Development of an Integrated Drought Risk Map Using the Water Resources Approach Process Model: a Case Study of the Zayandehrud Dam Catchment, Iran

الماسی نیا, محمد; مرادی, یوسف

doi:10.22093/wwj.2026.579368.3547

Development of an Integrated Drought Risk Map Using the Water Resources Approach Process Model: a Case Study of the Zayandehrud Dam Catchment, Iran

مقالات آماده انتشار

نوع مقاله : مطالعه موردی

نویسندگان

محمد الماسی نیا ¹

یوسف مرادی ²

¹ Assist. Prof., Dept. of Geography, Faculty of Humanities, Payame Noor University, Tehran, Iran

² Retired, Dept. of Water Engineering, Isfahan University of Technology, Isfahan, Iran

10.22093/wwj.2026.579368.3547

چکیده

Drought is a recurring and destructive natural hazard in arid and semi-arid regions, where its impacts are often intensified by human-induced factors such as land degradation and groundwater overexploitation. Conventional drought assessments typically depend only on climatic indices and overlook the physical characteristics of the catchment that determine actual vulnerability. This study presents an integrated methodology for drought risk assessment through the development of a Water Resources Approach Process model. The WRAP framework combines a meteorological drought index (Standardized Precipitation Index) with key physical catchment attributes–including geology, geomorphology, land use, slope, and erosion potential–to produce comprehensive hazard and vulnerability maps. The methodology is applied to the Zayandehrud Dam Catchment in central Iran, a semi-arid region facing severe water stress. Long‑term data (1971–2014) from 15 meteorological stations and 9 streamflow gauges are analyzed. Homogeneity tests (Pettitt, SNHT, Buishand, von Neumann) are used to ensure data quality, and the Mann‑Kendall test is applied to detect trends. Drought hazard is characterized using the 12–month SPI, while vulnerability is assessed by integrating thematic layers of landform, geology, slope, groundwater depth, and erosion risk through a weighted scoring approach within a GIS environment. The final drought risk map is generated by overlaying the hazard and vulnerability layers on a 20 × 20 km grid. Results indicate that approximately 45% of the catchment area falls into high or very high drought risk categories. The western and north‑eastern sub‑catchments exhibit the highest risk due to a combination of high climatic variability, steep slopes, erosive soils, and intensive groundwater abstraction that has led to land subsidence. The central parts show moderate to low risk because of more favorable geological conditions for water retention. The WRAP model proves to be a robust tool for identifying drought‑prone areas and for supporting integrated water resources management and disaster risk reduction strategies in semi‑arid catchments.

کلیدواژه‌ها

Drought Risk, Water Resources Approach Process Model, Standardized Precipitation Index

Vulnerability Mapping, GIS, Zayandehrud Dam Catchment

Abramowitz, M. and Stegun, I. A., 1965. Handbook of Mathematical Functions: with Formulas, Graphs, and Mathematical Tables (Dover Books on Mathematics). Dover Publications, New York. 1072 pages. [Link]

Arnold, J. G., Moriasi, D. N., Gassman, P. W., Abbaspour, K. C., White, M. J., Srinivasan, R., et al., 2012. SWAT: model use, calibration, and validation. Transactions of the ASABE, 55(4), 1491-1508. http://dx.doi.org/10.13031/2013.42256.

Blaikie, P., Cannon, T., Davis, I. and Wisner, B., 2004. At Risk: Natural Hazards, People's Vulnerability and Disasters. 2^nd Edition. Routledge, London. 496 Pages. [Link]

Borgatti, L. and Soldati, M., 2010. Landslides as a geomorphological proxy for climate change: a record from the Dolomites (northern Italy). Geomorphology, 120, 56-64. https://doi.org/10.1016/j.geomorph.2009.09.015.

Droogers, P., Salemi, H. R. and Mamanpoush, A. R., 2001. Exploring basin scale salinity problems using a simplified water accounting model: the example of Zayandehrud Basin, Iran. Irrigation and Drainage, 50(4), 335-348. https://doi.org/10.1002/ird.25.

Dorafshan, M. M., Golmohammadi, M. H., De Michele, C. and Eslamian, S., 2024. Risk analysis of inflow to the Zayandehrud Dam under historical and future scenarios using reliability, resiliency, and vulnerability indicators: a comparative study of the runoff risk index and runoff risk ranking methods. Water Reuse, 15(1), 1-23, https://doi.org/10.2166/wrd.2024.070.

Eslamian, S., Safavi, H. R., Gohari, A., Sajjadi, M., Raghibi, V. and Zareian, M. J., 2017. Climate Change Impacts on Some Hydrological Variables in the Zayandeh-Rud River Basin, Iran. In: Mohajeri, S. and Horlemann, L., eds. Reviving the Dying Giant. Springer, Cham. pp.201-217. https://doi.org/10.1007/978-3-319-54922-4_13.

