73
while in other areas larger changes were observed with a range between −4.94 and
3.21 m year
−1
WL (wells 3TA and 6TA). Significant values of water level depletion
of wells of the order of 0.82 to −28.34 m year
−1
were observed (31SD, 37SD, and
29TA wells of the TA and SD aquifers).
Considering the average annual abatement rate estimated in this analysis
(2.01 m year
−1
) as a metric basis to diagnose seasonal trends, it was found that in
43% of the wells for this purpose (3TA, 71LH, and 76LH, Fig. 4.4b), more than
75% of that average was obtained; about 30% of the other wells reached between 20
and 40% (36SD and 42SD), in the rest wells <5%. This can mean a continuing trend
of depletion that may lead to a condition of water risk assessment (Brauman et al.
2016). In some wells, seasonally the rate of depletion can be converted into the
recharge rate, for example, between summer 2015 and 2016 at well 71LH, the Da
value changes from −8.1 to 3.7.
What we can see in these very diverse WL trends is the great need to continue to
monitor the depth of WL, but permanently and over a wider network of wells that
ensure reliable results in order to make projections and recommendations for sustainable management of aquifers to decision makers. Based on the results presented
here and assuming that the drop rates remain constant, the results point to an aggressive depletion of the aquifers that, if occurring, would bring serious economic and
social consequences to the region, such as an increase in the extraction costs and
conflicts among water users, e.g., agriculture vs. urban (Korus and Burbach 2009).
The large number of wells with signs of unsustainable depletion, mainly due to the
use of agricultural and domestic areas in urban areas in the aquifer TA (see Fig. 4.3),
as well as the opening of new agricultural wells in SD and LH by agricultural and
industrial activities, suggests that in a year ahead the level of wells will decrease
further, worsening the problem of groundwater availability.
To offset the depletion of aquifers in drylands, several options have been proposed, including reusing reclaimed water, artificial aquifer recharge, and waterefficient irrigation and plumbing fixtures (Gale 2005; Brauman et al. 2016). Even
though these options are given serious consideration, it is unlikely that the water
management practices in the study area will change rapidly enough to counteract
the rapid rate at which the aquifers are being depleted. The implementation of effective policies that would add sustainable practices is therefore a key factor for an
integral planning of water resources in the region. Despite these uncertainties, there
are numerous attempts at all levels of government and society to develop favorable
policy environments, build resilient management institutions, synthesize available
science, and increase the consciousness and participation of communities to protect
and promote the sustainable use of groundwater in SES of drylands (Morsy et al.
2017). An important component of aquifer management is the volume utilized for
irrigation in the agricultural sector, and a deciding factor for farmers to switch to
water-efficient irrigation systems water is the offering of incentives towards their
implementation. Since such incentives are not in place, farmers grow the more profitable crops, e.g., alfalfa, cotton, and pecans, which are water-intensive WL. Proper
water-saving incentives could significantly slow down the present rate of aquifer
abatement (Steward and Allen 2016; Scanlon et al. 2012). The land use changes also
4 Changes in the Vegetation Cover and Quality of Aquifers in the Drylands of Mexico…
while in other areas larger changes were observed with a range between −4.94 and
3.21 m year
−1
WL (wells 3TA and 6TA). Significant values of water level depletion
of wells of the order of 0.82 to −28.34 m year
−1
were observed (31SD, 37SD, and
29TA wells of the TA and SD aquifers).
Considering the average annual abatement rate estimated in this analysis
(2.01 m year
−1
) as a metric basis to diagnose seasonal trends, it was found that in
43% of the wells for this purpose (3TA, 71LH, and 76LH, Fig. 4.4b), more than
75% of that average was obtained; about 30% of the other wells reached between 20
and 40% (36SD and 42SD), in the rest wells <5%. This can mean a continuing trend
of depletion that may lead to a condition of water risk assessment (Brauman et al.
2016). In some wells, seasonally the rate of depletion can be converted into the
recharge rate, for example, between summer 2015 and 2016 at well 71LH, the Da
value changes from −8.1 to 3.7.
What we can see in these very diverse WL trends is the great need to continue to
monitor the depth of WL, but permanently and over a wider network of wells that
ensure reliable results in order to make projections and recommendations for sustainable management of aquifers to decision makers. Based on the results presented
here and assuming that the drop rates remain constant, the results point to an aggressive depletion of the aquifers that, if occurring, would bring serious economic and
social consequences to the region, such as an increase in the extraction costs and
conflicts among water users, e.g., agriculture vs. urban (Korus and Burbach 2009).
The large number of wells with signs of unsustainable depletion, mainly due to the
use of agricultural and domestic areas in urban areas in the aquifer TA (see Fig. 4.3),
as well as the opening of new agricultural wells in SD and LH by agricultural and
industrial activities, suggests that in a year ahead the level of wells will decrease
further, worsening the problem of groundwater availability.
To offset the depletion of aquifers in drylands, several options have been proposed, including reusing reclaimed water, artificial aquifer recharge, and waterefficient irrigation and plumbing fixtures (Gale 2005; Brauman et al. 2016). Even
though these options are given serious consideration, it is unlikely that the water
management practices in the study area will change rapidly enough to counteract
the rapid rate at which the aquifers are being depleted. The implementation of effective policies that would add sustainable practices is therefore a key factor for an
integral planning of water resources in the region. Despite these uncertainties, there
are numerous attempts at all levels of government and society to develop favorable
policy environments, build resilient management institutions, synthesize available
science, and increase the consciousness and participation of communities to protect
and promote the sustainable use of groundwater in SES of drylands (Morsy et al.
2017). An important component of aquifer management is the volume utilized for
irrigation in the agricultural sector, and a deciding factor for farmers to switch to
water-efficient irrigation systems water is the offering of incentives towards their
implementation. Since such incentives are not in place, farmers grow the more profitable crops, e.g., alfalfa, cotton, and pecans, which are water-intensive WL. Proper
water-saving incentives could significantly slow down the present rate of aquifer
abatement (Steward and Allen 2016; Scanlon et al. 2012). The land use changes also
4 Changes in the Vegetation Cover and Quality of Aquifers in the Drylands of Mexico…