Water vulnerability is contingent upon biophysical and social drivers operating at multiple scales and is difficult to assess. Vulnerability assessment evaluates a system’s sensitivity to potential threats, and to identify key challenges to the system in reducing or mitigating the risk associated with the negative consequences from adversarial actions. It supports to generate important evidence for the decision and policy makers for identifying and planning proper adaptation plan of action. Vulnerability indices are used to quantify the range and extent of vulnerability in a system.
Vulnerability is generally defined as the characteristics and circumstances of an individual, community, or system that makes it susceptible to the damaging effects of a challenge(s)/hazard(s). In relation to the disaster, the United Nations Office for Disaster Risk Reduction defines vulnerability as the conditions determined by physical, social, economic, and environmental factors or processes, which increase the susceptibility of a community to impact of hazards (UNDRR, 2017). Intergovernmental Panel on Climate Change (IPCC) defines vulnerability as the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes (IPCC, 2001). In social sciences, vulnerability typically refers to a set of socio-economic factors that determine people’s ability to cope with stress or change.
Water is becoming a vulnerable resource as pressure increases on the hydrological systems due to a combination of various climatic and anthropogenic factors. The vulnerability of water resources can be classified into several vulnerability factors, such as water-shortage, water pollution, and water-related natural disaster, i.e., flood or drought. The evaluation and identification of these key vulnerability factors of water resources in each river basin can help trace the local water resources vulnerability situation and provide guidance for adaptive water management. There are some other factors that makes community or water management systems vulnerable are:
- Physical factors: It includes water system infrastructures (pipelines, civil structures- dams and reservoirs), land use and land cover, water quality and quantity.
- Social factors: They are related to social conditions, poverty, social inclusion, gender discrimination, allocation, and access to water, reach to organization and power.
- Economic factors: The factors such as, physical, and natural assets, insurance, livelihood, economic diversity, degree of access to loan and credit.
- Environmental factors: It includes natural resource depletion and degradation, poor environment management, toxic and hazardous pollutants, reduced access to clean water, and sanitation.