Jeju Island: HYDROLOGY
The Gotjawal Forest
Dense Gotjawal Forest |
Diagram 1 - Underground Aquifer |
Drawdown & Recharge
Diagram 2 - Process of drawdown (water being extracted) |
Compaction & Subsidence
Removal of water from an aquifer without recharge would eventually cause compaction which would lead to subsidence. Absence of water in the aquifer’s pores would cause the pieces of sediment to “compact.” As a result, the water table (level at which the water rises) would lower and the ground would follow (subside). The average amount of percipation in Jeju, as displayed below in row four of chart 1, shows that dynamic equilibrium should have been maintained in Jeju for many years because of constant monthly rainfall. The residents have yet to notice any signs of subsidence in the Gotjawal Forest and their water source remains reliable.Climate data for Jeju-si, Jeju-do (1981−2010) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Average high °C (°F) | 8.3 (46.9) |
9.4 (48.9) |
12.8 (55.0) |
17.5 (63.5) |
21.6 (70.9) |
24.8 (76.6) |
29.0 (84.2) |
29.8 (85.6) |
25.8 (78.4) |
21.3 (70.3) |
16.0 (60.8) |
11.0 (51.8) |
18.9 (66.0) |
Average low °C (°F) | 3.2 (37.8) |
3.6 (38.5) |
6.1 (43.0) |
10.2 (50.4) |
14.4 (57.9) |
18.7 (65.7) |
23.3 (73.9) |
24.3 (75.7) |
20.4 (68.7) |
15.1 (59.2) |
9.8 (49.6) |
5.3 (41.5) |
12.9 (55.2) |
Precipitation mm (inches) | 65.2 (2.567) |
62.6 (2.465) |
88.6 (3.488) |
89.6 (3.528) |
96.4 (3.795) |
181.4 (7.142) |
239.9 (9.445) |
262.5 (10.335) |
221.6 (8.724) |
80.3 (3.161) |
61.9 (2.437) |
47.7 (1.878) |
1,497.6 (58.961) |
% humidity | 65.3 | 64.9 | 64.9 | 66.5 | 70.4 | 76.8 | 78.3 | 76.5 | 73.7 | 66.9 | 65.1 | 65.1 | 69.6 |
Avg. precipitation days (≥ 0.1 mm) | 12.6 | 10.3 | 11.2 | 10.0 | 10.4 | 11.8 | 12.5 | 13.5 | 10.8 | 7.0 | 9.3 | 10.8 | 130.2 |
Mean monthly sunshine hours | 70.4 | 105.4 | 158.9 | 194.4 | 211.9 | 170.9 | 195.6 | 195.6 | 161.7 | 178.5 | 126.0 | 84.8 | 1,854.1 |
Source: Korea Meteorological Administration[11] |
Chart 1
Saturated forest surface after rainfall |
Images taken from:
http://en.wikipedia.org/wiki/Jeju_Province
http://library.thinkquest.org/04oct/01590/humans/sources.html
http://en.wikipedia.org/wiki/File:Gotjawal_Forest.jpg
http://www.ramsar.org
http://dnr.wi.gov/org/water/dwg/OpCert/HTML/chapter3/wells4b.htm
Information taken from:
http://clasfaculty.ucdenver.edu/callen/1202/Battle/Destroy/Hydrology/HydrologyBasics.html
http://en.wikipedia.org/wiki/Jeju_Province
Great blog entry! I'm glad you included all of the information on ground water with the zone of aeration and the zone of saturation. Your diagrams were very helpful, as was your information on aquifers and drawdown and recharge. I was wondering though how the aquifer of the Gotjawal Forest compared to perhaps the Ogallala aquifer. Also, a little more information on aquicludes would be helpful, whether it's just comparing and contrasting. Also, information on ground water and pollution is important as well. All around very well written and researched!
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