The effects of changing land use and flood hazard on poverty in coastal Bangladesh

Maps or remote sensing can be interpreted as the process of reading using various sensors where data collected remotely can be analyzed to obtain information about the object, area or phenomenon. In this study, the author develops a flood disaster mapping information system applying overlays with scoring between the parameters. The determinant factors to provide flood hazard levels includes rainfall factors in the dasarian unit, land-use factors and land-use arbitrary factors. Of all these parameters, a scoring process will be carried out by assigning weights and values according to their respective classifications, then an overlay process will be performed using ArcGIS software. The author conducted this study in Nagan Raya Regency since this area experiences flooding annually. Framing a thematic map of flood-prone areas in Nagan Raya Regency was designed using the flood hazard method. Spatial data that has been presented in the form of thematic maps as parameters are land use maps, landform maps, and dasarian rainfall maps (per 10 daily). The design of thematic maps that are prone to flooding is done by overlapping (overlay process). In contrast, the determination of the classification is done by adding scores to each parameter, with low, medium and high hazard levels. Parameter analysis shows the level of flood vulnerability in Nagan Raya Regency of each district, namely Beutong: high 0.21%, medium 13.68%, low 86.12%. Seunagan District: high 51.17%, medium 48.83%, low 0%. Seunagan Timur District: high 10.07%, medium 46.18%, low 43.75%. Kuala Subdistrict: high 29.66%, medium 68.99%, low 1.35%. Darul Makmur District: high 8.57%, medium 63.37%, low 28.06%. From the overall results of the study, it can be concluded that the danger of flooding in Nagan Raya Regency with a level of vulnerability: high 9.92%, moderate 42.65% and low 47.43%.

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Land Use and Land Cover Change Assessment in the Context of Flood Hazard in Lagos State, Nigeria

Water ◽

10.3390/w13081105 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1105

Author(s):

Dorcas Idowu ◽

Wendy Zhou

Keyword(s):

Land Use ◽

Land Cover ◽

Flood Hazard ◽

The State ◽

Land Cover Type ◽

Lulc Change ◽

Cover Type ◽

Lulc Changes ◽

Lagos State ◽

Very High

Incessant flooding is a major hazard in Lagos State, Nigeria, occurring concurrently with increased urbanization and urban expansion rate. Consequently, there is a need for an assessment of Land Use and Land Cover (LULC) changes over time in the context of flood hazard mapping to evaluate the possible causes of flood increment in the State. Four major land cover types (water, wetland, vegetation, and developed) were mapped and analyzed over 35 years in the study area. We introduced a map-matrix-based, post-classification LULC change detection method to estimate multi-year land cover changes between 1986 and 2000, 2000 and 2016, 2016 and 2020, and 1986 and 2020. Seven criteria were identified as potential causative factors responsible for the increasing flood hazards in the study area. Their weights were estimated using a combined (hybrid) Analytical Hierarchy Process (AHP) and Shannon Entropy weighting method. The resulting flood hazard categories were very high, high, moderate, low, and very low hazard levels. Analysis of the LULC change in the context of flood hazard suggests that most changes in LULC result in the conversion of wetland areas into developed areas and unplanned development in very high to moderate flood hazard zones. There was a 69% decrease in wetland and 94% increase in the developed area during the 35 years. While wetland was a primary land cover type in 1986, it became the least land cover type in 2020. These LULC changes could be responsible for the rise in flooding in the State.

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Towards risk-based flood management in highly productive paddy rice cultivation – concept development and application to the Mekong Delta

Natural Hazards and Earth System Science ◽

10.5194/nhess-18-2859-2018 ◽

2018 ◽

Vol 18 (11) ◽

pp. 2859-2876 ◽

Cited By ~ 4

Author(s):

Nguyen Van Khanh Triet ◽

Nguyen Viet Dung ◽

Bruno Merz ◽

Heiko Apel

Keyword(s):

