Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers

  1. ํ•œ์–‘๋Œ€ํ•™๊ต ๋Œ€ํ•™์› ๊ฑด์„คํ™˜๊ฒฝ์‹œ์Šคํ…œ๊ณตํ•™๊ณผ ์„๋ฐ•์‚ฌ๊ณผ์ • (Hanyang University)
  2. ํ•œ์–‘๋Œ€ํ•™๊ต ๋Œ€ํ•™์› ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๊ณผ ์„๋ฐ•์‚ฌ๊ณผ์ • (Hanyang University)
  3. ์ค‘๋ถ€๋Œ€ํ•™๊ต ํ† ๋ชฉ๊ณตํ•™๊ณผ ๊ต์ˆ˜ (Joongbu University)
  4. ์–‘๋Œ€ํ•™๊ต ๊ณตํ•™๋Œ€ํ•™ ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๊ณผ ๊ต์ˆ˜ ( (Hanyang University)


๊ธฐํ›„๋ณ€ํ™”, ์œ„ํ—˜๋„ ๋ถ„์„, ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„, ์ธก์šฐ๊ธฐ
Bivariate drought frequency analysis, Cheugugi, Climate change, Risk analysis

  • 1. ์„œ ๋ก 

  • 2. ์—ฐ๊ตฌ์ง€์—ญ ๋ฐ ์ž๋ฃŒ

  • 3. ์—ฐ๊ตฌ๋ฐฉ๋ฒ•

  •   3.1 ๋™์งˆ์„ฑ ๋ถ„์„

  •   3.2 ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•

  •   3.3 ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„

  • 4. ์ ์šฉ ๋ฐ ๊ฒฐ๊ณผ

  •   4.1 ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ •์˜

  •   4.2 ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„

  •   4.3 ์œ„ํ—˜๋„ ๋ถ„์„

  • 5. ๊ฒฐ ๋ก 

1. ์„œ ๋ก 

์ตœ๊ทผ ๊ธฐํ›„๋ณ€ํ™”์˜ ์˜ํ–ฅ์œผ๋กœ ์ธํ•˜์—ฌ ์„ธ๊ณ„ ๊ณณ๊ณณ์—์„œ ์ด์ƒ๊ธฐํ›„ ํ˜„์ƒ์ด ๋นˆ๋ฒˆํžˆ ๋ฐœ์ƒํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ๊ทนํ•œ ๊ธฐํ›„ํ˜„์ƒ์˜ ๋ฐœ์ƒ๋„ ์ฆ๊ฐ€ํ•˜๊ณ  ์žˆ๋‹ค. ์ด๋กœ ์ธํ•˜์—ฌ ์„ธ๊ณ„ ๊ณณ๊ณณ์—์„œ ์‹ฌ๊ฐํ•œ ํ”ผํ•ด๊ฐ€ ๋ฐœ์ƒํ•˜๊ณ  ์žˆ๋‹ค. ํŠนํžˆ ๊ฐ€๋ญ„์˜ ๊ฒฝ์šฐ ๋„“์€ ์ง€์—ญ์— ์žฅ๊ธฐ๊ฐ„์— ๊ฑธ์ณ์„œ ์ง€์†๋˜๋Š” ํŠน์ง•์œผ๋กœ ์ธํ•˜์—ฌ ์ฆ‰๊ฐ์ ์ธ ์ธ์ง€๊ฐ€ ์–ด๋ ค์šฐ๋ฉฐ, ์ ์ ˆํ•œ ๋Œ€์ฒ˜๊ฐ€ ์ด๋ฃจ์–ด์ง€์ง€ ์•Š๋Š”๋‹ค๋ฉด ํ”ผํ•ด๊ฐ€ ๋งค์šฐ ์ปค์ง€๊ฒŒ ๋œ๋‹ค. ๋”ฐ๋ผ์„œ ๊ธฐํ›„๋ณ€ํ™”์˜ ์˜ํ–ฅ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ๊ฐ€๋ญ„ ํ”ผํ•ด๋ฅผ ์ตœ์†Œํ™”ํ•˜๊ณ  ์ด์— ๋Œ€ํ•œ ๋Œ€์ฑ…์„ ๋งˆ๋ จํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ๊ทนํ•œ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„์— ๋Œ€ํ•ด ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•  ํ•„์š”๊ฐ€ ์žˆ๋‹ค.

์žฅ๊ธฐ๊ฐ„์˜ ํ‰๊ท ๋ณด๋‹ค ๊ฐ•์ˆ˜๋Ÿ‰์ด ๋ถ€์กฑํ•˜๋‹ค๋Š” ๊ฐœ๋…์˜ ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•์„ ์ ์šฉํ•˜๋ฉด ๊ฐ€๋ญ„์˜ ์ •์˜๊ฐ€ ๋งค์šฐ ๊ฐ„๋‹จํ•ด์ง„๋‹ค. Yoo et al.(2013)์€ ์›”๊ฐ•์šฐ๋Ÿ‰์— ๋Œ€ํ•œ ๊ฐ€๋ญ„ ์ ˆ๋‹จ์ˆ˜์ค€์„ ๊ฒฐ์ •ํ•˜์—ฌ ๊ธฐ์ƒํ•™์  ๊ฐ€๋ญ„์„ ์ •์˜ํ•˜๊ณ  ๊ฐ€๋ญ„ํ•ด์„์„ ์ˆ˜ํ–‰ํ–ˆ์œผ๋ฉฐ, Yu et al.(2017)์€ ํ•˜์ฒœ์œ ๋Ÿ‰์ด ์—ฐ์†ํ•ด์„œ ์ผ์ • ์ž„๊ณ„์ˆ˜์ค€ ์ดํ•˜๋กœ ๋ถ€์กฑํ•ด์ง€๋Š” ๊ธฐ๊ฐ„์„ ์ˆ˜๋ฌธํ•™์  ๊ฐ€๋ญ„์œผ๋กœ ์ •์˜ํ•˜๊ณ  ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์„ ํ†ตํ•ด ํ™•๋ฅ ๋ก ์  ์žฌํ˜„๊ธฐ๊ฐ„์„ ๋ถ„์„ํ•˜์˜€๋‹ค.

๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ง€์†๊ธฐ๊ฐ„ ๋ฐ ์‹ฌ๋„์— ๋Œ€ํ•˜์—ฌ ๋‹จ๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์ง„ํ–‰ํ•  ๊ฒฝ์šฐ ๊ฐ๊ฐ์˜ ๊ฒฐ๊ณผ๊ฐ€ ์ƒ์ดํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚˜๋Š” ๋ฌธ์ œ๊ฐ€ ๋ฐœ์ƒํ•œ๋‹ค. ๋”ฐ๋ผ์„œ ๊ฐ€๋ญ„์„ ์ผ๊ด€์„ฑ์žˆ๊ฒŒ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„๋ฅผ ๋™์‹œ์— ๊ณ ๋ คํ•˜๋Š” ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์ˆ˜ํ–‰ํ•ด์•ผ ํ•œ๋‹ค(Kim et al., 2003). ์˜ˆ๋ฅผ ๋“ค์–ด, Chen et al.(2013)์€ ๊ฒฐํ•ฉํ™•๋ฅ ๋ถ„ํฌ๋กœ ์•„๋ฅดํ‚ค๋ฉ”๋””์•ˆ(archimedean) ๋ฐ ๋ฉ”ํƒ€ํƒ€์›ํ˜•(metaelliptical) ์ฝ”ํ”Œ๋ผ๋ฅผ ์ ์šฉํ•˜์—ฌ ๋‹จ๋ณ€๋Ÿ‰ ๋ฐ ๋‹ค๋ณ€๋Ÿ‰ ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ ๊ฐ ๊ฒฐ๊ณผ๋ฅผ ๋ถ„์„ ๋ฐ ๋น„๊ตํ•˜์˜€๋‹ค. Yoo et al.(2016b)๋Š” ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ฐ€๋ญ„์˜ ์ง€์†๊ธฐ๊ฐ„-์‹ฌ๋„์˜ ๋ถ„ํฌ ํ˜•ํƒœ๋ฅผ ์œ ์ง€ํ•˜๊ณ  ๋‘ ๋ณ€๋Ÿ‰์˜ ๋ถˆํ™•์‹ค์„ฑ์— ๋Œ€ํ•ด ์ •๋Ÿ‰์ ์œผ๋กœ ํ•ด์„ํ•˜์˜€๋‹ค.

