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m-'/sec, of which about 1650 m-^/sec goes through the river IJssel into the 

 IJssel Lake) . 



A possible better solution would be to raise the water level of the 

 IJssel Lake as much as the sea level rises. The consequence is, of course, 

 that all the dikes around the IJssel Lake and partly along the river IJssel 

 must be made higher as well. Moreover, a great number of pumping stations 

 would have to be built along the lake for those areas that drain naturally 

 into the IJssel Lake. Until now only the direct consequences of sea level 

 rise on the water management of the Netherlands have been dealt with. If 

 temperature rises, this will not only lead to a higher sea level, but it 

 will also mean that the whole climate will have changed. It is possible 

 that during the winter precipitation will increase. This would not only 

 affect the drainage system, it would also mean higher extreme river 

 discharges of Rhine and Meuse, so again higher dikes (along the river) 

 would be necessary. In summertime, evaporation could be higher and 

 precipitation could be weaker. So shortage of fresh water during a dry 

 summer or even during a normal summer could be greater, with all its 

 consequences . 



Another important aspect is the supply of drinking water, already 

 mentioned when discussing saltwater intrusion. A major part of our 

 drinking water supply comes from the fresh water lenses under the dunes. 

 They are surrounded by saline water. To make it possible to subtract great 

 amounts of water from these lenses, infiltration with fresh (river) water 

 is currently necessary, because the precipitation surplus of the dunes is 

 not enough. These lenses are used as a storage basin for drinking water. 

 Moreover, the river water is filtered in this way, so it improves in 

 quality. A sea level rise may distort the equilibrium of these lenses, 

 especially where the dunes are rather small. Possible solutions would be: 

 more infiltration of fresh water and extraction of less drinking water. 



Ecological Impact - Distinguishing four areas where the impact of sea 

 level rise is concentrated and taking a sea level rise of 1 m within 100 

 years, we get the following ecological impacts: 



