Тяжелые металлы в окружающей среде
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- 4.2. Results
| 4. APPLICATION - 2
4.1. Material and method Burdur Lake is a large tectonic and saline lake, positioned at the frontier between Burdur and Isparta provinces. It has an area of 250.000 km2 and maximum depth recorded at variously times between 50 and 110 meter. Lake Burdur is among the largest and deepest lakes of Turkey, located at the Lake District Region in south-western Anatolia (37°43′351′′ N, 30°10′878′′ E), within a closed basin. Catchment area is 6150 km2. The average depth is 40 m and maximum depth 68 m. Maximum surface area is 140 km2 at 854 m elevation. It is salty and highly alkaline (pH 9.5) and it never freezes (URL 1). For monitoring the land use change of the Burdur Lake, Landsat imageries are used. The Landsat imageries are downloaded from USGS web site in 1975, 1984, 1987, 1989, 1995, 1998, 1999, 2000, 2001, 2002, 2003, 2009, 2011, 2014 and 2015 years. LANDSAT 1, 2, 3 and 4 MSS, LANDSAT 5 TM, LANDSAT 7 ETM and LANDSAT 8 OLI imageries are used to determine the land use changes. The imageries are classified via ArcGIS image analysis extension with supervised classification method. Classified imageries are converted to polygons to be able to calculate the area of the lake and the land use changes. Fig. 7. Study area. 4.2. Results The LANDSAT imageries are downloaded and raster band combinations are realized with ArcGIS software. Water surfaces are one of the main geographical objects that can be easily deter- mined via LANDSAT imageries. Thus, 1, 1, 7 band combination are used to detect the surface area of the Burdur Lake. The supervised classification technique is used to separate the water area from land. Evaluating the study area, it can be seen that water level decreased from 1795 to 2015 very rapidly. The deepness of the lake is very low in the North-West corner, thus, the decreasing can be 80 81 easily seen in LANDSAT imageries. The other boundaries of the lake are surrounded with small mountains. Therefore, the bare lands started to occur after 1990‘s. Due to the lake have very inten- sive salt rate, the area started to seem as white after 1990‘s. Considering the decreasing rate, the fu- ture of the lake is very critical. The water surface area values are examined for each year and the values are given in Fig. 4. The surface area of the Burdur Lake is 21050 ha in 1975 and 12177 ha in 2014. As can be seen in Table 4, the water level is getting decreased to the critical level. Fig. 4. Water area compare (hectare). Fig. 8. Water surface decreasing. The decreased bare lands than become agricultural land which are started from 2000‘s. While the water level is getting far away from the base line that determined in 1975, the salinity of the soil is getting decreased. Therefore, farming activities are being possible. Evaluating the Figure 3, the decreasing rate has the highest value between 1989-1995. Thus, the bare land can be deter- mined easily in 1995 LANDSAT imagery. Monitoring the environmental changes have a vital importance to determine the future of the lands. It can be seen that the deformation of the environment and water resources are increasing year by year. The preventations, procedures and the limitations should be specified with multi- disciplinary projects. The irrigation, agricultural activities, industrial facilities and land use should be considered carefully to determine the solutions. Burdur Lake is an important part of the habitat and decreasing water level will cause the migration of the bird species from the region. The future projection of the lake can be considered with Geographical Information System aided spatial analy- sis to predict the situation. жүктеу/скачать 6.49 Mb. Достарыңызбен бөлісу:
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