์ด๋Ÿฌํ•œ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์˜ ๊ฒฐ๊ณผ๋ฅผ ํ™œ์šฉํ•˜๋ฉด ํŠน์ • ๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์œ„ํ—˜๋„๋ฅผ ๋ถ„์„ํ•  ์ˆ˜ ์žˆ๋‹ค. ํŠนํžˆ ์ตœ๊ทผ์—๋Š” ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ ๋ฏธ๋ž˜ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•˜๋Š” ์—ฐ๊ตฌ๋“ค์ด ์ง„ํ–‰๋˜๊ณ  ์žˆ๋‹ค. Yoo et al.(2016a)์€ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ํ‘œ์ค€๊ฐ•์ˆ˜์ง€์ˆ˜(Standardized Precipitation Index, SPI) ๊ธฐ๋ฐ˜ ๋ฐ ํ‘œ์ค€๊ฐ•์ˆ˜-์ฆ๋ฐœ์‚ฐ๋Ÿ‰์ง€์ˆ˜(Standardized Precipitation Evapotranspiration Index, SPEI) ๊ธฐ๋ฐ˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ๋น„๊ตยท๋ถ„์„ํ–ˆ์œผ๋ฉฐ, Kim et al.(2015)๋Š” ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค๋ฅผ ์ ์šฉํ•˜์—ฌ, ํ•œ๋ฐ˜๋„ ๊ทนํ•œ ๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์‹œ๊ณต๊ฐ„์  ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ ์ˆ˜๋ฌธํ•™์  ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•˜๊ณ  ๋ฏธ๋ž˜ ๊ฐ€๋ญ„์— ๋Œ€ํ•˜์—ฌ ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ๋˜ํ•œ Yu et al.(2016; 2017)์€ ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋ฅผ ์ ์šฉํ•œ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•˜์—ฌ ๋น„์ดˆ๊ณผํ™•๋ฅ ์— ๋”ฐ๋ฅธ ์ž„๊ณ„์‹ฌ๋„๋ฅผ ๊ฒฐ์ •ํ–ˆ์œผ๋ฉฐ, ์ด๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ทนํ•œ ๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์ˆ˜๋ฌธํ•™์  ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•˜์˜€๋‹ค.

ํ˜„์žฌ ๊ฐ€๋ญ„์˜ ์œ„ํ—˜๋„ ํ‰๊ฐ€์— ๊ด€ํ•œ ์—ฐ๊ตฌ๋“ค์ด ๋‹ค์–‘ํ•˜๊ฒŒ ์ง„ํ–‰๋˜๊ณ  ์žˆ์ง€๋งŒ, ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„์— ๋Œ€ํ•ด ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•˜๋Š” ์—ฐ๊ตฌ๋Š” ์•„์ง๊นŒ์ง€ ๋ถ€์กฑํ•œ ์‹ค์ •์ด๋‹ค. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ธก์šฐ๊ธฐ ์ž๋ฃŒ์™€ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ๊ทนํ•œ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ๊ธฐ์ƒํ•™์  ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ–ˆ์œผ๋ฉฐ, ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ๋ฅผ ๊ธฐ์ค€์œผ๋กœ ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ๋น„๊ตยท๋ถ„์„ํ•˜์˜€๋‹ค. ๋˜ํ•œ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„ ์‚ฐ์ • ๊ณผ์ •์— ๊ฐ€๋ญ„์˜ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„๋ฅผ ๋™์‹œ์— ๊ณ ๋ คํ•˜๋„๋ก ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋ฅผ ์ ์šฉํ•˜์—ฌ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•˜์˜€๋‹ค.

2. ์—ฐ๊ตฌ์ง€์—ญ ๋ฐ ์ž๋ฃŒ

๊ธฐํ›„๋ณ€ํ™”์— ๋”ฐ๋ฅธ ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๊ณผ๊ฑฐ์™€ ํ˜„์žฌ ์ž๋ฃŒ์— ๋Œ€ํ•œ ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์„ ํ†ตํ•œ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•˜๊ณ  ์ด๋ฅผ ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„์™€ ๋น„๊ตยท๋ถ„์„ํ•˜๋Š” ๊ฒƒ์ด ํ•„์š”ํ•˜๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๊ณผ๊ฑฐ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋ฅผ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์ธก์šฐ๊ธฐ ๊ธฐ๋ก์„ ํ™œ์šฉํ•˜์˜€๋‹ค. ์ธก์šฐ๊ธฐ ๊ธฐ๋ก์€ 1770๋…„๋Œ€ ์ดํ›„๋ถ€ํ„ฐ ์Šน์ •์›์ผ๊ธฐ์™€ ์ผ์„ฑ๋ก์„ ๋น„๋กฏํ•œ ์—ฌ๋Ÿฌ ๋ฌธํ—Œ์— ๊ด€์ธก๊ธฐ๋ก์ด ๋‚จ์•„์žˆ์œผ๋ฉฐ, Jhun and Moon(1997)์ด ์Šน์ •์›์ผ๊ธฐ์™€ ์ผ์„ฑ๋ก์— ๊ธฐ๋ก๋œ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ ์ธก์šฐ๊ธฐ ์ž๋ฃŒ(1777~1907๋…„)๋ฅผ ๋ณต์›ํ•˜์˜€๋‹ค. ํ˜„์žฌ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋Š” ๊ธฐ์ƒ์ฒญ์˜ ๊ด€์ธก์ž๋ฃŒ(1912~2015๋…„)๋ฅผ ์‚ฌ์šฉํ–ˆ์œผ๋ฉฐ, ๋ฏธ๋ž˜ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋Š” IPCC 5์ฐจ ํ‰๊ฐ€๋ณด๊ณ ์„œ์—์„œ ์„ ์ •ํ•œ 4๊ฐœ์˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ค‘ ํ˜„์žฌ ์ถ”์„ธ๋กœ ์˜จ์‹ค๊ฐ€์Šค๊ฐ€ ๋ฐฐ์ถœ๋˜๋Š” ๊ฒฝ์šฐ๋ฅผ ์˜๋ฏธํ•˜๋Š” RCP 8.5 ์‹œ๋‚˜๋ฆฌ์˜ค์— HADGEM-ES ๋ชจ๋ธ์„ ์ด์šฉํ•˜์—ฌ ์ถ”์ •ํ•œ ์ž๋ฃŒ(2016~2099๋…„)๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค(Park et al., 2013). ์„œ์šธ์ง€์—ญ์˜ ๊ฒฝ์šฐ, ๋ณต์›๋œ ์ธก์šฐ๊ธฐ ์ž๋ฃŒ์˜ ์‹ ๋ขฐ์„ฑ์ด ์ธ์ •๋˜์–ด ์žˆ๊ณ (Yoo et al., 2007), 100๋…„ ์ด์ƒ์˜ ๊ฐ•์ˆ˜๋Ÿ‰ ๊ด€์ธก์ž๋ฃŒ๊ฐ€ ๊ตฌ์ถ•๋˜์–ด ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์˜ ๋Œ€์ƒ์ง€์—ญ์€ ๊ณผ๊ฑฐ, ํ˜„์žฌ, ๋ฏธ๋ž˜์˜ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋ฅผ ํ™•๋ณดํ•  ์ˆ˜ ์žˆ๋Š” ์„œ์šธ์ง€์—ญ์œผ๋กœ ์„ ์ •ํ•˜์˜€๋‹ค.

