Drought evaluation using unstructured data: a case study for Boryeong area

Jinhong Jung; Dong-Hyeok Park; Jaehyun Ahn

doi:10.3741/JKWRA.2020.53.12.1203

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2020 Vol.53, Issue 12 Preview Page Next Page

Research Article

Drought evaluation using unstructured data: a case study for Boryeong area 비정형 데이터를 활용한 가뭄평가 - 보령지역을 중심으로 -

31 December 2020. pp. 1203-1210

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Abstract

Drought is caused by a combination of various hydrological or meteorological factor, so it is difficult to accurately assess drought event, but various drought indices have been developed to interpret them quantitatively. However, the drought indexes currently being used are calculated from the lack of a single variable, which is a problem that does not accurately determine the drought event caused by complex causes. Shortage of a single variable may not be a drought, but it is judged to be a drought. On the other hand, research on developing indices using unstructured data, which is widely used in big data analysis, is being carried out in other fields and proven to be superior. Therefore, in this study, we intend to calculate the drought index by combining unstructured data (news data) with weather and hydrologic information (rainfall and dam inflow) that are being used for the existing drought index, and to evaluate the utilization of drought interpretation through verification of the calculated drought index. The Clayton Copula function was used to calculate the joint drought index, and the parameter estimation was used by the calibration method. The analysis showed that the drought index, which combines unstructured data, properly expresses the drought period compared to the existing drought index (SPI, SDI). In addition, ROC scores were calculated higher than existing drought indices, making them more useful in drought interpretation. The joint drought index calculated in this study is considered highly useful in that it complements the analytical limits of the existing single variable drought index and provides excellent utilization of the drought index using unstructured data.

Keywords

Drought

Drought index

Big data

Unstructured data

가뭄은 다양한 수문학적 또는 기상학적 인자들이 복합적으로 작용하여 발생하기 때문에 가뭄의 사상을 정확히 평가하는 것은 어려운 일이나, 이를 정량적으로 해석하기 위해 다양한 가뭄지수들이 개발되어 왔다. 하지만 현재 활용중인 가뭄지수들은 단일변량의 부족량을 통해 산정되며, 복합적인 원인으로 발생하는 가뭄의 사상을 정확히 판단하지 못하는 문제가 있다. 단순 단일변량의 부족을 가뭄이라고 판단하기는 어렵기 때문이다. 최근에는 빅데이터 분석에서 많이 활용되고 있는 비정형 데이터를 활용하여 지수를 개발하는 연구들이 타 분야에서 진행되고 있으며 우수성이 입증되고 있다. 따라서 본 연구에서는 기존 가뭄지수에 활용 중인 기상 및 수문정보(강수량, 댐 유입량)에 각각 비정형 데이터(뉴스데이터)를 결합하여 가뭄지수를 산정하고, 산정된 가뭄지수의 검증을 통해 가뭄해석의 활용성을 평가하고자 한다. 결합가뭄지수 산정을 위해 Clayton Copula 함수를 활용하였으며, 매개변수 추정은 교정방법을 이용하였다. 분석결과, 기존의 가뭄지수(SPI, SDI)보다 비정형 데이터를 결합한 가뭄지수가 가뭄기간을 적절히 재현하는 것으로 나타났다. 또한 Receiver Operating Characteristic (ROC) score가 기존의 가뭄지수들보다 높게 산정되어 가뭄해석에 있어 활용성이 우수하였다. 본 연구에서 산정된 결합가뭄지수는 기존 단일변량 가뭄지수의 해석적 한계를 보완하고 비정형데이터를 활용한 가뭄지수의 활용성이 우수하다는 점에서 활용성이 높다고 판단된다.

키워드

가뭄

가뭄지수

빅데이터

비정형 데이터

References

Choe, J.Y., and Go, Y,S. (2006). "Development of soil moisture index." Water of Future, Vol. 39, No. 3, pp. 24-28.