FAO, 2025. CHIRPS Rainfall Data for Iran, 2024-2025 Water Year. Food and Agriculture Organization of the United Nations. Rome, Italy. [Link]

Gohari, A., Eslamian, S., Mirchi, A., Abedi-Koupaei, J., Massah Bavani, A. and Madani, K., 2013. Water transfer as a solution to water shortage: a fix that can backfire. Journal of Hydrology, 491, 23-39. https://doi.org/10.1016/j.jhydrol.2013.03.021.

Guo, Y., Huang, S., Huang, Q., Wang, H., Fang, W., Yang, Y. et al., 2020. Assessing socioeconomic drought based on an improved multivariate standardized reliability and resilience index. Journal of Hydrology, 568, 904-918. https://doi.org/10.1016/j.jhydrol.2018.11.055.

Hayes, M. J., Wilhelmi, O. V. and Knutson, C. L., 2004. Reducing drought risk: bridging theory and practice. Natural Hazards Review, 5(2), 106-113. https://doi.org/10.1061/(ASCE)1527-6988(2004)5:2(106).

IRIMO, 2025. Annual Report on Precipitation and Drought Status in Iran (Water Year 2024-2025). Islamic Republic of Iran Meteorological Organization, Tehran. (In Persian). [Link]

IMNA, 2025. 40% Decrease in Rainfall in the Water Year 1403-1404 | New Statistics from the Meteorological Organization on Rainfall. (In Persian). [Link]

Javanshiri, Z. and Rahmdel, M., 2024. Climatological standard normals of IRAN, for the period 1981–2010 and 1991–2020: precipitation and temperature. Meteorology and Atmospheric Physics, 136, 16. https://doi.org/10.1007/s00703-024-01013-3.

Keshavarz, M., Karami, E. and Vanclay, F., 2013. The social experience of drought in rural Iran. Land Use Policy, 30, 120-129. https://doi.org/10.1016/j.landusepol.2012.03.003.

Madani, K. and Mariño, M. A., 2009. System dynamics analysis for managing Iran's Zayandehrud River Basin. Water Resources Management, 23, 2163-2187. https://doi.org/10.1007/s11269-008-9376-z.

McKee, T. B., Doesken, N. J. and Kleist, J., 1993. The relationship of drought frequency and duration to time scales. In Proceedings of the 8^th Conference on Applied Climatology. Anaheim, California. pp. 179-184. [Link]

Mishra, A. K. and Singh, V. P., 2010. A review of drought concepts. Journal of Hydrology, 391, 202-216. https://doi.org/10.1016/j.jhydrol.2010.07.012.

Modarres, R. and Sarhadi, A., 2009. Rainfall trends analysis of Iran in the last half of the twentieth century. Journal of Geophysical Research: Atmospheres, 114(D3). https://doi.org/10.1029/2008JD010707.

Naumann, G., Cammalleri, C., Mentaschi, L. and Feyen, L., 2021. Increased economic drought impacts in Europe with anthropogenic warming. Nature Climate Change, 11, 485-491. https://doi.org/10.1038/s41558-021-01044-3.

Pandey, R. P., Pandey, A., Galkate, R. V., Byun, H. R. and Mal, B. C., 2010. Integrating hydro-meteorological and physiographic factors for assessment of vulnerability to drought. Water Resources Management, 24, 4199-4217. https://doi.org/10.1007/s11269-010-9653-5.

Safavi, H. R., Khoshoei Esfahani, M. and Zamani, A. R., 2014. Integrated index for assessment of vulnerability to drought, case study: Zayandehrood River Basin, Iran. Water Resources Management, 28, 1671-1688. https://doi.org/10.1007/s11269-014-0576-4.

Tehran Times, 2025. Water Year Ends with Some 40% Less Rain. [Link]

Van Loon, A. F., Gleeson, T., Clark, J., Van Dijk, A. I. J. M., Stahl, K., Hannaford, J. et al., 2016. Drought in the Anthropocene. Nature Geoscience, 9, 89-91. https://doi.org/10.1038/ngeo2646.

Wilhelmi, O. V. and Wilhite, D. A., 2002. Assessing vulnerability to agricultural drought: a Nebraska case study. Natural Hazards, 25, 37-58. https://doi.org/10.1023/A:1013388814894.

Wilhite, D. A., Sivakumar, M. V. K. and Pulwarty, R., 2014. Managing drought risk in a changing climate: the role of national drought policy. Weather and Climate Extremes, 3, 4-13. https://doi.org/10.1016/j.wace.2014.01.002.

WMO, 2012. Standardized Precipitation Index User Guide. World Meteorological Organization. WMO-No. 1090, Geneva, Switzerland. [Link]