scholarly journals Catchment conceptualisation for examining applicability of chloride mass balance method in an area of historical forest clearance

2009 ◽  
Vol 6 (6) ◽  
pp. 7025-7053 ◽  
Author(s):  
H. Guan ◽  
A. Love ◽  
C. T. Simmons ◽  
Z. Ding ◽  
J. Hutson
Keyword(s):  
Mass Balance ◽  
Groundwater Recharge ◽  
Chloride Concentration ◽  
Water Transfer ◽  
Annual Precipitation ◽  
Chloride Mass Balance ◽  
Balance Condition ◽  
Forest Clearance ◽  
Match Type ◽  
Non Equilibrium

Abstract. Among various approaches for estimating groundwater recharge, chloride mass balance (CMB) method is one of the most frequently used, in particular, for arid and semiarid regions. Widespread native vegetation clearance, common history in many areas globally, has changed land surface boundary condition, posing a question whether the current system has reached new chloride equilibrium for CMB application. To examine CMB applicability for catchments, conceptual catchment types of various chloride equilibrium conditions are defined. The conceptualization, combined with some local climate conditions, is demonstrated to be useful in examining whether a catchment has reached new chloride equilibrium. The six conceptual catchment types are tested with eleven selected catchments in the Mount Lofty Ranges (MLR), a coastal hilly area in South Australia having experienced historical widespread forest clearance. The results show that six of the eleven catchments match type VI chloride balance condition (chloride non-equilibrium with a gaining stream), with the ratio of stream chloride output over atmospheric chloride input (catchment chloride O/I) ranging from 2 to 4. Two catchments match type V chloride balance condition (chloride non-equilibrium with a losing stream), with catchment chloride O/I values about 0.5. For these catchments, the CMB method is not appropriate to apply. The results also suggest that neither a below-one chloride O/I value nor a low seasonal fluctuation of streamflow chloride concentration (a factor below 4) guarantees a chloride equilibrium condition in the study area. But a large chloride O/I value (above one) and a large fluctuation of streamflow chloride concentration (a factor of 10 and above) generally indicates either a chloride disequilibrium, or cross-catchment water transfer, or both, for which CMB is not applicable. Based on the regression between chloride O/I values and annual precipitation for type VI catchments, a catchment with annual precipitation of 900 mm in MLR has most likely reached new chloride equilibrium, for which CMB can be applied given that no cross-catchment water transfer occurs. CMB is applied for one catchment at chloride equilibrium, resulted in a net groundwater recharge estimate of 30 mm, about 4% of annual precipitation.

scholarly journals Catchment conceptualisation for examining applicability of chloride mass balance method in an area with historical forest clearance

2010 ◽  
Vol 14 (7) ◽  
pp. 1233-1245 ◽  
Author(s):  
H. Guan ◽  
A. J. Love ◽  
C. T. Simmons ◽  
J. Hutson ◽  
Z. Ding
Keyword(s):  
Mass Balance ◽  
Groundwater Recharge ◽  
Chloride Concentration ◽  
Water Transfer ◽  
Annual Precipitation ◽  
Chloride Mass Balance ◽  
Balance Condition ◽  
Forest Clearance ◽  
Type V ◽  
Historical Forest

