Risk-sensitive Land Use Research Articles

Climate change extreme events and exposure of local communities to water scarcity: a case study of QwaQwa in South Africa

ABSTRACT The exposure of local communities to multiple climate change-related events is on the rise across the globe. Despite extensive disaster research on climate change, exposure and vulnerability, few studies have focused on the exposure of local communities to multiple climate change-related events. For over a decade QwaQwa, in South Africa, has experienced persistent water crises which have been attributed to climate change and socio-economic drivers. However, there is a lack of understanding of the risk drivers to provide a solid basis for disaster risk reduction and resilience-building. This paper; therefore, aims to conduct analyses of hazards and exposure as part of risk analysis of climate change-related events; notably drought, flooding, wildfires, and water scarcity in QwaQwa. Quantitative and qualitative data sources included key informant interviews, household surveys, and field observations. The study employed the indicator method to analyse both the hazard and exposure. Qualitative data were anlysed using thematic analysis. On a five-point scale, the findings showed high indices of multiple hazards (3.6) and exposure (3.2). Analysis results were validated at a stakeholders’ workshop. The study recommends efficiency in implementing risk-sensitive land use plans, improving early warning systems, and the use of unmanned aerial vehicles to mitigate disaster risks.

Liquefaction hazard mapping of the south-central coastal areas of Bangladesh

Liquefaction can cause significant damage to the built environment; therefore, assessing the liquefaction hazard in a seismically active region is essential to minimize the risk. This study attempted to evaluate the liquefaction potential of the south-central coastal areas of Bangladesh by calculating the liquefaction potential index (LPI) considering a scenario earthquake of Mw ​= ​7.5 having a peak ground acceleration of 0.15g. For calculating LPI, both standard penetration test blow count (SPT-N) and shear wave velocity (Vs) data have been used in this study. The results show that the study area's LPI values vary from 0 to 37. A liquefaction hazard map is prepared for the area using the calculated LPI values from Vs data shows about 8% of the study area is very highly susceptible to liquefaction hazard, whereas 62% of the area falls under high hazard-prone area while about 28% and 2% area of the study have respectively low (0<LPI ≤5) and very low (LPI ​= ​0) liquefaction potentiality. In addition, after analyzing the study area's fluctuating groundwater level (GWL) during the last 20 years, it has been observed that the GWL is likely to rise, thereby intensifying the potentiality of liquefaction hazards in the future. The outcome of this study will help engineers, urban planners, and policymakers to prepare a risk-sensitive land use plan and to develop a robust earthquake emergency response plan to reduce seismic risk.

Multi-hazard based land use planning in isolated area; learning from the experience of Pul-e-Khumri City, Afghanistan

Afghanistan is a hazard-prone country where conflicts and security concerns have restricted researchers' access to resilience-related data and information. The objective of this study is to establish a practical framework for Risk-Sensitive Land Use Planning (RSLUP), referred to as the Multi-Hazard based Land Use Plan (MHLUP), in the city of Pul-e-Khumeri where data and information are difficult to access due to security concerns. We implemented a four-step methodology that commenced with the with updating and converting the existing city land use map into a zoning framework. Subsequently, the multi-hazard intensity map was created by employing the weighted sum function in ArcGIS Map 10.8, utilizing the pairwise comparison method. The evaluation of the exposure level was then conducted by overlaying the single hazards and multi-hazard intensity maps onto the existing zoning map. Finally, based on a distinct decision matrix the existing zoning map was modified and the final output was generated. The findings indicate that the utilization of this approach significantly enhances the resilience of Pul-e-Khumri city. The novelty of this approach lies in its consideration of multi-hazard intensity, in addition to single hazard intensity, and its inclusion of exposure analysis for both population and critical facilities. The proposed approach would also facilitate resilience research in the global south, particularly in isolated areas, by leveraging existing studies and open-source data.

Simplified engineering geomorphic unit-based seismic site characterization of the detailed area plan of Dhaka city, Bangladesh

Severe failure of improperly designed and poorly constructed structures may occur due to the amplified and prolonged ground motion during an earthquake, and hence prediction of the ground motion characteristics at the soil surface is crucial. In this study, based on the prepared simplified engineering geomorphic map, we performed a one-dimensional (1D) nonlinear site response analysis for seismic site characterization of the recently proposed Detailed Area Plan (DAP) area of Dhaka City, the Capital of Bangladesh. The engineering geomorphic unit-based map was prepared from image analysis and verified with the collected borehole data and surface geology map. The study area was classified into three major geomorphic units and seven sub-units subject to the subsurface soil profiles. Nine earthquake time histories, seven from the PEER NGA WEST2 data set and two synthetics, and seven identified subsurface soil profiles were used for nonlinear site response analysis, along with the BNBC 2020 uniform hazard spectrum as the target spectrum. For the selected earthquake ground motions, the near-surface soil response of the DAP area showed de-amplification of acceleration in the short period and amplification of acceleration in the long period. The amplified long-period acceleration could cause severe damage in inappropriately designed and poorly constructed long-period structures. The outcome of this study could be used to prepare a seismic risk-sensitive land use plan for the future development of the DAP of Dhaka City.

