Land use changes can affect biodiversity by altering or removing natural habitats , leading to the fragmentation of habitat . This limits the ability of wildlife to access suitable habitat and resources ( McKinney , 2008 ), as well as altering the natural cycling of water and nutrient resources . Residential development inhibits the replenishment of groundwater due to the change in land cover , mostly from the introduction of impervious surfaces ( e . g ., driveways , boardwalks , roofs ). These surfaces cover or alter exposed soils , which would otherwise naturally facilitate the percolation of accumulated rainfall into the ground . Landscape changes , such as removing trees and installing turfgrass , reduce the ability for stormwater to infiltrate soils within a suburban forest . Due to their dense root structures , turfgrass tends to shed water similarly to impervious surfaces . In contrast , live oaks have deeper , less dense root systems that are much more favorable for water to infiltrate through the soil . Additionally , live oak canopies can intercept more than 20 % of the rainfall before it reaches the soil , further decreasing the magnitude of potential runoff ( Xiao et al ., 2000 ).
The expansion of impervious land cover increases the volume of excess stormwater runoff that flows into Kiawah Island ’ s interconnected stormwater pond system . In the majority of cases on the island , each developed parcel is graded to allow the conveyance of stormwater into low-lying areas and roadways during a rainfall event . The water then flows to the lowest points in the roads and is directed into the network of stormwater ponds . The volumetric flow of stormwater in this process is influenced by the permeability of land cover , ground saturation , and any obstruction in drainage . If stormwater runoff is conveyed into the drainage network too quickly due to too much impervious cover , there is less of a chance for replenishing groundwater reserves and a higher risk of overtaxing our stormwater infrastructure in major rainfall events ( i . e ., 50-year rainfall ). Alternatively , if the same system ’ s conveyance were slowed without any intervention to promote infiltration , localized flooding may present itself . At the terminus of the pond systems , excess stormwater flows into tidal salt marshes via the outfalls during low tide events , similar to the mechanisms behind natural groundwater discharge but at a larger scale .
Changing coastal conditions , weather , and climate have negatively impacted ecosystem services and processes ( Walther et al ., 2002 ). Over the past century , climate change has presented new challenges to coastal regions . Global sea level rise is caused by the combination of thermal expansion of warming ocean waters and the addition of water mass into the ocean from the melting of glaciers and ice sheets ( Sweet et al ., 2022 ). As a result , sea levels are rising at an unprecedented rate . In the past 100 years alone , the Charleston Harbor Tide Gauge ( 8665530 ) has observed 1.11 feet of sea level rise ( NOAA , 2022 ). Sea levels are projected to continue rising into the future , with intermediate estimates ranging from 2-3 feet in the next 50 years ( Sweet et al ., 2017 ; City of Charleston , 2019 ; Lindsey , 2020 ). As sea levels continue to rise , available freshwater in coastal areas is threatened by the change in the energy gradient between groundwater and tidally influenced seawater . As sea levels continue to rise the energy gradient between tidal forces and groundwater will shift . This will cause the subsurface freshwater aquifer to rise and gradually become more saline .
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NATURE-BASED SOLUTIONS MANUAL FOR KIAWAH ISLAND