Abstract. Of the various approaches for estimating groundwater recharge, the chloride mass balance (CMB) method is one of the most frequently used, especially for arid and semiarid regions. Widespread native vegetation clearance, common in many areas globally, has changed the land surface boundary condition, posing the question as to whether the current system has reached new chloride equilibrium, required for a CMB application. Although a one-dimensional CMB can be applied at a point where the water and chloride fluxes are locally in steady state, the CMB method is usually applied at a catchment scale owing to significant lateral flows in mountains. The applicability of the CMB method to several conceptual catchment types of various chloride equilibrium conditions is examined. The conceptualisation, combined with some local climate conditions, is shown to be useful in assessing whether or not a catchment has reached new chloride equilibrium. The six conceptual catchment types are tested with eleven selected catchments in the Mount Lofty Ranges (MLR), a coastal hilly area in South Australia having experienced widespread historical forest clearance. The results show that six of the eleven catchments match a type VI chloride balance condition (chloride non-equilibrium with a gaining stream), with the ratios of stream chloride output (O) over atmospheric chloride input (I), or catchment chloride O/I ratios, ranging from 2 to 4. Two catchments match a type V chloride balance condition (chloride non-equilibrium with a losing stream), with catchment chloride O/I ratios about 0.5. For these type V and type VI catchments, the CMB method is not applicable. The results also suggest that neither a chloride O/I ratio less than one nor a low seasonal fluctuation of streamflow chloride concentration (a factor below 4) guarantees a chloride equilibrium condition in the study area. A large chloride O/I value (above one) and a large fluctuation of streamflow chloride concentration (a factor of 10 and above) generally indicates either a chloride disequilibrium, or cross-catchment water transfer, or both, for which the CMB method is not applicable. Based on regression between chloride O/I values and annual precipitation for type VI catchments, a catchment with annual precipitation of 900 mm in MLR has most likely reached new chloride equilibrium, and the CMB method can be applied if no cross-catchment water transfer occurs. CMB is applied to one catchment at chloride equilibrium, suggesting a net groundwater recharge of 27 mm/yr, about 3% of annual precipitation.

Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance

2010 ◽  
Vol 45 (4) ◽  
pp. 451-461 ◽  
Author(s):  
Nandana Perera ◽  
Bahram Gharabaghi ◽  
Peter Noehammer ◽  
Bruce Kilgour
Keyword(s):  
Mass Balance ◽  
Management Practices ◽  
Chloride Concentration ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Road Salt ◽  
Winter Period ◽  
Chloride Mass Balance ◽  
Creek Watershed ◽  
Chloride Concentrations

Abstract Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.

Estimating groundwater recharge and its associated uncertainty: Use of regression kriging and the chloride mass balance method

2018 ◽  
Vol 561 ◽  
pp. 1063-1080 ◽  
Author(s):  
Russell S. Crosbie ◽  
Luk J.M. Peeters ◽  
Natasha Herron ◽  
Tim R. McVicar ◽  
Alexander Herr
Keyword(s):  
Mass Balance ◽  
Groundwater Recharge ◽  
Balance Method ◽  
Regression Kriging ◽  
Chloride Mass Balance ◽  
Mass Balance Method

Anion exclusion effects on estimates of soil chloride and deep percolation

Soil Research ◽  
1993 ◽  
Vol 31 (4) ◽  
pp. 455 ◽  
Author(s):  
PG Slavich ◽  
GH Petterson
Keyword(s):  
Mass Balance ◽  
Soil Water ◽  
Electrolyte Concentration ◽  
Chloride Concentration ◽  
Deep Percolation ◽  
Chloride Mass Balance ◽  
Water Extracts ◽  
Mass Balance Models ◽  
Anion Exclusion ◽  
Soil Chloride

Anion exclusion affects estimates of deep percolation determined using chloride mass balance models. This paper evaluates potential errors arising from ignoring anion exclusion in both soil analysis methods and model assumptions. Soil chloride analysis from saturated paste and 1:5 soil/water extracts are compared with that of field soil water extracted using a filter paper technique. The influence of anion exclusion on estimates of soil water chloride concentration (Clsw mmol/L) and chloride content per unit mass of soil (CIT mmol/kg soil), both which are required by chloride mass balance models, is examined for these methods. The relative importance of total electrolyte concentration and sodium absorption ratio (SAR) on the anion exclusion volume of a clay was also determined using a simple laboratory leaching technique. The chloride concentration of soil water at field moisture contents was more closely related to estimates calculated from saturated paste extracts than from 1:5 soil/water extracts. Although the amount of excluded water estimated in the saturated paste was larger than that estimated at the field water content, the proportion of non-excluded water in each was similar. The ClT was overestimated when analysis from saturation extracts was used. Electrolyte concentration and SAR were shown to have similar (but opposite) relative effects on the exclusion volume. However, because these variables were positively correlated, their effects were not apparent in the field samples. For the clay soil under study, deep percolation could be overestimated by up to 1.64 times if anion exclusion effects were ignored when using 1:5 extracts to estimate Clsw. The errors were considerably less if saturation extracts were used to estimate Clsw and ClT.

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