Investigating Spatiotemporal Variations of Precipitation across Iran over 1957-2016 using the CRU Gridded Dataset

Document Type : Original Research

Authors
1 Research Officer, The Centre for Crop Science, The University of Queensland, Australia
2 Assistant professor, Dept. of Water Sciences and Engineering, Imam Khomeini International University
Abstract
Precipitation affects quantity and quality of water resources and agricultural production. Therefore, the estimation and analysis of its spatial-temporal variations is of great importance. In many regions of Iran, limited spatial-temporal information is available due to sparse distribution of monitoring stations and short observational records. On the other hand, dependency of rain-fed and irrigated production systems on precipitation increases the importance of the analysis of spatiotemporal variations of this weather variable. One way to address this limitation is to use regional/global gridded datasets. In this study, monthly precipitation data were obtained from the CRU dataset (developed principally by the UK's Natural Environment Research Council (NERC) and the US Department of Energy) and used to investigate temporal trends in annual, seasonal and monthly precipitations in 675 grid cells (0.5°×0.5°) across Iran over two periods, 1957-1986 and 1987-2016. The results of the previous studies showed that the CRU gridded dataset offers quality data in Iran, especially for trend analysis. Also, the accuracy of the CRU dataset was validated in 14 selected stations regarding monthly precipitations and temporal trends over two different periods, pre-1987 and post-1987. The significance of temporal trends was assessed using a modified version of the rank-based nonparametric Mann-Kendall (MK) test. Trend magnitudes (i.e. slope) were estimated with the Theil-Sen approach and the Trend Free Pre-whitening (TFPW) procedure was applied to remove the effect of serial correlation. The results confirm the acceptable accuracy of the CRU dataset for trend analysis purposes, especially over the last three decades, except in the northern strip of the country (RMSE=10.71mm, R2=0.84). Two 30-year periods (1957-1986 and 1987-2016) were compared in terms of spatial patterns and temporal trends. Annual precipitation over the last three decades (1987-2016) has decreased as compare to the previous 30-year period (1957-1986) in most parts of the country. Over the last three decades, around 42% and 50% of the country’s total area experienced significant and insignificant decreasing trends in annual precipitation, respectively. National average annual precipitation has decreased by 15.78 mm/decade over the same period. Three important regions regarding agricultural production experienced the most significant reductions in annual precipitation: (1) Ardebil, East Azerbaijan, Kurdistan, Kermanshah, Ilam, Lorestan, Zanjan, Hamadan, and parts of West Azerbaijan, Markazi and Gilan (in the west and northwest), (2) Sistan and Baluchestan, Kerman, and southern parts of South Khorasan (in the south and south east), and (3) North Khorasan, northern parts of Razavi Khorasan and east of Golestan (in the east and north east). Reduced annual precipitation was mainly attributed to the reduction in seasonal precipitations in winter and spring, which have critical role in agricultural production and domestic water supply. Temporal trends were also analysed at the monthly scale. January, February, March and December revealed the largest number of grid cells with significant decreasing trends over 1987-2016 while November is the only month with significant number of grid cells experiencing significant increasing trends. The results of this study show that the monthly time series of the CRU TS 4.01 dataset, which has an almost complete spatial and temporal coverage in Iran over the last 60 years, are promising alternatives to weather station observations especially in data-scarce regions of Iran. Analysis of variations and the seasonal and monthly scales help understand the recent climate change and target the most crucial features of it when it comes to formulating adaptation strategies.