Multi-Criteria Earthquake Risk Sensitivity Mapping at the Local Level for Sustainable Risk-Sensitive Land Use Planning (RSLUP)

Risk-Sensitive Land-Use Planning (RSLUP) is a critical process for integrating disaster-risk management (DRM) considerations into land-use planning, for which first it is necessary to understand the existing risk sensitivity. This study aims to develop a GIS-based multi-criteria zoning approach to mapping earthquake-risk sensitivity of land use at local level. The methodology comprises two main steps. Firstly, the spatial earthquake-risk sensitivity of land use is evaluated based on some risk themes related to development, land use, and emergency facilities. Secondly, earthquake-risk sensitivity is mapped by overlaying the spatial risk-theme maps, using weights determined through the Analytical Hierarchical Process (AHP). Overall, four earthquake-risk-sensitive zones were identified in the study area, ranging from high-risk-sensitive zones to low-risk-sensitive zones. This research contributes to the theory and practice of DRM by proposing a multi-criteria risk-sensitivity assessment and mapping methodology. The findings demonstrate that the risk-sensitivity map provides policymakers with a guide to identify “where” and “why” RSLUP interventions are necessary. This will serve as a decision-support system to formulate the “what” and “how” of the RSLUP at the local level, reflecting the risk sensitivity accordingly and thereby ensuring sustainability.

Approach to multi-disaster risk assessment and policy recommendation for disaster resilient urban development: A study of Birgunj–Simara Corridor

This study identified multiple nature of disasters in Tarai in general and Birgunj - Simara Urban Corridor, one of the hotspots of urbanization in Nepal in particular. Using geospatial technology, secondary sources of information, and stakeholder’s consultations, this study evaluated floods, earthquakes, windstorms, and fire impacts, identified factors contributing to vulnerability, and solutions for increasing resilience. Although rivers have limited floodplains, floods have been increased because of floodplain encroachment, improper drainage, land use changes in upper catchment, and climate change. Although the earthquake could have a high impact, the seismicity is low compared to the national context. During pre- and monsoon seasons, windstorms have a high impact over a limited area and are hard to predict. Fires are not widespread in the settlements but common during hot, dry months due to compact rural settlements, nonresilient house designs, and inadequate safety measures. Besides, lack of adaptation capacity as a result of poor awareness, widespread poverty, and poor disaster response have contributed to a high vulnerability to multihazards. Mitigation actions identified include risk-sensitive land use planning, flood control and hydraulic structure design, efficient urban drainage, waste management, resilient housing, and disaster safety plans. Local communities should be involved in developing early warning systems, disaster preparedness, and response measures.

Exploring the Scope of Public Participation for Risk Sensitive Land Use Planning in Nepal: A Policy Review

Risk Sensitive Land Use Planning (RSLUP), a process that has implications for Disaster Risk Reduction (DRR) as well as Urban Planning and Development, requires the participation of the public and wider stakeholders. Public participation has been conceptualized in Nepal’s disaster governance after the country transitioned into a federal democracy. It has undergone decentralization as part of the federal reform process, including its undertakings towards DRR. However, it remains unclear what this redistribution of authority means for public participation in relation to RSLUP. It is important to ask whether the current institutional set up and policy instruments are conducive for public participation. Therefore, this article examines how participation is construed within relevant federal and local policies in Nepal. The article presents a thematic analysis of leading policy instruments. The research reveals that participation emerges as a constitutional principle but the concept of participation itself is characterised by definitional ambiguity. Although most policies encourage the creation of spaces for public participation, this research reveals that these spaces are limited in implementation and impact. Lack of clear guidelines on how to design and implement public participation can hinder effective practice. Non-binding language within policy documents makes it difficult to understand the intended outcome of participation. This paper illustrates the extent to which participation has become a malleable construct that can have repercussions for ways in which RSLUP is enacted and enforced, in both Nepal and other countries who share similar socio-political context.

