dc.description.abstract | Sufficient provision of high-quality drinking water is vital to a healthy society and the prosperity of local
industries, agriculture, and energy sectors. For the sandy Pleistocene regions of the Netherlands, phreatic
aquifers are the primary sources of drinking water. However, future socio-economic and climatological
stresses increasingly exert pressure on the sustainable utilization of these sources; resulting in an onset of
groundwater depletion, drought enhancement, and degradation of groundwater-dependent ecosystems. To
ensure adequate water availability whilst maintaining hydro-environmental functioning, the strategic and
sustainable management of groundwater is crucial. Changing to alternative manners of exploitation (i.e.
strategies) of these regional groundwater sources could help to reduce impacts. However, which alternative
strategies are viable, and how they affect the regional hydro-environment remains poorly understood.
This thesis presents an explorative regional study in pursuit of a sustainable drinking water provision system
from groundwater for these regions. The approach followed the identification and conceptualization of two
innovative alternative extraction strategies: decentralized extractions and seasonal extractions. By a
comprehensive quantitative scenario analysis, specified to the northern Achterhoek as case-study, both
strategies were evaluated by their impacts on regional groundwater levels, soil moisture content, and
evapotranspiration. The hydrological and environmental effects were quantified using the novel developed
geohydrological model AMIGO (v3.1) and compared to a reference scenario for the period 01-04-2004 to
31-12-2019.
The results showed that decentralization, and to less extent seasonal extractions, can have a beneficial effect
on regional groundwater levels. Decentralized extractions indicated a positive relation to the reduction of
local drawdown, increasing under higher quantities of decentralized volumes (0 – 15%). Both the extent
and intensity outweighed the adverse effects at decentral locations. Seasonal extractions were found slightly
less effective (0 – 5%), except when applied in large volumes (5 – 15%), but showed potential to optimize
annual water containment on a regional-scale. The positive effects of both strategies, however, only locally
propagated to soil moisture content (0 – 10%) and minimally enhanced regional evapotranspiration (< 1%).
The deep groundwater tables prohibited effective interactions ensuing changes in groundwater level,
indicating that hydro-environmental functioning could only limitedly be improved under both strategies.
Whilst the results were bilateral, the implications are likely valuable to water managers assessing strategies
from a multi-directional perspective. Inevitably, a transdisciplinary approach is required to meet demand
and achieve a sustainable drinking water provision. This explorative work thereby contributes by paving
the road to more detailed studies and hinting at rough directions of potential future sustainability. | |