The fight against soil subsidence- RE:PEAT

Soil subsidence problems in peat meadows

Sinking of the soil leads to problems. The means to prevent that lead to problems too. Involved parties must come up with solutions together, but do they already have a clear picture of the complexity of the problem? RE:PEAT offers the insight.

Soil subsidence in peat meadows is a major problem in the Netherlands. Peat soil is ubiquitous in the country. Much of it is used as agricultural land, but housing areas have also been built on it. Because peat is subject to oxidation and subsidence, the soil sinks in unevenly. This has major consequences for buildings and agriculture, think of crack damage in buildings, fractures in the road surface and underground pipes and an increasing difference between the water behind the dikes and the land that needs to be kept dry.

The most obvious solution for subsidence is to stop the oxidation. Peat that is under water does not oxidise, so by keeping the soil wet the subsidence is significantly delayed. But this remedy also has its disadvantages. A wetter soil causes moisture damage in homes as well as has a result in crop damage and reduced water storage in case of severe rainfall.

Calculation models of the experts

Tygron was commissioned by the Stichtse Rijnlanden Water Board (HDSR) to develop RE:PEAT, an instrument to provide insight into the problem of subsidence. Using the water board’s expert knowledge as a starting point, the Tygron Geodesign Platform calculates soil subsidence over a period of 1 to 100 years. The results of this calculation are then used in calculation models to determine how much worse (or better) the situation becomes as the soil subsidence increases or decreases.

A forecast is made of the costs of water management, damage to buildings and infrastructure, flooding in case of heavy rainfall, the profitability of the farm, and the quality of both nature and water.

Solutions

RE:PEAT has also been developed to explore solutions. Different stakeholders are represented within the tool.

  • The water board is in charge of water management. It can manipulate the water levels, but also bears the costs that are a result of their management.
  • Farmers have refined their business operations for the land where they now work. With this tool they can explore whether a change in their business operations is profitable in a new situation.
  • The municipality has the obligation to keep the quality and liveability of the area high, but at the same time knows that a healthy economy is of great importance.

Together, the parties negotiate and choose a set of measures that represent their interests.

Henk van Hardeveld of HDSR: “Farmers, residents, nature lovers: everyone sits at the table looking at the same screen. Everyone can see the consequences of ground subsidence for each individual stakeholder. They can react to this directly. It doesn’t get much more powerful than that to really start working together on solutions”.

Current themes

RE:PEAT has been frequently used in recent years to tackle soil subsidence, but it also appears to work very well as a means of calculation. Because the calculation models are so closely linked to the current themes there are, for example, sensitivity analyses are carried out with different scenarios. It also works as a planning tool for potential measures to tackle the problems.