https://web.iitd.ac.in/~arunku/files/CEL311_Y13/Adsorption%20Theory%20to%20practice_Dabrowski.pdf

Adsorption — from theory to practice

The interactions between groundwater and surface water are complex. To understand these interactions in relation to climate, landform, geology, and biotic factors, a sound hydrogeoecological framework is needed. All these aspects are synthesized and exemplified in this overview. In addition, the mechanisms of interactions between groundwater and surface water (GW–SW) as they affect recharge–discharge processes are comprehensively outlined, and the ecological significance and the human impacts of such interactions are emphasized. Surface-water and groundwater ecosystems are viewed as linked components of a hydrologic continuum leading to related sustainability issues. This overview concludes with a discussion of research needs and challenges facing this evolving field. The biogeochemical processes within the upper few centimeters of sediments beneath nearly all surface-water bodies (hyporheic zone) have a profound effect on the chemistry of the water interchange, and here is where most of the recent research has been focusing. However, to advance conceptual and other modeling of GW–SW systems, a broader perspective of such interactions across and between surface-water bodies is needed, including multidimensional analyses, interface hydraulic characterization and spatial variability, site-to-region regionalization approaches, as well as cross-disciplinary collaborations.

/pdf/interactions-between-groundwater-and-surface-water-the-state-521l9polte.pdf

Interactions between groundwater and surface water: the state of the science

DOI 10.1007/s10040-0010176-2 Abstract Various techniques are available to quantify recharge; however, choosing appropriate techniques is often difficult. Important considerations in choosing a technique include space/time scales, range, and reliabili- ty of recharge estimates based on different techniques; other factors may limit the application of particular tech- niques. The goal of the recharge study is important be- cause it may dictate the required space/time scales of the recharge estimates. Typical study goals include water-re- source evaluation, which requires information on re- charge over large spatial scales and on decadal time scales; and evaluation of aquifer vulnerability to contam- ination, which requires detailed information on spatial variability and preferential flow. The range of recharge rates that can be estimated using different approaches should be matched to expected recharge rates at a site. The reliability of recharge estimates using different tech- niques is variable. Techniques based on surface-water and unsaturated-zone data provide estimates of potential recharge, whereas those based on groundwater data gen- erally provide estimates of actual recharge. Uncertainties in each approach to estimating recharge underscore the need for application of multiple techniques to increase

http://images.water.nv.gov/images/Misc/spring%20valley%20hearings/SNWA/568.pdf

Choosing appropriate techniques for quantifying groundwater recharge

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

/pdf/ground-water-and-climate-change-2rw9i70xw8.pdf

Ground water and climate change

http://files.aprendiendoquimica7.webnode.com.co/200000006-1247d13423/Limousin,%20G%20et%20al.%20Sorption%20Isotherms%20A%20review%20on%20Physical%20Bases,%20modeling%20and%20measurement.pdf

Sorption isotherms: A review on physical bases, modeling and measurement

Theoretically, three types of flow systems may occur in a small basin: local, intermediate, and regional. The local systems are separated by subvertical boundaries, and the systems of different order are separated by subhorizontal boundaries. The higher the topographic relief, the greater is the importance of the local systems. The flow lines of large unconfined flow systems do not cross major topographic features. Stagnant bodies of groundwater occur at points where flow systems meet or branch. Recharge and discharge areas alternate; thus only part of the basin will contribute to the baseflow of its main stream. Motion of groundwater is sluggish or nil under extended flat areas, with little chance of the water being freshened. Water level fluctuations decrease with depth, and only a small percentage of the total volume of the groundwater in the basin participates in the hydrologic cycle.

A Theoretical Analysis of Groundwater Flow in Small Drainage Basins

Multiwall carbon nanotubes purification and oxidation by nitric acid studied by the FTIR and electron spectroscopy methods

On the basis of the parallel pattern of the water divides and the valleys in parts of central Alberta and the inferred difference in permeability between the Paskapoo and Edmonton formations, basins are considered to be separate units of flow in the groundwater regime. For the cross-sectional distribution of the fluid potential in a basin of homogeneous lithology an equation is found that relates the fluid potential to the acceleration of gravity, topographic gradient of the valley flank, horizontal distance between water divide and valley bottom, elevation of the water table at the valley bottom above the horizontal impermeable boundary, elevation above the horizontal impermeable boundary, and horizontal distance from the valley bottom. The validity of the assumption that groundwater runoff is discharged mainly at the valley bottoms is disputed. A boundary between areas of recharge and discharge is proved mathematically. A theory is advanced to explain the systematic deviation of the theoretical value of the fluid potential from the observed values. Local anomalies of the piezometric surface are accounted for by the presence of lenticular bodies of relatively high permeability. Mathematical formulas are used to express the relation between those anomalies and the permeability ratios and the size and shape of the lenses. A schematic cross section of possible potential distribution and flow pattern across a watershed is presented.

/pdf/a-theory-of-groundwater-motion-in-small-drainage-basins-in-4j467c0vdi.pdf

A theory of groundwater motion in small drainage basins in central Alberta, Canada

The objective of the present paper is to show that groundwater is a general geologic agent. This perception could not, and did not, evolve until the system nature of basinal groundwater flow and its properties, geometries, and controlling factors became recognized and understood through the 1960s and 1970s.

József Tóth

Papers

A Theoretical Analysis of Groundwater Flow in Small Drainage Basins

Multiwall carbon nanotubes purification and oxidation by nitric acid studied by the FTIR and electron spectroscopy methods

A theory of groundwater motion in small drainage basins in central Alberta, Canada

Groundwater as a geologic agent: An overview of the causes, processes, and manifestations

C sp2/sp3 hybridisations in carbon nanomaterials – XPS and (X)AES study