Land Use ◽

Flood Risk ◽

Large Scale ◽

Flood Hazard ◽

Mekong Delta ◽

Flood Management ◽

Paddy Rice ◽

Rice Cultivation ◽

Spatially Explicit ◽

Risk Maps

Abstract. Flooding is an imminent natural hazard threatening most river deltas, e.g. the Mekong Delta. An appropriate flood management is thus required for a sustainable development of the often densely populated regions. Recently, the traditional event-based hazard control shifted towards a risk management approach in many regions, driven by intensive research leading to new legal regulation on flood management. However, a large-scale flood risk assessment does not exist for the Mekong Delta. Particularly, flood risk to paddy rice cultivation, the most important economic activity in the delta, has not been performed yet. Therefore, the present study was developed to provide the very first insight into delta-scale flood damages and risks to rice cultivation. The flood hazard was quantified by probabilistic flood hazard maps of the whole delta using a bivariate extreme value statistics, synthetic flood hydrographs, and a large-scale hydraulic model. The flood risk to paddy rice was then quantified considering cropping calendars, rice phenology, and harvest times based on a time series of enhanced vegetation index (EVI) derived from MODIS satellite data, and a published rice flood damage function. The proposed concept provided flood risk maps to paddy rice for the Mekong Delta in terms of expected annual damage. The presented concept can be used as a blueprint for regions facing similar problems due to its generic approach. Furthermore, the changes in flood risk to paddy rice caused by changes in land use currently under discussion in the Mekong Delta were estimated. Two land-use scenarios either intensifying or reducing rice cropping were considered, and the changes in risk were presented in spatially explicit flood risk maps. The basic risk maps could serve as guidance for the authorities to develop spatially explicit flood management and mitigation plans for the delta. The land-use change risk maps could further be used for adaptive risk management plans and as a basis for a cost–benefit of the discussed land-use change scenarios. Additionally, the damage and risks maps may support the recently initiated agricultural insurance programme in Vietnam.

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Flood hazard, Santa Cruz do Bispo Sector, Leça River, Portugal: a methodological contribution to improve land use planning

Journal of Maps ◽

10.1080/17445647.2014.974226 ◽

2014 ◽

Vol 11 (5) ◽

pp. 760-771 ◽

Cited By ~ 7

Author(s):

Pedro Gonçalves ◽

Inês Marafuz ◽

Alberto Gomes

Keyword(s):

Land Use ◽

Land Use Planning ◽

Flood Hazard ◽

Santa Cruz

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Distribution of Flood Risk Area in Bodri Watershed of Kendal Regency

Sriwijaya Journal of Environment ◽

10.22135/sje.2021.6.2.59-69 ◽

2021 ◽

Vol 6 (2) ◽

pp. 59-69

Author(s):

Husna Fauzia ◽

◽

Eka Cahyaningsih ◽

Hery Hariyanto ◽

Satya Nugraha ◽

...

Keyword(s):

Land Use ◽

Spatial Modeling ◽

Flood Risk ◽

Flood Hazard ◽

Risk Level ◽

Flood Hazards ◽

Risk Area ◽

Flood Peak ◽

Risk Levels ◽

Central Java

Flooding is a catastrophic phenomenon that can occur due to various factors, such as uncontrolled landuse changes, climate change, and weather anomalies, and drainage infrastructure damage. The Bodri watershed in Kendal Regency is one of the watersheds in Central Java, which is categorized as critical based on Decree No.328/Menhut-II/2009. Some of the problems in the Bodri watershed include land use that is not suitable for its designation, flooding, erosion, and landslides. This study aims to conduct spatial modeling to create flood hazard maps and flood risk level maps in the Bodri watershed. The method used is hydrograph analysis, flood modeling, potential flood hazards, and flood risk levels. Analysis of the potential for flood hazards from the spatial modeling inundation map with the input of the flood peak return period of 2 years (Q2), 5 years (Q5), and 50 years (Q50). Vulnerability analysis based on land use maps of flood hazard areas. The distribution of flood-prone areas in the Bodri watershed is in Pidodo Kulon Village, Pidodo Wetan Village, and Bangunsari Village.

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Analysis of Flood Vulnerability as a Support to Water Sensitive Urban Design Planning in Klaten Regency

MEDIA KOMUNIKASI TEKNIK SIPIL ◽

10.14710/mkts.v26i2.31929 ◽

2021 ◽

Vol 26 (2) ◽

pp. 183-193

Author(s):

Desyta Ulfiana ◽

Yudi Eko Windarto ◽

Nurhadi Bashit ◽

Novia Sari Ristianti

Keyword(s):

