✅✅¿Cómo ENTENDER los HIDROGRAMAS?

What Are Hydrograms and Their Importance?

Introduction to Hydrograms

• The video introduces the concept of hydrograms, emphasizing their differences and significance in understanding river flow.

• A hydrogram is defined as a graph that illustrates the variation of a river's flow rate throughout the year, with months on the x-axis and monthly flow coefficients on the y-axis.

Understanding Flow Rates

• The average flow rate (or module) is measured in cubic meters per second. For example, if a river has an average flow of 13.86 m³/s, a value of 1 in March indicates it matches this average.

• If August shows a value of 2, it means the river's flow has doubled compared to its average.

Applications of Hydrograms

• Hydrograms help identify peak water transport periods, allowing for better management of water resources by adjusting dam operations before flood seasons or dry months.

Types of River Regimes in Spain

High Mountain Rivers

• Found above 2,500 meters altitude, these rivers show significant peaks around June due to snowmelt.

• They have small average flows because they are smaller rivers without many tributaries; peak flows occur from spring thawing until late summer.

Nival-Pluvial Rivers

• Located between 2,000 and 2,500 meters altitude, these rivers receive both snowmelt and rainfall. Their maximum flows coincide with melting snow but also experience summer low points followed by autumn rain peaks.

Identifying Pluvio-Nival vs. Pluvial Regimes

Key Characteristics

• In pluvio-nival regimes, rainfall is more significant than snowfall; thus identifying them requires careful observation of seasonal patterns.

• Indicators include maximum melt occurring later (May/June), suggesting less snow influence if peaks are earlier (March/April).

Conclusion on River Types

Understanding Mediterranean River Dynamics

Seasonal Water Flow Characteristics

• The perception that rivers run almost dry in summer is misleading; while there is a relative decrease in average flow, significant water volume remains during warmer months.

• These rivers experience slow, steady flows due to minimal contributions from snowmelt, resulting in smooth curves on hydrographs with gradual rises and falls throughout the year.

• Mediterranean rivers typically have low and irregular flows, characterized by several peaks and troughs annually but generally remain close to a consistent level without extreme fluctuations.

Sources of Water Supply

• Most Mediterranean rivers derive their water from the Iberian System or the Pyrenees, which provide relatively stable water input due to their elevation and rainfall patterns.

Identifying River Regimes

• It’s crucial to analyze hydrographs carefully; these rivers exhibit small modules with pronounced summer droughts and peak flows coinciding with wet months.

• Differentiating between oceanic and continental Mediterranean river regimes relies on flow size: larger flows indicate oceanic systems while smaller ones suggest continental characteristics.

Irregular Flow Patterns

• Rivers classified as sporadic depend heavily on torrential rains (e.g., "gota fría") and often have very low base flows due to their proximity to arid regions near the sea.