Towards an earthquake risk-sensitive land use planning: a case study for Tangail Municipality, Bangladesh

Towards an earthquake risk-sensitive land use planning: a case study for Tangail Municipality, Bangladesh

A Multi-Criteria Analysis Based Technique to Integrate Socio Economic and Geo-Physical Aspects in Risk Sensitive Land Use Plan: A Case Study on Mirsharai Upazila, Chattogram District, Bangladesh

Bangladesh is a developing and densely populated country. The process of urbanization is increasing day by day in this country. But planned development is challenging here. Bangladesh is the largest delta in the world. Due to geographical location, Bangladesh is naturally prone to disasters. Not only that Bangladesh is also under the thread of global worming and climate change related issues. Although Bangladesh is not contributing much to global greenhouse gas increase, Bangladesh is one of the largest victims of the adverse impacts of global worming and climate change. To reduce the impact and damage it is necessary to formulate risk reduction land use plan incorporating socioeconomic and geo-physical aspects. Mirsharai is a coastal Upazila situated in Chattogram District of Bangladesh. The area is highly prone to disaster and affected by climate change related problems. So, the area is ideal for this kind of study. In this paper, socioeconomic characteristics such as affordability, investment potentiality, demand and need has been analyzed. Result shows that people’s affordability is not good in most of the places of Mirsharai Upazila but in some isolated areas like small urban area or growth centres, people’s affordability and other socioeconomic conditions are good. Geo-physical aspects such as Infrastructure, ground water recharge, water logging tendency, Road accessibility, Ground elevation, Agricultural crop pattern and Land use were used to calculate development suitability and development conflict using Multi-criteria Analysis technique. Based on development suitability and conflict 4 category were identified as highly suitable, suitable, moderately suitable and less suitable area for development. Similarly, highly conflicted, conflicted, moderately conflicted and less conflicted areas for development were identified. Finally, by comparing development conflict and suitability maps, a relative development suitability map was produced marking highly suitable, suitable, moderately suitable, less suitable, partially unsuitable and completely unsuitable areas for development. These types of socioeconomic and geo-physical condition analysis can help making clear understanding on the study area for making risk sensitive land use plan.

Integration of earthquake risk- sensitivity into landuse planning: An approach for a local level area at development phase

Earthquake risks in cities are compounded due to unplanned development in high-risk areas. To address this issue, Risk-sensitive landuse planning (RSLUP) has been considered very important in recent years. It is the process of mainstreaming disaster risk reduction and management parameters in landuse planning is termed as Risk-sensitive Land Use Planning (RSLUP). This research aims to propose a methodology to integrate earthquake risk sensitivity in landuse planning (RSLUP strategies) for a local level area at the development phase. For this purpose, Uttara Residential Model Town (URMT) (third phase), Dhaka, Bangladesh has been selected as the study area considering its earthquake risk for exposure to a potential earthquake. The area is in the process of development. So there is still scope to integrate risk sensitivity in the proposed landuse plan. This research has been carried out in two steps. Firstly, assessment of the earthquake risk sensitivity of the proposed landuse plan of the study area on the basis ofbased on the risk themes: macro-form risks, risks in urban texture, risks in land-use incompatibilities, risks in hazardous uses, special risk areas, risks in building stocks, open space scarcity risk, and risks in critical facilities. Secondly, formulate RSLUP strategies to be incorporated in the proposed plan addressing the assessed risks accordingly. Here, a combination of analytical and participatory approaches has been applied to ensure applicability as well as acceptability. This research will may guide policymakers to understand the importance and application of RSLUP and thereby take necessary steps for this purposeto mainstream RSLUP in the process of landuse planning and thereby to increase earthquake resiliency of an area.

Integrated Approach of Risk Sensitive Land Use Zoning: A Case Study of Banepa Municipality

Land is a basic source of livelihood for most of the Nepalese. Land fragmentation, improper use of land, rapid urbanization and lack of formal plan has created serious problems mostly in urban areas including study area. So proper Land use planning is necessary for getting optimum benefit from land resource in sustainable way. Risk factor has to be considered in land use planning process. Since Expert driven (Top down) approach has not gained satisfactory achievement, Participatory (Bottom up) approach has emerged to ensure public participation in land use planning. Participatory approach has also some limitations. So the study seeks to implement integration of both expert driven and participatory approach to identify low risk land use zones in study area. Study targeted to identify risk areas from participatory approach before land use zoning. The case study was carried out in Banepa Municipality. The research was completed by following integrated approach using both primary and secondary data. Both desk study and case study method has been applied. Questionnaire, focus group discussion, interview techniques has been used in the study for collecting primary information where as high resolution satellite imagery, municipal GIS database, Census data etc. were used as secondary data. GIS application was used for Multi-criteria Analysis (MCA). To determine corresponding weight for each factor for land use zoning AHP (Analytical Hierarchy process) has been implemented. Different risk zones in the study area are identified using participatory approach. Final risk free land use zoning map of the study area is prepared. Study concludes that integrated approach is useful for effective land use zoning and risk should also be considered in this process. Different kinds of risk like landslide, flooding, industrial hazard etc. are dominant in the study area. Legal, organizational and technical improvement is required for effective implementation of land use zoning.

