دوماه نامه

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشگاه آیت الله بروجردی

2 دانشگاه آیت الله العظمی بروجردی (ره)

چکیده

تخمین عدم قطعیت اثرات تغییر اقلیم در مطالعات اخیر توجهات بسیاری را به خود جلب کرده است، اما بر عدم قطعیت روش‌های ریزمقیاس نمایی کمتر توجه شده است. امروزه مطالعات فراوانی پیرامون اثرات تغییر اقلیم در آینده بر زندگی بشر و منابع آب موجود صورت می‌پذیرد. توسعه شهر‌ها، چالش مصارف آب و افزایش گاز‌های گلخانه‌ای بر این پدیده در آینده شدت خواهد افزود و جریان رودخانه‌ها را دستخوش تغییر خواهد نمود. این تحقیق بر روی حوضه آبریز رودخانه قره‌سو واقع در غرب کشور ایران و با چهار ایستگاه باران‌سنجی و دو ایستگاه سینوپتیک انجام شده است، همچنین بر چندین مدل اقلیمی مختلف حاصل از گزارش چهارم و پنجم انجمن IPCC تمرکز نموده و برای لحاظ نمودن عدم قطعیت‌های مختلف از روش‌های ریزمقیاس نمایی آماری و تناسبی و همچنین سناریو‌ها و مدل‌های اقلیمی مختلف استفاده شده است. نتایج شاخص‌ها حاکی از برتری مدل‌های CANESM2 و HADCM3 (برای هر دو متغیر) در روش آماری و HADCM3 (بارش) و HADGEM (دما) در روش تناسبی می‌باشد. داده‌های دما و بارش دوره آینده (2069-2040 روش آماری و 2052-2040 روش تناسبی) ریزمقیاس شده و به مدل HEC-HMS که از قبل مورد واسنجی و صحت‌سنجی قرار گرفته است جهت چشم انداز جریان حوضه در دوره آینده داده شد. نتایج ضریب تعیین روزانه برابر 7/0 برای دوره واسنجی و 6/0 برای دوره صحت-سنجی بود. در نهایت تغییرات رواناب مورد بررسی قرار گرفت که در کل اکثر مدل‌ها در فصل زمستان، افزایش رواناب و در بقیه فصول کاهش رواناب نسبت به دوره پایه را پیش‌بینی می‌کنند.

کلیدواژه‌ها

عنوان مقاله [English]

Uncertainty of Downscaling Methods in Future Catchment Flow under Climate Change Effect

نویسندگان [English]

  • Mohammad Reza Goodarzi 1
  • Alireza Faraji 2
  • Mahdi Komasi 1

1 University of Ayatollah Ozma Borujerdi

2 University of Ayatollah Ozma Borujerdi

چکیده [English]

