scholarly journals Simulation of 1D surface and 2D subsurface water flow and nitrate transport in alternate and conventional furrow fertigation

2011 ◽  
Vol 31 (3) ◽  
pp. 301-316 ◽  
Author(s):  
Hamed Ebrahimian ◽  
Abdolmajid Liaghat ◽  
Masoud Parsinejad ◽  
Enrique Playán ◽  
Fariborz Abbasi ◽  
...  
2015 ◽  
Vol 520 ◽  
pp. 123-133 ◽  
Author(s):  
Yong Li ◽  
Jirka Šimůnek ◽  
Zhentin Zhang ◽  
Manli Huang ◽  
Lixiao Ni ◽  
...  
Keyword(s):  

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 121 ◽  
Author(s):  
Laura Gatel ◽  
Claire Lauvernet ◽  
Nadia Carluer ◽  
Sylvain Weill ◽  
Claudio Paniconi

The migration and fate of pesticides in natural environments is highly complex. At the hillslope scale, the quantification of contaminant fluxes and concentrations requires a physically based model. This class of model has recently been extended to include coupling between the surface and the subsurface domains for both the water flow and solute transport regimes. Due to their novelty, the relative importance of and interactions between the main model parameters has not yet been fully investigated. In this study, a global Sobol sensitivity analysis is performed on a vineyard hillslope for a one hour intensive rain event with the CATHY (CATchment HYdrology) integrated surface/subsurface model. The event-based simulation involves runoff generation, infiltration, surface and subsurface solute transfers, and shallow groundwater flow. The results highlight the importance of the saturated hydraulic conductivity K s and the retention curve shape parameter n and they reveal a strong role for parameter interactions associated with the exchange processes represented in the model. The mass conservation errors generated by the model are lower than 1% in 99.7% of the simulations. Boostrapping analysis of sampling methods and errors associated with the Sobol indices highlights the relevance of choosing a large sampling size (at least N = 1000) and raises issues associated with rare but extreme output results.


2020 ◽  
Vol 17 (3) ◽  
pp. 641-652 ◽  
Author(s):  
Zhen Han ◽  
Xiao-yan Chen ◽  
Yu-han Huang ◽  
Bang-lin Luo ◽  
Hang Xing ◽  
...  

2011 ◽  
Vol 30 (1) ◽  
pp. 85-105 ◽  
Author(s):  
Lee Florea ◽  
H. Vacher

The direction of cave and karst science throughout its history has been partly determined by communication—or, more commonly, the lack of communication—between non-scientist cavers and non-caving physical geologists writing about karst. Within each community, advancement of ‘cave awareness’ occurred through a hermeneutic circle in which ‘forestructures’ guided progress. One result was regionalism of speleo-genetic theories developed within karst science because of the weight of evidence placed upon local or regional observations. Many speleogenetic theories of the mid-1900s suffer from this parochialism, failing to take into account findings from karst of different geologic settings. During the past half-century, the accumulated worldwide data on caves and karst suggest larger, more encompassing theories of speleogenesis. One such example of how speleogenetic theories have changed, partly explored in this essay, is the relation of cave formation to the position of the water-table. In many karst aquifers, including but not limited to alpine systems, one modern view envisions the enlargement of caves to proceed in a punctuated manner, driven by floods.


2014 ◽  
Vol 15 (2) ◽  
pp. 327-338 ◽  
Author(s):  
Shiyang Li ◽  
Rabin Bhattarai ◽  
Li Wang ◽  
Richard A. Cooke ◽  
Fang Ma ◽  
...  

Because of increased use of fertilizers to feed the increasing global population, the nutrient loads in surface and subsurface water have increased substantially in the last few decades. Many studies have been conducted to investigate the factors affecting nitrate load in surface and subsurface flow. The objective of this study is to investigate the relationship between the various factors affecting nitrate transport using principal component analysis (PCA) and nearest neighborhood analysis methods. Hydrological and biogeochemical data from a small (<500 km2) agricultural watershed in east central Illinois, USA for the duration of 10 years have been used in this study. The PCA approach divided various factors that influence nitrate transport into three principal components. The first component contained air temperature, cover phenotype, evapotranspiration, cover factor and dry mass factors. The second component contained precipitation and flow, which was defined as the hydrologic component. The third component included tillage practices and nitrogen application and was termed the anthropogenic component. The results from the PCA approach suggested all three components had significant influence on nitrate transportation and transformation. Among these three components, the hydrological components had the highest contribution on both surface and subsurface nitrate load. The nearest neighborhood analysis yielded a similar conclusion.


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