Table 1 Indicators used to evaluate global eco-environmental vulnerability including data description, and brief explanation of their roles

Hydrometeorology (B₁)

Soil moisture

(C₁)

Soil moisture is vitally important in controlling the exchange of water and heat energy between land surface and atmosphere through evapotranspiration and as a key variable to define flood control, soil erosion, and slope failure

Precipitation

(C₂)

Precipitation is important for soil and plant growth and useful for determination of weather patterns regarding to early warning of drought and flood

Temperature

(C₃)

Average global air temperature is useful to classify weather patterns in combination with precipitation and soil moisture

Distance from hydrological network

(C₄)

Availability of surface water is important for environment especially in urban cities for cooling heat island effect

Socioeconomics (B₂)

Population

(C₅)

Population plays an important role in eco-environmental vulnerability assessment since it contributes to determine human pressure on eco-environment. In general, more people and higher population density likely cause heavier pressure on environment resulting in higher vulnerability

Income

(C₆)

This indicator shows average income of each country from high to low income (highly developed countries to developing countries). In general, in the developing countries, the eco-environment is likely to be disturbed more than developed countries since they are on the fast growing processes of urbanization and industrialization. Income also reflects the education level as well as public awareness of eco-environmental protection

Distance from urbanized areas

(C₇)

This indicator determines the influence from the urban by spatial distance. Exposure from urban affected the eco-environment by the stress from the city like pollution from vehicles and air condition, and trash from households, and wastewater. It is likely that the farther from the urban the better the eco-environment

Land resource (B₃)

Land use/land cover

(LULC)

(C₈)

LULC is an important determinant of eco-environmental vulnerability due to its contribution to and general influence on environmental quality. The areas without or with less vegetation cover are more vulnerable than the dense vegetation areas. Impervious surface materials conserve more heat during the day and release it more slowly at night than natural materials like soil or vegetation

Normalized Difference Vegetation Index (NDVI)

(C₉)

NDVI is a crucial indicator to measure the greenness of vegetation and vegetation plays an important role in maintaining good eco-environment. Regions that are less or without vegetation may cope with higher vulnerability

Natural hazards (B₄)

Drought (C₁₀)

These indicators determine the areas constantly affected by natural hazards resulting in environmental decline

Tropical cyclones (C₁₁)

Landslides (C₁₂)

Flood

(C₁₃)

Topography (B5)

DEM

(C₁₄)

DEM plays an important role in defining topographic condition, determining the features of land surface such as incoming solar radiation, tree types, and potential exposure to hazards like landslide, and drought

Slope constraint

(C₁₅)

Slope constraint is a factor influencing land-use decision and the item “Land utilization possibilities”. The influence of terrain on erosion is great important. Steeper slopes are also associated with shallower soils in general and with a higher risk for soil degradation and landslides

Slope aspect

(C₁₆)

Slope aspect and topographic position contribute to define annual mean temperature, potential energy incoming and evapotranspiration. Resulting in vegetation structure, ground moisture, snow retention, plant communities and surface temperature are all characteristics influenced by aspect