Introduction: Uncertainty estimation of climate change impacts has been given a lot of attention in the recent literature, However, uncertainty in downscaling methods have been given less attention. Today many studies have been done about the future impact of climate change on human life and water resources. Urban development, water conflicts, and Green House Gases increasing will intensify this event in future and will alter rivers flow. Basin catchment has faced to flow recession and also runoff decreasing in few last decades. At this field the climate change effects will intensify this conditions in future decades too. The first step of climate change impacts studies is the projection of future climate variables (e.g precipitation and temperature). GCMS models and their outputs are useful tools for this projection. The main problem is the mismatch of spatial scale between the scale of global climate models and the resolution needed for impacts assessments.
Materials and Methods: The Gharesou River Basin is located in the west of Iran. Its area is approximately equal to 5793km2, and the maximum and minimum of its heights are 1237 and 3350 m, respectively. The average of annual rainfall varies from 300 to 800mm. This study focuses on various climate models from IPCC fourth and fifth reports and has been used two downscaling methods including the statistical and proportional downscaling methods and also scenarios and different climate models for considering different uncertainty. The new scenarios as Representative Concentration Pathways (RCPs) of greenhouse gasses have been used in fifth assessment reports (AR5) of IPCC. The Representative Concentration Pathways describe four different 21st-century pathways of greenhouse gas (GHG) emissions and atmospheric concentrations, air pollutant emissions and land use. The RCPs represent the range of GHG emissions. Different kinds of downscaling method include 1) Proportional downscaling that is adding coarse-scale climate changes to higher resolution observations (the delta approach); 2) Statistical method (eg SDSM model; CLIGEN; GEM; LARS-WG and etc); 3) Dynamical method that is application of regional climate model using global climate model boundary conditions (e.g, RegCM3; MM5 and PRECIS). statistical downscaling method processes establish relating large scale climate features (e.g., 500 MB heights), predictors, to local climate (e.g, daily, monthly temperature at a point), predictands. The SDSM software reduces the task of statistically downscaling daily weather series into seven discrete processes that are consist of quality control and data transformation; screening of predictor variables; model calibration; weather generation (observed predictors); statistical analyses; graphing model output and scenario generation (climate model predictors). HEC-HMS (Hydrologic Modeling System) has been designed by HEC (Hydrologic Engineering Center) for simulation of precipitation-runoff processes in a drainage basin. The HEC-HMS simulation methods represent - Watershed precipitation and evaporation: These describe the spatial and temporal distribution of rainfall on and evaporation from a watershed. - Runoff volume: These address questions about the volume of precipitation that falls on the watershed: How much infiltrates on pervious surfaces? How much runoff of the impervious surfaces? When does it run off? - Direct runoff: including overland flow and interflow. These methods describe what happens as water that has not infiltrated or been stored on the watershed moves over or just beneath the watershed surface. Baseflow: simulate the slow subsurface drainage of water from a hydrologic system into the watershed’s channels.- Channel flow: These so-called routing methods simulate one-dimensional open channel flow, thus predicting time series of downstream flow, stage, or velocity, given upstream hydrographs. HEC-HMS includes several models for calculation of cumulative precipitation losses but only the SMA module is continuous (a module that simulates the losses for both wet and dry weather conditions). Other loss models are event based.
Results and Discussion: The results of criteria and models weighting show that CANESM2 and HADCM3 are better than other models for future temperature and precipitation projection for statistical downscaling and HADCM3 for future precipitation and HADGEM for future temperature assessment for Proportional downscaling. According to various scenarios, future temperature and precipitation projection (2040-2069 period for the statistical and 2040-2052 period for Proportional downscaling) have downscaled and have given to HEC-HMS model for future flow projection. Already the rainfall-runoff model has calibrated and validated base on observed flow data in reference period that daily coefficient of determine was 0.7 for calibrated period and 0.6 for validated period. Finally, flow variation has investigated that Most of GCMS represent increases in winter flows and reductions in other season flows.

کلیدواژه‌ها [English]

