A water quantity SD model and a water quality SD model were structured separately to address all relevant land-sea interactions. The two SD sub-models were then connected to develop an integrated MAL3 land-sea system model that describes key policy indicators (KPIs) for water quantity (water availability for socio-economic sectors, water availability for natural sub-systems and proxy of seawater intrusion risk) and water quality (total Nitrogen (TN) and total Phosphorous (TP) to and from socio-economic sectors, TN and TP to and from natural water systems, policy and management indicators for water quality). This integrated model has been used to simulate water quantity and quality changes under scenarios of shared socioeconomic pathways (SSPs), representing various land cover changes related to urbanization, forest expansion, and agricultural development, as well as climate change impacts related to representative concentration pathways (RCPs). Effects of management alternatives targeting agriculture, wastewater treatment plants and legacy sources on water quality have also been simulated under the different SSP scenarios. Further simulations will allow investigating the effectiveness of other measures and combinations of measures.
System Dynamics Model - Norrström-Baltic region (Sweden)
The system dynamics (SD) model developed for MAL3 focuses on water availability and quality, and their interactions with and implications for key inland and coastal sectors as a land-sea and sector interaction and impact tracer.