Quantification of water related ecosystem services in urban and periurban watersheds: a methodological assessment


SERENGİL Y. , Şengönül K., Uzun A., İNAN M. , ERDEM N. , YURTSEVEN İ. , ...More

IUFRO 2013 - Impacts of Air Pollution and Climate Change on Forest Ecosystems, Brazil, vol.1, no.1, pp.99

  • Publication Type: Conference Paper / Full Text
  • Volume: 1
  • Country: Brazil
  • Page Numbers: pp.99

Abstract

Quantification of water related ecosystem services in urban and peri
urban watersheds: a methodological assessment
 
Ecosystem services are the benefits that ecosystems provide for humans. However as the
number of people increase with urbanization the quantity and quality of the services per
person diminish gradually. The urban planners generally use percentage of green spaces to
evaluate the urbanization-green space equilibrium. However, neither all green spaces have
the same capacity to produce the same quantity nor quality of services nor the demands
are same for every urban area. In cases of intense population, water stress, fast
industrialization and wavy topography the major services generally become all related with
water. This paper is a preliminary assessment on the quantification of ecosystem services in
fast urbanizing regions around Istanbul. We propose watersheds as the study units for the
evaluation of water related ecosystem services but as development plans consider
landscapes instead of watersheds we face with a challenge to combine landscape level
assessments with watersheds approach. Another challenge in terms of ecosystem services
quantification is the field verification of the results. It is not possible to identify carbon cycle
in an urban watershed considering many complicated fluxes involved (e.g. CH4, N2O, CO2
fluxes between vegetation and atmosphere or DOC fluxes to the streams) and actually not
necessary. The methodology we applied in carbon assessments was to develop a
comparative quantification based on IPCC 2006 guidelines. But in the case of soil
conservation we had the chance to verify the estimations in the field with sediment and
turbidity measurements.
The ecosystem services we focused in this study were soil and water conservation together
with carbon sequestration and biodiversity conservation. Three water basins on the
European side of the city were selected because of their importance in terms of water
quantity and quality. These three basins were separated into smaller catchments for a finer
scale assessment. In this paper we present the conceptual methodology of the study with
the preliminary results on soil conservation service.