Abstract:
Studies on freshwater bodies in Ghana for their sustainability are mostly concentrated on a few large rivers. However, other equally important rivers that do not attract research attention provide varied services and benefits to inhabitants and living organisms in their riparian communities. The basin of River Amissa as a major source of freshwater supply for several communities within its catchment has undergone various changes due to rapid socioeconomic and increasing anthropogenic disturbances. This consequently has led to increased sediment yield on the reservoir beside the river and the river basin itself. Hence the need to estimate the amount of sediment accumulated in the reservoir and in the river\'s catchment for their sustainability and management purposes. Sediment yield in the reservoir and the river basin were estimated using a bathymetric survey integrated with Geographic Information System (GIS) and the Soil and Water Assessment Tool (SWAT) hydrological model respectively. Results from the bathymetric survey estimated the current capacity of the reservoir to be 4,321,060 m3. Reservoir storage capacity lost to sedimentation was 1,438,940 m3 representing 25% of the reservoir volume. Additionally, the SWAT (Arc SWAT) performance was very good with Nash-Sutcliffe efficiency coefficient (NSE) for calibration and validation being 0.88 and 0.84 respectively. For the entire 28-year period, simulated sediment yield increased by 10,263 tons per kilometer square.
摘要:
关于加纳淡水水体可持续性的研究主要集中在几条大河上。然而,其他同样重要的河流没有引起研究关注,为河岸社区的居民和生物提供各种服务和利益。由于快速的社会经济和人为干扰的增加,阿米萨河流域是其流域内几个社区的主要淡水供应来源,经历了各种变化。因此,这导致河流旁边的水库和流域本身的沉积物产量增加。因此,需要估算水库和河流集水区的沉积物累积量,以达到可持续性和管理目的。使用分别与地理信息系统(GIS)和土壤和水评估工具(SWAT)水文模型集成的测深测量估算了水库和流域的沉积物产量。测深测量的结果估计该水库的当前容量为4,321,060m3。因沉积而损失的水库储存容量为1,438,940m3,占水库容积的25%。此外,SWAT(ArcSWAT)性能非常好,校准和验证的Nash-Sutcliffe效率系数(NSE)分别为0.88和0.84.在整个28年期间,模拟产沙量每平方公里增加10263吨。