TY  - JOUR
A1  - Böttcher, Steven
A1  - Merz, Christoph
A1  - Lischeid, Gunnar
A1  - Dannowski, Ralf
T1  - Using Isomap to differentiate between anthropogenic and natural effects on groundwater dynamics in a complex geological setting
JF  - Journal of hydrology
N2  - Due to increasing demands and competition for high quality groundwater resources in many parts of the world, there is an urgent need for efficient methods that shed light on the interplay between complex natural settings and anthropogenic impacts. Thus a new approach is introduced, that aims to identify and quantify the predominant processes or factors of influence that drive groundwater and lake water dynamics on a catchment scale. The approach involves a non-linear dimension reduction method called Isometric feature mapping (Isomap). This method is applied to time series of groundwater head and lake water level data from a complex geological setting in Northeastern Germany. Two factors explaining more than 95% of the observed spatial variations are identified: (1) the anthropogenic impact of a waterworks in the study area and (2) natural groundwater recharge with different degrees of dampening at the respective sites of observation. The approach enables a presumption-free assessment to be made of the existing geological conception in the catchment, leading to an extension of the conception. Previously unknown hydraulic connections between two aquifers are identified, and connections revealed between surface water bodies and groundwater. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Groundwater
KW  - Lake
KW  - Interaction
KW  - Isometric feature mapping
KW  - Time series analysis
Y1  - 2014
U6  - https://doi.org/10.1016/j.jhydrol.2014.09.048
SN  - 0022-1694
SN  - 1879-2707
VL  - 519
SP  - 1634
EP  - 1641
PB  - Elsevier
CY  - Amsterdam
ER  -