Land Use ◽

Urban Design ◽

Flood Hazard ◽

Flood Management ◽

Flood Vulnerability ◽

Geological Conditions ◽

Order Preference ◽

Water Sensitive Urban Design ◽

High Flood ◽

High Level

Klaten Regency is one of the regions that has a high level of flood vulnerability. The area of Klaten Regency which is huge and has diverse characteristics makes it difficult to determine an appropriate flood management model. Water Sensitive Urban Design (WSUD) is a model that focuses on handling water management problems with environmentally friendly infrastructure. Therefore, an analysis is carried out to determine the level of flood vulnerability and factors causing flooding to plan a WSUD design that is suitable for each sub-districts of Klaten Regency. The Analytical Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods are used to help the analysis. Aspects used as criteria are rainfall, slope, soil type, geological conditions, and land use. Based on the analysis, it could be concluded that Klaten Regency has two sub-districts with high flood hazard category, 21 sub-districts with medium category, and three sub-districts with low category. Bayat and Cawas are sub-districts that have a high level of flood vulnerability category. Meanwhile, Kemalang, Karangnongko and Polanharjo are districts with a low level of flood vulnerability category. The main factors causing flooding in Klaten Regency are slope and land use.

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GIS and remote sensing techniques for the assessment of land use changes impact on flood hydrology: the case study of Yialias Basin in Cyprus

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-1-4833-2013 ◽

2013 ◽

Vol 1 (5) ◽

pp. 4833-4869 ◽

Cited By ~ 2

Author(s):

D. D. Alexakis ◽

M. G. Gryllakis ◽

A. G. Koutroulis ◽

A. Agapiou ◽

K. Themistocleous ◽

...

Keyword(s):

Land Use ◽

Catchment Area ◽

Nearest Neighbor ◽

Flood Hazard ◽

Land Use Changes ◽

Economic Losses ◽

Gis And Remote Sensing ◽

Chain Analysis ◽

Multi Temporal ◽

Remote Sensing Techniques

Abstract. Flooding is one of the most common natural disasters worldwide, leading to economic losses and loss of human lives. This paper highlights the hydrological effects of multi-temporal land use changes in flood hazard within the Yialias catchment area, located in central Cyprus. Calibrated hydrological and hydraulic models were used to describe the hydrological processes and internal basin dynamics of the three major sub-basins, in order to study the diachronic effects of land use changes. For the implementation of the hydrological model, land use, soil and hydrometeorological data were incorporated. The climatic and stream flow data were derived from rain and flow gauge stations located in the wider area of the watershed basin. In addition, the land use and soil data were extracted after the application of object oriented nearest neighbor algorithms of ASTER satellite images. Subsequently, the CA-Markov chain analysis was implemented to predict the 2020 Land use/Land cover (LULC) map and incorporate it to the hydrological impact assessment. The results denoted the increase of runoff in the catchment area due to the recorded extensive urban sprawl phenomenon of the last decade.

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A GIS-BASED PROCEDURE FOR MEASURING THE EFECTS OF THE BUILT ENVIRONMENT ON URBAN FLASH FLOODS

Journal of Green Building ◽

10.3992/jgb.11.3.110.1 ◽

2016 ◽

Vol 11 (3) ◽

pp. 110-125 ◽

Cited By ~ 1

Author(s):

Yan Li ◽

Chunlu Liu

Keyword(s):

Land Use ◽

Built Environment ◽

Urban Areas ◽

Flood Hazard ◽

Land Use Changes ◽

Flash Floods ◽

Flood Inundation ◽

Storm Events ◽

Severe Problem ◽

The Impact

Urban flooding has been a severe problem for many cities around the world as it remains one of the greatest threats to the property and safety of human communities. In Australia, it is seen as the most expensive natural hazard. However, urban areas that are impervious to rainwater have been sharply increasing owing to booming construction activities and rapid urbanisation. The change in the built environment may cause more frequent and longer duration of flooding in floodprone urban regions. Thus, the flood inundation issue associated with the effects of land uses needs to be explored and developed. This research constructs a framework for modelling urban flood inundation. Different rainfall events are then designed for examining the impact on flash floods generated by land-use changes. Measurement is formulated for changes of topographical features over a real time series. Geographic Information System (GIS) technologies are then utilised to visualise the effects of land-use changes on flood inundation under different types of storms. Based on a community-based case study, the results reveal that the built environment leads to varying degrees of aggravation of urban flash floods with different storm events and a few rainwater storage units may slightly mitigate flooding extents under different storm conditions. Hence, it is recommended that the outcomes of this study could be applied to flood assessment measures for urban development and the attained results could be utilised in government planning to raise awareness of flood hazard.

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