Seismic site characterization for Moulvibazar town, Bangladesh

In recent years, decision-making and site-planning strategies for earthquake mitigation have shifted away from a crisis management approach, to a greater emphasis on risk reduction. The earthquake hazard of a particular area can be assessed using geophysical and geotechnical site investigations. In the present study, seismic site characterization was carried out to evaluate earthquake risk for the town of Moulvibazar, Bangladesh, by integrating geophysical and geotechnical approaches. The study revealed that the average shear wave velocity to a depth of 30 m (AVS30) varied from 150 to 235 m/s, and US National Earthquake Hazards Reduction Program (NEHRP) soil site classes D and E were predominant, with soil amplification factors (SAF) of 1.3 and 1.45 for site classes D and E, respectively. In addition, peak ground acceleration (PGA) at the ground surface ranged from 0.325 to 0.3625 g, foundation layer depths for the deep foundation varied from 15 to 29 m, and the predominant periods ranged from 0.35 to 0.72 s. These soil parameters can be used to prepare an earthquake risk-sensitive land use plan for future urban development and to design earthquake-resistant structures.

Utilization of Open Source Spatial Data for Landslide Susceptibility Mapping at Chittagong District of Bangladesh—An Appraisal for Disaster Risk Reduction and Mitigation Approach

Since creation of spatial data is a costly and time consuming process, researchers, in this domain, in most of the cases rely on open source spatial attributes for their specific purpose. Likewise, the present research aims at mapping landslide susceptibility at the metropolitan area of Chittagong district of Bangladesh utilizing obtainable open source spatial data from various web portals. In this regard, we targeted a study region where rainfall induced landslides reportedly causes causalities as well as property damage each year. In this study, however, we employed multi-criteria evaluation (MCE) technique i.e., heuristic, a knowledge driven approach based on expert opinions from various discipline for landslide susceptibility mapping combining nine causative factors—geomorphology, geology, land use/land cover (LULC), slope, aspect, plan curvature, drainage distance, relative relief and vegetation in geographic information system (GIS) environment. The final susceptibility map was devised into five hazard classes viz., very low, low, moderate, high, and very high, representing 22 km2 (13%), 90 km2 (53%); 24 km2 (15%); 22 km2 (13%) and 10 km2 (6%) areas respectively. This particular study might be beneficial to the local authorities and other stake-holders, concerned in disaster risk reduction and mitigation activities. Moreover this study can also be advantageous for risk sensitive land use planning in the study area.

Flood-risk assessment in urban environment by geospatial approach: a case study of Ambala City, India

Looking at land use and functional structure characteristics, floods in urban environment are costlier and difficult to manage than in rural environment. In India, flooding is an inevitable problem for several cities. In the state of Haryana, Ambala City has a long history of serious flooding problem. Based on primary as well as secondary data, the present study attempts to examine the natural and anthropogenic causes of flooding on catchment and city scale. Geographic Information System (GIS)-based flood-risk modeling and consequences of flooding are presented for the selected most critical zone. Based on the past 21-year maximum discharge data of the Tangri River, flood probability is calculated for a 2-, 5-, 10-, and 20-year return period using Weibull’s plotting position formula, and the likely maximum discharge of 500, 1000, 1200, and 1500 m3, respectively, is used for the prediction of flood extent using Hydraulic Engineering Center-River Analysis System (HEC-RAS) software. Flood depth is calculated by employing spatial interpolation method using observed flood depth samples. Model result revealed that the flood inundation areas are 690, 1135, 1530, and 2300 ha, respectively, and accordingly likely impact on land use and population are assessed. The modeled 5-year return flood extents were validated using the observed data of the latest flood event in July 2010, including remote sensing imagery and field survey. Hence, in order to mitigate adverse impact of flooding in urban environment, such output can be used by urban local bodies, town planners, and policy makers to support decision-making in risk-sensitive land use planning by integrating climate change scenarios.

