نتایج جستجو برای: karst

تعداد نتایج: 4636  

2003
MASON D. BRYANT DOUGLAS N. SWANSTON

Study area.-All the study streams are on the northern quarter of Prince of Wales Island (Figure 1) and traverse a mixture of karst and nonkarst geology. Some streams are fed directly by resurgence from limestone caves, whereas others are fed by overland flow. Hecata Limestone and Bay of Pillars are the major karst formations (Wissmar et al. 1997). Many of the streams flow along contact zones be...

2012
Cyril Fleurant G. E. Tucker H. A. Viles C. Fleurant H. A. VILES

The purpose of this article is to present a model of the formation processes of cockpit karst landscapes. The CHILD software was used to simulate landscape evolution including dissolution processes of carbonate rocks. After examining briefly how the CHILD model operates, two applications of this model involving dissolution of carbonate rocks are presented. The simulated landscapes are compared ...

2016
Martin Hendrick Philippe Renard

Understanding the complex structure of karst networks is a challenge. In this work, we characterize the fractal properties of some of the largest coastal karst network systems in the world. They are located near the town of Tulum (Quintana Roo, Mexico). Their fractal dimension df , conductivity exponent μ̃ and walk dimension dw are estimated using real space renormalization and numerical simulat...

2012
M. D. Covington A. J. Luhmann C. M. Wicks M. O. Saar

[1] Simple mathematical models often allow an intuitive grasp of the function of physical systems. We develop a mathematical framework to investigate reactive or dissipative transport processes within karst conduits. Specifically, we note that for processes that occur within a characteristic timescale, advection along the conduit produces a characteristic process length scale. We calculate char...

2013
Fuyuan Liang Yunyan Du

Mapping specific landform entities in the past is mainly achieved by manually examining contour lines on topographic maps. Automated delimitation of specific landform from digital elevation data remains difficult in geomorphologic mapping. This paper presents a method to automatically identify five common surface features of karst landscapes: isolated karst hill or sinkhole, clustered karst hil...

Journal: :Ground water 2007
Lee J Florea H L Vacher

Eogenetic karst lies geographically and temporally close to the depositional environment of limestone in warm marine water at low latitude, in areas marked by midafternoon thunderstorms during a summer rainy season. Spring hydrographs from such an environment in north-central Florida are characterized by smooth, months-long, seasonal maxima. The passage of Hurricanes Frances and Jeanne in Septe...

2015
Junjie Tao Qingwen Qi Ming Kang Hongwen Huang Maria Anisimova

Limestone Karst areas possess high levels of biodiversity and endemism. Primulina is a typical component of Karst endemic floras. The high species richness and wide distribution in various Karst microenvironments make the genus an idea model for studying speciation and local adaptation. In this study, we obtained 10 full-length sequences of the phytochrome PHYE from available transcriptome reso...

2017
Zhenxing Jia Hongfei Zang Xiuqing Zheng Yongxin Xu Marco Franchini

Due to climate change and human activities over the last fifty years, the spring flow volume of karst groundwater has sharply diminished in China. Climate change is one of the critical factors that initiates a series of karst hydrogeologic and water ecological environmental problems, because the precipitation shows a decreasing trend while the temperature shows an increasing trend. The Jinci Sp...

2018
Nalaka Geekiyanage Uromi Manage Goodale Kunfang Cao Kaoru Kitajima

Karst hills, that is, jagged topography created by dissolution of limestone and other soluble rocks, are distributed extensively in tropical forest regions, including southern parts of China. They are characterized by a sharp mosaic of water and nutrient availability, from exposed hilltops with poor soil development to valleys with occasional flooding, to which trees show species-specific distr...

Journal: :Environmental science & technology 2014
Helen P Jarvie Andrew N Sharpley Van Brahana Tarra Simmons April Price Colin Neal Alan J Lawlor Darren Sleep Sarah Thacker Brian E Haggard

Karst landscapes are often perceived as highly vulnerable to agricultural phosphorus (P) loss, via solution-enlarged conduits that bypass P retention processes. Although attenuation of P concentrations has been widely reported within karst drainage, the extent to which this results from hydrological dilution, rather than P retention, is poorly understood. This is of strategic importance for und...

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