8 Groundwater Resources of Poland
153
within the borders of river basins and water catchment areas. It could be assumed
that a large water catchment area is approximately proportional to the underground
basin. Consequently, multiannual meteorological and hydrogeological data can be
found for river drainage areas, and additionally, for the majority of catchment areas
and water economic regions in Poland, there is abundant hydrogeological documentation containing disposable groundwater resources assessment calculated using the
numerical flow models.
The most important feature of groundwater reservoirs, from the perspective of
disposable resource assessments, is the sustainability of their resources understood
as regular replenishment of groundwater resources of a particular reservoir using
natural infiltration of meteoric water in order to complement the loss of groundwater
due to natural drainage or exploitation.
According to Krajewski [30], disposable resources of aquifer levels in hydraulic
connection with surface waters should be understood as renewable resources reduced
by underground run-off ensuring the natural river flow, which protects aquatic life
and other environmental resources and qualities. The author also claims that the
definition above does not concern Artesian aquifers and other forms of deep groundwater occurrence, where there is no direct link between groundwater and surface
waters. Paczy´ nski [31] emphasized a close connection between groundwater renewable and disposable resources, maintaining that the former guarantee the credibility
and sustainability of disposable resources, their position in the water balance, and
indirectly, environmental consequences of water extraction. According to him, the
quantitative characteristics of groundwater recharge form an integral part of the
model simulation of disposable and exploitable resources.
The first stage in the process of identifying disposable resources in the balance
area using this method is the assessment of groundwater resource sustainability.
The size of groundwater sustainability is determined by the average value of the
multiannual groundwater run-off to rivers, which is most frequently accepted to be
equal to the multiannual mean low flow (SNQ) in rivers [32–34]. The SNQ value,
which is the result of hydrological measurements, is the starting point in the process
of disposable groundwater resources assessment using the method in question. By
identifying sustainability with efficient infiltration recharge, it is possible to assess
the distribution of the water recharge within the borders of a given water balance area
using the constant volume conversion method [35]. The weighting factors controling
the distribution of water recharge is here the lithology of surface formations and the
distribution of mean long-term precipitation rates.
The second stage of disposable resources identification concerns the development
of the mathematical model for groundwater flow in which the estimated distribution of
water recharge, equal to the groundwater run-off to rivers, is a boundary condition. At
this stage, the criteria of disposable resources assessment as well as weighting factors
controlling their distribution are defined. Using the method of successive approximations, it is possible to determine the participation of disposable resources in the
overall renewable resources as well as the proportion of disposable resources division
between the modelled aquifers [36]. The distribution of the disposable resources in
153
within the borders of river basins and water catchment areas. It could be assumed
that a large water catchment area is approximately proportional to the underground
basin. Consequently, multiannual meteorological and hydrogeological data can be
found for river drainage areas, and additionally, for the majority of catchment areas
and water economic regions in Poland, there is abundant hydrogeological documentation containing disposable groundwater resources assessment calculated using the
numerical flow models.
The most important feature of groundwater reservoirs, from the perspective of
disposable resource assessments, is the sustainability of their resources understood
as regular replenishment of groundwater resources of a particular reservoir using
natural infiltration of meteoric water in order to complement the loss of groundwater
due to natural drainage or exploitation.
According to Krajewski [30], disposable resources of aquifer levels in hydraulic
connection with surface waters should be understood as renewable resources reduced
by underground run-off ensuring the natural river flow, which protects aquatic life
and other environmental resources and qualities. The author also claims that the
definition above does not concern Artesian aquifers and other forms of deep groundwater occurrence, where there is no direct link between groundwater and surface
waters. Paczy´ nski [31] emphasized a close connection between groundwater renewable and disposable resources, maintaining that the former guarantee the credibility
and sustainability of disposable resources, their position in the water balance, and
indirectly, environmental consequences of water extraction. According to him, the
quantitative characteristics of groundwater recharge form an integral part of the
model simulation of disposable and exploitable resources.
The first stage in the process of identifying disposable resources in the balance
area using this method is the assessment of groundwater resource sustainability.
The size of groundwater sustainability is determined by the average value of the
multiannual groundwater run-off to rivers, which is most frequently accepted to be
equal to the multiannual mean low flow (SNQ) in rivers [32–34]. The SNQ value,
which is the result of hydrological measurements, is the starting point in the process
of disposable groundwater resources assessment using the method in question. By
identifying sustainability with efficient infiltration recharge, it is possible to assess
the distribution of the water recharge within the borders of a given water balance area
using the constant volume conversion method [35]. The weighting factors controling
the distribution of water recharge is here the lithology of surface formations and the
distribution of mean long-term precipitation rates.
The second stage of disposable resources identification concerns the development
of the mathematical model for groundwater flow in which the estimated distribution of
water recharge, equal to the groundwater run-off to rivers, is a boundary condition. At
this stage, the criteria of disposable resources assessment as well as weighting factors
controlling their distribution are defined. Using the method of successive approximations, it is possible to determine the participation of disposable resources in the
overall renewable resources as well as the proportion of disposable resources division
between the modelled aquifers [36]. The distribution of the disposable resources in