چكيده لاتين :
Introduction
Every day, many natural processes occur around the world that some of them are turning to natural hazards. Natural hazards are actually caused by the occurrence of a risky natural process such as a flood which cause great damage and loss to human societies. In recent decades, the incidence of floods and the damage resulting from them have been increased dramatically in Iran.Today, climate change and population growth and consequently construction in floodplains put wide areas of the country at risk of flood. Kurdistan province in west part of Iran is located in the cold and semi-arid climate characterized by high spatial and temporal variability of precipitation. This component has increased the potential for flooding in the area.The size, frequency, and potential flooding event in each region depends on many factors that most important are physical features and watershed morphometric parameters.Understanding these factors and classifying them in any area is the basics of flood control and reducing risks.This was carried out with the aim of zoning flood basin catchment using morphometric indices.For this purpose, based on previous studies, topographic properties and hydrographic network of 18 basins were analyzed located in Kurdistan province and also with other neighboring provinces.
Materials and Methods
The method used in this research combines theoretical studies, and statistical analysis software conducted in Excel, SPSS, and GIS. For this purpose, drainage network were classified based on Estrahller.Twelve morphometric parameters such as area, length basin, drainage density, bifurcation ratio, frequency channels, the surface flow, form factor, basin, basin shape, slenderness ratio, roundness index, index compression ratio were calculated that has an important role in hydrology estimations.In the next step, to classify and analyze, the data was standardized. Then, to conduct the final analysis of the available data were analyzed using cluster analysis.Cluster analysis was performed using cumulative class due to wider application related to the issue and earth sciences.Finally, dendrogram obtained was drawn for every eighteen area studies and was cut by the largest gap.
Discussion and Result
To achieve the research goals based on the combined studies which were mentioned in Materials and Methods,watersheds were recognized and subsequently coded.In this regard, 18 were identified as 8 areas entirely within the province of Kurdistan and 10 areas were in partnerships with the neighborhood provinces.Cluster 1 has 11 sub-areas including Bijar, Goltapeh, Ismailhill, Bukan, Razab, Saqez, Angouran, Qorveh, Sanandaj. And Cluster 2 has 7 sub-areasasPaveh, Sardasht, Baneh, Rawansar, Kamyaran, Marivan and Qezelcheh.Basins located in cluster 1 are in the East and basins that are in the second cluster have been studied in the West area.Meanwhile basins located in clusters show high values in the standardizeTable 1which is evidence of potential for flooding in most of the basinsand to be the result of climate, vegetation, and lithogicconditions.
Conclusion
The approach provided in this study, in fact, is the use of physiographic and hydrographic variables in a large area for classification of watersheds.Having this in mind, the watersheds located in the province of Kurdistan were evaluated by systemic approach.Cluster analysis was employed to classify and compare basins based on effective and standardized morphometric parameters on flood.The final finding of statistical analysis and the dendrogram suggests that areas of study are classifiedinto two clusters of significant different location in terms of potential flooding.Most of this is due to differences in lithology and tectonic structures in the area. The results of this research can be used in operations management and environmental protection.