3. ์—ฐ๊ตฌ๋ฐฉ๋ฒ•

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ์— ๋Œ€ํ•œ ๋™์งˆ์„ฑ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•œ ํ›„, ์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก ์ž๋ฃŒ ๋ฐ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ ๊ฐ๊ฐ์— ๋Œ€ํ•ด ์ž„๊ณ„์ˆ˜์ค€ ๋ฐฉ๋ฒ•์„ ์ ์šฉํ•˜์—ฌ ๊ฐ€๋ญ„์˜ ํŠน์„ฑ์„ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ์‚ฐ์ •๋œ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„๋ฅผ ๊ฒฐํ•ฉํ•˜๊ธฐ ์œ„ํ•ด ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋ฅผ ํ™œ์šฉํ•˜์—ฌ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์ˆ˜ํ–‰ํ–ˆ์œผ๋ฉฐ, ๊ทธ ๊ฒฐ๊ณผ์ธ ์žฌํ˜„๊ธฐ๊ฐ„์„ ๋ฐ”ํƒ•์œผ๋กœ ๊ณผ๊ฑฐ, ํ˜„์žฌ, ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค.

3.1 ๋™์งˆ์„ฑ ๋ถ„์„

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์„ธ ๊ฐœ์˜ ์„œ๋กœ ๋‹ค๋ฅธ ๊ฐ•์šฐ๋Ÿ‰ ์ž๋ฃŒ๋ฅผ ์‚ฌ์šฉํ•˜๋ฏ€๋กœ, ์„ธ ๊ฐœ์˜ ์ž๋ฃŒ๊ฐ€ ๊ฐ๊ฐ์˜ ๋ชจ์ง‘๋‹จ ๋ถ„ํฌ๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค๋Š” ๊ฒƒ์„ ์ž…์ฆํ•ด์•ผ ์œ ์˜๋ฏธํ•œ ๊ฒฐ๊ณผ๋ฅผ ์–ป์„ ์ˆ˜ ์žˆ๋‹ค. ์ด๋ฅผ ์œ„ํ•ด ์„ธ ๊ฐœ์˜ ๊ฐ•์šฐ๋Ÿ‰ ์ž๋ฃŒ ์ง‘๋‹จ์— ๋Œ€ํ•œ ๋ถ„์‚ฐ๋ถ„์„(Analysis of variance, ANOVA)์„ ์‹ค์‹œํ•˜์˜€๋‹ค.

๋ถ„์‚ฐ๋ถ„์„์€ ๋‘ ๊ฐœ ์ด์ƒ ์ง‘๋‹จ์˜ ๋ชจํ‰๊ท ์— ๋Œ€ํ•œ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ ์ฃผ์–ด์ง„ ์ž๋ฃŒ์— ๋Œ€ํ•œ ๋™์งˆ์„ฑ ๊ฒ€์‚ฌ๋ฅผ ์‹ค์‹œํ•˜๋Š” ๊ฒƒ์ด๋‹ค. ์ฆ‰, ์ง‘๋‹จ ๋‚ด ๋ถ„์‚ฐ ๋ณ€๋™๊ณผ ๊ฐ ์ง‘๋‹จ ๊ฐ„ ๋ถ„์‚ฐ์˜ ๋น„๊ต๋ฅผ ํ†ตํ•ด ์ƒ์„ฑ๋œ F ๋ถ„ํฌ๋ฅผ ์ด์šฉํ•˜์—ฌ, ๊ฐ ์ง‘๋‹จ์˜ ๋ชจ์ง‘๋‹จ ๋ถ„์‚ฐ ๋ฐ ํ‰๊ท ์ด ์ฐจ์ด๊ฐ€ ์žˆ๋Š”์ง€ ๊ฒ€์ •ํ•˜๋Š” ๊ฒƒ์ด๋‹ค(Nam et al., 2010). ๋ถ„์‚ฐ๋ถ„์„์€ ์š”์ธ ์ˆ˜์— ์˜ํ•ด ์ผ์›๋ถ„์‚ฐ๋ถ„์„, ์ด์›๋ถ„์‚ฐ๋ถ„์„ ๋ฐ ๋‹ค์›๋ถ„์‚ฐ๋ถ„์„์œผ๋กœ ๋ถ„๋ฅ˜๋œ๋‹ค. ์ด ์ค‘ ์ผ์›๋ถ„์‚ฐ๋ถ„์„์€ ์ข…์†๋ณ€์ˆ˜ 1๊ฐœ์— ๋‹จ์ผ๋…๋ฆฝ๋ณ€์ˆ˜๋ฅผ ๊ฐ€์ง€๋ฉฐ, ๋‹จ์ผ๋…๋ฆฝ๋ณ€์ˆ˜ ๋‚ด์˜ k๊ฐœ ์ง‘๋‹จ์˜ ํ‘œ๋ณธ๋“ค์„ ๋น„๊ตํ•˜์—ฌ ์ง‘๋‹จ ๊ฐ„ ํ‰๊ท ์น˜์˜ ์ฐจ์ด๊ฐ€ ์œ ์˜ํ•œ์ง€ ๊ฒ€์ฆํ•œ๋‹ค. ๋ถ„์‚ฐ๋ถ„์„์„ ํ†ตํ•˜์—ฌ ๋™์งˆ์„ฑ ๊ฒ€์ •์„ ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ k๊ฐœ์˜ ๊ฐ ์ง‘๋‹จ์—์„œ์˜ ๋ชจ์ง‘๋‹จ ๋ถ„์‚ฐ์€ ๋™์ผํ•˜๋‹ค๋Š” ๊ท€๋ฌด๊ฐ€์„ค์„ ์„ค์ •ํ•˜๊ณ  F ๊ฒ€์ •์„ ์‹ค์‹œํ•œ๋‹ค. Eq. (1)์€ F ๊ฒ€์ •์˜ ๊ธฐ๊ฐ์—ญ์„ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค.

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์—ฌ๊ธฐ์„œ, ฮฑ๋Š” ์œ ์˜์ˆ˜์ค€, k๋Š” ์ง‘๋‹จ์˜ ๊ฐฏ์ˆ˜, nT๋Š” ์ด์ž๋ฃŒ์ˆ˜์ด๋ฉฐ, MSB๋Š” ์ง‘๋‹จ๊ฐ„ ํ‰๊ท ์ œ๊ณฑ์ด๊ณ , MSW๋Š” ์ง‘๋‹จ๋‚ด ํ‰๊ท ์ œ๊ณฑ์ด๋‹ค.

3.2 ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•

๊ฐ€๋ญ„์‚ฌ์ƒ์„ ์ •์˜ํ•˜๊ธฐ ์œ„ํ•ด ๋ฏธ๋ฆฌ ๊ฒฐ์ •๋œ ์ž„๊ณ„์ˆ˜์ค€์„ ๊ธฐ์ค€์œผ๋กœ ํ™œ์šฉํ•˜๋Š” ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

