نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار / پژوهشی مرکز تحقیقات حفاظت خاک و آبخیزداری و استاد مدعو دانشکده مهندسی عمران و محیط زیست، دانشگاه صنعتی امیرکبیر
2 کارشناس ارشد /سازمان جهاد کشاورزی استان گلستان – مدیریت آبخیزداری
3 کارشناس ارشد / سازمان جهاد کشاورزی استان گلستان – مدیریت آبخیزداری
4 استادیار /دانشگاه علوم کشاورزی و منابع طبیعی گرگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
One of the major governing factors in flood trends is the changes in land use. Golestan Dam basin in North-East of Iran has recently experienced devastating floods. Land use changes are believed to be partialy reponsible for this flood intensification. In this paper, using GIS tools and HEC-HMS model, the effects of changing vegetation cover on flood hydrographs in Golestan Dam basin are assessed. The flood condition corresponding to two limiting land use scenarios are then evaluated. Landuse maps from 1967 and 1996 along with the soil map were overlaid using GIS tools to produce CN maps. HEC-HMS hydroloigc model was calibrated and validated based on three methods; curve number (CN) method for infiltration, SCS unit hydrograph for subwatershed rainfall-runoff routing, and Muskingum method for river routing. The results show that recent changes in land use has caused upward trend in flood magnitudes of different frequencies, e.g., 31.7 and 17.8 percent increase in flood peak corresponding to 5-yr and 1000-yr return periods, respectively. This impact reduces as return period increases. Also, the results of deteriorating land use in the pessimistic scenarios show that loss of forests and rangelands increases flood peaks of 5 and 1000-yr by as much as 35 and 24 percent, respectively.
کلیدواژهها [English]