The hydrological cycle is responsible for the circulation of water around the Earth, between the different systems in the planet. The knowledge of the entire cycle and its components, including precipitation, the different flows and stores involved in the cycle, one is able to gain insights into the movement of water and thus devise means to prevent floods. The key aspect of the hydrological cycle is that of the water input on land, which is precipitation. Understanding the seasonal variations in the inputs would allow us to gain nsights into the seasonality of flooding and possibly even the frequency of flooding in a given area. As such, water at dams can be released at appropriate times so that the lakes can subsequently be used to hold back floodwaters when the high intense precipitation sets in. This way, flooding can be prevented. Precipitation in the form of snow would spend longer time on the land as it flows into channels only when they melt.
Knowledge of the volume of water contained in the snow and the time taken for the melting would help assess if the area has the capacity to hold the water formed rom snow melt. Flood can be prevented by attempting to melt some of the snow 1 during the winter time and allowing greater discharge during the season so that when summer comes, the discharge do not increase too much suddenly. An understanding of the stores available to hold back water before they drain into a channel can be helpful as these components would eventually determine the lag time of the drainage basin. Deforestation removes interception storage and urbanization (which increases the area f concrete pavements, roads and walkways, would remove the soil moisture storage and the catchment area for groundwater store. Both of these activities would result in shortened lag time within the drainage basin.
Thus, understanding these features in the hydrologic cycle would allow us to reverse these developments and take actions to prevent flooding that may result because of increased surface run-off due to lack of exposed land area to capture water in the groundwater stores. Afforestation projects may be undertaken to raise interception storage in barren areas so that recipitation is intercepted and do not reach the channels that quickly. Large urban areas can be planned with more parkland so that there are spaces between covered ground that can accommodate the precipitation and would allow percolation so that groundwater stores are utilized efficiently. This would also provide the opportunities for groundwater recharge. Urban drainage systems can also be designed to allow water to seep into the ground rather than to deliver water efficiently to a central channel. All these measures that are derived from an nderstanding of the components of the hydrological cycle would help prevent flooding through the increase in lag time of the drainage systems on land. The understanding of the flows within the hydrologic system would also help devise measures for flood prevention.
By studying the discharge patterns of the river in concern, and the flood events, the capacity and pattern of flooding can be worked out. This way, developments of settlements can be guided in a way 2 that avoids the areas more prone to flooding. Assessing lood peaks can also help making decisions on how much flood space to allow when building artificial levees. Artificial flows can also be created through river engineering and knowledge of the flows and behavior of the river can also help determine the potential negative impacts of the river engineering or any chance that the engineering would backfire and worsen flooding downstream.
While this essay has broken down the hydrological cycle into parts where knowledge of certain components of the cycle can be used to devise flood prevention measures, in reality, the entire ydrological cycle must be taken into consideration as the relations between the precipitation, flows and stores are complex and these variables and interdependent. The precipitation would influence the flows and this in turn can change the natural capacity of the rivers. At the same time, the knowledge of infiltration capacity of the area inferred from local geology needs to be combined with knowledge of precipitation patterns to assess the flows in the area and thus work out the necessary measures to prevent flooding.