The provided illustration portrays comparison between water cycle seen in area where there are a lot trees in contrast with area where buildings are common.
By studying the left side of the picture, it can be seen that some water reaches only down to permeable topsoil, then it evaporates later. Despite heavy rainfall, much water is not managed to travel through subsoil on rock layer. Around the basement of the hill where plants experience transpiration and water starts getting momentum to flow down to the river where slight erosion occurs.
Unlike forested area, urban’s rainfall has an adverse effect on its land beacuse of less evaporation as a result of buildings. Due to the lack of trees only a minimal amount of transpiration can be witnessed. As a result, there is more contamination deposited at the base of the hill along with massive runoff which leads to the river. To make things worse, less infiteration is also an issue underground through which water flows directly to the base.