River Basin and Land Use Lessons from Japan: Influences of Changes of Industrial Structure on Land Use of Nagara Basin and Flood Risk Control

Involving citizens in river and flood risk management is critical for risk reduction and sustainable development within river basins, but local community input is often limited. This is partly due to the difficulty of quantifying the perceived values and risks related to the rivers, because these are based on personal knowledge and opinions. There is a need for more data on locals’ opinions and how they are spatially distributed across the river basin. Studies analyzing how perceived risks match evidence-based data can be a first step to including local knowledge in the decision-making process and pose the basis to enhance preparedness. Here, we present a blueprint questionnaire to characterize the perception of flood risk and its spatial distribution across the river basin. Respondents are asked their perception of the role of the river in terms of flood risk and management, as well as to pinpoint on a map the areas they identify as the most dangerous during floods. The approach is tested on the Tagliamento River in the Italian Alps, characterized by debates regarding flood protection, flood management and ecological conservation. The flood risk perception map shows good agreement between perceived risk and existing flood risk assessment maps in the lower basin, where major floods happened in recent memory (1966). In the upper basin, despite having suffered frequent floods, participants are more uncertain about the risks. There is interest in being involved in the risk management debate, and most respondents believe that risk reduction and river conservation are compatible. Land use planning is identified as a factor that can increase flood risk. The results point to the necessity to tackle together conservation, risk management and land use planning in order to develop risk-oriented river management strategies. Our study demonstrates how online participatory mapping can be used to improve the understanding of citizens’ perceptions and expectations with regards to their river, and support participation in sustainable river management.

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Flood Risk Index for Land-Use Changes: Case Study of Pakpanang River Basin

Engineering Journal ◽

10.4186/ej.2020.24.5.25 ◽

2020 ◽

Vol 24 (5) ◽

pp. 25-40

Author(s):

Chonlatid Kittikhun ◽

Sitang Pilailar ◽

Suwatana Chittaladakorn ◽

Eakawat Jhonpadit

Keyword(s):

Land Use ◽

River Basin ◽

Land Use Planning ◽

Flood Risk ◽

Urban Areas ◽

Risk Index ◽

Land Use Changes ◽

Flood Depth ◽

Arc Gis

Flood Risk Index (FRI) is the multi-criteria linked with the factors of vulnerability; exposure, susceptibility, and resilience. In order to establish local FRI, crucial local information have to be accumulated. However, under the limitation of land-use data, particular techniques were applied in this study. CA Markov model was used to analyze the past missing land-use data and, also forecast the future land-use of Pakpanang river basin under conditions of plan and without plan. The ratio changes of forest, agriculture, wetland and water, and urban areas were considered. Then, the result of LULC spatial-temporal changes was then applied to Hec-HMS and Hec-Ras , with Arc GIS extension of Hec-GeoHMS and Hec-GeoRas software, in order to evaluate the flood hydrographs and flood severity in three municipalities corresponding to 100-year return period rainfall. Afterward, the FRI of Pakpanang, Chianyai, and Hua-sai, which ranges from 0 to 1, were evaluated by using the modified FRI equations. It was found that sensitivity analysis in the area of forest on flood depth and inundation areas is incoherent. Nevertheless, without land-use planning, the changes in these three cities cause higher flood risk, where Chianyai is the riskiest as the FRIE is 0.58. Further consideration of FRIE and FRIP proportion that reveals the FRI deviation indicates that to reduce flood risk, Chianyai would need the most resources and highest effort comparison to Pakpanang and Hua-sai.

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Flood Risk Zoning of Satluj River Basin, Himachal Pradesh, India

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.40.6 ◽

2015 ◽

Vol 40 ◽

pp. 6-15 ◽

Cited By ~ 1

Author(s):

Sandeep Kumar ◽

Santosh

Keyword(s):

At Risk ◽

Land Use ◽

River Basin ◽

Flood Risk ◽

Low Risk ◽

Risk Zone ◽

Risk Zoning ◽

Risk Zones ◽

Satluj River ◽

Very High

Increasing intensity and frequency of rainfall coupled with gradual retreating of glaciers due to climate change in Himalayan region likely to increase the risk of floods. A better understanding of risk zones which are vulnerable to flood disasters can be evolved from the detailed studies on slope, geomorphology and land use/ land cover pattern. Information of these parameters is an important input for the identification of vulnerable areas. Flood risk maps provide useful information about places that may be at risk from flooding. It offers a cost-effective solution for planning, management and mitigation strategies in risky areas. Traditional methods of flood risk mapping are based on ground surveys and aerial observations, but when the phenomenon is widespread, such methods are time consuming and expensive. The possible combination of DEM and other maps of area using an overlay operation method within the Geographical Information System (GIS) platform can lead to derivation and the understanding of spatial association between various parameters which could be used to predict flood risk zones. The study area i.e. Satluj River Basin has been broadly divided into five risk zones viz., very low, low, moderate, high and very high which helped to differentiate between areas that are at risk of different intensities of flood. The very high flood risk zone covers only 3.25 % of total study area, while the very low risk zone covers 13.63 %. The area falls within the very high and high risk constitutes 9.52 % of total basin area. Domain of moderate risk covers an area of 30.66 %. But the maximum area of river basin is constituted by low risk zone i.e. 46.19 %. Identification of such zones will help in timely adopting of mitigation and adaptation measures. Preparation of flood risk zoning maps also helps in regulating indiscriminate and unplanned land use practices in risky areas.

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