Keyantash, J., and Dracup, J.A. (2002). "The quantification of drought: An evaluation of drought indices." American Meteorological Society, Vol. 83, No. 8, pp. 1167-1180. 10.1175/1520-0477-83.8.1167

Kim, S.D., Ryu, J.S., Oh, K.R., and Jeong, S.M. (2012). "An application of copulas-based joint drought index for determining comprehensive drought conditions." Journal of Korean Society of Hazard Mitigation, KOSHAM, Vol. 12, No. 1, pp. 223-230. 10.9798/KOSHAM.2012.12.1.223

Kwak, J.W., Lee, S.D., Kim, Y.S., and Kim, H.S. (2013). "Return period estimation of droughts using drought variables from standardized precipitation index." Journal of Korea Water Resources Association, KWRA, Vol. 46, No. 8, pp. 795-805. 10.3741/JKWRA.2013.46.8.795

Kwon, H.J., Park, H.J., Hong, D.O., and Kim, S.J. (2006). "A study on semi-distributed hydrologic drought assessment modifying SWSI." Journal of Korea Water Resources Association, KWRA, Vol. 39, No. 8, pp. 645-658. 10.3741/JKWRA.2006.39.8.645

Lee, B.R., Bae, B.G., and Choi, S.H. (2015). "Drought analysis using comparison of standardized precipitation index and social bigdata." Journal of Computing Science and Engineering, Vol. 6, No. 6, pp. 16-18.

Mckee, T.B., Doesken, N.J., and Kleist, J. (1993). "The relationship of drought frequency and duration to times cales." 8th Conference on Applied Climatology. Anaheim, CA, U.S.

National Drought Mitigation Center (NDMC) (2002). Three years and counting: What's new with the drought monitor, drought mitigation center faculty publication 4. NE, U.S.

Palmer, W.C. (1965). Meteorological drought, research paper. No. 45, U.S. Weather Bureau, Silver Spring, MD, U.S.

Park, S.H., Kwon, J.H., and Kim, T.I. (2018). "Developing the maritime news index using news bigdata analysis." Marin Poilcy Reserch, Vol. 33, No. 1, pp.281-301. 10.35372/kmiopr.2018.33.1.011

Shiau, J.T., Feng, S., and Nadarajah, S. (2007). "Assessment of hydrological droughts for the Yellow river, China, using copulas." Hydrological Processes, Vol. 21, No. 16, pp. 2157-2163. 10.1002/hyp.6400

Sklar, K. (1959). "Fontions de reprartition an dimensionset leurs marges." Publications de l'Institut Statistique de l'Université de Paris 8, pp. 229-231.

So, J.M., Sohn, K.H., and Bae, D.H. (2014). "Estimation and assessment of bivariate joint drought index based on copula functions." Journal of Korea Water Resources Association, KWRA, Vol. 47, No. 2, pp. 171-182. 10.3741/JKWRA.2014.47.2.171

Yoo, C.S., and Ryoo, S.R. (2003). "Analysis of drought return and duration characteristics at seoul." Journal of Korea Water Resources Association, KWRA, Vol. 36, No. 4, pp. 561-573. 10.3741/JKWRA.2003.36.4.561

Yoo, J.Y., Shin, J.Y., Kim, D.H., and Kim, T.W. (2013). "Drought risk analysis using stochastic rainfall generation model and copula functions." Journal of Korean Water Resources Association, KWRA, Vol. 46, No. 4, pp. 425-437. 10.3741/JKWRA.2013.46.4.425

Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 53
No :12
Pages :1203-1210
Received Date : 2020-11-10
Revised Date : 2020-11-20
Accepted Date : 2020-11-20
DOI :https://doi.org/10.3741/JKWRA.2020.53.12.1203

Journal of Korea Water Resources Association ISSN:2799-8746(Print) 2799-8754(Online) 한국수자원학회 논문집

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