Case Studies - Coastal Lagoons: Ecosystem Processes and Modeling for Sustainable Use and Development - page 437

formed by streams and plains that are located around Koycegiz Lake. The distances
between the northwest boundary of the watershed and Koycegiz Lake are 22 and
27 km in west and north directions, respectively. The Dalyan Channel network
connects Koycegiz Lake to the Mediterranean Sea with a delta formation downstream
of the channel network. 1 Topography maps of 1:25,000 scale obtained from the
Turkish Armed Forces General Command of Mapping (TAFGCM) are used to
conduct topographical and geographical analyses.
9.5.1.1.1.2 Climate
A literature review, including information obtained from meteorology experts, indi-
cates that the area is characterized by a Mediterranean climate with a hot, dry summer
season and a warm, rainy winter season. Although the region is controlled by the
terrestrial, marine or semimarine, and semiterrestrial low- and high-pressure systems,
the high-pressure system is more effective. Precipitation usually occurs during the
cold period and drought occurs during the hot period.
9.5.1.1.1.3 Meteorology
Although five meteorological stations exist within and in the vicinity of the water-
shed, only Koycegiz Station (+24 m), which is close to the northern shore of the
lake, was relevant to represent the watershed for modeling purposes. The Dalaman
(+13 m), Marmaris (+19 m), Fethiye (+3 m), and Mu ˇ la Stations (+ 646 m) are
situated outside the watershed boundaries.
Long-term time series for meteorological data consisting of daily measurements
of precipitation (47 years), pan evaporation (18 years), air temperature (25 years),
humidity (28 years), wind (22 years), cloudiness (28 years), and solar radiation
(6 years) were gathered from the Turkish State Meteorological Service. The data
were reorganized and analyzed by a data analysis system developed via the integrated
use of Microsoft® Excel * for analysis and Microsoft® Access † for database man-
agement. This system has the ability to create time series, to conduct queries, and
to support statistical evaluations. The chart presented in Figure 9.5.2 is an example
of the results of these statistical analyses and reflects the comparative analysis of
precipitation, pan evaporation, and estimated potential evapotranspiration (PET)
parameters as a basis for the water budget in the watershed.
General meteorological characteristics of the watershed were determined from
these analyses. A comprehensive meteorological database to be used for further
studies was also created.
9.5.1.1.1.4 Air Quality
No field study on the air quality of the watershed has been made. Coal with a high
sulfur content is used for heating purposes. High SO 2 is the main cause of air
pollution, which is greatly affected by the local topography and meteorological
conditions. The impact of SO 2 on the biogeochemical cycles of the Koycegiz-Dalyan
Lagoon is still unknown, but a future study is planned.
† Registered trademark of Microsoft Corporation, Seattle, WA, U.S.A.