Temporal change of land use in the Protection Basin of Tahtalı Dam (1990-2015), (Izmir, Turkey) (original) (raw)

Purpose of this study is to evaluate temporal changes of land use in the Protection Basin of Tahtalı Dam in terms of sustainable use of natural resources through 1990 and 2015. In the study, we used Landsat TM satellite image dated 06.08.1990 with spatial resolution of 15 km and Landsat OLI satellite image dated 06.08.2015 in order to determine conditions of land use through the years of 1990 and 2015. Despite a 12% decrease in cropland areas and 1.4% in forest-maquis areas, a 119% increase in water surfaces, 34% in residential areas and 17539% in greenhouse areas occurred through 1990-2015 in the Protection Basin of Tahtalı Dam. There is an incompatibility between capability classes of lands and their use. Indeed, in the basin, agriculture (18%) has been carried out in non-arable 6th, 7th, and 7th class lands and there have been settlement areas (2%). Some part of arable lands of 1st, 2nd, and 3rd, and 6th has been used as settlement areas. 4% of 1st, 2nd, and 3rd, and 6th class lands submerged under the dam’s water. The said situation has resulted in some disadvantages. As a matter of fact, severe erosion which is seen at the part of 54% of the basin has the impact on lands which are inclined and devoid of natural vegetation cover. There is an increase stemming from domestic and industrial wastes in Parameters for Chemical Oxygen Need and Biological Oxygen Need in the basin. As a result of land degradation and erosion, nearly 25% of lands of the basin have become unusable losing their natural characteristics. Land use pattern suitable for natural environment potentials of lands should be generated so that this loss can be prevented; and agriculture of xeromorphic species which consume less water instead of products which need plenty of water should be carried out. Chemical fertilizer/drug use in agricultural areas; industrial facilities; and reaching canalization sewages, including the Menderes county town, to the dam through rivulets should be prevented, which all are essential pollutant elements of the dam’s water. To become a cooperative should be encouraged for a continuous and planned marketing in the basin, and alternative sustainable economic activities should be promoted. Furthermore, basin protection activities should be formed by an interdisciplinary understanding and collaboration should be established among local people. Key words: The Protection Basin of Tahtalı Dam, Temporal Change of Land Use, Land Capability Classes, GIS-Remote Sensing