تاثير مالچ هاي چوبي، سنگي و تراشه هاي لاستيكي بر تبخير و تعرق با استفاده از مدل هاي ZEP، REF-ET و QpTIWAT

چكيده انگليسي :

Effect of Wood Sand and Tire Chips Mulches on Evapotranspiration Using ZFP REF ET and OPTIWAT Models Mahsa Rahmani Mahsarahmani39@yahoo com Date of submission October 10 2010 Department of Water Engineering Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsikoupai@cc iut ac irJ Abedi koupai Ph D Assoc Prof Supervisor mousavi sf@yahoo comS F Mousavi Ph D Prof Supervisor AbstractIn arid and semi arid regions evaporation from the soil surface represents the major water balance componentthat causes losses of water On the other hand the population growth and the related increase in drinking water development in urban industrial and agricultural sectors put a lot of pressure on available water resources Urban landscape particularly grass cover consumes a large amount of water in urban areas About 72 percentwater loss is through evaporation in Iran for all these reasons application of methods to cope with low wateruse and water management can be regarded as an appropriate solution Using mulch is a proper method toreduce the cost of irrigation weeds and grass green space maintenance The use of mulch in the landscape canbe a step in the reform of water use patterns In the first phase of this study the effect of different mulches withdifferent thicknesses on reduction rate of evaporation and water requirement were evaluated The experimentwas completely randomized blocks with eight treatments with three replications during 70 days Theexperiment consisted of wood sand and tire chips mulches with 2 5 and 5 cm thickness in the plots Three plotswere planted with grass and three plots were with no covered In each plot Chrysanthemum ChrysanthemumPompona was planted Results indicated that treatment with a thickness of 5 cm of sandy mulch had thegreatest performance Then sandy mulch with a thickness of 2 5 cm the tire chips mulch with a thickness of 5cm and woody chips mulch with a thickness of 5 cm had the best performance on reducing water consumption respectively The plot of grass and uncovered plot consumed the greatest volume of water during theexperimental period In the second stage evapotranspiration was measured by zero flux plane ZFP method The experiment was factorial design 3 8 in the basic design of a randomized complete blocks that the firstfactor included the types of mulch and the second factor was the depth of soil The field trial was conducted for44 days The results showed that the depth of ZFP varied in different mulches Model ZFP indicated that theexperiment plot with no mulch had the greatest evapotranspiration 178 mm and then woody chips mulch witha thickness of 5 cm tire chips mulch with a thickness of 5 cm tire chips mulch with a thickness of 2 5 cm sandy mulch with a thickness of 2 5 cm the woody chips mulch with a thickness of 2 5 cm and sandy mulchwith a thickness of 5 cm had more evapotranspiration respectively Results obtained from the ZFP model wascompared with REF ET and OPTIWAT models The results showed that the amount of evapotranspirationobtained by the ZFP model with the results of the REF ET and OPTIWAT model were different REF ET andOPTIWAT models under stimated the actual evapotranspiration obtained by ZFP In REF ET model theequation of modified Blany Cridle had the nearest estimation to the evapotranspiration determined by ZFPmodel In OPTIWAT model the modified Jensen Haise method had the nearest estimation to the ZFP model Key Words Evapotranspiration Wood sand and tire chips mulches ZFP REF ET and OPTIWAT models

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تاثير مالچ هاي چوبي، سنگي و تراشه هاي لاستيكي بر تبخير و تعرق با استفاده از مدل هاي ZEP، REF-ET و QpTIWAT

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