์ž„๊ณ„์ˆ˜์ค€์„ ๊ฒฐ์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์€ ๋‹ค์–‘ํ•˜๋ฉฐ, ์ž„๊ณ„์ˆ˜์ค€์— ๋”ฐ๋ผ ๊ฐ€๋ญ„์˜ ํŠน์„ฑ์ด ๋‹ฌ๋ผ์ง€๋ฏ€๋กœ ์ ์ ˆํ•œ ๋ฐฉ๋ฒ•์„ ์„ ํƒํ•ด์•ผ ํ•œ๋‹ค(Yu et al., 2017). ์ž„๊ณ„์ˆ˜์ค€์€ ๊ณผ๊ฑฐ ๊ฐ•์ˆ˜๋Ÿ‰์˜ ๊ฒฝํ—˜์  ๋ˆ„์  ๋ถ„ํฌ ํ•จ์ˆ˜์— ๊ธฐ์ดˆํ•˜์—ฌ ๊ฐ•์ˆ˜๋Ÿ‰์ด๋‚˜ ์œ ํ™ฉ๊ณก์„ ์˜ ๋ฐฑ๋ถ„์œจ์„ ๊ธฐ์ค€์œผ๋กœ ๊ฒฐ์ •๋œ๋‹ค(Carrรฃo et al., 2014). ์ผ๋ฐ˜์ ์œผ๋กœ ์ง€์—ญ์˜ ํŠน์„ฑ์„ ๊ณ ๋ คํ•˜์—ฌ ์œ ํ™ฉ๊ณก์„ ์˜ 70% (Q70)์™€ 95% (Q95) ์‚ฌ์ด์—์„œ ์ž„๊ณ„์ˆ˜์ค€์ด ๊ฒฐ์ •๋œ๋‹ค. ์ž„๊ณ„์ˆ˜์ค€์€ ํฌ๊ฒŒ ๊ณ ์ • ์ž„๊ณ„์ˆ˜์ค€๊ณผ ๋ณ€๋™ ์ž„๊ณ„์ˆ˜์ค€์œผ๋กœ ๊ตฌ๋ถ„๋œ๋‹ค. ๊ณ ์ • ์ž„๊ณ„์ˆ˜์ค€์€ ์ „์ฒด ํ†ต๊ณ„ ๊ธฐ๊ฐ„ ๋™์•ˆ ํ•˜๋‚˜์˜ ์ž„๊ณ„๊ฐ’์„ ๊ฐ€์ง€๋ฉฐ, ๋ณ€๋™ ์ž„๊ณ„์ˆ˜์ค€์€ ๊ธฐ์ค€ ๊ธฐ๊ฐ„(์ผ๋ณ„, ์›”๋ณ„, ๊ณ„์ ˆ๋ณ„)์— ๋”ฐ๋ผ ์„œ๋กœ ๋‹ค๋ฅธ ์ž„๊ณ„๊ฐ’์„ ๊ฐ–๊ณ  ์žˆ๋‹ค. ๋ณ€๋™ ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•์˜ ๊ฒฝ์šฐ, ๊ณ ์ • ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•์— ๋น„ํ•ด ๊ฐ•์šฐ๋Ÿ‰ ๊ณผ๋ถ€์กฑ์— ๋Œ€ํ•œ ์ •ํ™•์„ฑ์„ ์ฆ๊ฐ€์‹œ์ผœ ๊ฐ€๋ญ„๋ถ„์„์— ๋”์šฑ ์ ์ ˆํ•˜๋‹ค(Karimi and Shahedi, 2013). Fig. 1์€ ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•(threshold level method)์„ ์‚ฌ์šฉํ•˜์—ฌ ๊ฐ€๋ญ„์„ ์ •์˜ํ•œ ๊ฒƒ์ด๋‹ค. โ‘ , โ‘ก, โ‘ข์€ ๊ฐ๊ฐ ๊ฐ€๋ญ„์‚ฌ์ƒ์„ ์˜๋ฏธํ•˜๋ฉฐ, ์ง€์†๊ธฐ๊ฐ„(duration)์€ ๊ฐ€๋ญ„์ด ์‹œ์ž‘ํ•  ๋•Œ๋ถ€ํ„ฐ ๋๋‚  ๋•Œ๊นŒ์ง€์˜ ๊ธฐ๊ฐ„์ด๋‹ค. ๋˜ํ•œ ์ง€์†๊ธฐ๊ฐ„๋™์•ˆ์˜ ์ด ๊ฐ•์šฐ ๋ถ€์กฑ๋Ÿ‰์„ ์‹ฌ๋„(severity)๋ผ๊ณ  ํ•˜๋ฉฐ, ๊ฐ€๋ญ„์˜ ์‹œ์ž‘๋ถ€ํ„ฐ ๊ทธ ๋‹ค์Œ ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์‹œ์ž‘๊นŒ์ง€์˜ ๊ธฐ๊ฐ„์„ ๋ฐœ์ƒ๊ฐ„๊ฒฉ(interarrival)์ด๋ผ ํ•œ๋‹ค.

Fig. 1.

Drought Definition Using a Threshold Level Method

Figure_KSCE_38_3_02_F1.jpg

3.3 ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„

๊ฐ€๋ญ„์‚ฌ์ƒ์€ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„์˜ ๋‘ ๊ฐ€์ง€ ํŠน์„ฑ์ธ์ž๋กœ ๋ถ„์„๋  ์ˆ˜ ์žˆ์œผ๋ฉฐ, ๋™์ผํ•œ ์‹ฌ๋„๋ฅผ ๊ฐ€์ง€๋”๋ผ๋„ ์ง€์†๊ธฐ๊ฐ„์ด ๋‹ฌ๋ผ์ง„๋‹ค๋ฉด ๋นˆ๋„ํ•ด์„์˜ ๊ฒฐ๊ณผ๊ฐ€ ์ƒ์ดํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚œ๋‹ค. ๋”ฐ๋ผ์„œ ๊ฐ€๋ญ„์˜ ๋นˆ๋„ํ•ด์„์„ ์ˆ˜ํ–‰ํ•  ๋•Œ ํ•˜๋‚˜์˜ ํŠน์„ฑ๋งŒ์„ ๊ณ ๋ คํ•œ๋‹ค๋ฉด ์ผ๊ด€์„ฑ ์žˆ๋Š” ๊ฒฐ๊ณผ๋ฅผ ์–ป์„ ์ˆ˜ ์—†์œผ๋ฏ€๋กœ(Kim et al., 2006), ๊ฐ€๋ญ„์˜ ์‹ฌ๋„์™€ ์ง€์†๊ธฐ๊ฐ„ ๋ชจ๋‘๋ฅผ ๊ณ ๋ คํ•˜๋Š” ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•ด์•ผ ํ•œ๋‹ค.

์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•˜๊ธฐ ์œ„ํ•ด์„œ ๋จผ์ € ๊ฐ€๋ญ„์˜ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„์— ์ ํ•ฉํ•œ ํ™•๋ฅ ๋ถ„ํฌํ•จ์ˆ˜๋ฅผ ์‚ฐ์ •ํ•ด์•ผ ํ•œ๋‹ค. ์‚ฐ์ •๋œ ๋‘ ๋ณ€๋Ÿ‰์˜ ์ฃผ๋ณ€ํ™•๋ฅ ๋ถ„ํฌ๋ฅผ ๊ฒฐํ•ฉํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ฒฐํ•ฉํ™•๋ฅ ๋ฐ€๋„ํ•จ์ˆ˜๋ฅผ ์ถ”์ •ํ•˜๊ณ , ์ด๋ฅผ ํ†ตํ•˜์—ฌ ์ด๋ณ€๋Ÿ‰ ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•œ๋‹ค. ์ตœ๊ทผ์—๋Š” ๊ฒฐํ•ฉ๋ฐ€๋„ํ•จ์ˆ˜๋ฅผ ์ถ”์ •ํ•˜๊ธฐ ์œ„ํ•ด์„œ ๋‘ ๋ณ€์ˆ˜๊ฐ„์˜ ์˜์กด๊ตฌ์กฐ๋ฅผ ์ž˜ ๋ฐ˜์˜ํ•˜๊ณ  ๊ฐ๊ฐ์˜ ํ™•๋ฅ ๋ถ„ํฌ๊ฐ„์˜ ๊ฒฐํ•ฉ ๋ฐ ๋ถ„๋ฆฌ๊ฐ€ ์šฉ์ดํ•œ ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๊ฐ€ ๋งŽ์ด ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋‹ค(Zhang and Singh, 2006; Wong et al., 2010; Lee and Salas, 2011; Yoo et al., 2016b; Yu et al., 2016). ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๊ฒฐํ•ฉํ™•๋ฅ ๋ถ„ํฌ๋ฅผ ์‚ฐ์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์€ Eq. (2)์™€ ๊ฐ™๋‹ค.

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์—ฌ๊ธฐ์„œ, d๋Š” ์ง€์†๊ธฐ๊ฐ„, s๋Š” ์‹ฌ๋„๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค. FD๋Š” ์ง€์†๊ธฐ๊ฐ„์— ๋Œ€ํ•œ ๋ˆ„์ ๋ถ„ํฌํ•จ์ˆ˜์ด๊ณ  FS๋Š” ์‹ฌ๋„์— ๋Œ€ํ•œ ๋ˆ„์ ๋ถ„ํฌํ•จ์ˆ˜์ด๋ฉฐ, C๋Š” FD์™€ FS๋ฅผ ๊ฒฐํ•ฉํ•˜๋Š” ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜์ด๋‹ค.

