The purpose of this study is to examine the characteristics of wetlands and the processes of their formation by the hydromorphology in Gyunggi-do. Six areas were studied - Gobongsan at Goyang, Chilbosan at Ansan, Daejangdong at Sungnam, Seounsan at An...
The purpose of this study is to examine the characteristics of wetlands and the processes of their formation by the hydromorphology in Gyunggi-do. Six areas were studied - Gobongsan at Goyang, Chilbosan at Ansan, Daejangdong at Sungnam, Seounsan at Ansung, Chunggyesan at Euwang and Undoosan at Gapyun. This study analyzes the circumstances of the wetlands-geology, geomorphology, hydrology, water quality, soil texture, soil characteristics, and researched six small wetlands in Gyunggi-do Mountains.
The results are as follows :
1) The weathering of many granules of moscovite in bedrock is made to helping the wetlands in geology. The areas that included many granules of mica(specially biotite) in bedrock is adapted to the wetlands.
2) The wetlands located at the nick point is that the mountains exchanges the plains through the process of dissection of mountains. Long-termed denudation has made the nick point. If these areas were cut by any reasons, the groundwater leaks on the earth through the seepages, and the water flowes the earth and joins in the wetlands.
3) The wetlands at the mountains have two types : 1. The slope-type: that develops in the slopes not having surrounded the hill slope that have the flowing water(surface or ground water) from the mountains. 2. The basin-type: that have three hill slopes, and join the water(surface or ground water) from hill slopes. This area have the wet soils. If the series of these process was steadied, this becomes the permanent wetlands
Anywhere if the water was not supplied steadily, the soil becomes wet temporary. This is the temporary wetlands.
These areas have a slope-type wetlands(Gobongsan wetlands) and the five basin-type wetlands (Chilbosan wetlands, Daejanddong wetlands, and Seounsan wetlands Chunggye wetlands, and Undoo wetlands).
4) Six wetlands are the 'muknon' wetlands and restored wetlands on the nick point, the basis of mountains.
5) Six wetlands, all the two types of wetlands, have the seepage that was squeezed through the broken slopes. This seepage is the spot of the surface water that started from the ground water table. And these wetlands are almost not related with the river.
Therefore the water source of the wetlands is formed in the groundwater more than the river or precipitation.
6) Anyway, the wetlands water is sucked, and recharged. Sometimes the recharged groundwater makes the another wetlands blow the slopes. Or the wetlands water change the little first river.
7) The slope-type wetlands is tend to make the sheetflow, on the other hands, the basin-type wetlands is tend to make the first stream of river on the earth.
8) Six wetlands water quality became the eutrophication. They have a high value of COD, T-P than our country on the standard amount of lakes water quality.
9) The soil texture composed the sand and silt. Six wetland soil texture say the ratio of sand 75 to silt 25. It has no clay. It shows the A horizon of soil profile, and the strong zone of eluviation. X90 is from fine sand to middle sized sand. These characteristics show the evenness of the soil texture.
10) The value of CEC(cation exchange capacity) is different by the wetlands, but Al2O3 value of the study of wetlands is more higher than others. Therefore it is doing cation exchange steadily in the soil.
11) The value of pH is very low from 4.47 to 5.13. It shows that the soil of the studied area is strong acid soil. The acid soil is anaerobic soil. Because the water table is very high, and the A horizon of soil is inundation, its color become grey.
12) O horizon of soil has much humus and its depth reaches from 10~30㎝, and A horizon is located below the O horizon, that is grey and has spot of red oxidated Iron.
13) By 1)~13) we get the mechanism of the wetlands on the mountain slope.
13-1) Generally the process of wetland formation is said the seepage of water table on the slope, bedrock, the weather of the soil, and impermeable layer. The basis of many landforms is geology. Geology - the bedrock, structures, the geology history is one of factors of landform processes. Generally speaking, it makes the wetland that the geology has characteristics of impermeable layer and so have the soil characteristics and texture. The groundwater on impermeable layer leak on the earth(seepage or discharge), this process makes the hollow. But If the groundwater moves steadily under the earth on the hill slope, it makes the permanent or temporary wetlands.
The permanent wetlands is adapted to begin from seepage on the hill slope or the spot of seepage makes the headward erosion, and moves toward the upper stream. The seepage or discharge is unique, the slope is slow, and the hollow by seepage makes a very little channel. Sometimes, the soil water in company with the first channel flows by the sheetflows.
In the temporary wetlands, if the wetlands becomes for rainy seasons or for low evaporations, the water flows just beneath the surface. As the result, these flows becomes sheetfloods, not a very little channel. And it has not inlet and outlet.
Table 43 and Fig 59 show the processes of the wetlands on the hill slope.