In My Views.docx

In my views, we need to learn hydrology because it is very important to me as civil engineer. Hydrology is the study of water, tracking its very movement between the atmosphere, water bodies and earth. In other terms, hydrology is an earth science that treats the water of the earth on their occurrence, distribution and movement. It is important for us as civil engineer to learn their interaction with the environment including interaction with living things and human being. In general sense, hydrology is tied to disciplines of climatology, meteorology, oceanography, geography, geology, environmental science, physics and hydraulics. Hydrology has evolved as a science in response to the need to understand the complex water system of the earth and help solve water problems. In every civil engineering project, be it a roadway/railway/shopping complex/buildings/whatever, one of the fundamental duties of the design/engineering team is to make sure that there is no issue with the on-site drainage. i.e., the development activity should have no/minimal impact on the existing conditions in the case of a storm event. Hydrologic analysis of a development area is the starting point of this analysis. This is where we study the historical rainfall data, land usage type, and terrain of the ground to calculate the runoff/discharge/flow rate that could result in that area. Based on the calculated runoff, engineers do the hydraulic design to minimize the impacts of the proposed development. I am not sure if you have heard of something called “Factor of Safety”, in case you have not, it is something engineers consider while designing for the worst-case scenario. Let’s say if a bridge is meant to carry a maximum load of 100 tons. Let’s also assume Factor of Safety of 2.0 is required for this bridge (this is usually dictated by the authorities depending on the project’s importance), then engineers will design the bridge to be capable of carrying 200 tons. It will however be operated under 100 tons. A factor of safety is used more commonly in the structural design of a project. In the similar fashion, we need to design for other calamities such as floods. This is where hydrology comes into play, depending on the location and type of project, there will be a design standard set up by the local authorities. Most of engineering projects are designed for a 1% annual chance occurrence event, this means the design we produce shall not have any negative impacts during the storm events equal to or lower than the 1% annual chance occurrence. In sheer comparison, the storm event that devastated Texas (hurricane Harvey) is a 0.1% annual chance occurrence and none of the development was designed for such a rare event (nuclear facilities are the only exception). This example just so to give us an idea of what’s going to happen if we discard hydrology during a design. For example, design of dams, headworks/barrages, Canals all require detailed hydrological studies. Similarly design of Highways also require comprehensive hydrological study for establishing location and spans of bridges and culverts. I have seen poorly designed highways literally washed away by flash floods because of inadequate number of culverts or spans of bridges.