A development of multivariate drought index using the simulated soil moisture from a GM-NHMM model

Jong-Hyeon Park; Joo-Heon Lee; Tae-Woong Kim; Hyun Han Kwon

doi:10.3741/JKWRA.2019.52.8.545

All Issue

2019 Vol.52, Issue 8 Preview Page Next Page

Research Article

A development of multivariate drought index using the simulated soil moisture from a GM-NHMM model GM-NHMM 기반 토양함수 모의결과를 이용한 합성가뭄지수 개발

31 August 2019. pp. 545-554

PDF XML

Abstract

The most drought assessments are based on a drought index, which depends on univariate variables such as precipitation and soil moisture. However, there is a limitation in representing the drought conditions with single variables due to their complexity. It has been acknowledged that a multivariate drought index can more effectively describe the complex drought state. In this context, this study propose a Copula-based drought index that can jointly consider precipitation and soil moisture. Unlike precipitation data, long-term soil moisture data is not readily available so that this study utilized a Gaussian Mixture Non-Homogeneous Hidden Markov chain Model (GM-NHMM) model to simulate the soil moisture using the observed precipitation and temperature ranging from 1973 to 2014. The GM-NHMM model showed a better performance in terms of reproducing key statistics of soil moisture, compared to a multiple regression model. Finally, a bivariate frequency analysis was performed for the drought duration and severity, and it was confirmed that the recent droughts over Jeollabuk-do in 2015 have a 20-year return period.

Keywords

Soil Moisture

Copula

Drought Index

NHMM

가뭄평가 시 단일 수문인자를 활용하여 가뭄지수를 산정하고 가뭄의 출현, 심도 및 지속기간 등을 평가하는 것이 일반적이다. 하지만 가뭄은 여러 요인이 복합적인 연관성을 가지며 나타나는 현상이므로 단일인자로 가뭄을 평가하는 경우 불확실성 및 한계가 존재한다. 이에 따라 다양한 수문기상 특성을 고려할 수 있는 가뭄지수의 개발이 지속적으로 요구되고 있다. 본 연구에서는 강우량 및 토양수분을 이용하여 가뭄을 평가하고자 은닉 마코프 모형(Hidden Markov chain Model)기반의 토양수분 모의기법을 통해 과거(1973-2014년) 토양의 수분함량을 모의하였으며, Copula 함수를 활용하여 강우량과 토양수분을 동시에 고려한 합성가뭄지수를 산정하였다. 본 연구에서 제안된 토양수분산정 모델은 다중 회귀 모형의 모의결과와 비교를 통해 모델의 적합성을 검증하였으며, 가뭄의 지속기간과 심도를 고려하여 이변량 빈도해석을 수행하였다. 이변량 빈도해석결과 2015년 전라북도 지역에 발생하였던 가뭄은 약 20년의 재현기간을 갖는 것으로 분석되었다.

키워드

토양수분

코플라 함수

가뭄지수

비동질성 은닉 마코프 모형

References

Baun, L. E., Petrie, T., Soules, G., and Weiss, N. (1970). "A maximization technique occurring in the statistical analysis of probabilistic functions of markov chain." The Annals of Mathematical Statistics, Vol. 41, pp. 164-174.

10.1214/aoms/1177697196

Cioffi, F., Conticello, F., Lall, U., Marotta, L., and Telesca, V. (2017). "Large scale climate and rainfall seasonality in a mediterranean area: insights from a non‐homogeneous markov model applied to the agro‐pontino plain." Hydrological Processes, Vol. 31, No. 3, pp. 668-686.

10.1002/hyp.11061

Farahmand, A., and AghaKouchak, A. (2015). "A generalized framework for deriving nonparametric standardized drought drought indicators." Advances in Water Resource, Vol. 76, pp. 140-145.

10.1016/j.advwatres.2014.11.012

Hao, Z., and AghaKouchak, A. (2013). "Multivariate standardized drought index: a parametric multi-index model." Advances in Water Resource, Vol. 57, pp. 12-18.

10.1016/j.advwatres.2013.03.009

Jang, N.-J., Jo, H.-J., and Lee, E.-J. (2016). "A study on the reuse of water reuse in Jeollabuk-do in response to climate change." Jeonbuk Institute, Vol. 16, No. 24.

Khalil, A. F., Kwon, H.-H., Lall, U., and Kaheil, Y. H. (2010). "Predictive downscaling based on non-homogeneous hidden markov models." Hydrological Sciences Journal, Vol. 55, No. 3, pp. 333-350.

10.1080/02626661003780342

Kim, G.-G., and Lee, J.-W. (2011). "Evalutation of drought indices using the drought records." Journal of Korea Water Resources Association, Vol. 44, No. 8, pp. 639-652.

10.3741/JKWRA.2011.44.8.639

Kim, T.-W., Valdés, J. B., and Yoo, C. S. (2006). "nonparametric approach for bivariate drought characterization using palmer drought index." Journal of Hydrologic Engineering, Vol. 11, No. 2, pp. 134-143.

10.1061/(ASCE)1084-0699(2006)11:2(134)

Kwak, J. W., Kim, Y. S., Lee, J. S., and Kim, H. S. (2012). "Analysis of drought characteristics using copula theory." Journal of the Korean Civil Engineering, Vol. 32, No. 3B, pp.161-168.

10.1061/9780784412312.175

Kwon, H.-H., and Lall, U. (2016). "A copula-based nonstationary frequency analysis for the 2012~2015 drought in California." Water Resources Research, Vol. 52, No. 7, pp. 5662-5675.

10.1002/2016WR018959

McKee, T. B. (1995). "Drought monitoring with multiple time scales." In Proceedings of 9th Conference on Applied Climatology, Boston.

McKee, T. B., Nolan J. D., and John, K. (1993). "The relationship of drought frequency and duration to time scales." Proceedings of the 8th Conference on Applied Climatology. Vol. 17. No. 22. Boston, MA: American Meteorological Society.

Mehrotra, R., and Sharma, A. (2005). "A nonparametric nonhomogeneous hidden Markov model for downscaling of multisite daily rainfall occurrences." Journal of Geophysical Research: Atmospheres, Vol. 110, No. D16.

10.1029/2004JD005677

Park, S. Y, Park, S. M, Im, J. H, Rhee, J. Y, Shin J. H., and Park, D. J. (2017). "Downscaling GLDAS soil moisture data in east asia through fusion of multi-sensors by optimizing modified regression trees." Water, Vol. 9, No. 5, pp. 332, doi:10.3390/w9050332.

10.3390/w9050332

Srivastava, P. K., Han, D., Ramirez, M. R., and Islam, T. (2013). "Machine learning techniques for downscaling SMOS satellite soil moisture using MODIS Land surface temperature for hydrological application." Water Resources Management, Vol. 27, No. 8, pp. 3127-3144.

10.1007/s11269-013-0337-9

Xing, C., Chen, N., Zhang, X., and Gong, J. (2017). "A machine learning based reconstruction method for satellite remote sensing of soil moisture images with in situ observations." Remote Sensing, Vol. 9, No. 5, doi:10.3390/rs9050484.

10.3390/rs9050484

Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 52
No :8
Pages :545-554
Received Date : 2018-10-16
Revised Date : 2019-08-02
Accepted Date : 2019-08-16
DOI :https://doi.org/10.3741/JKWRA.2019.52.8.545

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

All Issue