Water Sources and Rivers PDF

Here is the text from the images you sent, converted into a markdown format: ### Water Sources and Rivers #### Surface Water Safety Surface water is not safe to drink, as it may contain bugs, dirt, rocks, minerals, and/or chemicals. Animals may drink and bathe in it. This water has not been clean...

Here is the text from the images you sent, converted into a markdown format: ### Water Sources and Rivers #### Surface Water Safety Surface water is not safe to drink, as it may contain bugs, dirt, rocks, minerals, and/or chemicals. Animals may drink and bathe in it. This water has not been cleaned and filtered, so it is not safe to drink. #### Rainwater Tanks Rainwater tanks collect and conserve water, but the water may not be safe to drink. It can contain bugs, dirt and/or minerals. Anything on the roof or in the gutters can end up in the rainwater tank. This water can be used for watering the garden and washing cars or clothes. Cleaning the gutters is vital if the water is for drinking. #### Other Water Sources Waterholes, rock holes, and springs can also provide water, combining ground and surface water. #### Rock Holes Rock holes are surface water features holding water in a rock or rocky area. They are significant to Aboriginal people living in arid Australia, providing a crucial water supply in dry landscapes and assisting travel and resource access. The first picture shows a rock hole scene. A relatively flat area of land has a small collection of water at its center. #### Springs Springs occur naturally where water comes to the surface from an underground aquifer. The amount of water that flows from springs depends on various factors, including water pressure in the aquifer, rainfall, and human water usage. Spring water is usually very clear but can be discolored due to the naturally occurring minerals in the ground. The second picture shows a small, clear, natural spring of water that flows out of a natural rock formation. ### Rivers #### General River Information A river is a large natural stream of water flowing over land. Although rivers hold a tiny fraction of Earth's total water, they have always been essential to human civilization. Rivers carry freshwater to people, plants, and animals across Earth, provide transport and water power, and shape the land by carving out valleys and canyons. Here is a list of common river terms: * Upper course * Middle course * Lower course * Valley * Channel * Waterfall * Rapids * Gorge * Meander * Tributary * Floodplain * Delta * Estuary #### Stages of a River Rivers can be divided into three stages: 1. **The Upper Course:** Rain in highland areas flows downwards, collects in channels, and forms a stream. As the stream runs downhill, it joins other streams, increasing in size and speed. The point where two rivers join is called a confluence. Eventually, the creek grows into a river. In its upper course, the river flows rapidly, cuts through the land, and picks up soil and gravel. The moving water and material wear away more rock and soil. Over thousands or millions of years, the river creates canyons and deep valleys. The picture shows a fast flowing river through dense forest. 2. **The Middle Course:** As a river reaches its middle course, the fast-flowing water causes erosion, making it deeper and wider. The river erodes left and right, forming horse-shoe-like loops called meanders. In its middle course, the river flows down gentler slopes, getting larger and slower. Soil, gravel, and sand sink to the bottom, with some material building up to form sandbars and islands. The image shows a curved river cutting a path through the land to create a new meandering path. 3. **The Lower Course:** In the lower course, a river is in flatland and flows slowly. The force of the water is lower than in the other stages, so the river deposits the eroded land it has been carrying. In its lower course, the river flows even more slowly and drops more solid material. Some material is carried to the mouth where the river enters the sea, building up into a delta. The image shows a wide, slow flowing river making its way to the ocean through a flat plain. ### Erosion and Deposition #### Why Rivers Aren't Straight Rivers don't travel in straight lines because: * They have to avoid obstacles as they flow downhill. * People have altered river courses over time. Erosion and deposition can change the shape of a river. Erosion involves materials like soil or rocks being moved by wind or water. Called sediments, deposition occurs when these sediments are dropped off in a new location. #### River Deposition Rivers show deposition when materials from erosion are dropped in a new location. Their moving waters pick up sand, dirt, and other sediments, carrying them downstream. Rivers often turn brown or murky, with the sediments being deposited into lakes or oceans, changing the water color. #### Meanders Over Time * As meanders grow, water can erode away so much of the river's banks that two meanders merge. * The water will take this newer, shorter route and not travel the previous course. * Over time, deposition of the river's load will block the old part of the river, and an oxbow lake will form. The picture shows an oxbow lake in an open field with trees.