Contents 1 A decision platform for landslide risk reduction in developing countries 1.1 Owner 1.2 Summary 1.2.1 Example 1.3 Use Case/User Story/Scenario 1.4 Description and Constraints 1.5 Extra Credit 1.6 Current State and Solutions

[edit] A decision platform for landslide risk reduction in developing countries

[edit] Owner

Problem owned by the MoSSaiC team and the winning RHoK#1 team, working simultaneously in the Eastern Caribbean and Chicago.

• RHoK 2.0 - Saint Lucia
• RHoK 2.0 - Chicago

Contact mossaic@emailplus.org

[edit] Summary

In tropical developing countries rainfall triggered landslides pose a significant risk to vulnerable communities and present a complex problem to Governments. A fundamental question is: “given a limited budget for landslide risk reduction, how and where should the money be spent?” The Management of Slope Stability in Communities (MoSSaiC) project has demonstrated that there are practical ways of improving slope stability – evidence shows that improving slope drainage can often reduce landslide risk in the most vulnerable ‘shanty-town’ communities. The MoSSaiC Decision Platform will enable decision makers and engineers to prioritise investment in landslide risk reduction in such communities. It will bring together a suite of tools to assess: i) the relative landslide hazard (how landslide prone an area is), ii) exposure (who/what might be affected by landsides), iii) vulnerability (how badly will they be affected), iv) the potential effectiveness and cost of slope drainage as a means of landslide risk reduction. For each community these components will be expressed numerically as a ‘score’, probability, or cost. These values will then be summarised and sorted in a Decision Matrix, and the prioritised list of communities generated.

[edit] Example

How do you prioritise limited expenditure on landslide risk reduction measures in vulnerable communities in devloping coutries? As the RHoK#1 team, we have already put the landslide risk visualisation platform developments in the hands of local engineers in the Eastern Caribbean working on real landslide risk reduction construction projects with the MoSSaiC team and the World Bank.

[edit] Use Case/User Story/Scenario

Rainfall-triggered landslides in ‘shanty-town’ communities are an everyday occurrence, and large events can cause loss of life, require community relocation, and cost millions of dollars.

• The MoSSaiC project in the Eastern Caribbean has shown that urban landslide risk can be reduced if highly localised landslide triggers are identified at a community level. In many cases simple measures such as improving surface drainage can improve the stability of the slope.
• However, given the limited budget for landslide risk reduction, the first stage is for a government to decide which communities to prioritise for such a project. Often there is very little information to support this decision.
• What is needed is a transparent way of assessing which communities are most at risk, and determining the potential effectiveness and relative cost of improving slope drainage.
• The first stage will be for the government to login to the proposed new MoSSaiC Decision Platform (MoSSaiC-DP) and list potential communities for such an intervention in the main Decision Matrix.
• For each community they will then need to assign a relative landslide susceptibility score reflecting how landslide prone the slope is. This could be done in a number of ways depending on the data available such as expert-judgement or existing landslide susceptibility studies. Links to other MoSSaiC-DP pages will give access to tools to generate this information e.g. using a check-list of slope characteristics, or fields in which data can be directly input from other studies. The results will appear in the ‘Susceptibility’ column of the Decision Matrix.
• An optional ‘quantitative’ score may be given if site-specific landslide hazard modelling has been undertaken (e.g. using the CHASM slope stability software). The probability of a landslide would then be entered into the ‘Hazard’ column of the Decision Matrix.
• Next, the user will need to define the exposure of the community – how many people are in the community, and how many households there are. This data could come from census data or a household survey. It could also be stated as population density (households per unit area).
• The vulnerability of the community should then be defined. This is sometimes expressed in terms of the level of poverty (a reflection of the ability to recover from a disaster – or the community ‘resilience’). This could be calculated using a new app on a separate MoSSaiC-DP page e.g. using a formula for calculating the Core Welfare Index from census data or a simple survey.
• Finally, the impact of rainfall on slope stability, and the potential to improve stability by constructing drains should be calculated. Applications on separate MoSSaiC-DP pages could be used to build-up this information and return the results to the Decision Matrix:
  • the Rational Equation for calculating surface water runoff during a storm;
  • a calculator for determining total roof area for rainwater interception and harvesting;
  • a continuity equation for calculating potential drain depth and flow rates;
  • a simple quantity estimation method for calculating the cost of drains and roof-guttering;
  • an option to use CHASM to confirm the effectiveness of drainage in reducing landslide frequency.

Once all the columns in the decision matrix have been completed, the user can sort the table and prioritise communities according to the relative landslide risk score (susceptibility or hazard x exposure x vulnerability) and/or estimated project costs.

[edit] Description and Constraints

Task 1 The first part of this project is to develop the user login and main page of the Decision Platform – the Decision Matrix. This table will summarise, for each community (rows), the numerical outputs obtained from each tool for each aspect of landslide risk (columns). This table should be designed so that the data can be sorted by the values in certain columns. Some columns may need to be multiplied or added together first. The user can then obtain a prioritised list indicating how and where the budget might best be allocated. This platform could link to other disaster risk assessment platforms in the future. Tasks 2+ The data that will populate the Decision Matrix table will come from the other pages on the platform – each of which will eventually contain one of the risk assessment tools. New applications will need to be created for the other tools. These will be based on simple, readily available equations or methods. A description, method (or equation) and test case will be provided for each app. These applications can be developed in any order depending on team size, skill-set and time available (subsequent RHoK events could continue such developments). One such tool will be the interface to the CHASM slope stability software developed at RHoK#1 in June 2010, which will be tested in the Eastern Caribbean during the RHoK#2 event. The platform will be fully extensible in that new links could be made to different landslide risk assessment tools as they become available.

[edit] Extra Credit

As the winning team from RHoK#1 we have deployed the landslide risk visualisation tool in the Eastern Caribbean where it is already being refined by local engineers. The RHoK#2 definition uses this tool and embeds it in a comprehensive, easy to use, decision platform allowing developing countries to identify (and thus priortitise) those communities with the greatest need for landslide risk reduction constuction.

[edit] Current State and Solutions

This problem definition links the RHoK#1 team, the MoSSaiC team, local engineers on the ground in St Lucia (which has just experienced a 1 in 500 year rainfall event with Hurrican Tomas), and World Bank funded landslide risk reduction projects managed by MoSSaiC. The developments can therefore be used immediately to assist vulnerable communities, and there is an opportunity to test the platform in a World Bank funded landslide risk reduction project starting in Jamaica.