What are some negative effects on polders?

* Loss of biodiversity: Polders can lead to the loss of biodiversity by destroying or fragmenting natural habitats. This can have a negative impact on the ecosystem, as it can reduce the resilience of the environment and make it more susceptible to change.

* Salinization: Polders can also lead to salinization of the soil, which can make it difficult for plants to grow. This can have a negative impact on agriculture, as it can reduce crop yields and make it difficult for farmers to make a living.

* Waterlogging: Polders can also lead to waterlogging, which can damage crops and make it difficult for people to live in the area. This can also lead to the spread of diseases, such as malaria and dengue fever.

* Increased vulnerability to flooding: Polders can also make an area more vulnerable to flooding, as they can prevent water from flowing away naturally. This can lead to devastating floods, which can damage property and cause loss of life.

* Displacement of people: Polders can also lead to the displacement of people, as they can make it difficult for people to live in the area. This can have a negative impact on the social fabric of the community, as it can lead to the loss of cultural heritage and the breakdown of social networks.