Detecting Morphological Changes in Hirmand River from Roodbar Afghanistan to Hamoon Sistan

Abstract

Natural rivers are constantly changing in terms of dimensions, shape, direction and patterns under the influence of various factors and variables, and the diversion of rivers is always studied. Features such as river flow trends, network route changes, river network patterns, and communication can be done using satellite imagery. The purpose of this study is to move Hirmand River from Rudbar Afghanistan to Hamoon Sistan with a length of 275 km using Landsat 5, 7 and 8 time series satellite images from 1988 to 2018. The image was taken and analyzed every 5 years, ie 1988, 1993, 1998, 2003, 2008, 2013, 2015 and 2018. GIS and ENVI softwares are the most important tools used in this research that were used to prepare and extract data. The studied river has geometric parameters such as mean and standard deviation, etc. for curvature coefficient, valley length and wavelength have been calculated. The results of this study showed that as we go from 1988 to 2018, the geometric parameters have had an increasing trend due to the changes in the river, and due to the long path of the river, the transverse changes have been divided into 11 intervals until the results be better and more accurately analyzed. The results also show that the average curvature coefficient in 1988 was 1.5 but in 2018 it reached to 2.5. This increase indicates many changes in the route and bed of the river. The longitudinal changes and the maze of the Hirmand River in the period 1988 to 2018 have changed a lot and the movement of the river has increased.

Keywords

• rudbar afghanistan
• hamoon sistan
• morphological changes
• hirmand river