 |
| Titel |
Regional-scale identification of groundwater-surface water interaction using hydrochemistry and multivariate statistical methods, Wairarapa Valley, New Zealand |
| VerfasserIn |
M. R. Guggenmos, C. J. Daughney, B. M. Jackson, U. Morgenstern |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 11 ; Nr. 15, no. 11 (2011-11-15), S.3383-3398 |
| Datensatznummer |
250013020
|
| Publikation (Nr.) |
 copernicus.org/hess-15-3383-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| Identifying areas of interaction between groundwater and surface water is
crucial for effective environmental management, because this interaction is
known to influence water quantity and quality. This paper applies
hydrochemistry and multivariate statistics to identify locations and
mechanisms of groundwater-surface water interaction in the pastorally
dominated Wairarapa Valley, New Zealand. Hierarchical Cluster Analysis (HCA)
and Principal Components Analysis (PCA) were conducted using site-specific
median values of Ca, Mg, Na, K, HCO3, Cl, SO4 and electrical
conductivity from 22 surface water sites and 246 groundwater sites. Surface
water and groundwater monitoring sites were grouped together in three of the
seven clusters identified by HCA, with the inference made that similarities
in hydrochemistry indicate groundwater-surface water interaction. PCA
indicated that the clusters were largely differentiated by total dissolved
solids concentration, redox condition and ratio of major ions. Shallow
aerobic groundwaters, located in close proximity to losing reaches of
rivers, were grouped with similar Ca-HCO3 type surface waters,
indicating potential recharge to aquifers from these river systems.
Groundwaters that displayed a rainfall-recharged chemical signature with
higher Na relative to Ca, higher Cl relative to HCO3 and an
accumulation of NO3 were grouped with neighbouring surface waters,
suggesting the provision of groundwater base flow to these river systems and
the transfer of this chemical signature from underlying aquifers. The
hydrochemical techniques used in this study did not reveal
groundwater-surface water interaction in some parts of the study area,
specifically where deep anoxic groundwaters, high in total dissolved solids
with a distinct Na-Cl signature, showed no apparent link to surface water.
The drivers of hydrochemistry inferred from HCA and PCA are consistent with
previous measurements of 18O, water age and excess air. Overall, this
study has shown that multivariate statistics can be used as a rapid method
to identify groundwater-surface water interaction at a regional scale using
existing hydrochemical datasets. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|