links between land use and groundwater - governance provisions and management strategies
TRANSCRIPT
Links between land useand groundwater
Governance provisions and
management strategies
Prof Dr Stephen FosterSenior Advisor, Global Water Partnership
Dr Jan CherletInternational Land Coalition Secretariat
Land-use change
Over the past 250 years:
half of ice-free land surface changed by human activity
primary forests 70% turned into arable land
30% into pasture land
Root drivers: growing population, need for food and resources
Water footprint of land-use change
Every change in land use has a water footprint
with long-lasting or irreversable impacts on groundwater
Water footprint of land-use change
Causal chain
need for resources ~ land-use change ~ impact on groundwater
Causal chain
BUT the links
need for resources ~ land-use change ~ impact on groundwater
are not deterministic
Causal chain
BUT the links
need for resources ~ land-use change ~ impact on groundwater
are not deterministic
Need for resources ~ land-use change
before 1950s after 1960
land-use change > pop. growth land-use change < pop. growth
land-use change mostly in
Europe, N-America, Asia
land-use change mostly in
tropical America, tropical Asia
Need for resources ~ land-use change
Need for resources ~ land-use change
since 1960
• global population x 2.3
• demand for food x 3
• agricultural area only +10%
most of production gains from
• intensification
• improved yields
• increase in irrigated agricultural land
Need for resources ~ land-use change
since 1960
• global population x 2.3
• demand for food x 3
• agricultural area only +10%
most of production gains from
• intensification
• improved yields
• increase in irrigated agricultural land
…this will
continue in the
near future
Need for resources ~ land-use change
Need for resources ~ land-use change
today 34% of global irrigated
food production
derives from
groundwaterirrigation
20% of all groundwater-
based food
production is
based on
unsustainable
abstraction
Causal chain
SO the links
need for resources ~ land-use change ~ impact on groundwater
are not deterministic
Facilitating/mitigating factors
Factors Scale of the factors
Causal chain
The links
need for resources ~ land-use change ~ impact on groundwater
are not deterministic
Land-use ~ groundwater
There are different techniques to address groundwater quality and
quantity in land-use planning and land zoning
Land-use ~ groundwater
There are different techniques to address groundwater quality and
quantity in land-use planning and land zoning
General rule:
Limiting land use in specific zones, defined by hydrogeological
criteria, provides better socio-economic and environmental returns
than treating all land equally.
What for? Where exactly? At which scale?
Land-use ~ groundwater
Example: groundwater quality protection
Land-use ~ groundwater
Example: soil salinisation control
Land-use ~ groundwater
Land-use ~ groundwater
Governance instruments to implement these techniques
• Through policies and planning at national level
o constrain diffuse pollution through agricultural guidelines (e.g. EU)
o abate of point-source pollution from agriculture, industry,…
o maintain forest areas or promote exstensive agriculture (in specific areas)
o public awareness raising
• Through regulatory frameworks at meso level
o compulsory consultations between land agency, groundwater agency
o Environmental Impact Assessments
o local land-use planning/zoning
• Through participatory processes or incentives
o agro-environmental management, stewardship schemes (e.g. PES, PWS)
o price setting etc.
Land-use ~ groundwater
Obstacles to a coordinated land~groundwater governance
• legal and institutional impediments
o poorly articulated institutions:
land institutions, groundwater institutions, agricultural institutions, …
o land rights, groundwater rights: better separate
• economic impediments
o land zoning can change the value of land by 200-700%
o those best placed to protect groundwater resources may not be
principal beneficiaries
