Evaluating some basic nature of half flooded land based on water level in entrails of reservoir of Son La hydroelectric plant

Abstract

The results showed that soil properties at the bottom of the Lake differ significantly according to water level: Sand particles content: from CT1 water level (215m water level: The highest water level) down to water level of CT2 (190 - 195m water level) has increased, from water level CT2 to water level CT3 has decreased, from water level CT3 (175 -190m water level flooded) to water level CT4 ( 175m dead water level) has increased. Limon particles content: this study shows that the average water level is opposed to grains of sand components, ranged from 31.50 to 58.52%. In which the largest is CT3 (from 175 - 190m flooded water levels) and the lowest water level is CT1.

Clay content: The average water levels in this research ranged from 19.48 to 29.37% . In which, the largest at CT1 (215m water level flooded). The water levels of the lowest levels of clay is CT4. Soil property indicates that at water level CT1 (The highest water level ) and water level CT2 (190-195m water level), shows the basic properties of soil is acid, poor nutrition, humus and nitrogen content, tend to accumulate according to depth, alkali cation, in the lower level of the following water level. Al³⁺ concentration increased gradually from 190 m to 195 m. CT3 (of the submerged from 175 - 190m) and CT4 (175m Dead water level) illustrate the deposition of nutrients pH hasincreased gradually to the dead water level, humus and nitrogen content tends to accumulate decreases with depth, Alkali cation dropped slightly to the level of dead water, Al3+ concentration has decreased steadily.