Planning to cope with tropical and subtropical climate change

This book provides examples of climate change characterization and decision-making tools for subtropical and tropical adaptation planning. It is intended for local operators, physical planners, besides researchers and students of these subjects. The first chapter describes the status of climate planning in large subtropical and tropical cities. The following six chapters discuss hazards (drought, intense precipitations, sea level rise, sea water intrusion) and early warning systems. Nine chapters enlarge on flood risk analysis and preliminary mapping, climate change vulnerability, comparing contingency plans in various scales and presenting experiences centred on adaptation planning. The last three chapters introduce some best practices of weather and climate change monitoring and flood risk mapping and assessment

Multihazard risk assessment for planning with climate in the Dosso Region, Niger

International aid for climate change adaptation inWest Africa is increasing exponentially, but our understanding of hydroclimatic risks is not keeping pace with that increase. The aim of this article is to develop a multihazard risk assessment on a regional scale based on existing information that can be repeated over time and space and that will be useful during decision-making processes. This assessment was conducted in Dosso (Niger), the region most hit by flooding in the country, with the highest hydroclimatic risk in West Africa. The assessment characterizes the climate, identifies hazards, and analyzes multihazard risk over the 2011–2017 period for each of the region’s 43 municipalities. Hazards and risk level are compared to the intervention areas and actions of 6 municipal development plans and 12 adaptation and resilience projects. Over the past seven years, heavy precipitation and dry spells in the Dosso region have been more frequent than during the previous 30-year period. As many as 606 settlements have been repeatedly hit and 15 municipalities are classified as being at elevated-to-severe multihazard risk. The geographical distribution of the adaptation and resilience projects does not reflect the risk level. A third of the local development plans examined propose actions that are inconsistent with the main hydroclimatic threats

Risk-Informed Sustainable Development in the Rural Tropics

Many people live in rural areas in tropical regions. Rural development is not merely a contribution to the growth of individual countries. It can be a way to reduce poverty and to increase access to water, health care, and education. Sustainable rural development can also help stop deforestation and reduce live-stock, which generate most of the greenhouse gas emissions. However, eorts to achieve a sustainable rural development are often thwarted by oods, drought, heat waves, and hurricanes, which local communities are not very prepared to tackle. Agricultural practices and local planning are still not very risk-informed. These deciencies are particularly acute in tropical regions, where many Least Developed Countries are located and where there is, however, great potential for rural development. This Special Issue contains 22 studies on best practices for risk awareness; on local risk reduction; on several cases of soil depletion, water pollution, and sustainable access to safe water; and on agronomy, earth sciences, ecology, economy, environmental engineering, geomatics, materials science, and spatial and regional planning in 12 tropical countries

Flood risk preliminary mapping in Niamey, Niger

Flood mapping is still rare in the large cities South of Sahara. The lack of information on the characteristics of floods, the orography of the sites and the receptors hampers its production. However, even with scant information, it is possible to create preliminary risk mapping. This tool can be used by local administrations in decision making on emergency plans or on climate change (CC) action plans. From 2010 onwards the River Niger at Niamey (1.1 million inhabitants, 123 km2 in 2014) swelled at unseasonal times. That new river flood pattern can be linked to CC. Each flooding event affected thousands of people and homes. The unceasing development of areas that did not seem to be flood prone in the past is the main cause of these impacts. These areas require special measures if further impact is to be avoided in the future. This chapter presents the flood risk preliminary map of Niamey 1:20,000. The map is built up using an historic approach (flooded area derived from satellite images) and considering risk (R) as the result of hazard (H) and damage (D), R = H * D. Risk is measured according to two scenarios: medium and high probability of flooding. The inverse of the return period of river and pluvial flooding (H) and the potential damage to buildings and crops according the water depth are used. Information to measure risk components is sourced by daily rainfall and daily discharge of the River Niger from 1946 to 2014 and from high-resolution satellite images (2014). The risk map identifies hot spots for emergency and CC action planning. The fifth district alone contains 52% of the potential damage. 99% of the potential damage is concentrated within 225 hectars. Reinforcing existing embankments and constructing new ones to protect these areas seems more appropriate than resettlement. The cost of the works would equal the potential damage if it remains within 2,580 euro/ml

