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