--- Created: 2026/10/21 00:39 --- # EWCE 461 - Past Examination Question Recurrence | **What is included** | The supplied PDF contains six exam sittings: June 2019; February 2021; July-August 2021; 2023; 2024; and 2025. | | ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | **Missing years** | No 2020 or 2022 paper is present in the supplied PDF. The file name indicates 2019-2025, but the actual included sittings are non-contiguous. | | **How recurrence is counted** | One occurrence per exam sitting when a closely equivalent question appears. If a topic appears more than once within the same sitting, that sitting counts once for that row. | | **Wording normalization** | Similar conceptual prompts are merged, but different numerical data/formulations are grouped only when they test substantially the same method or idea. These are not claimed to be verbatim duplicates. | | **Section assignment** | River-engineering questions printed under Section B have been reassigned to Section A (e.g., scour, dredging, river training, river morphology, and navigability). Flood-management questions remain in Section B. | | **References** | References use the section/question labels as printed in each source paper. 'Printed B' is called out where a question is reassigned to Section A. | | **Sheets** | Use 'Section A - River Eng' and 'Section B - Flood Mgmt'. Each is sorted by Times appeared, from highest to lowest. | ## Section A - River Engineering Questions are grouped by river-engineering topic regardless of the printed section. Counts are by exam sitting; closely equivalent phrasings are merged. | **Normalized question / prompt family** | **Times appeared** | **Exact paper sittings (year/session)** | **Question references in source PDF** | **Grouping note** | | -------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------ | ---------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ | | Bridge-pier/local scour: influencing factors, complex piers/effective diameter, and scour estimation | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q4(a-c,e-f); 2021-Feb: A Q3(a); 2021-Jul-Aug: A Q3(c), printed B Q6(a-b); 2023: A Q4(b-c,e), printed B Q8(b); 2024: A Q1(e), Q4(c); 2025: A Q1(f), Q4(a-b,d) | River-engineering questions printed in Section B are reassigned to Section A. | | Channel geometry/hydraulic geometry: width-discharge relation, width-depth ratio, bankfull discharge and related channel dimensions | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q1(c), Q2(a); 2021-Feb: A Q1(d); 2021-Jul-Aug: A Q1(a,c); 2023: A Q1(b); 2024: A Q1(b), Q2(d); 2025: A Q2(a) | This is a broad family of channel-dimension questions; the exact variable/data differ by paper. | | Dredging: processes, types, impacts, capital dredging and sustainability | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: printed B Q7(a); 2021-Feb: printed B Q7(c); 2021-Jul-Aug: A Q4(c-d), printed B Q7(d); 2023: printed B Q8(f); 2024: printed B Q5(c), Q7(a), Q8(b); 2025: A Q4(c), printed B Q8(b) | Dredging questions are classified under River Engineering even where printed in Section B. | | River slope: downstream longitudinal variation, slope-discharge relationship, or slope effect on the channel | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q2(d); 2021-Feb: A Q1(a); 2021-Jul-Aug: A Q1(b); 2023: A Q1(c); 2024: A Q1(a); 2025: A Q1(b) | Merged at the topic level because the prompt varies between longitudinal slope, slope-discharge, and the effect of slope on pattern. | | River-training and bank-protection measures: groynes/spurs, riprap, gabion, revetments and active/passive structures | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q4(d), printed B Q6(c); 2021-Feb: A Q3(c); 2021-Jul-Aug: A Q4(a), printed B Q6(d), Q8(c); 2023: printed B Q8(a,c-d); 2024: A Q1(f); 2025: A Q4(c), printed B Q8(a,c) | Closely related river-training/bank-protection prompts merged. | | River/channel pattern and the factors controlling it (e.g., slope, sediment