The methodologies outlined in the methods section facilitate the determination of flood occurrences, magnitude, and ages. Through these techniques, paleoflood data can be extended back over thousands of years, enriching the precision of flood-frequency curves. This extended historical perspective is invaluable in contemporary flood-frequency analysis, significantly amplifying the effective length of the record. The incorporation of historical flood data enhances the analysis, offering a more comprehensive understanding of the dynamics and patterns involved in flooding events.
Paleohydrological data serves as a valuable tool in unraveling the climatic variability of the past. Evidence of climatic changes is seen in lake and ocean sediment, as well as in the mass balance of glaciers. Over the last 10,000 years, the climate has undergone significant fluctuations, impacting floods, droughts, and hydrologic patterns. Understanding this historical climatic variability is crucial for predicting future climate changes. Take, for instance, the Colorado River, a vital freshwater source for the southwestern United States. By analyzing data from past droughts, it becomes evident that recent climatic variability could potentially reduce streamflow by 35 percent. This knowledge is indispensable for informed future planning, ensuring water availability for the populations that depend on it.
Hydrological fluctuations are linked to the factors causing them, and paleohydrological data can be used to validate climate models. On the orbital time scale, paleohydrological data reflects variations in the Earth's orbit and the cycle of glacial periods and interglacials. For example, variations in the water level of Lake Lisan correlates with data showing temperature fluctuations collected from polar ice core samples. On a shorter time scale, minuscule climatic variations can have large hydrological effects as when excess rainwater entering the North Atlantic was linked with a serious drought in the eastern Mediterranean. The Little Ice Age in northern Europe was linked with drought in East Africa, heavy rains in the African lakes, and persistent El Niño–Southern Oscillation conditions in the Pacific.
Another application is in the quantification of erosion caused by rivers under differing climatological conditions. Increased erosion rates following deforestation, and pollution resulting from lead-mining activities by the Romans show up in lake sediments.