The Relationship between Agriculture, Economic Activity, Settlement Patterns and River Water Quality 1991-2011

Cathal O’Donoghue*, Cathal Buckley*, Aksana Chyzheuskaya*, Stuart Green*, Peter Howley**, Stephen Hynes***, Vincent Upton*

* Teagasc Rural Economy and Development Programme** University of York

*** National University of Ireland, Galway

Project Funded by EPA-Strive

Research Question

Relationship between economic drivers and water quality

Economic Drivers Agriculture Settlement and Water Treatment Industrial Structure

Water Quality Ecological Status

Environmental Context Soils Elevation Weather

Literature

Local or Catchment Scale O’Dywer et al, 2013

National Scale Donohoe et al (2005)

Bivariate correlations water chemistry O’Donoghue et al (2010)

Ordered Probit QValues Curtis and Morgenroth (2013)

Lakes Regression Model Chemical measures

Not a static relationship

Research Gap Trends over time

Drivers of Water Quality

Intensity The intensity of activity such as the livestock density, the

population density or the extent of septic tanks Efficiency

The environmental efficiency in terms of the relationship between a given level of activity and water quality

Environmental Context Local hydrological conditions

Data

Water Quality Ecological status as measured by Q-Values collected by EPA Q-values – ordered from 1 – Bad to 5 – High Target to get to Q-Value 4-5 under Water Framework Directive

Economic Activity and Septic Tanks Census of Population

Agricultural and Forestry Activity Census of Agriculture Forestry Service Data

Hydrological Characteristics Teagasc Spatial Data Archive

Link spatial attributes to downstream water quality points Study period 1991-2011

Summary StatisticsShare of Q-value 1-3

10

12

14

16

18

20

22

24

1985 1990 1995 2000 2005 2010 2015

Sha

re Q

V <

= 3

Downward trend in share of worst water quality over time

Trends in Water Quality (Share by Q-Value)

QV 1991 2002 2011

Worst 1.9 0.2 0.7

2 7.1 4.0 2.0

3 16.4 16.07 14.2

4 37.7 56.7 68.4

Best 26.9 23.0 16.6

Share unsatisfactory

25.4 20.3 16.9

Biggest Reduction in worst water quality areasHowever also a reduction in best areasGreater Bunching in Q-value 4

Trends in Intensity Variables (1991 – 100)

year Septic Tank Density Organic N per ha

1991 100.0 100.0

2002 116.5 94.7

2011 119.7 81.3

Increase in Septic Tanks Density over time, - but reduction in Organic N per hectareshift in intensities

Kernel Density – Organic N

0.0

05

.01

.01

5D

ensi

ty

0 50 100 150 200mned_org_N_perhet

2002 2011

kernel = epanechnikov, bandwidth = 5.3594

Kernel density estimate

Distribution of Organic N per ha across space between 2002-2011-Shifted to left, reflecting lower mean-More variable

Kernel Density – Septic Tank Density

0.0

2.0

4.0

6.0

8.1

Den

sity

0 10 20 30 40 50SepticTanksDensity

2011 2002

kernel = epanechnikov, bandwidth = 0.8739

Kernel density estimate

Little difference in distribution of Septic Tanks (except at tails)

Unsatisfactory Water Quality 1991-93 to 2009-2011

Fewer Unsatisfactory – particularly in SWSituation worse in NWConcentrations around Dublin, Coastal Towns, Border, W. Limerick, E. Donegal

Model Results – Basic Model

Model 1: Basic Model Pseudo R2 0.35% Septic Tanks –ve ** Organic N per ha –ve **

Model 2: Inter-temporal Model Pseudo R2 1.76% Septic Tanks –ve ** Organic N per ha –ve ** Organic N per ha x 1991 -ve Organic N per ha x 2011 +ve ** Cereal Share –ve** Cereal Share x 2002 +ve** Cereal Share x 2011 +ve**

Model 1: “Correct signs”, water quality worsens with more Organic N & Septic TanksModel 2: No change in relationship with septic tanks, improves for given Organic N and Cereal Share