size/load, width-depth ratio, sinuosity, multichanneling, bank/bed material) | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q1(a), Q2(a); 2021-Feb: A Q1(a); 2021-Jul-Aug: A Q1(a); 2023: A Q1(a); 2024: A Q1(c); 2025: A Q1(a-b), Q2(c) | Closely related formulations merged; the number counts papers/sittings, not repeated subparts within one sitting. | | Sediment erosion threshold / critical shear stress / Shields parameter, including whether a bed is erodible and the relation to sediment diameter | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q3(b); 2021-Feb: A Q3(b); 2021-Jul-Aug: A Q2(d); 2023: A Q2(e); 2024: A Q2(b), Q3(d); 2025: A Q2(e) | Includes conceptual and numerical variants testing the same threshold/erodibility methods. | | Sediment fall/settling velocity vs shear velocity, including erosion/deposition and suspension behaviour | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q3(c); 2021-Feb: A Q2(b-c); 2021-Jul-Aug: A Q3(d); 2023: A Q3(d); 2024: A Q3(e), Q4(a); 2025: printed B Q8(c) | Related velocity questions are grouped, while sphericity-specific wording is listed separately below. | | Sediment-load classification and differences among wash load, suspended load, suspended bed-material load, bed load and bed-material load | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q2(b); 2021-Feb: A Q1(c); 2021-Jul-Aug: A Q2(b-c); 2023: A Q2(b-d); 2024: A Q3(a-b); 2025: A Q1(d) | Reworded classification and comparison questions are grouped. | | Suspended-sediment concentration/distribution with depth; Rouse number and fall velocity in sediment suspension | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q3(c); 2021-Feb: A Q2(b); 2021-Jul-Aug: A Q3(d); 2023: A Q3(c-e); 2024: A Q1(d), Q4(a-b); 2025: A Q2(d), Q3(c) | Includes concentration-profile explanation and calculation variants. | | Flow regimes and bed resistance/roughness: upper vs lower regime, grain vs form roughness | **5** | 2019; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: A Q1(b); 2021-Jul-Aug: A Q3(a); 2023: A Q3(a-b); 2024: A Q3(c); 2025: A Q1(e) | No equivalent standalone upper/lower-regime prompt was identified in February 2021. | | Expected river-morphology changes after dam construction/clear-water release, diversion, or changes in discharge and sediment supply | **4** | 2021-Feb; 2021-Jul-Aug; 2024; 2025 | 2021-Feb: A Q3(d); 2021-Jul-Aug: A Q3(b), printed B Q6(e); 2024: printed B Q8(d); 2025: A Q3(b) | Scenario-specific questions grouped because each asks for morphological response to altered flow and/or sediment conditions. | | Numerical estimation of bed-load transport, including Meyer-Peter–Müller and dune-bedform approaches | **4** | 2019; 2021-Feb; 2024; 2025 | 2019: A Q3(e); 2021-Feb: A Q2(d); 2024: A Q4(e); 2025: printed B Q8(e) | The data and formula differ, but each requires a bed-load estimate. | | Relative stability of river patterns / planform-stability ratios / why meandering may be more stable than braided rivers | **4** | 2021-Jul-Aug; 2023; 2024; 2025 | 2021-Jul-Aug: A Q2(b); 2023: A Q2(a); 2024: A Q2(a); 2025: A Q2(c) | Count is by sitting; 2019 included channel-pattern questions but not a directly comparable stability prompt. | | Clear-water scour vs live-bed scour: differences and which may be greater | **3** | 2019; 2021-Jul-Aug; 2025 | 2019: A Q4(e); 2021-Jul-Aug: printed B Q6(a); 2025: printed B Q8(c) | River-engineering questions printed in Section B are reassigned to Section A. | | Contraction scour: definition, conditions and why it may be insignificant at a bridge site | **3** | 2021-Feb; 2021-Jul-Aug; 2023 | 2021-Feb: A Q1(b); 2021-Jul-Aug: A Q3(c); 2023: A Q4(c) | Similar wording across three sittings. | | Navigation and navigability: factors affecting navigation, methods to improve navigability, and advantages of river transport | **3** | 2021-Jul-Aug; 2023; 2024 | 2021-Jul-Aug: A Q4(b-c); 2023: A Q4(d); 2024: A Q4(d), printed B Q8(a) | No direct navigability question was found in the 2025 paper. | | Stream