UNEP is systematically tracking the generation of debris from damaged buildings and infrastructure in the Gaza Strip since the outbreak of the conflict in October 2023. The debris quantification assessments aim to inform debris management planning approaches, resource requirements and timeframes for debris clearance and processing operations.
UNEP is also playing a leading role in promoting effective coordination and collaboration amongst UN agencies and other stakeholders on sustainable debris management as co-chair of the UN and Partners Gaza Debris Management Working Group, established in April 2024. To support the outputs of the working group, UNEP and UNDP have agreed to undertake an area-based emergency-based debris management pilot intervention to: support humanitarian access in priority areas; demonstrate feasibility and cost-effectiveness of debris recycling; and to inform future, expanded debris management programming in the Gaza Strip.
Note on methodology: UNEP’s debris quantification assessments are based on UNOSAT Comprehensive Damage Assessment and are undertaken in collaboration with UN-Habitat. Three variables are used to calculate the amount of debris generated from destroyed and damaged buildings:
- The area covered by the building or its “footprint”;
- Height of the building to determine the number of floors; and
- "Living space,” which is a function of multiplying the footprint of the building by the number of floors.
A ratio of debris tonnes per living space area is then applied to calculate the quantity of debris from the damaged or destroyed building. For the debris quantification modelling, the building footprint and height data was extracted from the Palestinian Central Bureau of Statistics database, which covers the period up to 2017. For buildings constructed after 2017, the building footprint was determined by digitizing building boundaries from high-resolution satellite imagery from May 2023.
The building heights were obtained by approximation from the European Commission’s Global Human Settlement Built-H data layer, with the average height per story being established at 3 metres. Each destroyed or damaged built square metre is considered to have generated one tonne of debris, based on an average estimate from previous post-conflict debris management programs in Gaza. For example, for a three-storey destroyed building with a footprint area of 300 square metres, the total living space will be 900 square metres (300m2 x 3) generating 900 tonnes of debris (900m2 x 1 tonne/m2).