Local and scientific knowledge integration for multi-risk assessment in rural Niger

In the rural Tropics, the participatory risk assessment, based on local knowledge only, is very widespread. This practice is appropriate for hazard identification and for raising the awareness of local communities in relation to the importance of risk reduction, but it is still imprecise in determining risk level, ranking and treatment in a context of climate change, activities in which technical knowledge is unavoidable. Integration of local and technical-scientific knowledge within the framework of an encoded risk assessment method (ISO 31010), could favour more effective decision making with regard to risk reduction. The aim of this chapter is to verify the applicability of a multi-risk local assessment-MLA which combines local knowledge (participatory workshop, transect walk, hazard and resource mapping, disaster historical profile) and scientific knowledge (climate downscaling modelling, hazard probability and scenarios, potential damages, residual risk). The test is carried out in two villages of the Western Niger, particu-larly exposed to flooding and agricultural drought. The risk (hazard probability * potential damages) is identified, analysed (level of risk) and evaluated (residual risk, adaptation measures compared with potential damage costs). The MLA is feasible. The two villages, while bordering on one another, have a different risk ranking. Depending on the village, the risk treatment could reduce the risk level to 17% and to 41% of the current risk, with costs equating to 34% and 28% of the respective potential damages

Flood risk assessment at municipal level in the Tillabéri region, Niger

The Tillabéri region (population 2.7 million, 97,250 km2) is the hinterland of the Niger’s capital city and the second most susceptible region to flooding of the country, with 416 settlements hit from 2008 to 2013. This chapter aims to present the potential benefits of flood risk assessment at municipal scale: a tool that can help local authorities in disaster risk reduction. Risk (R) is considered here a function of Hazard (H), Exposure (E) and Damages (D) according the equation R = H * E * D. Risk is measured using six indicators. The probability in each year to have e rain causing settlement flooding is measured for each municipality using daily rainfall from meteorological stations (1981-2010) and three-hourly Tropical Rainfall Measuring Mission (TRMM) datasets by NOAA (1998-2011). Settlements flooded (E), people affected, homes destroyed, fields flooded and livestock killed (D) are sourced from Niger’s early warning system and disaster prevention unit (EWS DP), all errors corrected and units of measurement standardised. From the results, it emerged that 765 settlements have been flooded between 1998 and 2013. Contrary to what one might expect, the floods caused by the swelling of the River Niger hit few settlements. Most of the areas susceptible to flooding are located in the vast Bosso and Maouri dallols, two fossil rivers that run from Mali towards Niger for over 300 km. The right-bank tributaries of the Niger and along the minor hydrographic network are the next most affected areas. 95 settlements were hit more than once and 19 flooded in two or more consecutive years. Seven municipalities out of 41 are at very high or high risk of being flooded. These are crossed by the River Niger or by its main tributaries on the right bank, by the Ouallam intermittent creek or the Bosso dallol. Seven municipalities show damage in three areas (people, dwellings, fields)

Risk-informed sustainable development in the rural tropics

This Editorial presents the special issue Risk-informed sustainable development in the rural tropics published by the journal Sustainabilit

Multi-Hazard Risk Assessment at Community Level Integrating Local and Scientific Knowledge in the Hodh Chargui, Mauritania

Hydro-climatic risk assessments at the regional scale are of little use in the risk treatment decision-making process when they are only based on local or scientific knowledge and when they deal with a single risk at a time. Local and scientific knowledge can be combined in a multi-hazard risk assessment to contribute to sustainable rural development. The aim of this article was to develop a multi-hazard risk assessment at the regional scale which classifies communities according to the risk level, proposes risk treatment actions, and can be replicated in the agropastoral, semi-arid Tropics. The level of multi-hazard risk of 13 communities of Hodh Chargui (Mauritania) exposed to meteorological, hydrological, and agricultural drought, as well as heavy precipitations, was ascertained with an index composed of 48 indicators representing hazard, exposure, vulnerability, and adaptive capacity. Community meetings and visits to exposed items enabled specific indicators to be identified. Scientific knowledge was used to determine the hazard with Climate Hazards Group Infra-Red Precipitation with Station (CHIRPS) and Tropical Rainfall Measuring Mission (TRMM) datasets, Landsat images, and the method used to rank the communities. The northern communities are at greater risk of agricultural drought and those at the foot of the uplands are more at risk of heavy rains and consequent flash floods. The assessment proposes 12 types of actions to treat the risk in the six communities with severe and high multi-hazard risk

