Land use suitability classification for the actual agricultural areas within the Bartın stream watershed of Turkey

Abstract

Suitability classification of the land uses particularly involves the lands’ qualification based on their ecological characteristics. Hence, ecological land use serves the sustainable planning objectives which ultimately constitute the fundamentals of environmental landscape planning. Among the diverse land uses, suitable agricultural areas occupy a significant interest not only because of their scarcity but also because of their environmental vulnerability. For this purpose, in this study, the land use suitability classification was performed for the actual agricultural areas within the Bartın stream watershed. The mesoscale watershed that covers approximately 1943 km2 is located at the Western Black Sea Region of Turkey. The watershed is mountainous with the average slope of 15° and with the altitudes ranging between 20 m and 1735 m asl. The actual agricultural areas cover almost 37% of the watershed and particularly located within the lower altitudinal gradients of the watershed. Based on the slope degree and soil depth parameters, land use suitability classification was conducted for the agricultural areas. Between the slope degrees of 0° and 25°, five categories of slope degree ranges each of which was 5°, were determined. On the other hand, the soil depth parameter was divided into two categories; “moderate deep and deep (50> cm)” and “too shallow and shallow (50< cm)”. Merging the digital map values of these two parameters using the GIS (Geographical Information Systems), yielded the 10 classes of land suitability for the agricultural areas. These 10 classes of land suitability for agricultural areas were displayed on the ultimate digitized map. According to the results of this study, only 25% of the agricultural areas were within the first three land suitability classes. However, almost 32% of the agricultural areas were within the last three land suitability classes. Furthermore, these problematic agricultural areas are particularly located at the higher altitudinal gradients within the watershed. These results indicated the significant misuse of the agricultural areas within the watershed. Consequently, re-arrangement of the land use plans and programs should be proposed in order to achieve the sustainable use of the agricultural areas within the watershed. This re-arrangement and re-handling will serve the objectives of landscape planning compatible with the environmental ethics and morality.