Work to know the capacity of nitrate fixation of the coastal wetlands of the Mar Menor: this research is relevant to verify the effectiveness of semi-natural wetlands provided in the MAPMM. The ministry is carrying out the largest research ever carried out on the hydrogeological knowledge of the catchment basin.
He Ministry for the Ecological Transition and the Demographic Challenge (MITECO) The execution of five surveys (field drilling) has begun in the La Hita wetland (Los Alcázares, Murcia) to estimate the reduction of nitrates in groundwater that these natural nutrient binders are able to treatthus avoiding its arrival at Mar Menor.
The commissioner of MITECO Water Cycle and Ecosystem RestorationFrancisca Baraza, has visited one of these piezometers, which is executing the General Directorate of Waterand that will allow us to quantify the nitrate fixation from coastal wetlands located on the coastal edge of the salt lagoon (Playa de la Hita- Marina de Punta Galera, Marina del Carmolí, Saladar de Lo Poyo, Salinas de Marchamalo and Punta de Las Lomas).
Los wetlands They can act as nitrate fixation mechanisms, reducing their concentration in groundwater and, thereby, reducing the nitrate content that reaches the groundwater. Mar Menorso it is a relevant investigation to confirm the contribution of existing wetlands on the coastal edge y verify the behavior that the semi-natural wetlands planned in the Green Belt of the Framework of Priority Actions to Recover the Mar Menor (MAPMM) will have..
These piezometers will be placed in nests at the entrance and exit of the wetland, just before the water reaches the sea. The nests consist of the construction of several piezometers arranged next to each other with variable depths in order to capture water from the aquifer at different depths.
In this way, the reduction of nitrate content can be analyzed vertically due to the denitrifying power of the wetlandas well as possible changes in the chemical composition of the aquifer’s groundwater.
The piezometers will have depths of between 8 and 22 meters and will be executed using the rotation technique with continuous core acquisition.
This study, financed by the Ministry for the Ecological Transition and the Demographic Challenge through Line 8.2 of the MAPMM, will have the collaboration of the Polytechnic University of Cartagena (UPCT) within the framework of the REMEDIATE research project, in turn financed by the Ministry of Science, Innovation and Universities.
Analysis of the aquifers of Campo de Cartagena
These works are part of Line 8 of the MAPMM (Knowledge Improvement and Monitoring), whose investment exceeds 15.6 million euros, and have the objective of developing, among other tasks, the largest research carried out to date for hydrogeological knowledge. from Campo de Cartagena.
Specifically, the improvement of the hydrological, geological and water quality information network is being carried out, as well as the numerical modeling of the hydrological cycle and pollution, especially diffuse pollution caused by nitrogen and phosphorus, which directs the General Directorate of Water of MITECOtogether with the Segura Hydrographic Confederation (CHS).
Research in the Mar Menor basin has resulted in several milestones:
- Study of the geometry of the Quaternary aquifer using geophysical techniques based on 120 vertical electrical surveys and 18 km of electrical tomography.
- Study of the deep geometry of the Pliocene and Messinian aquifers based on 157 vertical electrical surveys and 50 km of electrical tomography.
- Ten research probes (ground drilling) up to 80 meters deep to advance knowledge of the Quaternary aquifer.
- Establishment of a groundwater control network based on 60 points.
- Periodic campaigns to monitor the level of aquifers and the concentration of nitrates and other possible contaminants, in which more than 500 level measurements have been carried out and 230 water samples analyzed in the laboratory.
These actions will be completed over the next few months with the execution of 30 boreholes between 80 and 300 meters deep, permeability tests and an isotopic study that will allow establishing in detail the composition and functioning of the aquifers of the Cartagena Field and its relationship with Mar Menor.
All the data obtained will be used in the development and calibration of the mathematical model of Campo de Cartagena, which will constitute the key tool for groundwater management and decision making..