Model Results – Inter-temporal and Industry Models

Model 3 Inter-temporal Model + Industry Pseudo R2 5.3% Septic Tanks –ve ** Organic N per ha –ve ** Organic N per ha x 1991 -ve Organic N per ha x 2011 +ve ** Cereal Share –ve** Cereal Share x 2002 +ve** Cereal Share x 2011 +ve** Landfill within 3km – ve** Cumulative Afforestation +ve** Pigs per ha - ve Poultry per ha - ve Sectors (Industry, Commerce, Public Sector, Other) - ve**

Model 3: Conclusions Robust to more sectors

Model Results – Inter-temporal and Environmental Models

Model 4 Inter-temporal Model + Industry + Environment (Soil, elevation, weather, X/Y) Pseudo R2 9.3% Septic Tanks –ve ** Organic N per ha –ve ** Organic N per ha x 1991 -ve Organic N per ha x 2011 +ve ** Cereal Share –ve** Cereal Share x 2002 +ve Cereal Share x 2011 +ve** Landfill within 3km – ve** Cumulative Afforestation +ve** Pigs per ha - ve** Poultry per ha – ve Sectors (Commerce) - ve**

Model 3: Addition of environmental variables improve fit, but results robust

Model Results – Geographically Weighted Regression

There is an existence of spatial correlation Use of GWR has a consistent story as OLS model however

Dependent Variable – Good Water Quality (QV 4-5) Model 5: Inter-temporal Model + Environmental + County dummies

Pseudo R2 13.9% (Logit) Septic Tanks –ve ** Septic Tanks x 1991 –ve** Septic Tanks x 2011 +ve Organic N per ha –ve ** Organic N per ha x 1991 -ve Organic N per ha x 2011 +ve ** Cumulative Afforestation +ve** Pigs per ha - ve** Poultry per ha – ve* Sectors (Commerce, Other) - ve**

Model 5: Conclusions Robust to more spatial correlation

Drivers of Improvement

The improvement in the relationship between Agricultural Activity and Water Quality is unsurprising given Investment of €2.9 billion by farmers between 2005 and 2011 on

improved facilities, Improved farm management practices, including closed periods and

minimum storage requirements More efficient use of fertiliser, Significant participation in Agri-Environmental improvement

programmes and Compliance with Nitrates Directives and compliance with cross-

compliance measures within the Common Agricultural Policy.

Drivers of Improvement

It should be noted that Environmental lag times are also quite long for practice improvement

and investments to impact upon water quality, so it is expected that these investments will have a stronger impact into the future

• Many of the measures that improve water quality have the win-win of improving profitability.

Incentives created by public policy and the active participation by farmers Have been instrumental in this improved situation.

Sustainable farm practice is a vital pillar in underpinning Ireland’s Green image that is central to the Food Harvest 2020 strategy

Policy Solutions

Data Challenges Data QV value points only sampled once every 3 years variation due to weather over

year Agricultural Catchments – 6 catchments, with continuous monitoring

Weather Hydrology Stocking Rate

Measures have been successful on average Challenge to target those areas with QV3 Maintaining QV5’s even more challenging

Improvements Localised not generally across country Localised rather than national solutions?

More efficient to target problems rather than have a national solution Farm Level MAC analysis farms have their own MAC curves

Regulation may not be optimal.

Summary and Conclusions

Coefficient on Septic Tanks Constant over time, but density of septic tanks increasing Contribution of septic tanks to water quality increasing

Coefficient on Organic N (Agriculture) falling significantly between 2000 and 2010 and density of Organic N falling Production Function of Agriculture becoming more efficient Tallies with policy and investment changes

Consistent with field studies Lalor et al. (2010) report a reduction in soils with excessively high levels of P over that

period; At the national level, P fertiliser use has declined by 6 kg ha-1 (55 %) for grassland

and 5 kg ha-1 (16-30 %) for arable crops between 2003 and 2008. P-problem growing

The proportion of tested soils with excessive P (Index 4) has declined from 30 % to 22 % between 2007 and 2011 (Lalor et al., 2010), falling to 18% in 2012.

Thank You

Proving Green Credentials

Ireland is in a good starting position…

Context – Water Quality

Source: European Commission, 2010

Share of Water Bodies Ground Water by mg/L – Ireland relatively strong – only 5 countries have a greater share of water bodies with < 40 mg/L. However mid-ranking in terms of <25mg/L

Proving Green Credentials

Ireland is in a good starting position…

Context – Water Quality (Freshwater Trophic Classes)

Source: European Commission, 2010