Rivers are losing water for a variety of possible reasons, say the researchers, including the installation of dams and the use of water for agriculture. But in many cases the decrease in flow is because of climate change, which is altering rainfall patterns and increasing evaporation because of higher temperatures.
Most of the peninsular rivers are seasonal in nature eg. Godavari, Krishna, Tungbhadra, Narmada, Tapi, Mahanadi etc. because they are dependent upon rain (monsoons) for their charge of water.
An arroyo also called a wash, is a dry creek,stream bed or gulch that temporarily or seasonally fills and flows after sufficient rain.