Quantitative Regionalization of W. Mujib-Wala Sub-Watersheds (Southern Jordan) Using GIS and Multivariate Statistical Techniques

Abstract

In arid and semi-arid watersheds, sustainable management of natural re-sources (i.e. land, water and ecological resources), and watershed manage-ment are crucial issues in applied morphometric studies. Geomorphometric parameters and their interrelationships are of paramount importance in cha-racterizing the morphology, topography, geology and structure, hydrological potential, and geomorphic evolution of such catchments. An analysis of spa-tial characteristics and morphological development of the demarcated 76 sub-watersheds related to W. Mujib-Wala catchment, was carried out using ASTER DEM and GIS. Multivariate statistical techniques such as Principal Compo-nent Analysis (PCA), Cluster Analysis (CA), and Discriminant Analysis (DA), were also employed to assess different aspects of drainage networks, and their morphometric properties. Principal Component Analysis (PCA) reduces the 22 morphometric parameters to five components, which explain 90.4% of to-tal variance. The relationship of these components to the morphometric va-riables and to the individual sub-watersheds was evaluated, and then the de-gree of inter-correlation among the morphometric descriptors was explored. The 76 sub-watersheds were classified according to their individual relation to the components, and similarities in their morphometric characteristics. Re-gionalization of sub-watertsheds was achieved using hierarchical Cluster Ana-lysis (CA). The validity of the resultant cluster groups was tested statistically by means of Discriminant Analysis. The present investigation provides infor-mation which highlights the benefit of geomorphometric analysis and multi-variate statistics in modeling hydrological responses: i.e., surface runoff and sediment yield, hydrological assessment, water resources planning, and water-shed management. Furthermore, the results can be useful for soil and water conservation planning, and assessment of flash floods potential.