Floodplains and Connectivity Zones: Enhancing the Provision of Ecosystem Services

Floodplains cover only 6% of the Earth’s surface. Connectivity occurs in multidirectional patterns in riverbeds, throughout both the drainage paths of the tributaries and the areas contiguous to the riverbed. This study discusses the variations in the levels of the water table as a component of a spatiotemporal representation for evaluating the importance of floodplains as hydric regulatory elements, and the application of this knowledge for developing techniques for the renaturalization of water functions to produce ecosystem services. We measured the variation in the water table level in a floodplain of the Paraiba do Sul River (southeastern Brazil), whose 77 floodplains occupy only 3.87% of the basin and present a high potential for the renaturalization of their water functions. The litho-structural control point (LSCP) is situated in the river channel and mark the end of the floodplain. Areas near the LSCP remain continually saturated, storing water and contributing to dry-season hydrographs. Areas up to 4400 m away from the LSCP perform hydric regulation, storing water from floods of the riverbed and reducing its flow downstream. Areas up to 7500 m away from the LSCP have an increased absorption potential. These three areas operate differently and integrally in absorbing floodwaters and recharging the water table, influencing the increase in minimum flows in the riverbed. The understanding of the functions of these sectors enables the design of objective measures that safeguard and increase the likelihood of the renaturalization of the hydrological functions of floodplains.