Welcometh to Whitemud Creek Oxbow Earth Cache !!
Welcome to whitemud creek oxbow earth cache ! Who is't doesn't like an oxbow? (But sounds like a medieval weapon or tool if 't be true thee asketh me). But nay - its a ingraft natural geological phenomen yond can occur ov'r time on any river.
Oxbows in HISTORY
In olden times these natural formations were of strategic importance as they formed a natural barrier, when incorporated with man-made fortifications, such as the Citadel of Besancon. The Citadel occupied 11 hectares (27 acres) on Mount Saint-Etienne, one of the seven hills that protect Besançon, the capital of Franche-Comté. Mount Saint-Etienne occupied the neck of an OXBOW formed by the river Doubs, giving the site a strategic importance that Julius Caesar recognised as early as 58 BC. The Citadel overlooked the old quarter of the city, which was located within the OXBOW, and had views of the city and its surroundings.
This Earthcache has been placed for the Medieval CARW2023 event with the intention that it not be "found" prior to 09:00h Saturday March 4, 2023.
Should you head out and claim a "find" on this earthcache before the event start, it will not count for the event, and the FTF points are only valid as of 09:00h Saturday March 4, 2023.
THANK YOU.
WHITEMUD CREEK OXBOW AND OXBOW LAKE :
Located at the confluence of Twin Brooks, MacGrath and BlueQuill Neighbourhoods, here we find the meandering Whitemud Creek. Over the years, the creek has worked its way around and through, leaving a changing landscape behind. Often these type of geographic phenomena are best seen from above. Here is a googlemap view of the area.
WHAT IS AN OXBOW ??
An oxbow wetland is a meander of a stream, river or creek, that has become separated from the flow of water. Oxbow wetlands store excess water that might otherwise lead to flooding, filter water to improve water quality and provide habitat to a variety of wildlife. Over time, some oxbows fill in with sediment due to erosion of soil in surrounding areas.
As river loops get bigger and more and more sediment deposits, water finds an easier course to follow. Over time, new channels form and bypass the old loop. The old, isolated loop is often referred to as an oxbow.
Whitemud Creek possesses numerous oxbows. The one in Larch Sanctuary is bound by an old beaver dam at the north end and a wall of accreted sediments on the south end. Groundwater and seepage from the west side of the ravine feeds the oxbow, as does spring and surface runoff. Notice when you visit how the level of the water varies with the seasons.
SOME OXBOW FUN FACTS:
Oxbows Improve Water Quality
The ability of an oxbow wetland to process and filter out excess nutrients depends on how long the oxbow can store water before it flows into the nearby stream. Nitrates are a common nutrient necessary for agricultural production but are detrimental to water quality when introduced at high levels. Restored oxbows remove nitrate from flood waters. Studies have shown that, on average, oxbows filter 42 percent of excess nutrients from water that flows into them.
Oxbows that intercept agricultural tile drainage can filter nearly 100 percent of nitrates from the water, if given enough time. Tile drainage is a type of drainage system that removes excess water in soil from below its surface. In many Iowa streams, a significant percentage of water flow is from tile drainage. Urban oxbows also capture and treat a variety of urban contaminants when linked to stormwater discharge.
Oxbows Increase Flood Storage
Oxbows store up to one million gallons of water per acre of oxbow and can slow stormwater before it enters rivers and streams. When stream flows increase during and after precipitation events, oxbows can intercept some of the flood water and slowly release it back into the stream, helping to reduce the peak flows. As precipitation events become more extreme due to climate change, this role for oxbow wetlands will become more important. When coupled with stormwater wetlands or basins, oxbows can lead to significant reductions in flooding.
To watch how an oxbow forms click on the image below:
OXBOW LAKES :
Meanwhile an oxbow lake is a type of lake which is formed when a wide meander from a stream or a river is cut off to form a lake. They are called oxbow lakes due to the distinctive curved shape that results from this process. In Australia, an oxbow lake is called a billabong.
More information on oxbow lakes can be found here.
The Larch Sanctuary’s Riparian Zone:
The riparian zone that borders Whitemud Creek and the oxbow is essential to the Sanctuary’s ecology. The riparian area includes the floodplain, streamside vegetation, and lower slopes of the forest influenced by moisture from the wet areas.
The stream side vegetation is indigenous: native plants with complex root systems. These root systems stabilize the banks, prevent soil erosion and help improve water quality.
Riparian vegetation in general provides habitat for many species. In Alberta, approximately 80% of all wildlife use a riparian area at some point in their life cycle.
Large and small animals, herbivores as well as predators, use them as travel corridors. They are often stopovers on longer migration routes.
Fish habitat is improved by the overhanging vegetation of the riparian zone, which shades the water and regulates temperature. If riparian vegetation is cleared or trampled by humans, the water temperatures may rise. This will affect the number and species of fish that inhabit water ways such as Whitemud Creek.
The riparian area around the oxbow is clearly visible from its north end. Semi-aquatic mammals including beaver, muskrat and possibly mink, as well as amphibians such as chorus frogs, wood frogs and salamanders frequent the area. You can also observe emergent riparian plants here, including cattails, bulrushes, duckweed, marsh marigold, water sedges, marsh reed grass, horsetails, manna grass, slough grass, spike rushes, wild mint, and water crowfoot.
To claim credit for this Earth Cache you must answer the following questions by directly messaging me:
- At posted GZ, estimate the width of the oxbow lake.
- Comment on the level of the water at the time of your visit. Take note on the banks on either side estimate how high the water may rise (or fall) here.
- Based on the information above about the Riparian Zone, where do you see this most clearly? Estimate the length in metres of this area. What type of vegetation to you see here?
- ** OPTIONAL - with your log, welcome to post a photo of yourself, your caching party, your GPSr near posted coords. Bonus points for creative logs and photos!
Please do not post your answers in your log. You do not need to wait for confirmation of correct answers to log a find. However, logs without messages to me will be deleted.
*** THANK YOU FOR VISITING!! ***