ACTION C.3: Hydraulic interventions for habitat recovery and conservation
The hydraulic intervention aims at mitigating the aridity due to climate change that has affected the two project sites over the last decades. The system is designed to ensure a proper water balance to the forest ecosystem by providing a supplementary water resource during the driest periods. It is based on the interception of surface waters, limiting rapid runoff of rainfall, and loss of a precious quantity of water. Meteoric water and surface runoff are intercepted by a drainage trench which stores collected water during the rainy periods (November-February) in an underground tank, and release it during the drought periods. Water flows naturally by gravity towards the distribution network.
The system has a demonstrative character to propose the use of hydraulic solutions, typically used in the field of irrigation (installation of a drainage trench, underground tanks and gravity water distribution network), in the restoration of threatened and degraded forest ecosystems. It meant to be a suitable solution for the adaptation to climate change, and a good option to mitigate climate change effects. The mechanism of water distribution for gravity allows energy independence and reduced environmental effects (no use of fossil fuels needed to operate pumps and distribution channels), the underground tank ensures low visual impact. The channels are covered with local excavation material with no use of concrete.
The water accumulated in the underground tank is released onto a forest surface of about 5 hectares by a remotely controlled pumping system powered by solar panels. The network of channels contains micro-cracked pipes that guarantee a requisite amount of moisture in the soil during dry months, allowing the maintenance of suffering tree species. The water supply is essential to mitigate aridity and to reduce soil salinity and sodicity. This operation is expected to last up to 30 years. After 30 years, the ecosystem is expected to have reached a state of balance that will require little human intervention.
The mitigation of aridity attributed to climate change will allow, together with the other conservation actions, to:
- recover the woodland of the Natura 2000 site of Palo Laziale and the ecological conditions necessary for restoring and conserving the associated Mediterranean temporary ponds (habitat 3170*);
- restore and conserve 40 ha of the alluvial forest (habitat 91E0*) located along the final section of the river Nestos in the Natura 2000 of Nestos Delta habitat and the ecological conditions necessary for restoring and conserving the associated Mediterranean temporary ponds (habitat 3170*).
In this way, the restoration of the woodland will also improve the delicate ecological connection of the sites and, therefore, the conservation of the related wildlife, including E. orbicularis, T. hermanni and C. quadripunctaria* (Habitat Directive 92/42/CEE).
The construction of the trenches and the water tank will be carried out during the summer/fall of 2020 to collect seasonal rainfall that will be released already over the following spring/summer. The system will remain enabled throughout the 5-years project and beyond for a period of a maximum of 30 years.
Beneficiary responsible for implementation:
The Dep. DICEA of Sapienza Univerisity coordinates the action, including the design of the whole hydraulic system.
DICEA employs:
- 1 Associate Professor to provide execution of the project, technical supervision of the works and revision of the technical reports;
- 1 Environmental Engineer to supervise the implementation of the system in the field and to prepare the technical reports;
- 1 Researcher to provide technical advice on water requirements of topsoil, and to supervise the creation of the drainage and water distribution network;
- 5 students in environmental engineering to follow the interventions as extra-curriculum (non-paid).