Objectives

The objectives of challenge 7 – River Inputs are:

  • To provide an overview on the temporal and spatial variability of riverine material fluxes to the Mediterranean Sea and eels capture data.
  • To identify the major trends that could threat these ecosystems in the near future because of climate change and socio-economic development.
  • To assess the uncertainty in these scenarios, as their reliability could be examined in the light of knowledge limitations on current modelling algorithms and input data sets that naturally impact the resulting river scenarios.
  • To allow identification of major data and knowledge gaps which have to be closed by future research efforts in order to assess the potential impact of global change in the Mediterranean region via the riverine link between land and sea.

Methodology

Regarding water discharge and nutrients (Total Nitrogen and Total Phosphorous) time series from in-situ and model data, the selection of stations was based on the following criteria:

  1. Station distance from the coast less than 100 km. A buffer zone of 100 km from the Mediterranean coast was created in order to define the distance threshold for the stations to be considered as representative.
  2. River runoff greater than 10 m3/sec. Rivers with water discharge lower than 10 m3/s (or 0.315 km3/y) were disregarded, since they are usually inadequately monitored. Regarding North African rivers, due to the scarcity of river flows and lack of data availability, most of the representative stations were included in the dataset regardless of their discharge volume.
  3. No stations influenced by sea water were included, since they are not representative for water discharge, TSM and nutrient concentrations and fluxes.

Since the origin of the data comes from a great diversity of research programs, where each program had its own purpose and data collection design, there was a need for a reference dataset common for all basins to guide us through the selection process and to help us avoid the bias inserted through the spatial and temporal heterogeneity. Thus, the E-Hype’s basin classification by mean annual discharge was used to determine which basins meet our 10 m3/s threshold regardless of the station’s position or the time period during which the data was collected. This comparison of the in-situ data with the model data can be seen as a first means of validation process for our results.

Regarding Total Suspended Matter concentration, time series were retrieved from satellite data due to the lack of proper and homogeneous in situ datasets in terms of temporal coverage and accessibility. For each river mouth we set a box of ~ 20 x 20 km2 (i.e., 2-3 times the river-induced Rossby radius of deformation) and extracted TSM concentration daily data from the CoastClour Project database. For each box we selected the daily mean TSM within the range 0.001-1000 mg/l in order to avoid underestimated values and spikes. This technique aims to simulate a TSM station (i.e., a single station) at the mouth of each river and allows for a homogeneous and synoptic collection of the data.

methodology_river_inputs

Data Sources

The production of time series from in situ, model and satellite data, which constituted the targeted products of this challenge was based on the following data sources.

For the River Discharge characteristic:

The data source SMHI – Hypeweb– Europe was used for the production of the model time series for the relevant components of targeted products 1 and 2.
The data sources CISL Research Data Archive, Global River Discharge-Rivdis and SESAME (Southern European Seas: Assessing and Modelling Environmental Changes, obtained through PERSEUS project), were used for the production of the in situ time series for the relevant components of targeted products 1 and 2.

For the nutrient (Total Nitrogen and Total Phosphorous) characteristics:

The data source SMHI – Hypeweb– Europe was used for the production of the model time series for the relevant components of targeted products 5 and 7, as well as for the products 6 and 8.
The SESAME data set was also used through PERSEUS project, for the production of the annual time series from TN and TP in situ data, for the relevant components of targeted products 5 and 7.

For the Total Suspended Matter (TSM) characteristic:

The CoastColour Project, is the most important dataset we could find and fully satisfied the necessary requirements to build the targeted products 3 and 4.

For Eels Production characteristic:

The FAO data base was used for the production of eels time series for targeted product 9. Although it didn’t provide a complete dataset, it could be a starting point for the fitness of purpose.

Browse Data Source

Targeted Products

Name of Targeted product Short description Format
MEDSEA_CH7_Product_1 Annual time series of Water Discharge (Qw) [m3/s] from in situ and model data

excel file

MEDSEA_CH7_Product_2 Monthly time series of Water Discharge (Qw) [m3/s] from in situ and model data

excel file

MEDSEA_CH7_Product_3 Annual time series of Total Suspended Matter (TSM) from satellite data [mg/l]

excel file

MEDSEA_CH7_Product_4 Monthly time series of Total Suspended Matter (TSM) from satellite data [mg/l]

excel file

MEDSEA_CH7_Product_5 Annual time series of Total Nitrogen [mg/l] from in situ and model data

excel file

MEDSEA_CH7_Product_6 Monthly time series of Total Nitrogen [mg/l] from model data

excel file

MEDSEA_CH7_Product_7 Annual time series of Total Phosphorous [mg/l] from in situ and model data

excel file

MEDSEA_CH7_Product_8 Monthly time series of Total Phosphorous from model data [mg/l]

excel file

MEDSEA_CH7_Product_9 Annual time series of Eels Production per country [tons]

excel file

 

Please contact back-end-medsea-ckpt@cls.fr for further information on products.

Team Involved

Nikos Skoulikidis (HCMR), Dora Kouvarda (HCMR), Nektarios Kalaitzakis (HCMR), Federico Falcini (CNR)