Plizh River

The Plizh River is the third longest river in the world, and fourth largest by outflow. It originates from Lake Oromoro in Dagaland and empties into Lake Adau in Wildemarkh. The Plizh is heavily influenced by seasonal sandstorms in the Central Desert, especially during Spring and Sunfall. Shifting sand dunes can cause the river to rapidly change course without warning, causing flash flooding downstream and completely drying up old courses. During the height of the Spring and Sunfall sandstorms, the Plizh changes course so often that the river will stop flowing into Lake Adau for a couple of weeks. River traffic must be suspended until the Plizh settles into its new course for the next season.
River Use
The Plizh River is an important waterway connecting the regions of Dagaland and Wildemarkh. Grains, textiles, and iron tools are shipped upriver from Wildemarkh, while fruit, dreamwater, and medicinal plants are shipped back from Dagaland. Traveling upriver requires the use of a rowing crew in Summer when the winds are calm, but during Autumn, Winter, and Hibern, winds out of the Spial Mountains allow rigged vessels to sail upriver. Travel during Spring and Sunfall is treacherous due to persistant sandstorms that cross over the river's course.
Ecology
The Plizh River can be divided into three distinct ecological regions. The river leaves Dagaland through the Argonons, a sprawling mangrove forest filled with diverse plant and animal life. The mangroves follow the river's course for several miles, protecting it from the heat and sandstorms of the Central Desert.
Once the river makes its way further into the desert, the trees and other plant life on its banks thin out and no longer protect it from shifting sand dunes. This ecological segment of the river can be referred to as the transient zone. Plants in the transient zone have adapted to the shifting riverbeds in many unique ways. Seeds from plants in this region can survive buried in the sand for decades, waiting for the river to shift back. Once the river settles into a new course for the season, seeds that have been buried in the sand undergo a rapid germination process aided by the life-giving properties of the river water. These plants can go from seed to flower in as little as three weeks, dropping their own seeds before the river shifts once more. Other plants have rhizomes that can quickly self-dessicate once their watersource has disappeared. By intentionally drying out their outer layer, the inside of the rhizome stays moist for years in a dormant state until the river flows nearby once again. Nomadic groups such as the Markhors have learned how to identify and dig for these rhizomes to use as a source of food and hydration while crossing this region of the desert.
After the river crosses through the transient zone, it enters a wide, flat grassland that channels the varying courses of the Plizh toward its usual entrypoint into Lake Adau. The initial flooding of the grassland at the beginning of Summer and again at the beginning of Autumn are celebrated as essential phenomena for the growing season. The Plizh floodplains are the location of some of the largest wheat harvests in the world and have elevated the city of Tsoo and the country of Wildemarkh into a prosperous kingdom.
Origins
The Plizh river began flowing when the Dreamwater overflowed through a gap in the Dagas, the series of steep ridges surrounding Dagaland. It broke banks in the afternoon of the 8th of Hibern in the year 1718, and cut through the sand toward the Adau basin, reaching (the much smaller at the time) Adau Lake at sundown on the 9th. Adau Lake was a small, brackish lake with no outflow that was fed primarily from snowmelt from the Spial Mountains. The influx of water from the newly formed Plizh River caused the lake to grow steadily until Lake Adau broke its own banks on the 4th of Autumn in the year 2124 with the formation of the Trogondic River which empties into Wyde Bay.