نتایج جستجو برای: karst hydrology

تعداد نتایج: 11544  

2017
Xianwei Song Yang Gao Sophie M Green Jennifer A J Dungait Tao Peng Timothy A Quine Bailian Xiong Xuefa Wen Nianpeng He

Karst topography covers more than 1/3 of the People's Republic of China in area. The porous, fissured, and soluble nature of the underlying karst bedrock (primarily dolomite and limestone) leads to the formation of underground drainage systems. Karst conduit networks dominate this system, and rainfall takes a crucial role on water cycle at China karst area. Nitrogen loss from the karst system i...

Karstic zones play an important role in feeding the karstic aquifers؛ therefore, recognizing the factors affecting the karst mutation and its zonation in the field of studies concerned with karst water resources is of great concern. The results of these studies can be applied to quantitative and qualitative management and protection of these resources against the pollutions coming from human ac...

Journal: :پژوهش های جغرافیای طبیعی 0
مهران مقصودی دانشیار ژئومورفولوژی، دانشگاه تهران هانیه اخوان دانشجوی کارشناسی ارشد ژئومورفولوژی، دانشگاه تهران مجتبی مهدیان ماهفروزی دانشجوی کارشناسی ارشد اقلیم شناسی، دانشگاه تهران غدیر عشورنژاد دانشجوی دکتری، سنجش از دور و سامانة اطلاعات جغرافیایی دانشگاه تهران

introduction the iran has vast areas of karst landforms due to the relatively high carbonaceous rocks deposited during different geologic eras. karst landforms are noteworthy for investigation from many aspects. the primary importance of these regions is the considerable amount of underground water stored in karst formations. these reserves are favorable, both in quality and quantity, as natura...

2008
Caihong Hu Yonghong Hao Tian-Chyi J. Yeh Bo Pang Zening Wu

In China, 9Ð5% of the landmass is karst terrain and of that 47,000 km2 is located in semiarid regions. In these regions the karst aquifers feed many large karst springs within basins of thousands of square kilometres. Spring discharges reflect the fluctuation of ground water level and variability of ground water storage in the basins. However, karst aquifers are highly heterogeneous and monitor...

2012
ROBERT BRINKMANN

With growing populations and ever increasing pressure on resources, the need to live sustainably with our environment has increased in significance. When considering such anthropogenic pressures, karst landscapes are as vulnerable, if not more so, than any other environment. Such vulnerability arises from the rapid transit times of percolating water, the poor filtering ability of carbonate bedr...

2014
Lindsay Ivey

The objective of this project was to investigate the current state of the practice with regards to karst detection methods and current karst construction practices and to recommend the best practices for use by the Virginia Department of Transportation (VDOT). A comprehensive review of literature available on the subject was conducted. Various karst detection technologies were summarized with r...

2015
Bo Li

Strong karstlize effect forming surface and underground double-space structure in karst area, what resulting groundwater systems are extremely sensitive to outside interference. This article mainly focuses on the vulnerability assessment of karst groundwater, proposing that the vulnerability assessment of karst groundwater should be considered from three perspectives: the inherent vulnerability...

2017
Stuart V Nielsen Paul M Oliver

Exposed limestone karst landscapes, especially in the tropics, are often home to distinctive and specialized biotas. Among vertebrates, a particularly large number of karst-associated lizard taxa have been described, but for the vast majority, evidence of specific adaptions to karst is lacking. A number of studies, however, have provided evidence of consistent morphological trends in lizards th...

2006
Yonghong Hao Tian-Chyi J. Yeh Caihong Hu Yanrong Wang Xia Li

Karst regions, occupy approximately 25% of the land surface of the earth. Karst aquifers are often major sources of water supply in these areas. However, karst aquifers are generally considered to be particularly vulnerable to pollution and anthropogenic impacts. Large withdrawals of water in karst areas for municipal, agricultural, and industrial use may competitively affect water supply in su...

1999
N. Doerfliger P. - Y. Jeannin F. Zwahlen

Groundwater resources from karst aquifers play a major role in the water supply in karst areas in the world, such as in Switzerland. Defining groundwater protection zones in karst environment is frequently not founded on a solid hydrogeological basis. Protection zones are often inadequate and as a result they may be ineffective. In order to improve this situation, the Federal Office for Environ...

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