نتایج جستجو برای: karst

تعداد نتایج: 4636  

2017
R Sharapov

Karst processes greatly complicate the construction and operation of buildings and structures. Due to the karstic deformations at different times there have been several major accidents, which analysis showed that in all cases the fundamental errors committed at different stages of building development: site selection, engineering survey, design, construction or operation of the facilities. The...

2016
Chao Wang Qiangyong Zhang Yue Zhang

As the major field in petroleum reserve growth, fractured-vuggy reservoir is the key research in the future. However, in the development of fracture-cavity reservoir, collapse may occur in karst cave which greatly affects the oil well output. In order to forecast the cave collapse before drilling, this work adopts the method of span dichotomy reduction to determine the critical karst collapse o...

Journal: :مرتع و آبخیزداری 0
مهرنوش قدیمی دکتری ژئومورفولوژی دانشگاه تهران حسن احمدی استاد گروه آبخیزداری دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران ابراهیم مقیمی استاد دانشکده جغرافیا، دانشگاه تهران منصور جعفربیگلو استادیار دانشکده جغرافیا، دانشگاه تهران

to evaluate the hydrogeochemical characteristics of karst water resources of oshtorankooh, chemistry details of springs has been considered as the most important evacuator of karst resources. this research has been performed to study hydrogeochemical nature of karst springs and their origin with an emphasis on the type of formation.  accordingly, five samples of the water of permanent springs o...

2002
Alan Glennon ALAN GLENNON

A major emphasis in geomorphology over the past six decades has been on the development of quantitative physiographic methods to describe the evolution and behavior of surface-drainage networks (Horton 1945; Leopold & Maddock 1953; Leopold & Wolman 1957; Abrahams 1984). These parameters have been used in various studies of geomorphology and surface-water hydrology, such as flood characteristics...

Journal: :Ground water 2007
Laura Toran Ellen K Herman William B White

The permeability of some karst aquifers consists of networks of poorly integrated conduits and dissolution-widened fractures. The flow includes conduit flow, especially during storm recharge, but lacks the focused recharge into single master conduits that occurs in more highly developed karst systems. The proportions of conduit and dispersed flow are difficult to quantify in such systems. This ...

2017
Ernesto Medina Elvira Cuevas Ariel E. Lugo

Forests on calcareous substrates constitute a large fraction of the vegetation in Puerto Rico. Plant growth on these substrates may be affected by nutrient deficiencies, mainly P and Fe, resulting from high pH and formation of insoluble compounds of these elements. The occurrence of these forests in humid and dry areas provides an opportunity to compare nutrient relations, water use efficiency,...

2017
Z.F. Zhang F. Liu X. Zhou X.Z. Liu S.J. Liu L. Cai

Karst caves are distinctly characterised by darkness, low to moderate temperatures, high humidity, and scarcity of organic matter. During the years of 2014-2015, we explored the mycobiota in two unnamed Karst caves in Guizhou province, China, and obtained 563 fungal strains via the dilution plate method. Preliminary ITS analyses of these strains suggested that they belonged to 246 species in 11...

2018
Fei Li Ximin Zhang Jiyi Gong Lunxian Liu Yin Yi

Karst topography is formed from the dissolution of soluble rocks, such as limestone and dolomite. In soils of such a landform, excessive contents of exchangeable calcium seriously limit the growth of vegetations. Researches have proved that rhizosphere microorganisms and endophytes help host plants to adapt to various adverse environments. The adaptive capacity of plants that grow in adverse en...

2016
Cyril Mayaud Thomas Wagner Ralf Benischke Steffen Birk

A thorough data analysis combined with groundwater modelling was conducted in an Austrian binary karst aquifer to better understand changes in the hydrological behaviour observed at a karst spring. During a period of 4 years after a major flood event the spring hydrograph appears to be more damped with lower peak flow and higher baseflow than in the years before. The analysis of the hydrograph ...

2006
Jennifer M. Martin Elizabeth J. Screaton Jonathan B. Martin

Karst aquifers with high primary-porosity matrix, such as the Floridan aquifer, have the potential for movement of water between conduits and matrix, with important implications for karst development and the maintenance of groundwater quality. The Santa Fe River Sink and River Rise conduit system, along with the surrounding unconfined Floridan aquifer in north-central Florida, provides a study ...

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