Development-induced displacement and resettlement (DIDR) occurs when people are forced to leave their homes in a development-driven form of forced migration. Historically, it has been associated with the construction of dams for hydroelectric power and irrigation, but it can also result from various development projects such as mining, agriculture, the creation of military installations, airports, industrial plants, weapon testing grounds, railways, road developments, urbanization, conservation projects, and forestry. Development-induced displacement is a social problem affecting multiple levels of human organization, from tribal and village communities to well-developed urban areas. Development is widely viewed as an inevitable step towards modernization and economic growth in developing countries; however, for those who are displaced, the end result is most often loss of livelihood and impoverishment. Classification of development-induced displaced persons (DIDPs), refugees and internally displaced persons rests on fundamental differences in the type of assistance provided to each category. Refugees and internally displaced persons typically need international protection and assistance as a result of fleeing violence and persecution. Development-induced displaced persons require the restoration of their capacity to generate income and protection from the state. While people displaced as a result of development have similar experiences to refugees (as defined by the UNHCR) in terms of economic and social loss, they are not protected by international law. Types of displacement "Primary" or "direct" displacement occurs when people are moved from their traditional lands to make way for a development project or when people move towards a project to meet a new labor demand. Primary displacement is usually predictable and can therefore be mitigated through planning. "Secondary" or "indirect" displacement is a result of environmental, geographical and socio-political consequences of the development project that take place over time and distance from the initial project. This type of displacement is less predictable and difficult to control. One example of secondary displacement is if a community is forced to move because of pollution of their water supply by a mining project. Some examples of development-induced displacement are: Three Gorges Dam in China – A hydroelectric dam on China's Yangtze River constructed between 1994 and 2006, which displaced over 1.4 million people through primary and secondary displacement. Sardar Sarovar Dam in India – The largest dam in the Narmada Valley Project, which displaced over 40,000 people. The dam was the subject of protest by environment groups and tribal groups during the 1980s and 1990s. Ahafo Mine in