INVESTIGATING IMPACTS OF LARGE DAMS ON AGRICULTURAL LANDS AND DETERMINING ALTERNATIVE ARABLE AREAS USING GIS AND AHP IN ARTVIN, TURKEY

Abstract

Large dams are generally built for the purposes of providing drinking or irrigation water, flood control, and producing hydroelectric power, but their constructions also result in some negative outcomes such as decreasing in flora and fauna diversity, inundation of arable lands, forest areas, cultural sites and involuntary displacement of people. The city of Artvin has been facing almost all of those negative effects since five large dams have being constructed on the section of the Coruh River flowing within the city boundary. Three of those large dams completed submerged 795.60 ha of fertile agricultural land under the reservoir waters. The objective of this study was to determine potential suitable agricultural areas in substitution for those inundated due to these five dams. For this, the Analytic Hierarchy Process (AHP) method was used in this study. In the application, parameters including great soil groups, land use capability class, land use capability sub-class, soil depth, erosion degree, slope, aspect, elevation and other soil properties were used. A suitability map was created and separated into 5 categories according to the land suitability classification provided by the FAO. After deducting the forests, pastures, and reservoir areas, newly classified suitability map showed that 2.08% (11603.25 ha) of the study area was highly suitable, while 3.43% (19132.84 ha) was moderately suitable and 4.30% (23989.99 ha) was marginally suitable for agricultural production. It was interpreted that high slope, insufficient soil depth for agricultural production, and high erosion degree of the study area were effective factors in these findings.