Water and Soil Environment Division
Outline of Research ( pamphlet )
The Earth’s water is always in motion, and water is continually cycled between its various reservoirs such as atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater. The water cycle has been working for billions of years. Water in all reservoirs is vital to all life on Earth. Once the water environment has been polluted, the time and cost needed for its restoration are enormous. The Water and Soil Environment Division undertakes research from a variety of approaches on the environmental pollution and ecological changes that occur via the media of water and soil.
Variations of Water Quality in Lake and Sediment Porewater in Lake Kasumigaura
We have been monitoring trends in the water quality of Lake Kasumigaura on a monthly basis. Furthermore, sediment cores are collected at the center of the lake and the porewater samples are analyzed for dissolved organic carbon (DOC) and orthophosphate (PO4-P). The DOC concentration in porewater has been decreasing since 1997, as shown in the figure on the right. However, the PO4-P concentration has substantially increased. DOC increases as the sediment goes deeper whereas PO4-P shows a marked peak at a depth of 4 to 6 cm. Production mechanisms are likely to differ between DOC and PO4-P in the sediment of Lake Kasumigaura.
http://www.nies.go.jp/kanko/kankyogi/13/02-03.html
Effects of Changes in Nutrient Ratios of River Water on Marine Ecosystems
As human activities increase, the inflowing of nitrogen (N) and phosphorus (P) into oceans is also augmented. On the other hand, the amount of silicon (Si) that flows into oceans tends to decrease since silicon settles and gets trapped in still bodies of water such as dam reservoirs. It is therefore likely that, in these conditions, non-siliceous phytoplankton (including the harmful red tide algae) can thrive better than siliceous phytoplankton, which are mostly harmless. Our research aims to clarify these ecological changes through ocean observation by ferry and ecosystem modeling.
http://db.cger.nies.go.jp/gem/sea/SE_Pacific/me.html
Understanding the Current State of Heavy Metal Contamination in Soil
Solder is widely used to join metals in electric and electronic products. However, the use of solder is now restricted, due to the fact that the primary component of solder is lead, which is highly toxic to living things. This has brought about the increased use of lead-free solder. However, we still do not have a clear understanding of the behavior of the rare metals that are used in lead-free solder or their impact on the environment. In order to gain some answers to these questions, we are engaged in research on the dissolution properties of rare metals in a field environment and their transport characterization in soil. In particular, we are concentrating on the ability of organic matter secreted by trees to accelerate the dissolution of the metals and the differences in transport characterization depending on the existence form of metals in soil.
http://www.nies.go.jp/kanko/news/22/22-3/22-3-03.html
