Period of Decline

The upper layers unearthed at Mohenjodaro, Harappa, Kalibangan, and other places reveal certain conditions that indicate a period of decline in these ancient Indus Valley Civilization cities. This can be deduced from the following observations:

1. Construction without a prescribed plan:
The upper layers of these cities show that the construction was carried out without any prescribed plan. This implies that the careful urban planning and layout that characterized the earlier phases of these cities was absent. The lack of a structured plan suggests a decline in organized governance and administration.

2. Decay of public buildings:
The upper layers also reveal that public buildings were in a state of decay. These structures, which were once the pride of the cities, had fallen into disrepair. This further supports the idea that there was a decline in the maintenance and upkeep of public infrastructure. The neglect of these buildings points to a weakening of the social and economic systems that supported their construction and maintenance.

3. Disarray in water supply:
Another significant observation is the disarray in water supply. The advanced water management systems that were a hallmark of the Indus Valley Civilization, such as well-planned drainage systems and well-laid water channels, were found in a state of disrepair. This suggests a decline in the ability to manage and maintain the water supply infrastructure. The disruption in providing clean water to the residents would have had detrimental effects on the overall well-being and health of the population.

Implications:
The presence of these conditions in the upper layers of the cities indicates a period of decline in the Indus Valley Civilization. The deterioration of urban planning, decay of public buildings, and disarray in water supply point towards a weakening of the social, economic, and administrative systems that were once flourishing during the earlier phases of these cities.

This period of decline could have been caused by various factors such as environmental changes, natural disasters, internal conflicts, or external invasions. However, it is important to note that the specific cause of the decline is still a topic of debate among historians and archaeologists.

In conclusion, the upper layers unearthed at various Indus Valley Civilization sites provide evidence of a period of decline characterized by the absence of a prescribed plan in construction, decay of public buildings, and disarray in water supply. These factors indicate a decline in the overall prosperity and organization of these ancient cities.