  • Emission Scenarios
  • GCM models
  • HEC-HMS model
  • Proportional approach
  • SDSM Model
1- Clark C.O. 1945. Storage and the unit hydrograph: transactions. American Society of Civil Engineers, 110: 1419-1488.
2- Dooge J.C.I. 1959. A general theory of the unit hydrograph. Journal of Geophysical Research, 64(2): 241-256.
3- Graham L.P., Andreasson J., and Carlsson B. 2007. Assessing climate change impacts on hydrology from an ensemble of regional climate models, model scales and linking methods-A case study on the Lule River basin. Climate Change Journal , 81: 293-307.
4- Hussain M., Yusof K.W., Mustafa M.R., and Afshar N.R. 2015. Application of statistical downscaling model (SDSM) for long term prediction of rainfall in Sarawak, Malaysia. WIT Transactions on Ecology and The Environment Journal, 196: 269-278.
5- Hydrologic Modeling System HEC-HMS, Technical Reference Manual. 2000. US Army Corps Engineers Hydrologic Engineering Center, CA 95616 USA, 152pp.
6- Hydrologic Modeling System HEC-HMS, Quick Start Guide. 2013. US Army Corps Engineers Institute for Water Resources Hydrologic Engineering Center, CA 95616 USA, 52pp.
7- IPCC. 2000. A Special Report of Working Group III of the Intergovernmental Panel on Climate Change [Nakicenovic N., Davidson O., Davis D., Grübler A., Kram T., Lebre La Rovere E., Metz B., Morita T., Pepper W., Pitcher H., Sankovski A., Shukla P., Swart R., Watson R., and Dadi Z.]. Emissions Scenarios.
8- IPCC: IPCC Fourth Assessment Report: Climate Change 2007. (AR4), Tech. rep., The United Nations Intergovernmental Panel on Climate Change. Available at http://www.ipcc.ch/pdf/ assessment-report/ar4/syr/ar4_syr.pdf.
9- IPCC, Summary for Policymakers. 2013. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker T.F., Qin D., Plattner G.K., Tignor M., Allen S.K., Boschung J., Nauels A., Xia Y., Bex V., and Midgley P.M.,] Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 28pp.
10- Le T.B., and Sharif H.O. 2015. Modeling the Projected Changes of River Flow in Central Vietnam under Different Climate Change Scenarios. Journal of Water, 7: 3579-3589.
11- Mbaye M.L., Hagemann S., Haensler A., Stacke T., Thierno Gaye A., and Afouda A. 2015. Assessment of Climate Change Impact on Water Resources in the Upper Senegal Basin (West Africa). American Journal of Climate Change, 4: 77-93.
12- Musavi Nadoshan S.S., and Danandeh Mehr A. 2005. Hydrologic Modeling System HEC-HMS. Dibagaran Tehran, Tehran.
13- Saha G.C. 2015. Climate Change Induced Precipitation Effects on Water Resources in the Peace Region of British Columbia, Canada. Journal of Climate, 3: 264-282.
14- Saraf V.R., and Regulwar D.G. 2016. Assessment of Climate Change for Precipitation and Temperature Using Statistical Downscaling Methods in Upper Godavari River Basin, India. Journal of Water Resource and Protection, 8: 31-45.
15- Schlesinger M.E., and Mitchell J.F.B. 1987. Climate model simulations of the equilibrium climatic response to increased carbon dioxide. reviews of geophysics Journal, 25: 760-798.
16- Sharma S., Shrestha A., and Mclean C.E. 2016. Impact of Global Climate Change on Stream Low Flows in a Hydraulic Fracking Affected Watershed. Journal of Water Resource and Hydraulic Engineering, 5: 1-19.
17- USEPA. 2001. Our Built and Natural Environments: A Technical Review of the Interactions between Land Use, Transportation, and Environmental Quality. 4pp.
18- Van Roosmalen L., Christensen B.S.B., and Sonnenborg T.O. 2007. Regional differences in climate change impacts on groundwater and stream discharge in Denmark. Vadose Zone Journal, 6: 554-571.
19- Wetterhall F., Bardossy A., Chen D., Halldin S., and Xu C.Y. 2006. Daily precipitation-downscaling techniques in three chinese regions. Journal of Water Resouces Research, 42: W11423, doi:10.1029/2005WR004573.
20- Wilby R.L., and Harris I. 2006. A framework for assessing uncertainties in climate change impacts: Low-flow scenarios for the River Thames, UK. Journal of Water Resources Researcch, 42: W02419, doi:10.1029/2005WR004065.
21- Xu C.Y. 1999. Climate Change and Hydrologic Models: A Review of Existing Gaps and Recent Research Developments. Journal of Water Resources Management, 13: 369-382.
22- Xu C.Y., Widen E., and Halldin S. 2005. Modeling hydrological consequences of climate change Progress and challenges. Advance Atmosphere Science Journal, 22: 789-797.
23- Xu H., and Luo Y. 2015. Climate change and its impacts on river discharge in two climate regions in China. Hydrologic Earth System Science Journal, 19: 4609–4618.
24- Zahabiyoun B., Goodarzi M.R., and Massah Bavani A.R. 2010. Application of the SWAT Model in the Ghare Sou river Basin under climate change. Journal of Climate Research. 1(3-4): 45-61. (in Persian with English abstract)
25- Zahabiyoun B., Goodarzi M.R., Massah Bavani A.R., and Azamathulla H.M. 2013. Assessment of Climate Change Impact on the Gharesou River Basin Using SWAT Hydrological Model. Clean – Soil, Air, Water Journal, 41(6): 601-609.
26- Zarghami M., Hassanzadeh Y., Babaeian I., and Kanani R. 2009. Climate Change and Water Resources Vulnerability; Case study of Tabriz City. P. 94. SENSE Symposium on Climate Proofing Cities, 1 Dec, 2009. Amsterdam/Volendam. (in Persian with English abstract)
CAPTCHA Image