How can using a dam as a source of freshwater also harm agricultural resources?

The dam acts as a barrier between upstream and downstream.  Dams are also built for irrigation, but it is also deliberately destroyed in favor of irrigated farming. Though it provides freshwater, and makes people be protected by droughts, but it can also damage the agricultural resources by limiting the water in some areas. 

Dams can collect topsoil during floods.

hope this !

about 40,000,000 results (0.81 seconds)  

search results

what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.