power/shear stress relationships with velocity; bedform changes with increasing stream power | **3** | 2019; 2021-Jul-Aug; 2024 | 2019: A Q2(c); 2021-Jul-Aug: printed B Q6(c); 2024: A Q3(c) | Question forms differ: proportionality proof in 2019/2021 and bedform response in 2024. | | Theories/hypotheses explaining the formation of meanders | **3** | 2019; 2021-Jul-Aug; 2025 | 2019: A Q3(a); 2021-Jul-Aug: A Q2(a); 2025: A Q1(c) | Very similar conceptual question across the listed sittings. | | Active vs passive river-training structures, with examples | **2** | 2021-Jul-Aug; 2023 | 2021-Jul-Aug: printed B Q6(d); 2023: printed B Q8(a) | Both prompts explicitly compare active and passive training structures. | | Bed load is capacity-dependent while suspended load is supply-dependent | **2** | 2021-Feb; 2021-Jul-Aug | 2021-Feb: A Q1(c); 2021-Jul-Aug: A Q2(c) | This specific distinction is listed separately from the broader sediment-load classification row. | | Why pier scour is generally greater than abutment scour | **2** | 2019; 2025 | 2019: A Q4(a); 2025: A Q4(a) | The wording is closely matched. | | Effect of sediment sphericity on fall velocity | **1** | 2024 | 2024: A Q3(e) | Specific one-off variant of the broader sediment-velocity family. | | Hydraulic geometry equations defining a river | **1** | 2023 | 2023: A Q1(b) | Single-sitting question. | | Limitations of Lane's relationship for river equilibrium | **1** | 2025 | 2025: printed B Q8(d) | Reassigned to Section A as a river-engineering topic. | | Meander wavelength/length and width relationship from pool-to-pool distance data | **1** | 2024 | 2024: A Q2(d) | Single-sitting data-analysis question. | | Morphological changes downstream of a tributary confluence and a distributary off-take | **1** | 2023 | 2023: A Q4(a) | Single-sitting question; distinct from dam/diversion-response questions. | | Morphological consequences of a river cut-off | **1** | 2023 | 2023: printed B Q8(e) | Reassigned to Section A as a river-engineering topic. | | Pool and riffle forms and their cross-sections | **1** | 2024 | 2024: A Q2(c) | Single-sitting question. | | River system of Bangladesh and morphological evolution of the Brahmaputra-Jamuna | **1** | 2024 | 2024: printed B Q8(c) | Reassigned to Section A as a river-engineering topic. | | Scour vs degradation; sacrificial pile, Bandal, helical current and related short definitions | **1** | 2025 | 2025: printed B Q8(c); A Q4(c) | Specific terminology cluster appearing once. | ## Section B - Flood Management Questions are grouped by flood-management topic. Counts are by exam sitting; closely equivalent phrasings are merged. | **Normalized question / prompt family** | **Times appeared** | **Exact paper sittings (year/session)** | **Question references in source PDF** | **Grouping note** | | ------------------------------------------------------------------------------------------------------------------------------- | ------------------ | ---------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | | Flood risk/damage analysis or economic appraisal of mitigation/embankment projects, including annual risk reduction and benefit | **6** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: B Q7(c), Q8(b-c); 2021-Feb: B Q5(c); 2021-Jul-Aug: B Q5(c), Q7(c); 2023: B Q5(b), Q7(a); 2024: B Q7(c); 2025: B Q5(b) | Includes return-period risk, flood-damage assessment, and economic evaluation of flood-mitigation measures. | | Causes of flooding in Bangladesh, including geographic, hydro-meteorological, climatic and upstream factors | **5** | 2019; 2021-Jul-Aug; 2023; 2024; 2025 | 2019: B Q5(b); 2021-Jul-Aug: B Q7(a); 2023: B Q5(a), Q6(a); 2024: B Q5(b); 2025: B Q6(a) | 2019 asks specifically about the 1998 flood and contributing factors. | | Flood zoning/flood maps: purpose, required data, approaches, advantages and zones by probability | **5** | 2019; 2021-Feb; 2021-Jul-Aug; 2023; 2024 | 2019: B Q7(b); 2021-Feb: B Q6(c); 2021-Jul-Aug: B Q7(b); 