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1- AghaKouchak A, Nasrollahi N, Habibi E (2009) Accounting for uncertainties of the TRMM satellite estimates. Remote sensing 1(3):606-619
2- Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B, Klein Tank AMG, Haylock M, Collins D, Trewin B, Rahimzadeh F, Tagipour A, Rupa Kumar K, Revadekar J, Griffiths G, Vincent L, Stephenson DB, Burn J, Aguilar E, Brunet M, Taylor M, New M, Zhai P, Rusticucci M, Vazquez-Aguirre JL (2006) Global observed changes in daily climate extremes of temperature and precipitation. Journal of Geophysical Research Atmospheres 111, D05109. https://doi.org/10.1029/2005JD006290
3- Ashouri H, Nguyen P, Thorstensen A, Hsu K, Sorooshian S, Braithwaite D (2016) Assessing the Efficacy of High-Resolution Satellite-Based PERSIANN-CDR Precipitation Product in Simulating Streamflow. Journal of Hydrometeorology 17(7):2061-2076
4- Bajracharya SR, Shrestha MS, Shrestha, AB (2014) Assessment of high-resolution satellite rainfall estimation products in a streamflow model for flood prediction in the Baghmati basin, Nepal. Journal of Flood Risk Management 10:5-16
5- Balsamo G, Albergel C, Beljaars A, Boussetta S, Brun E, Cloke H, Dee D, Dutra E, Muñoz-Sabater J, Pappenberger F, de Rosnay P, Stockdale T, Vitart F (2015) ERA-Interim/Land: a global land surface reanalysis data set. Hydrology and Earth System Sciences 19:389-407
6- Bohnenstengel S, Schlüenzen KH, Beyrich F (2011) Representatively of in situ precipitation measurements - a case study for the LITFASS area in North-Eastern Germany. Journal of Hydrology 400(3-4):387-395
7- Bronaugh, D, Werner A (2015) Package ‘zyp.’ R Cran
8- De Leeuw J, Methven J, Blackburn M (2015) Evaluation of ERA-Interim reanalysis precipitation products using England and Wales observations. Quarterly Journal of the Royal Meteorological Society 141(688):798-806
9- Dee D, Uppala S, Simmons A, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda M, Balsamo G, Bauer P (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Quarterly Journal of the Royal Meteorological Society 137:553–597
10- Dembele M, Zwart SJ (2016) Evaluation and comparison of satellite-based rainfall products in Burkina Faso, West Africa. International Journal of Remote Sensing 37(17):3995-4014
11- Duan Z, Liu J, Tuo Y, Chiogna C, Disse M (2016) Evaluation of eight high spatial resolution gridded precipitation products in Adige Basin (Italy) at multiple temporal and spatial. Science of the Total Environment 573:1536-1553
12- Eini MR, Javadi S, Delavar M (2018) Evaluating the Performance of CRU and NCEP CFSR Global Reanalysis Climate Datasets in Hydrological Simulation by SWAT Model (Case Study: Maharlu Basin). Iran-Water Resources Research journal 14(1):32-44 (In Persian)
13- Ghajarnia N, Liaghat A, Arasteh PD (2015) Comparison and evaluation of high resolution precipitation estimation products in Urmia Basin Iran. Atmospheric Research 158:50-65.
14- Greene J, Morrissey M, (2000) Validation and Uncertainty Analysis of Satellite Rainfall Algorithms. The Professional Geographer 52:247–258.
15- Hajihoseini H, Hajihoseini M, Najafi A, Morid S, Delavar M (2014) Assessment of changes in hydrometeorological variables upstream of Helmand Basin during the last century using CRU data and SWAT model. Iran- Water Resources Research 10(3):38-52 (In Persian)
16- Harris I, Jones PD, Osborn TJ, Lister DH (2013) Updated high-resolution grids of monthly climatic observations - the CRU TS3.10 Dataset. International Journal of Climatology 34:623–642. https://doi.org/10.1002/joc.3711
17- Harris IC, Jones PD (2015) CRU TS3.23: Climatic Research Unit (CRU) Time-Series (TS) Version 3.23 of High Resolution Gridded Data of Month-by-month Variation in Climate (Jan. 1901 - Dec. 2014). Centre for Environmental Data Analysis doi:506 10.5285/4c7fdfa6-f176-4c58-acee-683d5e9d2ed5
18- Hong Y, Hsu K, Moradkhani H, Sorooshian S (2006) Uncertainty Quantification of Satellite Precipitation Estimation and Monte Carlo Assessment of the Error Propagation into Hydrologic Response. Water Resources Research 42:W08421.
19- IPCC (2012) Managing the risks of extreme events and disasters to advance climate change adaptation. Special Report of the Intergovernmental Panel on Climate Change, Ipcc. https://doi.org/10.1596/978-0-8213-8845-7
20- Javanmard S, Yatagai A, Nodzu M, BodaghJamali J, Kawamoto H (2010) Comparing high-resolution gridded precipitation data with satellite rainfall estimates of TRMM_3B42 over Iran. Advances in Geosciences 25:119-125
21- Katiraie-Boroujerdy PS, Nasrollahi N, Hsu K, Sorooshian S (2013) Evaluation of satellite-based precipitation estimation over Iran. Journal of arid environments 97:205-219
22- Kendall MG (1975) Rank Correlation Methods, Science Forum.
23- Kidd C, Dawkins E, Huffman, G (2013) Comparison of precipitation derived from the ECMWF operational forecast model and satellite precipitation datasets. American Meteorological Society 14:1463-1482.
24- Krogh SA, Pomeroy JW, McPhee J (2015) Physically Based Mountain Hydrological Modeling Using Reanalysis Data in Patagonia. Journal of Hydrometeorology 16(1):172-193.
25- Kumar D, Pandey A, Sharma N, Flugel WA (2015) Evaluation of TRMM-Precipitation with Rain-Gauge Observation Using Hydrological Model J2000. Journal of Hydrologic Engineering E5015007
26- Li Z, Yang D, Hong Y, (2013) Multi-scale evaluation of high-resolution multi-sensor blended global precipitation products over the Yangtze River. Journal of Hydrology 500:157-169.
