stationary.
		1–3 mph
		1–3 knot	0–1 ft
		0.3–1.5 m/s
2	अल्प समीर (Light breeze)	5.6–11 km/h	0.2–0.5 m	Small wavelets. Crests of glassy appearance, not breaking	Wind felt on exposed skin. Leaves rustle. Wind vanes begin to move.
		4–7 mph
		4–6 knot	1–2 ft
		1.6–3.4 m/s
3	मंद समीर (Gentle breeze)	12–19 km/h	0.5–1 m	Large wavelets. Crests begin to break; scattered whitecaps	पत्ते और छोटे तने लगातार हिलते हैं। ध्वज फैल जाता है।
		8–12 mph
		7–10 knot	2–3.5 ft
		3.5–5.4 m/s
4	अल्पबल समीर (Moderate breeze)	20–28 km/h	1–2 m	Small waves with breaking crests. Fairly frequent whitecaps.	धूल और फटे हुए कागज उड़ने लगते हैं। छोटे साखा हिलने लगते हैं।
		13–17 mph
		11–16 knot	3.5–6 ft
		5.5–7.9 m/s
5	सबल समीर (Fresh breeze)	29–38 km/h	2–3 m	Moderate waves of some length. Many whitecaps. Small amounts of spray.	Branches of a moderate size move. Small trees in leaf begin to sway.
		18–24 mph
		17–21 knot	6–9 ft
		8.0–10.7 m/s
6	प्रबल समीर (Strong breeze)	39–49 km/h	3–4 m	Long waves begin to form. White foam crests are very frequent. Some airborne spray is present.	Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic bins tip over.
		25–30 mph
		22–27 knot	9–13 ft
		10.8–13.8 m/s
7	अल्पबल झंझा (moderate gale), (near gale)	50–61 km/h	4–5.5 m	Sea heaps up. Some foam from breaking waves is blown into streaks along wind direction. Moderate amounts of airborne spray.	Whole trees in motion. Effort needed to walk against the wind.
		31–38 mph
		28–33 knot	13–19 ft
		13.9–17.1 m/s
8	झंझा (fresh gale)	62–74 km/h	5.5–7.5 m	Moderately high waves with breaking crests forming spindrift. Well-marked streaks of foam are blown along wind direction. Considerable airborne spray.	Some twigs broken from trees. Cars veer on road. Progress on foot is seriously impeded.
		39–46 mph
		34–40 knot	18–25 ft
		17.2–20.7 m/s
9	प्रबल झंझा (Strong gale)	75–88 km/h	7–10 m	High waves whose crests sometimes roll over. Dense foam is blown along wind direction. Large amounts of airborne spray may begin to reduce visibility.	Some branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over.
		47–54 mph
		41–47 knot	23–32 ft
		20.8–24.4 m/s
10	तूफान (Storm), whole gale	89–102 km/h	9–12.5 m	Very high waves with overhanging crests. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility.	Trees are broken off or uprooted, structural damage likely.
		55–63 mph
		48–55 knot	29–41 ft
		24.5–28.4 m/s
11	तीव्र तूफान (Violent storm)	103–117 km/h	11.5–16 m	Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility.	Widespread vegetation and structural damage likely.
		64–73 mph
		56–63 knot	37–52 ft
		28.5–32.6 m/s
12	प्रभंजन (Hurricane force)	≥ 118 km/h	≥ 14 m	Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility.	Severe widespread damage to vegetation and structures. Debris and unsecured objects are hurled about.
		≥ 74 mph
		≥ 64 knot	≥ 46 ft
		≥ 32.7 m/s