์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋Š” ํฌ๊ฒŒ Archemedean, Elliptical, Extreme value, Plackett ๋“ฑ 4๊ฐ€์ง€๋กœ ๊ตฌ๋ถ„๋œ๋‹ค. ์—ฌ๋Ÿฌ๊ฐ€์ง€ ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜ ์ค‘ Arche-medean ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜๋Š” ๋‹ค๋ฅธ ์ฝ”ํ”Œ๋ผ ํ•จ์ˆ˜์— ๋น„ํ•ด ๋งค๊ฐœ๋ณ€์ˆ˜ ์ถ”์ • ๋ฐ ๋ถ„ํฌํ•จ์ˆ˜ ์‚ฐ์ • ๊ณผ์ •์ด ๊ฐ„๋‹จํ•˜๊ณ , ๋‹ค์–‘ํ•œ ํ˜•ํƒœ์˜ ํ•จ์ˆ˜๋ฅผ ํฌํ•จํ•˜๊ณ  ์žˆ์–ด ๋ณ€์ˆ˜๊ฐ„์˜ ์ƒ๊ด€๊ด€๊ณ„๋ฅผ ์ž˜ ๋ฐ˜์˜ํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์—์„œ ๋งŽ์ด ์ ์šฉ๋˜๊ณ  ์žˆ๋‹ค(Nelson, 1999; Zhang and Singh, 2006; Yu et al., 2016). Archemedean ์ฝ”ํ”Œ๋ผ ์ค‘ Clayton, Frank, Gumbel ์ฝ”ํ”Œ๋ผ ์‚ฐ์ •์‹์€ Table 1๊ณผ ๊ฐ™๋‹ค. Table 1์—์„œ u์™€ v๋Š” ๊ฐ๊ฐ์˜ ๋ณ€์ˆ˜๋ฅผ ์˜๋ฏธํ•˜๋ฉฐ, ฮธ๋Š” ๋งค๊ฐœ๋ณ€์ˆ˜๋ฅผ ๋‚˜ํƒ€๋‚ธ๋‹ค.

๋นˆ๋„ํ•ด์„์€ ์–ด๋– ํ•œ ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง„ ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ๋ฐœ์ƒ ํŠน์„ฑ์„ ํ™•๋ฅ ๋ก ์ ์œผ๋กœ ์ถ”์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์œผ๋กœ์จ, ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์˜ ๊ฒฐ๊ณผ๋กœ ์ด๋ณ€๋Ÿ‰ ์žฌํ˜„๊ธฐ๊ฐ„์„ ์–ป์„ ์ˆ˜ ์žˆ๋‹ค. ์ž„์˜์˜ ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์žฌํ˜„๊ธฐ๊ฐ„์€ ํ•ด๋‹น ์‚ฌ์ƒ์˜ ์ดˆ๊ณผํ™•๋ฅ ์— ์—ญ์ˆ˜๋ฅผ ์ทจํ•˜์—ฌ ๊ณ„์‚ฐํ•  ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ ๊ฐ€๋ญ„์˜ ์žฌํ˜„๊ธฐ๊ฐ„์€ ๋‘ ๊ฐ€๋ญ„ ์‚ฌ์ด์˜ ํ‰๊ท  ๋ฐœ์ƒ๊ฐ„๊ฒฉ ๋˜๋Š” ํ‰๊ท ๊ฒฝ๊ณผ์‹œ๊ฐ„์„ ๊ณ ๋ คํ•ด์•ผ ํ•œ๋‹ค(Shiau and Shen, 2001; Kim et al., 2006; Serinaldi et al., 2009; Chen et al., 2013). ์ด๋ณ€๋Ÿ‰ ๊ฐ€๋ญ„๋นˆ๋„ํ•ด์„์˜ ๊ฒฝ์šฐ ์—ฌ๋Ÿฌ ๊ฐ€์ง€ ํ™•๋ฅ ์  ๊ฒฐํ•ฉ์‹œ๋‚˜๋ฆฌ์˜ค๊ฐ€ ๊ฐ€๋Šฅํ•˜๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด ์ˆ˜๋ฌธ์‚ฌ์ƒ์ด ๋‘ ๊ฐ€์ง€ ๋ณ€์ˆ˜(X์™€ Y)๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค๋ฉด, X์™€ Y ์ค‘ ์–ด๋–ค ํ•œ ๋ณ€์ˆ˜๊ฐ€ ์ดˆ๊ณผํ•˜๊ฑฐ๋‚˜ X์™€ Y ๋ชจ๋‘ ์ดˆ๊ณผํ–ˆ์„ ๋•Œ์˜ ์žฌํ˜„๊ธฐ๊ฐ„ ์‚ฐ์ •์ด ๊ฐ€๋Šฅํ•˜๋‹ค. ์ˆ˜์ž์› ์„ค๊ณ„์—์„œ๋Š” ์ดˆ๊ณผํ™•๋ฅ ์— ์˜ํ•ด ์‚ฐ์ •๋œ ์žฌํ˜„๊ธฐ๊ฐ„์ด ์ ์šฉ๋˜๊ธฐ ๋•Œ๋ฌธ์—, ์•ˆ์ •์ ์ธ ์„ค๊ณ„๋ฅผ ์œ„ํ•ด์„œ๋Š” ๋‘ ๋ณ€์ˆ˜ ๋ชจ๋‘ ์ดˆ๊ณผํ–ˆ์„ ๋•Œ์˜ ์žฌํ˜„๊ธฐ๊ฐ„์„ ๋ฐ˜์˜ํ•˜๋Š” ๊ฒƒ์ด ์ ์ ˆํ•˜๋‹ค(Kown and Kim, 2009). ๋”ฐ๋ผ์„œ ๊ฐ€๋ญ„์˜ ์ง€์†๊ธฐ๊ฐ„ ๋ฐ ์‹ฌ๋„๋ฅผ ๋ชจ๋‘ ๊ณ ๋ คํ•˜๋ฉฐ, ๋‘ ๋ณ€์ˆ˜ ๋ชจ๋‘ ์ผ์ • ํฌ๊ธฐ ์ด์ƒ์ผ ๊ฒฝ์šฐ(Dโ‰ฅd and Sโ‰ฅs)์—์„œ์˜ ์ด๋ณ€๋Ÿ‰ ์žฌํ˜„๊ธฐ๊ฐ„์€ Eq. (3)์— ์˜ํ•ด ์‚ฐ์ •ํ•  ์ˆ˜ ์žˆ๋‹ค.

Table 1. Equations of Archimedean Copula Families Table_KSCE_38_3_02_T1.jpg

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   PIC5AE3.gif 

์—ฌ๊ธฐ์„œ, E(L)์€ ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ํ‰๊ท  ๋ฐœ์ƒ๊ฐ„๊ฒฉ์ด๋ฉฐ, TDS๋Š” ๊ฐ€๋ญ„ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„์— ๋Œ€ํ•œ ๊ฒฐํ•ฉ์žฌํ˜„๊ธฐ๊ฐ„์ด๋‹ค.

์‚ฐ์ •๋œ ์ด๋ณ€๋Ÿ‰ ์žฌํ˜„๊ธฐ๊ฐ„์„ ํ†ตํ•ด ๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•  ์ˆ˜ ์žˆ๋‹ค. ์œ„ํ—˜๋„๋Š” ์„ค๊ณ„๋…„๋„ n๋…„ ์ด๋‚ด์— ์žฌํ˜„๊ธฐ๊ฐ„ PIC5AF3.gif๋ฅผ ๊ฐ–๋Š” ํฌ๊ธฐ์˜ ์‚ฌ์ƒ์ด ๋ฐœ์ƒํ•  ํ™•๋ฅ ์„ ์˜๋ฏธํ•˜๋ฉฐ(Yu et al., 2016), Eq. (4)์— ์˜ํ•ด ๊ณ„์‚ฐ๋œ๋‹ค. ๋”ฐ๋ผ์„œ Eq. (4)๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ๊ทน์‹ฌํ•œ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ์œ„ํ—˜๋„ ๋ถ„์„์„ ์‹ค์‹œํ•˜๊ณ , ์ด์— ๋Œ€ํ•œ ๋น„๊ต๋ฅผ ํ†ตํ•˜์—ฌ ๊ณผ๊ฑฐยทํ˜„์žฌ์— ๋น„ํ•ด ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„์˜ ๋ณ€ํ™”๋ฅผ ํŒŒ์•…ํ•  ์ˆ˜ ์žˆ๋‹ค.

