Simplifying complexity: the novel degradation index for urban stream landscapes—case of Tekirdag

Abstract

This study aims to examine the degradation process of urban stream landscapes in Tekirdağ by utilizing a newly developed degradation index (DI) that effectively defines degradation. The DI considers the vital factors that affect urban stream landscapes, making it possible to determine the level of degradation and resulting environmental quality. This index aims to provide valuable insight into the degradation of urban stream landscapes with a minimal amount of independent variables and training samples. The key enhancements of the DI include its clear computation of degradation value, ease of replication, and overall objectivity. The results indicate that the most substantial change has been observed on impermeable surfaces between 2000 and 2020, resulting in a 5.18% increase in impervious surfaces. Furthermore, there has been a decrease by 4.67% in agricultural lands, highlighting a pronounced shift towards impervious surfaces. The total percentage of areas categorized as high and very high degradation categories increased by 1.54% over the study period. Additionally, the area classified as high degradation expanded from 135.91 to 375.42 hectares between 2000 and 2020. Notably, there was no land classified as very high degradation in 2000, whereas in 2020, it reached 38.15 hectares. The DI has been proven to provide better representational information on how human activity affects ecosystems compared to both the Human Influence Index and the Human Footprint Index which has been used for this purpose. As a valuable tool for urban planning strategies, the DI can provide decision-makers with a more precise depiction of degradation, aiding in the preservation of sustainable urban stream landscapes, particularly in rapidly urbanizing areas.