27- Mann, HB (1945) Nonparametric tests against trend. Econometrica: Journal of the Econometric Society 245–259. https://doi.org/10.1017/CBO9781107415324.004
28- Miri M, Azizi G, Khoshakhlagh F, and Ramimi M (2017) Evaluation Statistically of Temperature and Precipitation Datasets with Observed Data in Iran. Iran-Watershed Management Science & Engineering 10(35):40-50 (In Persian)
29- Moazami S, Golian S, Hong Y, Sheng C, Kavianpour MR (2016) Comprehensive evaluation of four high-resolution satellite precipitation products under diverse climate conditions in Iran. Hydrological Sciences Journal 61(2):420-440
30- Moreau E, Bauer P, Chevallier F (2003) Vibrational retrieval of rain profiles from space borne passive microwave radiance observations. Journal of Geophysics Research 108:21-45
31- Morice CP, Kennedy JJ, Rayner NA, Jones P (2012) quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 data set. Journal of Geophysical Research 117:1-22
32- Ramezani Etedali H, Liaghat A, Parsinejad M, Tavakkoli AR, Bozorg Haddad O, Ramezani Etedali M, (2013) Water Allocation Optimization for Supplementary Irrigation in Rainfed Lands to Increase Total Income (Case Study: Upstream Karkheh River Basin). Journal of Irrigation and Drainage 62:74-83
33- Raziei T, Daneshkar Arasteh P, Saghfian B (2005) Annual Rainfall Trend in Arid and Semi-arid Regions of Iran, in: ICID 21st European Regional Conference. Frankfurt (Oder) and Slubice - Germany and Poland
34- Raziei T, Daryabari J, Bordi I, Pereira LS (2014) Spatial patterns and temporal trends of precipitation in Iran. Theoretical and Applied Climatology 115:531–540 https://doi.org/10.1007/s00704-013-0919-8
35- Raziei T, Mofidi A, Santos JA, Bordi I (2012) Spatial patterns and regimes of daily precipitation in Iran in relation to large-scale atmospheric circulation. International Journal of Climatology 32:1226–1237 https://doi.org/10.1002/joc.2347
36- Raziei T, Sotoudeh F (2017) Investigation of the accuracy of the European Center for Medium Range Weather Forecast (ECMWF) in forecasting observed precipitation in different climates of Iran. Journal of the Earth and Space Physics 43(1):133-147
37- Saboohi R, Soltani S, Khodagholi M (2012) Trend analysis of temperature parameters in Iran. Theoretical and Applied Climatology 109:529–547 https://doi.org/10.1007/s00704-012-0590-5
38- Sahlu D, Nikolopoulos EI, Moges SA, Anagnostou EN, Hailu D (2016) First evaluation of the day-1 IMERG over the upper Blue Nile Basin. Journal of Hydrometeorological 17:2875–2882
39- Shadmani M, Marofi S, Roknian M (2012) Trend Analysis in Reference Evapotranspiration Using Mann-Kendall and Spearman’s Rho Tests in Arid Regions of Iran. Water Resources Management 26:211–224 https://doi.org/10.1007/s11269-011-9913-z
40- Shi H, Li T, Jiahua W (2017) Evaluation of the Gridded CRU TS Precipitation Dataset with the Point Raingauge Records over the Three-River Headwaters Region. Journal of Hydrology 548:322-332 http://dx.doi.org/10.1016/j.jhydrol.2017.03.017
41- Steiner M, Bell T, Zhang Y, Wood E (2003) Comparison of Two Methods for Estimating the Sampling-Related Uncertainty of Satellite Rainfall Averages Based on a Large Radar Dataset. Journal of Climate 16:3759–3778
42- Tan ML, Ibrahim AL, Duan ZH, Cracknell AP, Chaplot V (2015) Evaluation of six high-resolution satellite and ground-based precipitation products over Malaysia. Remote Sensing 7:1504-1528
43- Tianobao ZH, Congbin F (2006) Comoarison of products from ERA-40, NCEP-2 and CRU with satation data for summer precipitation over China. Advance in Atmospheric Science 23(4):593-604
44- Tong K, Su F, Yang D, Hao Z (2014) Evaluation of satellite precipitation retrievals and their potential utilities in hydrologic modeling over the Tibetan Plateau. Journal of Hydrology 519: 432-437
45- Yue S, Pilon P, Phinney B, Cavadias G (2002) The influence of autocorrelation on the ability to detect trend in hydrological series. Hydrological Processes 16:1807–1829 https://doi.org/10.1002/hyp.1095
46- Zhao T, Yatagai A (2014) Evaluation of TRMM 3B42 product using a new gauge-based analysis of daily precipitation over China. International Journal of Climatology 34(8):2749-2762
47- Zhao T, Fu C (2006) Comparison of products from ERA-40, NCEP-2, and CRU with station data for summer precipitation over China. Advances in Atmospheric Sciences 23:593-604.