Ilknur Akiner1, M. Ernur Akiner2 , Atilla Akkoyunlu2
1 Mersin University, Architecture Faculty, Department of Architecture, Turkey
2 Bogazici University, Department of Civil Engineering, Turkey
Presented by
M. Ernur Akiner
Goksu Delta of
Silifke, Mersin.
Goksu Delta is one of the five Turkish Wetlands under protection of
Ramsar Convention. The Ramsar Convention is an international
agreement held in 1971 in the city Ramsar, Iran. Protection of ecological
values of wetlands, especially to protect the biodiversity of flora and fauna,
is the main purpose of the Convention.
Main pollution sources in city are the uncontrolled agriculture and
unplanned constructions.
Sustainable development is a pattern of resource use that aims to meet human
needs while preserving the environment.
It is crucial to achieve sustainable resources for an eco-friendly development.
As a sustainable construction technology, green roof application will be
proposed for the research area in order to decrease surface runoff.
Results of the study show that the green roof application will decrease the
stormwater runoff significantly.
Also a mathematical relation between rainfall and water quality parameters
will be investigated.
Surface water quality assessment
In this research, some pollution parameters were inspected in order to
determine the current pollution level of the Goksu River in the region.
Samples were collected from the three designated points and some water
quality parameters were measured.
Point
1
2
3
East
33° 55'
23"
33° 59'
4"
34° 2'
3"
North
36° 24'
24"
36° 22'
55"
36° 18'
56"
Sampling Location
Goksu River - Dam
Goksu River - City outlet
Goksu River - Menderes
Water quality classes according to
Turkish Water Pollution Control
Regulation
Water quality classification of waterbody according to Turkish
Water Pollution Control Regulation
One-sample T-Test was applied as a statistical test in order to judge on the
exact water quality class of the waterbody in aforementioned rivers and
channels.
Since the available NO2-N data is continuous and also approximately normal,
we can apply the One Sample T-Test
One-sample T-Test: Whether the mean of a normally distributed population
has a value specified in a null hypothesis.
Green roof application
Green roofs can be separated in to two main groups. These are; intensive and
extensive. Intensive roofs are usually more than 20 cm deep which allows for
the growth of larger plants such as trees.
Extensive roofs on the other hand, contain smaller plants, such as; shrubs,
sedums, and herbs. Parts of the typical extensive green roof system are shown
Green roof
cross-section
Compared to complete systems, modular green roof and pre-cultivated
blanket layer systems are very practical, and ease to apply systems.
Complete systems
Modular green roof
Pre-cultivated
blanket layer
There are seven main benefits to having a green roof.
They include increased energy efficiency, an increase in air quality, a decrease
in heat island effect, temperature regulation both on the roof and surrounding
areas, stormwater retention, an increase in roof lifespan and a LEED point.
Vegetation provides also nesting places for birds such as, blackbirds, song
thrushes and house sparrows.
Subbasin 2
48.71 km2
Subbasin 3
75.04 km2
Subbasin 1
5096.4 km2
Areas occupied by
subbasins
Delineated Subbasins of Goksu River Watershed
Goksu River flows through subbasin 1, 2 and 3, respectively.
There is no settlement at subbasin 1 since the area is roughly mountainous. Silifke district is
located and there is a mass settlement at subbasin 2. Subbasin 3 is the last subbasin of the whole
watershed and it is located around the outlet of the Goksu River and settlements are not allowed
in this area due to Ramsar Convention.
Osmunda Regalis and Sedum are local
plants that are approached as green roof
plant alternatives in this study in
accordance with the Mersin climate
Roof
Green roof surface area (m2)
900
Rain Fall
15
Regional 10 year storm (cm of rainfall)
Growth Media
20
Growth media depth (cm)
3
Dry Weight (kg/m )
0.64
3
Saturated Weight (kg/m )
1
Moisture Retention Fabric
Moisture retention fabric dry weight (kg/m2)
7.3
2
8.8
Moisture ret. fabric saturated weight (kg/m )
Drainage Core
Sedum plant
Osmunda regalis
According to sample calculation, when a
single building with a roof area of 900 m2
is considered, there will be 77 % water
retention by the usage of green roof
systems within the subbasin 2.
Top diameter of cups (cm)
0.65
Bottom diameter of cups (cm)
0.65
Cup height (cm)
1.30
Number of cups per m2
872
Water retained (lt/m2)
Volume of retained water (lt)
Total tons retained
Run off coefficient
1.67
1502.90
1.50
0.23
Potential rain water retention by a green
roof of a sample building at Silifke –
Mersin
Categories for Achieving LEED Points
•Sustainable Sites
•Water Efficiency
•Energy and Atmosphere
•Materials and Resources
•Indoor Environmental Air Quality
•Innovation in Design
LEED Credit Impacts
Primary Credit Impacts
Credits
5.1
Categories
Sustainable Sites
6.1, 6.2 Sustainable Sites
69 Available Points
Four Categories of Certification:
• Certified: 26-32 Points
• Silver: 33-38 Points
• Gold: 39-52 Points
• Platinum: 53-69 Points
7.2
1.1
1.0
Credits
Protect or Restore Open Space
Stormwater Management Rate, Quantity, and
Treatment
Sustainable Sites
Design to Reduce Heat Islands (Roof)
Water Efficiency
Water-Efficient Landscaping
Innovation and Design Innovation in Design
Secondary Credit Impacts
Categories
Energy and
Atmosphere
Energy and
4
Atmosphere
Materials and
4.1, 4.2
Resources
5.1, 5.2 Materials and
Resources
2
Water Efficiency
1.0
Point
s
1
Requirements
2
1
1
1
Point
s
Requirements
Optimizing Energy Performance
2
Ozone Depletion
1
Recycled Content (roof system components)
2
Local/Regional Materials (roof components,
plants)
Innovative Wastewater Technologies
2
3.1, 3.2 Water Efficiency
Water Use Reduction (20%, 30%)
TOTAL DERIVED POSSIBLE LEED POINTS :
6 + 10 =
1
2
16
Even subbasin 2 has a limited area over the whole watershed, it is revealed that application of
green roof systems helped the reduction of TP concentration of river water significantly, especially
when the rainfall value is low.
Observed and predicted values for monthly average TP concentrations in sampling
point 2 at subbasin 2, with or without green roof application.
Green roof application can be used as a sustainable construction material for the
buildings.
This system has a great influence on runoff reduction and the improvement of the
surface water quality.
Historical data is needed in order to foresee the possible future pollution status of the
watershed.
If trend of the pollution is investigated, necessary management techniques for the
reduction of the pollution can be specified.
For this purpose a non-linear mathematical model as a function of rainfall was defined
to show TP concentrations for the region.
Additionally possible reduction in TP concentrations in case of the green roof
application in subbasin 2 was calculated.
Silifke district of Mersin Province – Turkey, is a typical underdeveloped city with a
moderate population. It is clear that if this system is used in more developed, large and
crowded cities, more remarkable results in terms of runoff retention and pollution
prevention can be achieved.