PIC5AF4.gif (4)

4. ์ ์šฉ ๋ฐ ๊ฒฐ๊ณผ

4.1 ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ •์˜

๊ฐ€๋ญ„ ๋นˆ๋„ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜๊ธฐ ์ „, ๋ณธ ์—ฐ๊ตฌ์—์„œ ์‚ฌ์šฉํ•˜๋Š” ์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก์ž๋ฃŒ, ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ์˜ 3๊ฐ€์ง€ ๊ฐ•์šฐ๋Ÿ‰ ์ž๋ฃŒ์— ๋Œ€ํ•˜์—ฌ ๋™์งˆ์„ฑ ๊ฒ€์‚ฌ๋ฅผ ์‹ค์‹œํ•˜์˜€๋‹ค. ๊ณ„์‚ฐ๋œ F-ํ†ต๊ณ„๋Ÿ‰ ๊ฐ’์€ PIC5B05.gif์ด๋ฉฐ ์œ ์˜์ˆ˜์ค€ 0.05%๋‚ด์—์„œ โ€˜๊ฐ ์ž๋ฃŒ๋“ค์€ ๋™์ผํ•œ ๋ชจ์ง‘๋‹จ์„ ๊ฐ€์ง„๋‹คโ€˜๋Š” ๊ท€๋ฌด๊ฐ€์„ค์„ ๊ธฐ๊ฐํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ 3๊ฐ€์ง€์˜ ๊ฐ•์ˆ˜๋Ÿ‰ ์ž๋ฃŒ๋Š” ๋™์งˆ์„ฑ์„ ๊ฐ€์ง€์ง€ ๋ชปํ•˜๋ฏ€๋กœ ๊ฐœ๋ณ„์ ์œผ๋กœ ๋ถ„๋ฆฌํ•˜์—ฌ ๋ถ„์„์„ ์‹œํ–‰ํ•˜์˜€๋‹ค.

์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก์ž๋ฃŒ ๋ฐ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ์˜ ๊ฐ€๋ญ„์‚ฌ์ƒ์„ ์ถ”์ถœํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ๊ฐ•์šฐ๋Ÿ‰ ์ž๋ฃŒ๋ฅผ 3๊ฐœ์›”์”ฉ ๋ˆ„์ ์‹œํ‚จ ํ›„, ์‹œ๊ฐ„์  ์ˆœ์„œ์™€ ์ƒ๊ด€์—†์ด ํฌ๊ธฐ์ˆœ์œผ๋กœ ๋‚˜์—ดํ•ด์„œ ์–ป์€ ๊ฒฝํ—˜์  ๋ˆ„์ ๋ถ„ํฌํ•จ์ˆ˜๋ฅผ ๊ฐ ๊ฐ•์šฐ๋Ÿ‰ ์ž๋ฃŒ์— ์ ์šฉํ•˜์˜€๋‹ค. ๊ทธ ๊ฒฐ๊ณผ, ์ผ๋ฐ˜์ ์œผ๋กœ ๋งŽ์ด ์‚ฌ์šฉํ•˜๋Š” 70~95% ์ž„๊ณ„์ˆ˜์ค€ ์ค‘ ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ˆ˜๊ฐ€ SPI๋กœ ์‚ฐ์ •ํ•œ ๊ฒฐ๊ณผ์™€ ๊ฐ€์žฅ ๊ฐ€๊นŒ์šด 70%์— ํ•ด๋‹นํ•˜๋Š” ๊ฐ•์šฐ๋Ÿ‰์„ ์ž„๊ณ„์ˆ˜์ค€์œผ๋กœ ์„ค์ •ํ•˜์˜€๋‹ค. ์„ค์ •๋œ ์ž„๊ณ„์ˆ˜์ค€์„ ๋ฐ”ํƒ•์œผ๋กœ ๊ฐ€๋ญ„์‚ฌ์ƒ์„ ์ถ”์ถœํ–ˆ์œผ๋ฉฐ, ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ง€์†๊ธฐ๊ฐ„(duration)๊ณผ ์‹ฌ๋„(severity)์˜ ๋ถ„ํฌํŠน์„ฑ์„ Fig. 2์— ์ƒ์ž๊ทธ๋ฆผ(boxplot) ํ˜•ํƒœ ๋ฐ Table 2์— ํ‘œ๋กœ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก์ž๋ฃŒ ๋ฐ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ์—์„œ ๊ฐ€๋ญ„์‚ฌ์ƒ์€ ๊ฐ๊ฐ 198๊ฐœ, 145๊ฐœ ๋ฐ 127๊ฐœ์ด๋‹ค. ํ‰๊ท  ๊ฐ€๋ญ„ ์ง€์†๊ธฐ๊ฐ„์€ ํ˜„์žฌ์—์„œ 2.36๊ฐœ์›”๋กœ ๊ฐ€์žฅ ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๊ณ , ํ‰๊ท  ๊ฐ€๋ญ„ ์‹ฌ๋„๋Š” ๋ฏธ๋ž˜์—์„œ 182.9mm๋กœ ๊ฐ€์žฅ ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋Œ€์ฒด์ ์œผ๋กœ ๋ฏธ๋ž˜์—๋Š” ์ง€์†๊ธฐ๊ฐ„์€ ์งง์ง€๋งŒ ์‹ฌ๋„๊ฐ€ ๋†’์€ ๊ฐ€๋ญ„๋“ค์ด ๋งŽ์ด ๋ฐœ์ƒํ•˜๊ณ  ์žˆ๋‹ค. ์ด๋Š” ๊ฒฐ๊ตญ ๊ธฐ์กด ์—ฐ๊ตฌ๋“ค๊ณผ ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ ๋ฏธ๋ž˜์—๋Š” ๋‹จ๊ธฐ๊ฐ„์— ๊ฐ•ํ•œ ๊ฐ€๋ญ„๋“ค์ด ๋ฐœ์ƒํ•œ๋‹ค๋Š” ๊ฒƒ์„ ์˜๋ฏธํ•œ๋‹ค.

Fig. 2.

Distribution of Drought Characteristics

Figure_KSCE_38_3_02_F2.jpg
Table 2. Changes of Drought Characteristics According to Past, Table_KSCE_38_3_02_T2.jpg

