http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/179 2026-04-20T21:54:36Z 2026-04-20T21:54:36Z ALI, MALIHA ISLAM, RAFIA http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1036 2025-10-19T13:46:36Z 2023-02-01T00:00:00Z

HYDRO-MORPHOLOGICAL ANALYSIS OF TEESTA RIVER USING HISTORICAL DATA AND FLOOD INUNDATION MAPPING USING HEC-RAS 2D MODEL ALI, MALIHA; ISLAM, RAFIA Bangladesh is situated at the most downstream region of the GBM basin where the major three rivers meet. Only 7 percent of the basin area lies within Bangladesh. Most of the water flowing through Bangladesh is beyond the nation’s control. Besides, owing to flat lowlying geological formation, Bangladesh is a very flood prone country where flood stays for longer period. In the northwest region Teesta is a flashy river in nature for which the water level of river Teesta shows several peaks during the monsoon both at Dalia and Kaunia. During the monsoon, Teesta River overflow its banks. For this severe flooding is caused multiple times by Teesta River during monsoon in Bangladesh. Besides, Teesta is a morphologically active river which shows significant shifting of bankline and change in width over the years resulting from erosion and deposition. Therefore, the study is carried out to understand the hydrological and morphological nature of Teesta River and the flood characteristics of the river using mathematical model. For hydrological analysis, water level hydrograph for Dalia, Kaliganj and Kaunia stations and Discharge hydrograph at Dalia Station is prepared using historical data of daily water level and discharge from 2000-2022 year. Besides flood frequency analysis is also done using Gumbel’s distribution to determine the maximum discharge and water level for a return period of 50 and 100 years. For morphological analysis, planform analysis is done using satellite image to evaluate the bank line shifting and amount of erosion-deposition of both banks of Teesta River for the period 2000-2022. Cross section analysis is done to determine the changes in width of the river and thalweg movement over the year using cross section data from left bank of the river. As a part of the study, flood inundation maps were generated for monsoon season of 2020 using HEC-RAS 2D model. Later, the model generated map is also compared with Satellite based inundation map prepared by FFWC of BWDB. HEC-RAS 2D model is developed and calibrated for the year of 2020 August-September and validated for the year of 2013 August-October with a manning’s roughness n=0.032. Lastly, the model is simulated to generate flood inundation map for Teesta River of 2020 flood to compare it with the actual scenario to understand the model performance. HYDRO-MORPHOLOGICAL ANALYSIS OF TEESTA RIVER USING HISTORICAL DATA AND FLOOD INUNDATION MAPPING USING HEC-RAS 2D MODEL

2023-02-01T00:00:00Z MURSHIDA, MALIHA KHATUN, SOMAIYA http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1035 2025-10-19T13:47:24Z 2023-02-01T00:00:00Z

HYDRODYNAMIC AND MORPHOLOGICAL STUDY OF PADMA RIVER USING DELFT 3D MURSHIDA, MALIHA; KHATUN, SOMAIYA Due to the tendency for erosion and deposition, the Padma, which was once thought to be a mostly meandering stream, is now transitioning into a braided system. In order to determine the Padma River's optimal hydrodynamic and morphological behavior, it is necessary to do morphological analysis. In the process of this research, a two-dimensional model of the river Padma was constructed with the help of Delft3D for the purposes of analyzing the hydrodynamic and morphological behavior of the Padma River in Naria Upazila. The data on water level, discharge, sediment and bathymetry are gathered from BWDB. Time series discharge data is utilized as the upstream boundary and water level data as the downstream boundary for hydrodynamic and morphological computation. The model is simulated for the monsoon season of the year 2021 with Bilaspur Bazar as the upper-southern boundary and Islampur functioning as the lowersouthern boundary. The accuracy of the model is calibrated by comparing it to the water level that was actually present at Mawa in June of 2021. After the calibration process is complete, the model is evaluated at the same location during the months of September of the following year (2021). Once they have been calibrated and validated, the variation of hydrodynamic properties is investigated, including changes in velocity and discharge as well as variations in water level. Then, the morphological characteristics, such as the rate of sediment transport and cumulative erosion/deposition at vulnerable sections, are evaluated. Results show that in September, the velocity is observed to be at its highest around the river's lower middle and narrow parts. It is observed that the velocity of the river and the rate of sediment movement are highly correlated. When the critical high discharge and water level were used, the velocity was greater than the unsteady model simulation, where the monsoon data of 2021 was used. So, the erosion and deposition was greater for steady case HYDRODYNAMIC AND MORPHOLOGICAL STUDY OF PADMA RIVER USING DELFT 3D

