2023-05-11 マサチューセッツ大学アマースト校
◆彼らは、都市計画に最適な手法を取り入れ、持続可能な土地利用対策を実施することで、流域規模で将来を計画することができると述べています。これにより、降雨が地下水を浸透させ、堆積物が水中に含まれる可能性が低くなり、緑地や沼地を保護することができます。
◆森林を減らし、舗装面積を増やすと、年間の流量と流出量が増加し、水中の堆積物が増加し、リンと窒素の濃度も上昇します。
＜関連情報＞
- https://www.umass.edu/news/article/new-research-umass-amherst-links-changes-land-use-water-quality-and-quantity
- https://journals.plos.org/water/article?id=10.1371/journal.pwat.0000083
都市化する流域における土地利用変化が水資源に与える長期的影響について Long-term effects of land-use change on water resources in urbanizing watersheds
Ammara Talib,Timothy O. Randhir
PLOS Water Published: April 26, 2023
DOI:https://doi.org/10.1371/journal.pwat.0000083
Abstract
The changes in energy balance resulting from land-use change may significantly affect the amount and timing of water loss to the atmosphere as evapotranspiration (ET). Also, these will impact water fluxes in the watershed system, influencing runoff rate, flow volume, intensity, and frequency of floods. During the past century, land-use change in the SuAsCo (Sudbury-Assabet and Concord) watershed has altered basin hydrology, sediment, and nutrient load that is detrimental to water resources in SuAsCo. This study uses an integrated physically-based model Hydrological Simulation Program-FORTRAN (HSPF), along with Land Transformation Model (LTM), to assess predicted temporal and spatial changes in water, nutrient, and sediment yields for future land-use scenarios of 2035, 2065, and 2100. Results showed that a 75% increase in effective impervious area and a 50% decrease in forest area in 2100 (from 2005 baseline levels) are projected to cause a 3% increase in annual streamflow and a 69% increase in total yearly mean surface runoff. The average annual total suspended solid (TSS) yield at the watershed outlet is estimated to increase by 54% in 2100. An increase of 12% and 13% concentrations of average annual total phosphorus (TP) and total nitrogen (TN) are predicted by 2100 due to urban expansion and increased runoff volume. This integrated modeling approach will inform watershed managers and landowners about critical areas of the SuAsCo watershed to apply best management practices (BMPs) to mitigate the effects of land-use land cover (LULC) change.