4.2 ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„

4.1์ ˆ์—์„œ ์‚ฐ์ •๋œ ๊ฐ€๋ญ„ ์ง€์†๊ธฐ๊ฐ„ ๋ฐ ์‹ฌ๋„์˜ ์ตœ์ ๋ถ„ํฌํ•จ์ˆ˜๋ฅผ ๊ฒฐ์ •ํ•˜๊ธฐ ์œ„ํ•ด์„œ ๋‹ค์–‘ํ•œ ํ™•๋ฅ ๋ถ„ํฌ(exponential, normal, gamma, lognormal, Poisson, weibull, generalized extreme value, generalized pareto)์— ๋Œ€ํ•ด ์ตœ์šฐ๋„๋ฒ•์œผ๋กœ ๋งค๊ฐœ๋ณ€์ˆ˜๋ฅผ ์ถ”์ •ํ•˜๊ณ  PIC5B06.gif ๊ฒ€์ •์„ ์ด์šฉํ•˜์—ฌ ์ ํ•ฉ๋„ ๊ฒ€์ •์„ ์‹ค์‹œํ•˜์˜€๋‹ค. ๊ทธ ๊ฒฐ๊ณผ ์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก์ž๋ฃŒ ๋ฐ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ ๋ชจ๋‘ ์ง€์†๊ธฐ๊ฐ„์€ ์ง€์ˆ˜๋ถ„ํฌ๊ฐ€ ์ฑ„ํƒ๋˜์—ˆ์œผ๋ฉฐ, ์‹ฌ๋„๋Š” ๋Œ€์ˆ˜์ •๊ทœ๋ถ„ํฌ๊ฐ€ ์ฑ„ํƒ๋˜์—ˆ๋‹ค. ๋˜ํ•œ ์ง€์†๊ธฐ๊ฐ„๊ณผ ์‹ฌ๋„์˜ ์ฃผ๋ณ€ํ™•๋ฅ ๋ถ„ํฌ๋ฅผ ๊ฒฐํ•ฉํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์•„๋ฅดํ‚ค๋ฉ”๋””์•ˆ ์ฝ”ํ”Œ๋ผ(Clayton, Frank, Gumbel) ํ•จ์ˆ˜๋ฅผ ์ ์šฉํ•˜์˜€๋‹ค. ๊ฒฐํ•ฉ๋œ ํ™•๋ฅ ๋ถ„ํฌํ•จ์ˆ˜์— ๋Œ€ํ•˜์—ฌ ์ตœ์šฐ๋„๋ฒ•์„ ํ™œ์šฉํ•˜์—ฌ ์ ํ•ฉ๋„ ๊ฒ€์ • ๋ฐ ๋งค๊ฐœ๋ณ€์ˆ˜๋ฅผ ์ถ”์ •ํ•œ ๊ฒฐ๊ณผ ์„ธ ์ž๋ฃŒ ๋ชจ๋‘ Frank ์ฝ”ํ”Œ๋ผ๊ฐ€ ์ตœ์  ๊ฒฐํ•ฉํ™•๋ฅ ๋ฐ€๋„ํ•จ์ˆ˜๋กœ ์„ ์ •๋˜์—ˆ๋‹ค. ์„ ์ •๋œ Frank ์ฝ”ํ”Œ๋ผ ๊ฒฐํ•ฉํ™•๋ฅ ๋ฐ€๋„ํ•จ์ˆ˜๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ–ˆ์œผ๋ฉฐ, ๊ทธ ๊ฒฐ๊ณผ๋ฅผ Fig. 3์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. Fig. 3์˜ ๊ทธ๋ฆผ์—์„œ ๋‹ค์ด์•„๋ชฌ๋“œ๋กœ ํ‘œ์‹œ๋œ ๊ฐ ๊ธฐ๊ฐ„์˜ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ(maximum drought event)์€ ์œ„ํ—˜๋„ ๋ถ„์„์—์„œ ๊ธฐ์ค€์ด ๋˜๋Š” ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„์œผ๋กœ ์‚ฌ์šฉ๋˜์—ˆ๋‹ค.

Fig. 3.

Severity-Duration-Frequency Curves

Figure_KSCE_38_3_02_F3.jpg

4.3 ์œ„ํ—˜๋„ ๋ถ„์„

์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์˜ ๊ฒฐ๊ณผ๋ฅผ ๋ฐ”ํƒ•์œผ๋กœ ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ์ตœ๋Œ€ ๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์œ„ํ—˜๋„ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ–ˆ์œผ๋ฉฐ, ๊ทธ ๊ฒฐ๊ณผ๋Š” Table 3๊ณผ ๊ฐ™๋‹ค. ๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์ตœ๋Œ€ ์ง€์†๊ธฐ๊ฐ„์€ 11๊ฐœ์›”์œผ๋กœ์จ, 1904๋…„ 6์›”์—์„œ 1905๋…„ 4์›” ๊ทธ๋ฆฌ๊ณ  1942๋…„ 12์›”์—์„œ 1943๋…„ 10์›”์— ๋ฐœ์ƒํ•˜์˜€๋‹ค. ์‹ค์ œ๋กœ 2015๋…„ ๊ฐ€๋ญ„๊ธฐ๋ก์กฐ์‚ฌ ๋ณด๊ณ ์„œ์— ์˜ํ•˜๋ฉด 1942๋…„๋ถ€ํ„ฐ 3๋…„ ๋™์•ˆ ๊ฐ€๋ญ„์ด ๋ฐœ์ƒํ•˜๋ฉด์„œ ๋ฐœ์ „์šฉ์ˆ˜๊ฐ€ ๊ณ ๊ฐˆ๋˜๊ณ  ํ‰์ž‘์œผ๋กœ ์ธํ•œ ๊ธฐ๊ทผ์ด ๋ฐœ์ƒํ•˜๋Š” ๋“ฑ ํ”ผํ•ด๊ฐ€ ์‹ฌ๊ฐํ–ˆ์Œ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค(MLIT, 2016). ํ•˜์ง€๋งŒ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค์— ์˜ํ•œ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์€ 2065๋…„ 7์›”๊ณผ 2065๋…„ 12์›” ๋™์•ˆ ๋ฐœ์ƒํ•˜๋ฉฐ, ์ด๋•Œ์˜ ๊ฐ€๋ญ„์‹ฌ๋„๋Š” 1432.08mm์ด๋‹ค. ์ด ๊ธฐ๊ฐ„์— ๋ฐœ์ƒํ•œ ๊ฐ€๋ญ„์˜ ์œ„ํ—˜๋„๋„ ๋‹ค๋ฅธ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋น„ํ•ด ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ํŠนํžˆ, ์ด๋•Œ์˜ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•œ ์„ค๊ณ„์—ฐํ•œ 50, 70, 100๋…„๋„์—์„œ ์œ„ํ—˜๋„๋Š” ๊ฐ๊ฐ ์ฆ๊ฐ€ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ์„ค๊ณ„์—ฐํ•œ  50๋…„์ผ ๋•Œ์˜ ์œ„ํ—˜๋„๋Š” 0.8938, ์„ค๊ณ„์—ฐํ•œ 100๋…„์ผ ๋•Œ์˜ ์œ„ํ—˜๋„๋Š” 0.9887๋กœ์„œ ๋งค์šฐ ์‹ฌ๊ฐํ•œ ์œ„ํ—˜๋„๋ฅผ ๋‚˜ํƒ€๋‚ด๊ณ  ์žˆ๋‹ค. ์ด๋Š” ๊ณผ๊ฑฐ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ๊ณผ ํ˜„์žฌ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์˜ ์œ„ํ—˜๋„๋ณด๋‹ค ๊ฐ๊ฐ ์„ค๊ณ„์—ฐํ•œ 50๋…„์˜ ๊ฒฝ์šฐ 1.94๋ฐฐ, 1.81๋ฐฐ ๋†’์œผ๋ฉฐ, ์„ค๊ณ„์—ฐํ•œ 100๋…„์˜ ๊ฒฝ์šฐ ๊ฐ๊ฐ 1.39๋ฐฐ, 1.33๋ฐฐ ๋†’์€ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค.

