(a) How is income an important factor in assessing the development of a country? Mention the classification done by the World Bank.

(i) For comparing countries, their income is considered to be one of the most important attributes.

(ii) Countries with higher income are more developed than others with less income.

(iii) This is based on the understanding that more income means more of all things that human beings need.

(iv) Whatever people like, and should have, they will be able to get with greater income. So, greater income itself is considered to be one important goal.

Classification done by the World Bank-

According to the World Development Reports, brought out by the World Bank (in $\displaystyle 2019$),

(i) Countries with per capita income of US$ $\displaystyle 49,300$ per annum and above, are called high income or rich countries.

(ii) Countries with per capita income between US$ $\displaystyle 2500$ and US$ $\displaystyle 49,300$ are called middle-income countries.

(iii) Countries with per capita income of US$ $\displaystyle 2500$ or less are called low-income countries.

(iv) India comes in the category of middle-income countries because its per capita income in $\displaystyle 2019$ was just US$ $\displaystyle 6700$ per annum.

(b) How has the overuse of underground water created a serious crisis in many parts of India? Explain with examples in the context of sustainable development.

(i) Groundwater is an example of renewable resource. This resource is replenished by nature.

(ii) Even this resource may be overused by excessive irrigation, industries etc.

(iii) In the case of groundwater, if we use more than what is being replenished by rain then we would be overusing this resource.

Examples in the context of sustainability:

(i) Recent evidence suggests that the groundwater is under serious threat of overuse in many parts of the country.

(ii) Many districts have reported steep decline in water level.

(iii) Nearly one-third of the country is overusing their groundwater reserves.

(iv) In the coming years, if the present way of using this resource continues, most parts of the country will face a serious water crisis.

(v) Groundwater overuse is particularly found in the agriculturally prosperous regions of Punjab and Western U.P., hard rock plateau areas of central and south India, some coastal areas and the rapidly growing urban settlements.