This document discusses the importance of participatory geographic information systems (PGIS) for natural resource management and planning (NRM&P). PGIS combines geo-spatial tools like maps, imagery and GPS to represent local spatial knowledge and facilitate discussion, information sharing, and decision making. It aims to ensure sustainable NRM&P by giving voice to local communities and incorporating their knowledge. The document reviews the history and approaches of PGIS, describes methods like sketch mapping and participatory 3D modeling, and presents case studies on reducing disaster risk and mitigating arsenic poisoning through PGIS.