Desiccated areas in the Netherlands, 2000

Scale of the desiccation problem

The total desiccated area in 2000 was 492,000 ha (IPO/RIZA, 2000). Nature conservation was the primary designated land use of approximately 257,000 ha and the secondary designated land use for 235,000 ha, including meadow bird reserves and flower-rich banks.
Compared to the last survey in 1998, the desiccated area has decreased by 100,000 ha. Of this area, full hydrological recovery had been achieved in about 15,000 ha (3%) in 2000. After further investigation, the remaining 85,000 ha proved not to be desiccated or was no longer classified as desiccated because of a change in designated land use.
At present, desiccation projects are in progress or have been completed for approximately 185,000 ha. See the indicator Recovery of desiccated areas, 2001.

Policy

The objective for 2000 was a 25% reduction in the desiccated area compared to 1985 levels. In other words, full hydrological recovery of 25% of the area. It is not known how large the desiccated area was in 1985. The Water Evaluation Memorandum (Ministry of Transport and Public Works, 1994) set the area for 1985 at the same level as the area for 1994, the first year of the full national survey.
The surveys conducted in 1994, 1996 and 1998 showed that the desiccated area was about 600,000 ha (IPO/RIZA, 1994, 1996, 1998). A reduction of 25% corresponds to approximately 150,000 ha. The target for 2010 is a reduction compared to 1985 of 40% (Ministry of Housing, Spatial Planning and the Environment, 1997).

Survey of desiccated areas in 2003

The Association of Provincial Authorities (IPO) and the Institute for Inland Water Management and Wastewater Treatment (RIZA) will conduct another survey in 2003. This survey provides a national picture of:

desiccated areas (standard map);
progress made by anti-desiccation activities (action map);
the hydrological effects of recovery measures (recovery map);
the Optimal, Current and Desired Groundwater and Surface Water Regime (OGOR, AGOR and GGOR respectively) (Peereboom, 2002).

On the basis of that data and the picture established, it will be possible to formulate a desiccation objective that is measurable. This will link up with the recent studies for the structure of a national desiccation monitoring network (Zuidhoff et al., 2002).

See also the indicator Desirable Groundwater and Surface Water Regime in the Netherlands (GGOR): situation in 2001me (GGOR).

Technical note

There have always been major differences in definitions used by provincial authorities to determine the extent of desiccated areas. This became clear even as early as the first national survey conducted in 1994 (Beugelink et al., 1995). Some provincial authorities listed only desiccated sites. Others list the natural areas in which there is desiccation. And others also list areas located outside natural areas. Measures are required at the locations in this list in order to tackle desiccation inside the natural area. The differences between the provinces have become less obvious in the course of time but they are still present. Most provincial authorities now list the boundaries of the natural areas in which there is desiccation.

References

Beugelink, G.P. and F.A.M. Claessen (eds) (1995). Operationalisatie van 25%-doelstelling Verdroging; maatregelen, kosten en effecten. Achtergronddocument verdroging MV3/ENW. RIVM (report no. 715 001 001)/Institute for Inland Water Management and Wastewater Treatment, memorandum no. 95.029, Bilthoven/Lelystad.

IPO/RIZA (1994). Inventarisatie van verdroogde gebieden 1994. Association of Provincial Authorities/Institute for Inland Water Management and Wastewater Treatment, The Hague.

IPO/RIZA (1996). Inventarisatie van verdroogde gebieden 1996. Association of Provincial Authorities/Institute for Inland Water Management and Wastewater Treatment, The Hague.

IPO/RIZA (1998). Inventarisatie van verdroogde gebieden 1998. Association of Provincial Authorities/Institute for Inland Water Management and Wastewater Treatment, IPO publication no. 117, The Hague.

IPO/RIZA (2000). Inventarisatie van verdroogde gebieden 2000. Association of Provincial Authorities/Institute for Inland Water Management and Wastewater Treatment, IPO publication no. 145, The Hague.

Peereboom, I. (2002). Plan van Aanpak Verdrogingskaart 2003. Werkgroep verdrogingskaart 2003, RIZA, Lelystad.

Ministry of Housing, Spatial Planning and the Environment (1997). National Environmental Policy Plan 3. Ministry of Housing, Spatial Planning and the Environment, The Hague.

Ministry of Transport and Public Works, (1994). Evaluatienota Water. Ministry of Transport and Public Works. TK 21250, no. 29, 1993-1994.