Marguerite Thomas Williams was the first African-American person in the United States to receive a PhD in geology. In her thesis she analysed how the virulence of the Anacostia River, which causes tragic floods, was related to human activity, which for years had transformed its drainage basin through excessive urbanisation, intensive agriculture or deforestation. 

Read the following article from the magazine Neofrontiers, published on 7 September 2009, (https://neofronteras.com/?p=2822) and answer the questions at the end.

 
                                                Human activity as a driver of erosion 
                       A study shows that human activity produces as much erosion as the world's great rivers and glaciers.

Suppose we were to magically stop climate change and eliminate all pollution in one fell swoop. Suppose also that we miraculously stabilised the world's population at current levels and did not destroy all our fish stocks as we are about to do. Even without all these problems, the days of modern civilisation would be numbered. 
This is not new and has happened several times in history when various civilisations failed to manage their ecological resources well. One of the most important factors influencing the success or failure of a civilisation is whether it has managed to avoid erosion. 
Humans eat, if possible every day, and food comes from fields (livestock also need fields or pastures). But for plants to grow, the soil must provide them with a range of nutrients and must have the capacity to retain moisture and the very plants that grow in it.
Soil on Earth is one of the most sophisticated things there is, both physico-chemically and biologically. In the soil there is a whole community of living beings that participate in incredibly complex phenomena to transform organic and inorganic matter and allow plants to grow in it. The simple disappearance of earthworms takes away a lot of fertility from the soil. It is on the soil that our plants grow, and therefore our food. If the soil disappears, we are lost. There are processes that create soil and take thousands or millions of years to produce it, and other processes that destroy it, such as erosion. But humans, because of their activity, are another factor in erosion. How important is it? It seems to be as important as large rivers and glaciers. Although there are natural processes that erode certain places to create soil in others, in general, human activity is only destructive in this sense.
Contrary to popular belief, a study published in Nature Geosciences by researchers from the University of British Columbia and the University of Washington shows that humans are reshaping the planet at a rate comparable to the erosive capacity of large rivers and glaciers (...). In exploring this problem, they found that many areas are experiencing high levels of erosion caused by climate change, human activity and modern intensive agriculture (...). It is paradoxical that precisely our way of obtaining food mortgages the ability of future generations to obtain food. In other words, "bread for today and hunger for tomorrow" which will inevitably lead to a collapse of civilisation as it happened to Mayans, Pueblo Indians, Icelanders, Easter Islanders, etc. before.
 
QUESTIONS: 
1. Why is soil so important? 
2. How is soil defined in the article? 
3. Does human activity significantly affect soil erosion? 
4. Specifically, what human activity is given as an example in the text? 
5. The first person to realise the importance of human activities on soil erosion was Marguerite Thomas Williams. Find information about her and highlight a relevant event in her life.