Kecenderungan Hidrometeorologi.
Kecenderungan Hidrometeorologi di Daerah Aliran Sungai Citarum (Ruminta,
Bayong Tjasyono, The Houw Liong, dan Indratmo Soekarno)
KECENDERUNGAN HIDROMETEOROLOGI
DI DAERAH ALIRAN SUNGAI CITARUM
Ruminta1), Bayong Tjasyono2), The Houw Liong3), dan Indratmo
Soekarno4)
1)
Laboratorium Klimatologi Fakultas Pertanian Universitas Padjadjaran
Jatinangor,
Alamat e-mail : r_ruminta@yahoo.com
2)
Departemen Geofisika dan Meteorologi, FIKTM, ITB
3)
Departemen Fisika, FMIPA, ITB
4)
Departemen Teknik Sipil, FTSP, ITB
ABSTRAK
Penelitian terhadap kecenderungan hidrometeorologi telah dilakukan di
daerah aliran sungai Citarum bagian hulu, Jawa Barat. Penelitian
tersebut menggunakan data bulanan hasil observasi curah hujan,
evapotranspirasi, kelembaban, dan limpasan dari Januari 1968 hingga
Desember 2000. Hasil penelitian menunjukkan bahwa nilai
kecenderungan (rasio odd) curah hujan, evapotranspirasi, kelembaban,
dan limpasan masing-masing adalah -3.64, 3.88, 4.21, dan -1.11.
Curah hujan dan limpasan cenderung menurun masing-masing sebesar
-3.64% dan -1.11%. Penurunan curah hujan dan limpasan terutama
disebabkan oleh adanya penurunan pembentukan awan dan hujan
sebagai akibat dari perubahan iklim global. Evapotranspirasi dan
kelembaban udara cenderung meningkat masing-masing sebesar
3.88% dan 4.21%. Peningkatan evapotranspirasi dan kelembaban
udara tersebut di sebabkan oleh tingginya pemindahan uap air dari
permukaan ke atmosfer melalui baik evaporasi maupun transpirasi.
Kata kunci :
variabilitas
curah hujan, evapotranspirasi, kelembaban, limpasan, rasio odd,
TREND OF HYDROMETEOROLOGY IN THE CITARUM RIVER BASIN
ASTRACT
A study on trends of the hydrometeorology had been carried out in the
Upper Citarum River Basin, West Java. The investigations based on
monthly observations data of the rainfall, evapotranspiration, humidity,
and runoff from January 1968 to December 2000. The results indicated
that odds ratio of the rainfall, evapotranspiration, humidity, and runoff
are -3.64, 3.88, 4.21, and -1.11 respectively. The rainfall and runoff had
been decreased by about -3.64% and -1.11% respectively.
The
decreasing trend in the rainfall and runoff had controlled mainly by the
decreasing of the clouds and rains formation as a consequence of the
23
Jurnal Bionatura, Vol. 9, No. 1, Maret 2007 : 23 - 37
global climate change. On the other hand, the evapotranspiration and
air humidity had been increased by about 3.88% and 4.21%
respectively. The increasing trend in the evapotranspiration and air
humidity had influenced by the increasing of the water vapour removal
from vegetation lands surface to the atmosphere by both evaporation
and transpiration.
Key words : rainfall, evapotranspirastion, humidity, runoff, odds ratio, variability
24
Bayong Tjasyono, The Houw Liong, dan Indratmo Soekarno)
KECENDERUNGAN HIDROMETEOROLOGI
DI DAERAH ALIRAN SUNGAI CITARUM
Ruminta1), Bayong Tjasyono2), The Houw Liong3), dan Indratmo
Soekarno4)
1)
Laboratorium Klimatologi Fakultas Pertanian Universitas Padjadjaran
Jatinangor,
Alamat e-mail : r_ruminta@yahoo.com
2)
Departemen Geofisika dan Meteorologi, FIKTM, ITB
3)
Departemen Fisika, FMIPA, ITB
4)
Departemen Teknik Sipil, FTSP, ITB
ABSTRAK
Penelitian terhadap kecenderungan hidrometeorologi telah dilakukan di
daerah aliran sungai Citarum bagian hulu, Jawa Barat. Penelitian
tersebut menggunakan data bulanan hasil observasi curah hujan,
evapotranspirasi, kelembaban, dan limpasan dari Januari 1968 hingga
Desember 2000. Hasil penelitian menunjukkan bahwa nilai
kecenderungan (rasio odd) curah hujan, evapotranspirasi, kelembaban,
dan limpasan masing-masing adalah -3.64, 3.88, 4.21, dan -1.11.
Curah hujan dan limpasan cenderung menurun masing-masing sebesar
-3.64% dan -1.11%. Penurunan curah hujan dan limpasan terutama
disebabkan oleh adanya penurunan pembentukan awan dan hujan
sebagai akibat dari perubahan iklim global. Evapotranspirasi dan
kelembaban udara cenderung meningkat masing-masing sebesar
3.88% dan 4.21%. Peningkatan evapotranspirasi dan kelembaban
udara tersebut di sebabkan oleh tingginya pemindahan uap air dari
permukaan ke atmosfer melalui baik evaporasi maupun transpirasi.
Kata kunci :
variabilitas
curah hujan, evapotranspirasi, kelembaban, limpasan, rasio odd,
TREND OF HYDROMETEOROLOGY IN THE CITARUM RIVER BASIN
ASTRACT
A study on trends of the hydrometeorology had been carried out in the
Upper Citarum River Basin, West Java. The investigations based on
monthly observations data of the rainfall, evapotranspiration, humidity,
and runoff from January 1968 to December 2000. The results indicated
that odds ratio of the rainfall, evapotranspiration, humidity, and runoff
are -3.64, 3.88, 4.21, and -1.11 respectively. The rainfall and runoff had
been decreased by about -3.64% and -1.11% respectively.
The
decreasing trend in the rainfall and runoff had controlled mainly by the
decreasing of the clouds and rains formation as a consequence of the
23
Jurnal Bionatura, Vol. 9, No. 1, Maret 2007 : 23 - 37
global climate change. On the other hand, the evapotranspiration and
air humidity had been increased by about 3.88% and 4.21%
respectively. The increasing trend in the evapotranspiration and air
humidity had influenced by the increasing of the water vapour removal
from vegetation lands surface to the atmosphere by both evaporation
and transpiration.
Key words : rainfall, evapotranspirastion, humidity, runoff, odds ratio, variability
24