๋˜ํ•œ, ๋ฏธ๋ž˜ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„์˜ ๋ณ€ํ™”๋ฅผ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๊ณผ๊ฑฐ์™€ ํ˜„์žฌ์˜ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์„ ๊ตฌํ•˜๊ณ  ์ด๋ฅผ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์œผ๋กœ ์ •์˜ํ–ˆ์œผ๋ฉฐ, ๊ณผ๊ฑฐ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„๊ณผ ํ˜„์žฌ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„์„ ๊ธฐ์ค€์œผ๋กœ ๋ฏธ๋ž˜์—์„œ ๊ฐ๊ฐ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ๋ณด๋‹ค ์ง€์†๊ธฐ๊ฐ„, ์‹ฌ๋„ ๋ฐ ์žฌํ˜„๊ธฐ๊ฐ„์ด ํฐ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ์œ„ํ—˜๋„๋ฅผ ์‚ฐ์ •ํ•˜์—ฌ ๋น„๊ตยท๋ถ„์„ํ•˜์˜€๋‹ค. Table 4์— ์ œ์‹œํ•œ ๋ฐ”์™€ ๊ฐ™์ด, 2065๋…„ 7์›”๋ถ€ํ„ฐ 2065๋…„ 12์›”์— ๋ฐœ์ƒํ•œ ๊ฐ€๋ญ„์€ ์‹ฌ๋„๊ฐ€ ๊ฐ€์žฅ ํฐ ๊ฐ€๋ญ„์œผ๋กœ์จ ์œ ์ผํ•˜๊ฒŒ ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„๋ณด๋‹ค ๋ชจ๋‘ ํฐ ๊ฐ€๋ญ„์ด๋ฉฐ ๋ฏธ๋ž˜ ์ตœ๋Œ€ ๊ฐ€๋ญ„์‚ฌ์ƒ์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ฏธ๋ž˜์—์„œ ํ˜„์žฌ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„ ์ด์ƒ์˜ ๊ฐ€๋ญ„์ด ๋ฐœ์ƒํ•œ ์‚ฌ์ƒ์€ ํ•˜๋‚˜์ด์ง€๋งŒ ๊ณผ๊ฑฐ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„ ์ด์ƒ์˜ ๊ฐ€๋ญ„์ด ๋ฐœ์ƒํ•œ ์‚ฌ์ƒ์€ 10๊ฐœ์ด๋ฉฐ, ๊ณผ๊ฑฐ๋ณด๋‹ค ๊ทนํ•œ ๊ฐ€๋ญ„์˜ ๋ฐœ์ƒ๋นˆ๋„๊ฐ€ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚˜๊ณ  ์žˆ๋‹ค. ์ด์— ๋Œ€ํ•œ ์œ„ํ—˜๋„๋„ 0.9887๋ถ€ํ„ฐ ์ตœ๋Œ€ 1.0๊นŒ์ง€ ๋งค์šฐ ํฐ ๊ฐ’์„ ๊ฐ–๋Š” ๊ฒƒ์œผ๋กœ ์‚ฐ์ •๋˜์—ˆ๋‹ค.

Table 3. Results of Risk Analysis for the Maximum Drought Table_KSCE_38_3_02_T3.jpg
Table 4. Risk Analysis of Future Droughts More Severe than the Past and Present Maximum Drought Table_KSCE_38_3_02_T4.jpg

5. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ธก์šฐ๊ธฐ ์ž๋ฃŒ, ๊ด€์ธก์ž๋ฃŒ ๋ฐ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™” ์‹œ๋‚˜๋ฆฌ์˜ค ์ž๋ฃŒ๋ฅผ ํ™œ์šฉํ•˜์—ฌ ์„œ์šธ์ง€์ ์˜ ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์— ๋Œ€ํ•œ ์ด๋ณ€๋Ÿ‰ ๋นˆ๋„ํ•ด์„์„ ์‹ค์‹œํ•˜์˜€๋‹ค. ์ž„๊ณ„์ˆ˜์ค€๋ฐฉ๋ฒ•์„ ์‚ฌ์šฉํ•˜์—ฌ ๊ฐ€๋ญ„์‚ฌ์ƒ์„ ์ถ”์ถœํ•œ ๊ฒฐ๊ณผ, ํ‰๊ท ์ ์œผ๋กœ ์ง€์†๊ธฐ๊ฐ„์€ ํ˜„์žฌ์—์„œ, ์‹ฌ๋„๋Š” ๋ฏธ๋ž˜์—์„œ ๊ฐ€์žฅ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ฆ‰, ๋ฏธ๋ž˜์—๋Š” ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ์— ๋น„ํ•ด ๋‹จ๊ธฐ๊ฐ„์˜ ๊ทน์‹ฌํ•œ ๊ฐ€๋ญ„์ด ๋ฐœ์ƒํ•  ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

๋ฏธ๋ž˜์˜ ๊ทนํ•œ ๊ฐ€๋ญ„ ์œ„ํ—˜๋„๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•ด ๊ณผ๊ฑฐยทํ˜„์žฌยท๋ฏธ๋ž˜์˜ ์ตœ๋Œ€๊ฐ€๋ญ„์‚ฌ์ƒ์— ๋Œ€ํ•ด ๋จผ์ € ๋ถ„์„ํ•œ ๊ฒฐ๊ณผ, ์ง€์†๊ธฐ๊ฐ„์€ ๊ณผ๊ฑฐ์™€ ํ˜„์žฌ๋ณด๋‹ค ๋‚ฎ์ง€๋งŒ ์‹ฌ๋„๋Š” ๋”์šฑ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋˜ํ•œ, ์œ„ํ—˜๋„์˜ ๊ฒฝ์šฐ ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ์— ๋น„ํ•ด ํฌ๊ฒŒ ์‚ฐ์ •๋œ ๊ฒƒ์„ ํ†ตํ•ด ํ–ฅํ›„ ๋ฏธ๋ž˜์— ๊ทนํ•œ ๊ฐ€๋ญ„ ๋ฐœ์ƒํ™•๋ฅ ์ด ๋†’์€ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„์„ ๊ธฐ์ค€์œผ๋กœ ๋ฏธ๋ž˜์˜ ๊ฐ€๋ญ„์— ๋Œ€ํ•˜์—ฌ ๋ถ„์„ํ•œ ๊ฒฐ๊ณผ ๊ณผ๊ฑฐ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„ ์ด์ƒ์˜ ๊ฐ€๋ญ„์‚ฌ์ƒ์€ 10๊ฐœ, ํ˜„์žฌ ๊ธฐ์™•์ตœ๋Œ€๊ฐ€๋ญ„ ์ด์ƒ์˜ ๊ฐ€๋ญ„์‚ฌ์ƒ์€ 1๊ฐœ๋กœ ์‚ฐ์ •๋˜์—ˆ๋‹ค. ๊ฒŒ๋‹ค๊ฐ€ ์ด๋ ‡๊ฒŒ ์‚ฐ์ •๋œ ๊ฐ€๋ญ„์˜ ์œ„ํ—˜๋„๋Š” ๋ชจ๋‘ 0.9 ์ด์ƒ์˜ ๊ฐ’์„ ๊ฐ€์ง€๋ฏ€๋กœ ๊ทนํ•œ ๊ฐ€๋ญ„์˜ ๋ฐœ์ƒํ™•๋ฅ ์ด ๋งค์šฐ ํฐ ๊ฒƒ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ์ฆ‰, ๊ณผ๊ฑฐ ๋ฐ ํ˜„์žฌ์— ๋น„ํ•ด ๋ฏธ๋ž˜์— ๊ทนํ•œ ๊ฐ€๋ญ„์˜ ๋ฐœ์ƒ ๋นˆ๋„๊ฐ€ ๋†’์€ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค.

๋”ฐ๋ผ์„œ ํ˜„์žฌ์˜ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ์ˆ˜์ž์› ์‹œ์Šคํ…œ์˜ ์„ค๊ณ„ ๊ธฐ์ค€์€ ๋ฏธ๋ž˜ ๊ธฐํ›„๋ณ€ํ™”๋ฅผ ๊ณ ๋ คํ•˜์—ฌ ๊ฐ€๋ญ„์— ๋Œ€ํ•œ ๋Œ€์ฑ… ๋ฐ ์ •์ฑ…์„ ์ˆ˜๋ฆฝํ•  ์ˆ˜ ์žˆ๋„๋ก ๋ณ€๊ฒฝํ•ด์•ผ ํ•œ๋‹ค. ๋ณธ ์—ฐ๊ตฌ์˜ ๊ฒฐ๊ณผ๋Š” ์ˆ˜์ž์› ์‹œ์Šคํ…œ์— ๋Œ€ํ•œ ์ •๋Ÿ‰์ ์ธ ์„ค๊ณ„ ๊ธฐ์ค€์„ ๋งˆ๋ จํ•˜๊ธฐ ์œ„ํ•œ ์ž๋ฃŒ๋กœ ํ™œ์šฉ๋  ์ˆ˜ ์žˆ์„ ๊ฒƒ์ด๋‹ค.

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