9689

8933

كارشناسي ارشد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده منابع طبيعي

1393

[پانزده]،115ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

سعيد سلطاني

رضا جعفري،كيانفر پيامني

93/12/23

سعيد اسلاميان

مهندسي منابع طبيعي

ID8933

006 Assessment of Urbanization Impacts on Increasing Runoff Using HEC HMS Model and GIS Technique in Khoram abad Watershed Atefe kalhor Email Address A Kalhor@na iut ac ir December 7 2014 Department of Natural Resoueces Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc language FarsiSupervisor Dr Saeed Soltani SSoltani@cc iut ac ir Abstract Nowadays we witness some increasing trend of natural resources degradation and humaninterference in natural cycles is manifested in destroying plants in watershed regions illegal landuse developing impervious surfaces and affecting hydrological regime of the basin In recent yearsimproper and unplanned development of residential areas and consequences degraded forest landsled to especially in mountainous regions increasing changing of rain into runoffs and also decreasethe time of concentration lag time and time to reach peak flow the foregoning cases is true forKhoramabad watershed Therefore it is necessary to investigate the effect of land use changesespecially development of residential and urban areas on the runoff rate Having knowledge aboutthe increased runoff rate and its behavior requires some detailed statistics about hydrologicalcondition or river basin discharge data this goal can not be realized in rivers with seasonal orintermittent flow so the application of hydrologic models for runoff simulation and henceapplication of geographical information system GIS for visualization and analyzing site data areadopted in numerous studies In this research having been mapping land use CN and runoffCoefficient C in years 1985 2000 and 2013 were provided and their variations in the studiedperiod were analyzed and it was found the most important land use changes included degration offorest areas increased urbanization and buildings and in some sub basin reduced agricultural areaamong many others In sub basin 4 the highest changes were attributed to urbanization and ruraldevelopment and in this sub basin from 1985 to 2013 CN value varied from 82 135 to 85 28 and atthe same period C value ranged from 0 51 to 0 57 in order to determination of the impact of land use changes watershed behavior was simulatedbased on precipitation and recorded hydrographs Transformation of precipitation to runoff wasdone using curve number model CN in HEC HMS software After modeling calibration and validation resulted model was applied for watershed hydrologicalbehavior simulation and it was run for years 1985 2000 and return periods 2 to 100 years Theresults showed that land use change especially increased urban and rural areas development andconsequently increased CN caused an increase in Q peak from 42 5 to 400 percentage for 1985 2000 from 61 25 to 700 percentage for 1985 2013 and from 13 15 to 33 33 percentage for 2000 2013 And also the time of concentration and time to peak decreased to 12 45 and 9 64 respectively Also it was revealed that as return period of precipitation was increased discharge variationspercentage was decreased since 1985 to 2013 that indicating low impact of land use changes onlonger return period s discharges so that the peak flow of 2 and 100 return periods from 1985 to2013 increased to 22 558 and 16 874 percentage respectively Key words land use change urban and rural area development HEC HMS Model khoram abadwatershed peak flow

سعيد سلطاني

رضا جعفري،كيانفر پيامني

سعيد اسلاميان