Predicting improved optical water quality in rivers resulting from soil conservation actions on land.

摘要: Deforestation in New Zealand has led to increased soil erosion and sediment loads rivers. Increased suspended fine water reduces visual clarity for humans aquatic animals penetration of photosynthetically available radiation plants. To mitigate fine-sediment impacts rivers, catchment-wide approaches reducing are required. Targeting conservation rivers is possible through existing models; however, relationships between sediment-related attributes that affect both ecology human uses poorly understood. We present methods relating concentration, clarity, euphotic depth. The require upwards twenty concurrent samples depth at a river site where discharge measured continuously. related concentration regressions. When reduced by action, percentiles necessarily reduced, the corresponding increased. approach demonstrated on Wairua River Northland region Zealand. For this we show would increase relatively approximately 1.4 times relative reduction load. Median from 0.75m 1.25m (making more often suitable swimming) after load 50% associated with widespread pastoral land. Likewise 0.7 load, median 1.5m 2.0m reduction.