Identification of storm surge vulnerable areas in the Philippines through the simulation of Typhoon Haiyan-induced storm surge levels over historical storm tracks

Abstract. Super Typhoon Haiyan entered the Philippine Area of Responsibility (PAR) on 7 November 2013, causing tremendous damage to infrastructure and loss of lives mainly due to the storm surge and strong winds. Storm surges up to a height of 7 m were reported in the hardest hit areas. The threat imposed by this kind of natural calamity compelled researchers of the Nationwide Operational Assessment of Hazards (Project NOAH) which is the flagship disaster mitigation program of the Department of Science and Technology (DOST) of the Philippine government to undertake a study to determine the vulnerability of all Philippine coastal communities to storm surges of the same magnitude as those generated by Haiyan. This study calculates the maximum probable storm surge height for every coastal locality by running simulations of Haiyan-type conditions but with tracks of tropical cyclones that entered PAR from 1948–2013. One product of this study is a list of the 30 most vulnerable coastal areas that can be used as a basis for choosing priority sites for further studies to implement appropriate site-specific solutions for flood risk management. Another product is the storm tide inundation maps that the local government units can use to develop a risk-sensitive land use plan for identifying appropriate areas to build residential buildings, evacuation sites, and other critical facilities and lifelines. The maps can also be used to develop a disaster response plan and evacuation scheme.

Probabilistic storm surge inundation maps for Metro Manila based on Philippine public storm warning signals

Abstract. A storm surge is the sudden rise of sea water over the astronomical tides, generated by an approaching storm. This event poses a major threat to the Philippine coastal areas, as manifested by Typhoon Haiyan on 8 November 2013. This hydro-meteorological hazard is one of the main reasons for the high number of casualties due to the typhoon, with 6300 deaths. It became evident that the need to develop a storm surge inundation map is of utmost importance. To develop these maps, the Nationwide Operational Assessment of Hazards under the Department of Science and Technology (DOST-Project NOAH) simulated historical tropical cyclones that entered the Philippine Area of Responsibility. The Japan Meteorological Agency storm surge model was used to simulate storm surge heights. The frequency distribution of the maximum storm surge heights was calculated using simulation results of tropical cyclones under a specific public storm warning signal (PSWS) that passed through a particular coastal area. This determines the storm surge height corresponding to a given probability of occurrence. The storm surge heights from the model were added to the maximum astronomical tide data from WXTide software. The team then created maps of inundation for a specific PSWS using the probability of exceedance derived from the frequency distribution. Buildings and other structures were assigned a probability of exceedance depending on their occupancy category, i.e., 1% probability of exceedance for critical facilities, 10% probability of exceedance for special occupancy structures, and 25% for standard occupancy and miscellaneous structures. The maps produced show the storm-surge-vulnerable areas in Metro Manila, illustrated by the flood depth of up to 4 m and extent of up to 6.5 km from the coastline. This information can help local government units in developing early warning systems, disaster preparedness and mitigation plans, vulnerability assessments, risk-sensitive land use plans, shoreline defense efforts, and coastal protection measures. These maps can also determine the best areas to build critical structures, or at least determine the level of protection of these structures should they be built in hazard areas. Moreover, these will support the local government units' mandate to raise public awareness, disseminate information about storm surge hazards, and implement appropriate countermeasures for a given PSWS.

Opportunities, incentives and challenges to risk sensitive land use planning: Lessons from Nepal, Spain and Vietnam

This paper addresses one of the most pressing drivers of risk: land use planning and pressures placed on land use by private and public investors. Three case studies are developed, analyzing both private and public investment decisions and the interplay between regulations, acting as various incentives or disincentives. In Vietnam, dynamic urbanization is linked to political liberalization in terms of migration, private industries, land markets and urban planning. This has resulted in rapid urban growth, thereby increasing risk through urban sprawl into hazard prone areas that had previously been kept clear of urban development. In northwestern Spain, the “A Frouxeira” seashore lagoon and wetland are severely threatened by agriculture expansion, dune mining, tree plantations, tourism and the Prestige oil spill in 2002, which placed significant pressures on this fragile ecosystem, leading to social and environmental conflicts. Finally in Nepal, poor food security, landslides and changing climate conditions are pushing people out of mountainous areas to the plains and abroad, leading to illegal settlements springing up in flood-prone riverbanks. Governance is inadequate to prevent these illegal settlements but the city has now become liable for the safety of persons residing in these dangerous areas.These cases highlight how private and public investments at various levels are increasing risks and what public solutions are envisaged, if at all, to address these risks, while highlighting the difficult trade-offs between development, risk and governance. Perhaps one of the strongest arguments in favor of risk sensitive land use planning is its cost-effectiveness, considering the high costs of structural measures to reducing risk. This can include ecosystem-based approaches as part of integrated planning, an often overlooked element of DRR for mitigating hazards, reducing vulnerabilities by providing livelihood resources and even exposure when dangerous areas are converted to green belts. Finally, we conclude that more effective risk reduction is possible through improved spatial planning.