Patrick's Bio Blog: October 2010

Introduction

Rivers are a source of freshwater and they are a part of many ecosystems. The way many people see water, as a possession, is wrong, because it isn't. Water constantly flows, and is subject to change. The flows of rivers are very important, because it gives us information about the conditions or state of freshwater ecosystems, and freshwater abundance.

Factors

Many factors can put rivers at risk. Increased population means increased demands for water consumption. Food production requires a lot of water, from growing crops, to processing and making the meal. The demand of water for consumption has increased drastically as well. Climate change is another heavy factor in damaging weathers. Direct human activity like dams that alter natural patterns will also cause damage.

Climate Changes

Water is very sensitive to climate changes. Droughts, floods, excessive glacier melting, and changes in precipitation patterns can devastate the natural patterns of rivers. Frequent droughts will cause the river to evaporate, often leaving the river to dry up. Floods will increase the water level temporarily, but in that time it can do a lot of damage, like destroying habitats. If a glacier melts, not only do we lose our ice shelves, but it also permanently increases water levels, which will be very disruptive to ecosystems. These natural disasters and frequent changes in climates are indirectly caused by humans via Global Warming. In addition, when temperatures rise, the demand for water also rises.

Melting Himalayan Glacier

The dry riverbed of the Gan River,
near Nanchang, China.

Dam, where’s the flow?

There are many things that humans have done or created that have damaged the rivers, some are pretty obvious. These structures include dams, locks, weirs, and dykes. These structures were formed to prevent flooding, produce hydropower, and store water for irrigation and consumption.

These structures were designed to alter the flow of rivers for human use by changing the timing of the flow, the quantity of water flowing through, and the quality of the water that flows through. Sure, these inventions help reduce flooding and produce hydropower, but the price is the health of the river. The river flows are made useful to us, by altering their natural flow. This is devastating for not only the river, but also for organisms and ecosystems that relied on the natural water flow to survive. Sometimes, a river can be disconnected from its watershed (The water storage). Some rivers are in danger of not having enough water for a river because of excessive withdrawals for consumption and irrigation.

Mississippi River Lock

Yangtze River Dam

Help Can We Give

A way we can help is to take action on preventing dangerous climate changes. Another way is to alter the flows of the rivers back to a more natural state, and compromise its well-being with our needs. We can educate others about this problem, because they have the right to know what is happening to their world. We can keep water usage within nature’s limit. You can also help organizations like WWF to help protect our rivers.