2023: B Q7(b); 2024: B Q6(d) | No direct flood-zoning question was identified in the 2025 paper. | | Flood-proofing strategy: considerations, advantages/disadvantages, or FEMA/coastal approaches | **5** | 2021-Feb; 2021-Jul-Aug; 2023; 2024; 2025 | 2021-Feb: B Q6(b), Q7(a); 2021-Jul-Aug: B Q5(b); 2023: B Q6(b); 2024: B Q5(a), Q7(d); 2025: B Q6(c), Q7(c) | Multiple variants are grouped because they address the same flood-proofing strategy. | | Structural/non-structural flood-control measures and short-/long-term flood-management measures | **5** | 2019; 2021-Feb; 2023; 2024; 2025 | 2019: B Q5(a); 2021-Feb: B Q5(a); 2023: B Q6(a); 2024: B Q6(c); 2025: B Q7(b) | Different wording, but all ask for categories or time horizons of flood-management measures. | | Flood forecasting/warning and its role in flood management, including Bangladesh practice | **4** | 2019; 2023; 2024; 2025 | 2019: B Q8(a); 2023: B Q5(c); 2024: B Q7(b); 2025: B Q6(b) | 2021 papers did not contain a closely matching forecasting question. | | Flood frequency/return-period estimation from peak discharge, annual maximum rainfall, or river-stage data | **4** | 2019; 2021-Feb; 2021-Jul-Aug; 2023 | 2019: B Q7(c); 2021-Feb: B Q5(c); 2021-Jul-Aug: B Q5(c); 2023: B Q7(a) | Numerical datasets and requested return periods differ. | | Flood damage factors, hazard/risk/vulnerability, and tangible vs intangible losses | **3** | 2019; 2021-Jul-Aug; 2025 | 2019: B Q5(c), Q8(b-c); 2021-Jul-Aug: B Q7(c); 2025: B Q7(b) | Questions vary between listing damage factors and assessing types of flood loss. | | Flood diversion/channel for flood control and its advantages/disadvantages | **3** | 2021-Jul-Aug; 2023; 2024 | 2021-Jul-Aug: B Q5(a); 2023: B Q6(c); 2024: B Q5(d) | 2025 asks for a diversion dam only within a short-note set, not a directly comparable diversion-channel question. | | Urban flooding: definition, impacts, or comparison with rural flooding | **3** | 2021-Feb; 2024; 2025 | 2021-Feb: B Q7(b); 2024: B Q6(b); 2025: B Q7(a) | 2024 asks for urban-rural differences; the other prompts focus on urban flooding and impacts. | | Watershed management and why it is important for flood management | **3** | 2021-Feb; 2023; 2024 | 2021-Feb: B Q7(b); 2023: B Q7(c); 2024: B Q7(a) | Similar terminology across the three sittings. | | Land-use/land management and its effect on flood hazards or flood-management effectiveness | **2** | 2021-Feb; 2025 | 2021-Feb: B Q5(b); 2025: B Q5(d) | Closely related land-management prompts. | | Short notes on flood wall and levee; gravity dam; diversion dam | **2** | 2024; 2025 | 2024: B Q6(a); 2025: B Q5(a) | The three requested short-note topics repeat essentially verbatim. | | Estimating 100-year rainfall assuming normally distributed annual maximum rainfall | **1** | 2023 | 2023: B Q7(a) | Single-sitting numerical question; separated from flood-discharge frequency questions. | | Flood control vs flood management: definitions and distinction | **1** | 2021-Feb | 2021-Feb: B Q5(a) | Single-sitting question. | | Flood-proofing for coastal areas of Bangladesh | **1** | 2021-Jul-Aug | 2021-Jul-Aug: B Q5(b) | Coastal-specific variant of the broader flood-proofing family. | | Floodplain zones classified by probability of flood occurrence in a year | **1** | 2024 | 2024: B Q6(d) | Included with flood zoning above only when focusing on mapping/data; this row isolates the probability-based classification prompt. | | Planning for flood management | **1** | 2025 | 2025: B Q5(c) | Single-sitting question. | | Positive outcomes/benefits of flash floods | **1** | 2021-Jul-Aug | 2021-Jul-Aug: B Q8(b) | Single-sitting question. | | Probable Maximum Flood (PMF) vs Standard Project Flood (SPF) | **1** | 2021-Jul-Aug | 2021-Jul-Aug: B Q5(a) | Single-sitting question. | | Types of floods in Bangladesh and measures for flood control | **1** | 2023 | 2023: B Q6(a) | Single-sitting formulation. | --- References: - https://chatgpt.com/c/6ad7b1e4-4f34-83ec-8a1f-6fceef21a84a