نتایج جستجو برای: karst water

تعداد نتایج: 554389  

2004
W. Li L. J. Yu D. X. Yuan H. B. Xu Y. Yang

To determine the role of microbes in karst processes, it is necessary to investigate the ecological distribution and characteristics of soil microorganisms in karst areas. In this paper, a preliminary study was carried out in two different karst areas of Southwest China: Nongla and the Guilin Yaji Karst Experimental Site (Guangxi). Soil samples from 10–20 cm in depth were analyzed for the numbe...

2018
Yan Xu Shijie Wang Xiaoyong Bai Dongcai Shu Yichao Tian

This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fit...

2009
Douglas G. Boyer Ewa Kuczynska Ron Fayer

A major mode of transmission of Cryptosporidium parvum, a widespread waterborne pathogen, is via contaminated drinking and recreational waters. Oocyst transport to surface water can occur by deposition of manure directly in the water or by wash off in surface runoff. Oocyst transport to groundwater is less straightforward and requires that the oocysts move through soil and bedrock to reach the ...

2013
Daozhi Han Dong Sun Xiaoming Wang

Multiphase flow phenomena are ubiquitous. Common examples include coupled atmosphere and ocean system (air and water), oil reservoir (water, oil and gas), cloud and fog (water vapor, water and air). Multiphase flows also play an important role in many engineering and environmental science applications. In some applications such as flows in unconfined karst aquifers, karst oil reservoir, proton ...

Journal: :Environmental science & technology 2007
Michiel Pronk Nico Goldscheider Jakob Zopfi

Continuous monitoring of particle-size distribution (PSD), total organic carbon (TOC), turbidity, discharge and physicochemical parameters, together with analyses of fecal indicator bacteria, particularly Escherichia coli, made it possible to better understand the processes governing pathogen transport in karst groundwater and to establish PSD as indicator for possible microbial contamination o...

2004
Elizabeth Screaton Jonathan B. Martin Brian Ginn Lauren Smith

Much of the existing conceptualization of fluid flow in karst aquifers is based on work in extensively cemented and recrystallized Paleozoic and Mesozoic carbonates. Within these aquifers, flow is often primarily through conduits (White 1969, 1977; Smart and Hobbs 1986; Ford and Williams 1989), although diffuse flow may occur through secondary porosity, such as fractures and joints (Shuster and...

2011
Kristy A. Kollaus Timothy H. Bonner

Karst spring systems provide permanent water sources in semi-arid to arid environments, supporting a diverse aquatic community. Numerous karst streams in the Edwards Plateau and Trans-Pecos regions of Texas support two distinct fish assemblages, spring-associated species and riverine species. Previous studies have identified constant water temperature as the segregating factor but have lacked t...

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...

Journal: :Molecular ecology 2004
R Verovnik B Sket P Trontelj

The water louse Asellus aquaticus is a widespread, euryoecious species, mostly uniform throughout its range. However, six subspecies are known from the Dinaric karst in the northwestern Balkans. They include some specialized subterranean populations. The pattern of genetic variation among subterranean and surface populations in this hydrographically highly fragmented karst region was investigat...

2016
Martin Hendrick Philippe Renard

Karstic caves, which play a key role in groundwater transport, are often organized as complex connected networks resulting from the dissolution of carbonate rocks. In this work, we propose a new model to describe and study the structures of the two largest submersed karst networks in the world. Both of these networks are located in the area of Tulum (Quintana Roo, Mexico). In a previous work [1...

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