Web based calculator for forecasting population growth by arithmetic increase method | Environmental engineering

Population forecasting by arithmetic increase method.

Arithmetic increase method

This method is based upon the assumption that the population increases at a constant rate. The rate of change of population with time is constant.

\[\frac{{dp}}{{dt}} = constant = K\]

\[dp = K \times dt\]

\[\int\limits_{\mathop p\nolimits_1 }^{\mathop p\nolimits_2 } {dp} = K \times \int\limits_{\mathop t\nolimits_1 }^{\mathop t\nolimits_2 } {dt} \]

\[\mathop p\nolimits_2 - \mathop p\nolimits_1 = K \times \left( {\mathop t\nolimits_2 - \mathop t\nolimits_1 } \right)\]

Where, suffixes 1 and 2 represent the last and first decades or census respectively. Thus t₂-t₁= Number of decades.

The population data for the last 4 to 5 decades, is therefore, obtained and the population increase per decade(x) is calculated; The average of which (x) is then used as the design growth rate for computing future population.

P₁= population after 1 decade from present

\[\mathop p\nolimits_1 = \mathop p\nolimits_0 + 1\overline x \]

P₂= population after 2 decade from present

\[\mathop p\nolimits_2 = \mathop p\nolimits_0 + 2\overline x \]

The general equation of arithmetic increase method is shown below

\[\mathop p\nolimits_n = \mathop p\nolimits_0 + n\overline x \]

Procedure

Collect 4 to 5 decades of population growth data. Input these data into table. The webpage performs analysis based on arithmetic increase method explained above. This webpage also plots graph.

Table

Years	Population	Increase in Population
1930	25000
1940	28000
1950	34000
1960	42000
1970	47000

Graph

This graph indicates population growth increase or decrease. Arithmetic increase method helps in rough estimate of population forecasting.

Population forecasting by arithmetic increase method.

Edit the population growth data of five decades by clicking on data.

Year	Population	Increase in Population
1930	25000
1940	28000
1950	34000
1960	42000
1970	47000

Click on the calculate to forecast population for three decades.

Average increase per decade =

Population after 1^st decade =

Population after 2^nd decade =

Population after 3^rd decade =

Forecasting population.

1. First video

2. Second video

Refrences

1. Lal , D & Upadhyay, A.K. (2013). Water Supply and Waste Water Engineering (2nd ed.). S.K. Kataria & Sons

2. Rangwala. (2016). Water supply and sanitary engineering (29nd ed.). Charotar Publishing House pvt. Ltd.

3. Chatterjee, A. K. (2006). Water Supply, Waste Disposal and Environmental Engineering (8th ed.). by Khanna Publishers.

4. Practical Handbook on Water Supply Engineering (2011).Nabhi Publications.