IHP-V Theme 2
Ecohydrological processes in thesurficial environment
Kate Heal
Institute of Ecology & Resource Management
University of Edinburgh

Theme content
1.
2.
3.
4.

Vegetation, land-water use and erosion
processes
Sedimentation processes in reservoirs anddeltas
Interactions between river systems, flood
plains and wetlands
Comprehensive assessment of surficial
ecohydrological processes

Importance of theme
 Increasing recognition of interaction betweenhydrology and biota in catchments
 Water management goals framed as “ecologicalquality”
 Recognition that hydrotechnical solutions notsustainableStructure of theme Process-based

projects addressing
different topics within
ecohydrology
 Interaction between

scientific research andapplication

Conferences and workshops organised
 “International symposium on erosion and sedimentation”

UK 1996
 Advanced Study Course in Ecohydrology for young
scientists, Central Europe 1999
 “Science and the sustainable management of tropicalwaters” Conference, Kenya 1999
 “Hydrological and geochemical processes in large scaleriver basins” International Symposium, Brazil 1999
 “Asia Pacific workshop on ecohydrology”, Indonesia 2001

Achievements of Theme 2
 Diversity of projects and wide participation
 Involvement of young scientists
 Interaction between scientific research,

application and education
 Improved dialogue between ecologists andhydrologists
 Awareness of decision-makers raisedDifficulties encountered Ambitious aims
 Progress on processes slow
 Conflict between basic and appliedresearch: solutions demanded now, but
still a lot to learn
 Integrating the outcomes of the large
number of projects

Scales of ecohydrology
 Global: effects of climate on biota
 Catchment: characteristics of land surface

affect energy and momentum fluxes,
biogeochemical cycling Riparian zone: filtering and trapping ofnutrients, sediment and pollutants
 Reservoir/lake: sedimentation, retention

and conversion of nutrients

Ecohydrology principles
1.

2.

3.

Water and biota ≈ superorganism at thecatchment scale
Enhancing the absorbing capacity of catchment
ecosystems against human impact requires
understanding of the resistance and resilience ofthe superorganism
Ecosystem properties should be used as amanagement tool

Ecohydrology and sustainable water resources
Useful framework to communicate the essential role ofecohydrology to hydrologists and decision-makershighEC
OEF
FICIENlowCY

SUSTAINABLE WATER RESOURCES
SWR =E⋅e-x + ⋅e-x+ACE ln(1+y)]
Ecohydrologylo

ACE [1+ln(1+y)]E⋅e + ⋅e-x-xhigh

highlow
ABSORBING
of(resilience and)wIM
PReduction of impact Enhancement of ecosystem
ECO-EFFICIENCY ABSORBING CAPACITY(EH principle)
TheEcohydrology principle as component of theequation of sustainability water resources(SWR)
in the face of global change.
ACE - increase of ecosystem absorbing capacity
against human impact
E - reduction of energy use(global climate)M - reduction of material use (pollution)

Key ecohydrology questions
 Quantification of hydrological and biologicalprocesses
 Understanding the timing of nutrient, organic
matter and organism fluxes between terrestrial,
freshwater and floodplain systems
 Regulation of life strategies, lifecycles andintraspecific interactions of freshwater organisms
 The consequences of these for water quality

Contribution of ecohydrology to IHP-VI
 “Ecohydrology” has disappeared but

ecohydrologists are required to contribute to allthemes
 Theme 1: Global changes and water resources– 1.1 Global distribution of resources: water supply andwater quality: biophysical datasets, ecosystems– 1.3 Integrated assessment of water resources in thecontext of global land-based activities and climatechange: natural habitat availability, biophysical models,ecohydrological changes

Contribution of ecohydrology to IHP-VI
 Theme 2 Integrated watershed and aquifer

dynamics– 2.1 Extreme events in land and water resourcesmanagement: ecological vulnerability– 2.4 Methodologies for integrated river basin management:
environmental emergency situations, biotic responseprediction, biota as indicators of progress in integrated
river basin management
 Theme 3 Land habitat hydrology– Ecohydrology requirement permeates theme– Try to avoid losing sight of general ecohydrology
principles

Contribution of ecohydrology to IHP-VI
 Theme 4 Water and society– Little mention of ecohydrology– Suggest greater involvement ofecohydrologists as society very
sensitive to “ecological quality” ofwater bodies
 Theme 5 Water education andtraining– Suggest inclusion ofecohydrological training

Ecohydrology: where do we go from here?
 Continue quest for integratedframework
 Continue the work of IHP-V Theme 2
to improve communication between
ecologists and hydrologists,
especially young scientists
 Ecology and hydrology include
applied and basic scientific research.
Both should be encouraged.