An Empirical Investigation on Hydro-Morphological Process of Surma River: Substantiation from North-East Zone of Bangladesh

Abstract

Objective of the study is to know the inherent morphological process of the river system in the Haor areas of sylhet basin. The specific objective is to "validate the existing conceptual Model of the CEGIS". This research for the validation of the CEGIS Model. Primary data was collected through routine measurements of discharge, sediment concentration, measurements of cross-sections, sediment concentration measurements. Secondary data was collected on water level, discharge, velocity and cross-section from the BWDB. Satellite images have been collected from USGS. A thorough review of the manuals of different numerical models was carried out. After evaluation of the models HEC-RAS 5.0.3 has been selected. Validation of the CEGIS conceptual Model was tried using both conventional way of data analysis as well as from model output. Both the models have been fine-tuned and simulated to predict the future scenarios with 20% increase of discharge as well as 20% decrease of discharge at the upstream. Findings of the study confirms the acceptability of Hypothesis 1, Hypothesis 2 could not be (conclusively) validated. Concluded that, the bankfull water levels at the downstream decrease, changes in channel dimension, the change of both the area and the top width shows a scattered pattern and change of average depth shows a decreasing trend towards downstream direction. (i) Conventional analysis, Hypotheses 3 may be considered validated (ii) From Model output, it may be stated that the Hypothesis 3 may be considered as not validated. Hypotheses 4 and 5 relate to the hypothetical 'Regime Condition' of the river. Its clear that the Surma River is not in 'Regime Condition'. So the hypothesis could not be validated through the model output. But 'Regime Condition' is a theoretical condition of a river, the validity of these two hypotheses (4 and 5) can be accepted on Theoretical explanation basis.

Geospatial Modelling Geomorphic Typologies of the Binahaan River, Philippines

“…Many studies have already tackled issues concerning this, along with its predominant effect on the floral and faunal communities in the ecosystem. In fact, geomorphic characteristics such as land elevation have already been proven to have an effect on the diversity of plants (Zhang, W., Huang, D., Wang, R., et al, 2016;Menteş et al, 2019;Aghayev and Mahmudov2019) and animals, particularly benthic macroinvertebrates (Qu, X.D., Cao, M., Shao, M., Li, D.F., and Cai, Q., 2007;Rashidin et al, 2019;Çelik and Gazioğlu, 2020).…”