Up high in the sky, there is the atmosphere. Shown in the diagram, there is the sun and the clouds. The sun radiates heat energy and gives off rays, which heat the water on Earth's surface, being the hydrosphere, and making the water evaporate. When that water evaporates into the atmosphere, with temperature change, it condensates and then is put into the clouds, where it is later dispensed back down to Earth's surface through precipitation.
With rain, it may hit higher elevated areas, from which runoff streams are created. These streams go into bigger streams, which go into rivers, then lakes, and finally oceans.
The amount of precipitation depends on the time of year, or season as well as climate. Mozambique, the main country that Gorongosa National Park is a part of, is a tropical place. There are very wet times of the year and very dry. From December to March, there are heavy rains that flood the park. Mount Gorongosa itself receives 78 inches of rain per year.
Rain gets sucked into the ground, which later feeds the native grasses at Gorongosa. Those grasses are then consumed by herbivores, or consumers, such as the Waterbuck. Those Waterbuck use the energy and then produce waste. The waste goes into the ground, being the grass or dirt, and with time goes deeper as it is covered by new layers. Underground, this waste may be consumed by detritivores/saprotrophs. Detritivores/saprotrophs also eat dead animals that have been buried underground in a similar process.
Within the geosphere, water and other substances may be trapped undearneath rocks and near the center of the Earth. With movement of tectonic plates, and the movement of hot liquid near the core, some may be released over time and brought towards the top.
The native grasses at Gorongosa receive water from the ground through precipitation, which happens after Lago Urema evaporates due to the sun and condensates as it cools. It rains, and the water trickles down Mount Gorongosa, onto the plants, and back into Lago Urema. Herbivores, such as the reedbuck, eat this grass and fuels itself, which when eaten by a carnivore such as a lion, passes on that food that was originally grown through the rain. The same process of growing food happens with seasonal small and large amounts of rain, and evaporation when the sun shines its rays down.