Upstream, Downstream: Exploring Watershed Connections

Upstream, Downstream: Exploring Watershed Connections — page 5
in a folded leaf or an animal skin They followed animal herds learned which were the best fishing spots and paid attention to the seasons and to which plants produced food when The food and water-gathering activities of early humans affected the local environment where they lived If they killed an elk calf to eat that calf wouldn’t grow up to have its own calves If they used fire to cook the meat there would be fewer branches and sticks to decompose in the forest and some air pollution from the burning wood If they slipped and slid down an unstable riverbank to get water some of the soil would fall into the water and smother insect larvae or fish eggs These effects were small and in small areas As human history marched along people started learning how to get more from the land and water They got better and better at manipulating manipulating which means using or changing something in a skillful way their environment to get what they wanted And the more they manipulated their environment the bigger and more wide spread the effects became Farming Frenzy Farming Frenzy People’s relationship to land and water changed when farming began about 10,000 years ago in the Middle East and a bit later in China and the Americas It takes land to grow crops and it takes water to keep seedlings from drying up The perfect place to farm was on land alongside large rivers that flooded their banks every year Not only did this land get a surge of water in every flood season but the water brought sediments fine particles cles of sand soil and clay containing nutrients As floodwaters drained away these sediments often called silt settled onto the land making it very fertile or rich in nutrients The Nile River in Egypt has a particularly large delta The river branches into many fingers that spill into the Mediterranean Sea Some of the earliest agriculture in Water taken straight from a stream or lake needs to be filtered boiled or treated in some other way to make it safe to drink STOCKSTUDIOX GETTY IMAGES LOOK AND LEARN BRIDGEMAN IMAGES Ripples Ripples One of the earliest ways to lift a large amount of water from a stream or lake was to use a long pole with a bucket on one end and a counterweight on the other end The pole was mounted like a seesaw Called a shaduf in Egypt and a denkli in India this device was in use about 5,000 years ago and in some places is still used today 12