Drought is a long time when there is little rain or no rain. Drought occurs due to climate change and deforestation. It is hard to know when it started. Signs include: less rain, dry soil, high temperatures for weeks. According to statistics from 2019-2020, Southeast Asia is home to the most drought-stricken nations such as Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Thailand. It adversely affects the health and life of people. For example: Increasing temperatures cause health effects, many plants die due to lack of water, people become angry, uncomfortable ... So, to prevent drought we need to plant trees that need less water, can hold water, build a reservoir to store water ...

The relationship between communicable diseases and disasters merits special attention. This chapter does not address epidemics of emerging or reemerging diseases, chronic degradation of the environment, progressive climatic change, or health problems associated with famine and temporary settlements.In line with the definition of health adopted in the constitution of the World Health Organization , the chapter treats disasters as a health condition or risk, which, as any other "disease," should be the subject of epidemiological analysis, systematic control, and prevention, rather than merely as an emergency medicine or humanitarian matter.