Lessons from Lake Biwa and Other Asian Lakes: Global and Local Perspectives

Abstract

The freshwater resources of Asia are under enormous pressure given the high and increasing population densities of the region, and the serious degradation of many lakes and rivers due to agricultural, industrial and urban development. Global climate change is likely to exacerbate these pressures through changes in the hydrological balance; influences on stratification, algal blooms and deep water re-oxygenation; and for high altitude sites such as lakes on the Mongolian Plateau, accelerated permafrost melting and desertification. Eutrophication and other processes of water quality degradation are especially severe in many parts of China. At Lake Taihu, a drinking water supply for 40 million people in central China, toxic cyanobacterial blooms now occur throughout the year. In the Province of Yunnan, many of the shallow lake waters are highly polluted and are of human health concern. Lake Biwa, Japan's largest freshwater body, has experienced many environmental problems over the last 50 years including loss of species habitat, changes in oxygen content, and blooms of noxious cyanobacteria. Two multi-disciplinary research programs involving specialists in hydrodynamics, bio-optics, biogeochemistry and freshwater ecology have generated new insights into the structure and functioning of the Lake Biwa ecosystem, and have contributed an improved and lakes elsewhere, will especially depend on an improved scientific understanding of the Iimnological controls on water quality. It will also be fostered by cross-disciplinary and international exchanges of information, and a commitment by scientists, residents and others with a vested interest in water quality, including regulatory authorities, to work together towards the common goal of long term, integrated protection of the lake and its surrounding watershed.

Evaluation of Thermal Stratification and Flow Field Reproduced by a Three-Dimensional Hydrodynamic Model in Lake Biwa, Japan

“…The maximum width of Lake Biwa is 22.8 km, and its maximum depth is 103.6 m. It serves as a reservoir, providing drinking water for approximately 15 million people in Shiga and other surrounding prefectures. Since the 1950s, the deterioration of Lake Biwa's water quality has progressed [22]. In 1977, a large-scale freshwater red tide occurred in Lake Biwa.…”

“…Therefore, this research is the first step in validating the model. Since the 1950s, the deterioration of Lake Biwa's water quality has progressed [22]. In 1977, a large-scale freshwater red tide occurred in Lake Biwa.…”

Increasing benthic vent formation: a threat to Japan’s ancient lake

“…Plate tectonic activity is believed to have moved the lake to the present location about 0.4–1.5 million years ago 1 , 2 . The lake volume is 27.5 km 3 , or about 34% of Japan’s surface fresh water 3 . Lake Biwa is the drinking water source for > 14 million people living in the Kinki District, including the areas of Osaka, Kobe, Kyoto, Nara and Shiga.…”

“…Lake Biwa is the drinking water source for > 14 million people living in the Kinki District, including the areas of Osaka, Kobe, Kyoto, Nara and Shiga. The lake thus is a precious freshwater resource that requires close monitoring and strict conservation 3 , 4 .…”

Applicability of Mean Field Approximation to Numerical Experiments of Thermal Convection during the Cooling Period of Lake Biwa

“…Its value as an ancient lake offering habitat for rare indigenous species warranted it to be vested as UNESCO Ramsar's site. Alarming deterioration of water quality is a main concern with climate change such as increased air temperature being noted to be linked with cycles of warm winters which are related to low levels of DO (dissolved oxygen) around lake's bottom layer [1]. Fig.…”