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Land Use Change And Flooding | Earth Wise

September 30, 2020 By EarthWise Leave a Comment

Land use change refers to the conversion of a piece of land’s use by humans from one purpose to another. Land use change is commonly associated with biodiversity loss and increased greenhouse gas emissions. But how does land use change impact water cycles?

According to researchers from the University of Göttingen in Germany, IPB University, and BMKG (both in Indonesia), the expansion of monocultures, such as rubber and oil palm plantations, leads to more frequent and more severe flooding. The researchers explain the increase in flooding “with a complex interplay of ecohydrological and social processes, including soil degradation in monocultures, the expansion of oil palm plantations into wetlands, and the construction of flood protection dams.”

For the study, which was recently published in the journal Ecology & Society, the research team interviewed nearly 100 Indonesian farmers, villagers, and decision-makers in Sumatra. The team supplemented its research with data on precipitation, river and groundwater levels, soil properties, and regional mapping.

During large-scale land use change – like plantation expansions – newly-compacted soil causes rainwater to runoff as opposed to being absorbed. As more plantations are established in floodplains, the owners try to control flooding on their land by building barriers. But these dams often lead to increased flooding on neighboring lands. This understandably triggers social tensions between other farmers and plantation owners.

In order to reduce the negative impact of land use change on the water cycle, the research team suggests soil protection and improved planning – especially in floodplains – would be a good place to start.

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Land use change leads to increased flooding in Indonesia

Photo, posted October 8, 2018, courtesy of Artem Beliaikin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saved By The Trees

February 1, 2019 By EarthWise Leave a Comment

The island of Kokota, part of the Zanzibar Archipelago off the coast of Tanzania, is tiny – only one square kilometer and home to just 500 people. For centuries, its residents subsisted by harvesting the islet’s natural resources, including its trees.

By the early 21st century, the deforestation had become unsustainable and the islanders faced a crisis. Fisheries were depleted, and rivers ran dry. The changing climate brought rising sea levels, more erratic rainfall, and coral bleaching in the surrounding waters. The situation looked hopeless.

But in recent years, the island has come back from the brink of ruin. Reforestation efforts began in 2008 on the larger island of Pemba and on Kokota itself, led by a Pemba local and a Canadian tree planter who formed the non-profit Community Forests International. Since then, nearly 2 million trees have been planted on the two islands. Enthusiastic volunteers on Kokota usually help plant trees during the rainy season, when water is plentiful.

Community Forests International, along with spearheading the tree planting effort, also built Kokota’s first school, and installed rainwater storage tanks for the community.

The conservation group is now devising ways for Kokota to make more money by diversifying its agriculture with crops that grow well in its climate including spices like cloves, cinnamon, and nutmeg. They are also helping locals to grow more and different vegetables in their gardens.

Small, poor communities are often the most vulnerable to the effects of climate change, such as drought, powerful storms, and depleted fisheries. Tiny Kokota provides an example of an environmental comeback. Fighting climate change requires economic solutions along with environmental solutions. For this one tiny island, it appears to have been saved by the trees.

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