Estimation of long-term variation in nutrient loads from the Hii River by comparing the change in observed and calculated loads in the catchments

  title={Estimation of long-term variation in nutrient loads from the Hii River by comparing the change in observed and calculated loads in the catchments},
  author={Hiroshi Kamiya and Yoshihiro Kano and Koji Mishima and Katsuhiro Yoshioka and Osamu Mitamura and Yu Ishitobi},
  journal={Landscape and Ecological Engineering},
To study the long-term change in nutrient loads from the Hii River to Lake Shinji, water samples were taken repeatedly over a year in 1983/1984 and again in 2001/2002. Annual total nitrogen (TN) loads, estimated from observations of water quality and river flow, increased from 860 to 920 t with a corresponding increase in NO3–N concentration during the cool season. In contrast, total phosphorus (TP) loads decreased from 96 to 62 t. Annual TN and TP loads, calculated using emission factors and… 

Long‐term trends in nitrogen and phosphorus concentrations in the Hii River as influenced by atmospheric deposition from East Asia

The TN : TP ratios for both atmospheric deposition and river water indicate that changes in atmospheric nutrient deposition affect loading rates and N: P ratios, which could have significant ecological effects in eutrophic systems by lowering the N : P ratios.

Nitrogen mass balance and river concentration dependence in the stock in brackish Lake Shinji

Calculating the change of stock of each month of the nitrogen in Lake Shinji, a brackish lagoon in Japan, it is assumed that TN is released from the sediment. This relationship has not been observed

Comparison of measured and calculated loads using quadratic LQ equation for Hii River flows, eastern Shimane Prefecture, Japan

We sampled river water from 1 July 2010 to 30 June 2011 in the Hii River. Suspended solids (SS), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), and total phosphorus

Phosphorus release and sedimentation in three contiguous shallow brackish lakes, as estimated from changes in phosphorus stock and loading from catchment

In situ phosphorus release rates in three contiguous shallow brackish lakes were calculated by considering the amount of water inflow, changes in salinity and phosphorus stock, and loading from

Estimating Combined Loads of Diffuse and Point-Source Pollutants into the Borkena River, Ethiopia

Estimating the relative contribution of heavy metals and nutrients loads from diffuse and point sources and various hydrological pathways is a major research challenge in catchment hydrology.

Atmospheric Phosphorus and Nitrogen Originating in China: Forest Deposition and Infiltration of Stream Water in Japan

We analysed nutrients and basic ions (Na, Cl, K, Mg, Si, Ca, and SO4) for a period of 1 year, including every precipitation event, and sampled stream water every 2 weeks from a forest catchment in

The mechanism and rate of re-sedimentation of phosphorus released from the sediment during the summer months in shallow brackish lakes

Water, salt and phosphorus balance of the 19 years was calculated in Lake Shinji, a shallow brackish lake in Japan. Average annual freshwater inflow of 19 years into Lake Shinji was in the range of

Impacts and Policy Implications of Metals Effluent Discharge into Rivers within Industrial Zones: A Sub-Saharan Perspective from Ethiopia

Comparison with emission guidelines indicates poor environmental management by industries and regulating institutions in Kombolcha, with apparent mismatch between environmental enforcement and investment policies.

Herbicide-induced macrophyte-to-phytoplankton shifts in Japanese lagoons during the last 50 years: consequences for ecosystem services and fisheries

As expressed in the Ramsar Convention, the wise use of wetlands, including coastal lagoons, is one of the greatest environmental concerns across the globe. Seagrass beds are the key element for



Estimation of Water Quality and Nutrient Loads in the Hii River by Semi-Daily Sampling

Semi-daily sampling was carried out from July 1983 to June 1984 to evaluate nutrient loads in the Hii River. The variation of concentration was synchronized with the variation of flow for all

Episodic increases in nitrate concentrations in streamwater due to the partial dieback of a pine forest in Japan: runoff generation processes control seasonality

Nitrogen dynamics were investigated in tandem with groundwater monitoring in a temperate forest catchment in Japan, to determine the effect of the partial dieback of dominant tree stands on nutrient

Hypoxia in Chesapeake Bay, 1950–2001: Long-term change in relation to nutrient loading and river flow

A 52-yr record of dissolved oxygen in Chesapeake Bay (1950–2001) and a record of nitrate (NO3−) loading by the Susquehanna River spanning a longer period (1903, 1945–2001) were assembled to describe

Nitrogen Pollution in the Northeastern United States: Sources, Effects, and Management Options

Abstract The northeastern United States receives elevated inputs of anthropogenic nitrogen (N) largely from net imports of food and atmospheric deposition, with lesser inputs from fertilizer, net

Eutrophication of Chesapeake Bay: historical trends and ecological interactions

This review provides an integrated synthesis with timelines and evaluations of ecological responses to eutrophi- cation in Chesapeake Bay, the largest estuary in the USA. Analyses of dated sediment

Evaluation of long‐term tropospheric NO2 data obtained by GOME over East Asia in 1996–2002

Long‐term tropospheric nitrogen dioxide (NO2) column data obtained by the Global Ozone Monitoring Experiment (GOME) (G‐NO2) are evaluated to confirm the trends found in tropospheric NO2 abundances