Lake Water Level Changes Research Articles

The Eutrophication of Lake Okeechobee

ABSTRACT Average annual total phosphorus concentrations in Lake Okeechobee increased from 0.049 mg/L in 1973 to 0.098 mg/L in 1984. The increases in total phosphorus concentrations were not correlated to external phosphorus inputs, but to changes in lake water levels. It is proposed that the flooding of marshes and exposed lake bottom primarily caused increased total phosphorus concentrations, but that the resuspension of bottom sediments by wind action may also be a major factor influencing in-lake total phosphorus concentrations. Reducing phosphorus inputs by 40 percent as proposed by the Lake Okeechobee Technical Advisory Committee (LOTAC) will not significantly improve water quality in Lake Okeechobee. Average total phosphorus concentrations will not decline significantly. Chlorophyll a concentrations and Secchi transparencies are not correlated to total phosphorus concentrations so massive expenditures of public funds to reduce nutrient inputs will not protect long-term water quality at Lake Okeechobee.

Local pollen deposition in aquatic sediments on the Atherton Tableland, North-Eastern Australia

Modern pollen representation of aquatic vegetation communities at three sites on the Atherton Tableland is examined. Indicator pollen taxa are identified and are used to interpret the aquatic pollen components of two pollen diagrams from one of the sites. It is believed that detailed estimates of changes in lake water level have been derived from the identified fossil plant communities.

Post-Glacial water-level changes in Lake Växjösjön, central southern Sweden

Abstract A series of four layers of sandy gyttja found in Lake Vaxjosjon is described. The deposition of the sandy layers is connected with lowerings of the water-level. One layer deposited around the boundary between the Pre-Boreal and Early Boreal periods, and another during the later part of the Early Sub-Boreal period indicate the two major water-level lowerings in Post-Glacial time. The other two layers, which probably represent minor fluctuations, are deposited around the boundary between the Early and Late Atlantic periods and during the Early Sub-Atlantic period respectively.

東郷池の干拓が松崎・東郷・浅津の諸温泉におよぼす影響について

The lake Togo-ike with its area of 4. 1 km2 and maximum depth of 5. 2 m. is a brackish lake and situated on the middle part of Tottori Prefecture. There are many hot springs such as Togo, Shin-Togo and Asazu in and around the lake. The authors studied the influence of the change of lake level due to polderling on the discharge of hot springs. The results obtained are summarized as follows : (1) Togo hot spring group has the same chemical constituents and ground temperature, suggesting that they have the same origin under the ground.(2) Some of these springs discharge through the lake bottom into the lake, but they give little influence on the quality of lake water.(3) Factors which will affect the discharge of spring water are barometric pressure, rain-fall amount, lake level change, tidal change and pumping. Barometric change and tidal change are not separated. Distinguished effects of rain-fall and lake level upheaval are shown in Table 5. Pumping effect is also obvious.(4) The effect of lake water level change on the spring discharge, dQ/dh is larger at Azusa than that of at Togo (Table 6). It suggests that change of lake water level affects directly to the discharge of hot spring.The results above mentioned lead us to the conclusion that the polderling of this lake will cause the decrease of hot spring discharge.