Climate change characterisation and planning in large tropical and subtropical cities

In recent years, the number of large subtropical and tropical cities with defined climate plans has increased as a result of the initiatives of local governments, multi-bilateral development aid and development banks. Surveys carried out to date on climate planning consider the overall cities, at times by continent, without underscoring those that present planning deficiencies. For instance, we have no idea whether the cities that are most affected by hydro-meteorological and climatic disasters have plans, nor if their climate plans are ready to be implemented. Clarifying these aspects would strengthen the foundation of the current discussion on the United Nations’ Sustainable Development Goals 2016–2030. Hence, the objective of this chapter is to ascertain the relevance and quality of climate planning in large subtropical and tropical cities populated by over 1 million inhabitants. Our survey found 344 large cities in the two climate zones concerned, and 82 of these have mitigation, adaptation, resilience or emergency plans, strategies or policies. We verified the relevance of these tools for the climate zones concerned, the type of economy and the frequency of hydro-meteorological and climate-related disasters. The quality of plans was assessed, ensuring that they had taken climate characterisation into account, that every measure was managed by a designated agency or office, and that funds were secured for implementing measures, as well as a monitoring and reporting sytem was defined. The analysis of collected information underscores considerable differences between large cities in terms of per capita greenhouse gas emissions (which were double in the subtropics relative to the tropics) and exposure to hazards (which were greater in the subtropical zone). Emergency and mitigation plans were the most common, while adaptation plans and resilience strategies were more unusual. The relevance of plans is still weak, given that barely 1/4 of the large cities had a plan. Plans were unquestionably more common in the subtropics, especially in OECD countries and in the BRICS, while they were absent in the Least Developed Countries (LDCs), despite the presence of large cities that have been repeatedly affected by hydro-meteorological and climate-related disasters. Planning quality was good for 30% of cities only. In the remaining 70% of cities, climate characterisation was briefly defined; the planning process was fully funded by multi-bilateral development aid; measures were without a clear manager; cost, funds and monitoring of measures were not specified. Thus the indication being that local plans were still scarcely action-oriented. Hence, the fact that two sustainable development goals (# 11 and 13) address human settlements and climate change, respectively, especially through assistance to LCDs, seems justified

Renewing climate planning locally to attend the 11th Sustainable development goal in the tropics

In the last seven years, tropical cities with a climate plan have tripled compared to the previous seven years. According to the 11th United Nations’ Sustainable Development Goal, climate planning should significantly increase by 2030. The Sendai framework for disaster risk reduction (2015) and the New urban agenda signed in Quito (2016) indicate how to achieve this goal through analysis, categories of plans and specific measures. This chapter identifies the main obstacles to the significant increase in tropical human settlements with a climate plan and the possible solutions. First of all, the distribution and trend at 2030 of tropical human settlements are ascertained. Then local access to information on damage, hazard, exposure, vulnerability and risk, and the consideration of these aspects in the national guides to local climate planning are verified. Lastly, the categories of plans and climate measures recommended by the United Nations are compared with those that are most common today, using a database of 401 climate plans for 338 tropical cities relating to 41 countries. The chapter highlights the fact that the prescription for treating tropical cities affected by climate change has been prepared without an accurate diagnosis. Significantly increasing climate planning must consider that small-medium human settlements in the Tropics will prevail at least until 2030. And most effort will be required from Developing and Least Developed Countries. The recommendations of the United Nations concerning the preliminary analyses ignore the fact that local authorities usually do not have access to the necessary information