2023-02-01T00:00:00Z HRIDITA, NAFISA NURAEEN ELMA, SAJIDA FATIMA http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1034 2025-10-19T13:47:48Z 2024-03-01T00:00:00Z

EROSION-ACCRETION ANALYSIS OF A TIDAL REACH OF THE MEGHNA ESTUARY HRIDITA, NAFISA NURAEEN; ELMA, SAJIDA FATIMA The Meghna Estuary, situated in Bangladesh, is renowned for its dynamic morphological characteristics, influenced by sedimentation from the GangesBrahmaputra-Meghna Delta and intense tidal currents. This research delves into the erosion-accretion dynamics within the Meghna Estuary, particularly focusing on the reach between Urir Char and Char Elahi. Through a comprehensive study utilizing remote sensing, GIS analysis, and field surveys, this research aims to assess morphological changes and sediment transport patterns over thirty years. The study reveals significant erosion-accretion fluctuations, with accretion rates exceeding erosion rates, leading to the formation of new landmasses and alterations in the estuarine landscape. The image analysis results revealed that over the past thirty years (1993-2023), the study area experienced a total erosion of 1422.86 ha and 3658.47 of accretion. Analysis of sediment concentration profiles indicates a sediment surplus system, characterized by accretion-prone areas. The findings underscore the critical role of sediment dynamics in shaping estuarine morphology and highlight the potential of remote sensing and GIS techniques in monitoring and managing coastal environments so that appropriate measures or structures can be built to protect the island. Erosion-Accretion Analysis of a Tidal Reach of The Meghna Estuary

2024-03-01T00:00:00Z BHUIYAN, MUHAMMAD JUNAID MAHBUB, RAYUN http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1033 2025-10-19T13:48:38Z 2023-02-01T00:00:00Z

GROUNDWATER QUALITY ANALYSIS OF MANIKGANJ DISTRICT USING WATER QUALITY INDEX AND PRINCIPAL COMPONENT ANALYSIS BHUIYAN, MUHAMMAD JUNAID; MAHBUB, RAYUN Water Quality Index (WQI) is one of the simplest, most understandable and effective way to determine overall quality of drinking water as well as water used for other purposes. A study was attempted to assess the spatial variability of groundwater quality index of Manikganj district of Bangladesh. For this purpose, 31 water samples were collected and analyzed for potential sources and of contamination. pH, Total Dissolved Solids (TDS), Electric Conductivity (EC), Total Hardness (TH), Total Alkalinity (TA), Iron (Fe), Manganese (Mn), Sulphate (SO₄²- ), Chloride (Cl− ) and Turbidity were measured for calculating WQI. Their mean values were 7.05, 313.07 mg/L, 625.62 µS/cm, 207.35 mg/L, 214.57 mg/L, 5.0 mg/L, 0.093 mg/L, 14.16 mg/L, 104.38 mg/L and 62.06 respectively. The obtained values of WQI were distributed spatially through mapping using IDW interpolation via ESRI ArcGIS software. These values were categorized as excellent, good, poor, very poor, and unfit for every purposes. The WQI values ranged from 7 to 683 with an average value of 134.19. Among the 31 samples, 29.03% were excellent quality, 38.71% were good quality, 9.67% poor quality, 12.9% very poor and 9.67% were unfit for all purposes. The Kaiser–Meyer–Olkin test was 0.747 confirming that the dataset was sufficient for component analysis. The entire dataset could be represented by two components which accounted for 63.53% of the total variance of the dataset. Through PCA the influential contaminants came to light informing that naturally occurring Fe and Mn contaminations resulted in most of the pollution. Through this study, it can be proved that Spatial mapping and PCA are effective tools for determining ground water quality. The results of this study can be used to improve the current water quality situation of Manikganj district and ensure higher quality water resources for the citizens of this district. GROUNDWATER QUALITY ANALYSIS OF MANIKGANJ DISTRICT USING WATER QUALITY INDEX AND PRINCIPAL COMPONENT ANALYSIS

2023-02-01T00:00:00Z