نتایج جستجو برای: in semi arid area geomorphological impacts of dams are very major. dams

تعداد نتایج: 24530842  

Journal: :پژوهش های جغرافیای طبیعی 0
مریم بیاتی خطیبی فریبا کرمی داود مختاری

in semi arid area geomorphological impacts of dams are very major. dams, as man- made structures, have major impacts on river hydrology, primarly through in the timing, magnitude, and frequency of low and high flows, ultimately producing a hydrologic regime differing significantly from the pre-impoundment natural flow regime. despite the profiles of dams on river regulation for water resources ...

In the arid and semi-arid area's rainfall have considerable changes in terms of time and amount that make the water resource management an important issue. In this research, using both Boolean and Fuzzy logic were zoned potentiality suitable areas for construction of underground dams. The study area is located in the central region of Ardabil province with 7461 km2 area and semi-arid climate. F...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم اجتماعی و اقتصادی 1389

abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - دانشکده علوم انسانی و اجتماعی 1392

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

1. to determine whether difference in birth body mass influenced growth performance in pipistrellus kuhlii we studied a total of 12 captive-born neonates. bats were assigned to two body mass groups: light birth body mass (lbw: 0.89 ± 0.05, n=8) and heavy birth body mass (hbw: 1.35 ± 0.08, n=4). heavier body mass at birth was associated with rapid postnatal growth (body mass and forearm length) ...

2014
Philip M. Marren James R. Grove J. Angus Webb Michael J. Stewardson

The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, an...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده جغرافیا 1392

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...

2003
Alfredo Huete Tomoaki Miura Xiang Gao Carlos Borghi Ricardo Ojeda

Land degradation impacts on several critical environmental issues such as food security, diminishing quality and quantity of fresh water resources, preservation of natural resources, loss of biodiversity, and global climate change. Land degradation is responsible for soil erosion and can eventually lead to desertification. The International Convention to Combat Desertification (CCD) defines des...

1999
William L. Graf

Newly available data indicate that dams fragment the fluvial system of the continental United States and that their impact on river discharge is several times greater than impacts deemed likely as a result of global climate change. The 75,000 dams in the continental United States are capable of storing a volume of water almost equaling one year’s mean runoff, but there is considerable geographi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید