Soil loss assessment in the Tasik Chini catchment, Pahang, Malaysia

702001-100345-193-B
Author : Sujaul Islam Mir, Muhammad Barzani Gasim, Sahibin Abd. Rahim & Mohd Ekhwan Toriman
Publication : Bulletin of the Geological Society of Malaysia
Page : 1 - 7
Volume Number : 56
Year : 2010
DOI : https://doi.org/10.7186/bgsm56201001

Bulletin of the Geological Society of Malaysia 56, December 2010, pp. 1 - 7

 

Soil loss assessment in the Tasik Chini catchment, Pahang, Malaysia

Sujaul Islam Mir1, Muhammad Barzani Gasim1*, Sahibin Abd. Rahim1 & Mohd Ekhwan Toriman2

1School of Environment and Natural Resource Sciences, FST
2School of Social Development and Environmental Studies, FSSK
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
*Email address : dr.zani@ukm.my

 

Abstract: The Universal Soil Loss Equation (USLE) model is used to estimate average soil loss generated from splash, sheet, and rill erosion in agricultural plots at the Tasik Chini catchment. Use of the USLE has recently been extended for predicting soil loss and plan control practices in agricultural catchment by the effective integration of Geographic Information Systems (GIS) based on procedures to estimate the factor values in a grid cell basis. This study was performed to predict the soil erosion risk by the USLE/GIS methodology for planning conservation measures in the site. Rainfall erosivity (R), topographic factor (LS) and land cover management factor (C) values for the model were calculated from rainfall data, topographic and land use maps. Soil was analyzed for the soil erodibility factor (K). Soil samples were selected from the eleven soil series around the Tasik Chini area. A total of 55 samples were collected from the eleven soil series namely Tebok, Lating, Serdang, Kuala Brang, Kedah, Bungor, Kekura, Malacca, Rasau, Prang and Gong Chenak. Physical properties such as particle size distribution, texture, hydraulic conductivity and organic matter content (OM) were analyzed in order to support the erosion rate analysis. Results shows that five soil series have low rates of soil loss, i.e. Tebok, Lating, Bungor, Kekura and Gong Chenak series, having an average soil loss of 0.65, 0.10, 1.61, 4.23 and 0.53 ton/ha/year, respectively. Two soil series have moderate rates of soil erosion namely Serdang and Prang series (average of 47.41 and 41.10 ton/ha/year, respectively). Two soil series with moderately high rates of soil loss are Kuala Brang and Rasau soil (average of 57.16 and 57.93 ton/ha/year, respectively). Malacca Series has high rate of soil loss, ranges from 21.44 to 348.7 or average of 130.26 ton/ha/year. Kedah soil series has very high soil loss, ranges from 79.99 to 319.75 or average of 180.49 ton/ha/year. This high erosion rate is expected to generate higher sedimentation rate into the Tasik Chini water body, elevating the lake fills and eventually forming an extinct lake.

Keywords: erosion rate, soil loss assessment, soil series, Tasik Chini catchment

 

Penilaian kehilangan tanih di lembangan Tasik Chini, Pahang, Malaysia 

Abstrak: Pemodelan menggunakan Universal Soil Loss Equation (USLE) adalah bertujuan untuk menganggarkan purata kehilangan tanih yang ditimbulkan oleh percikan hujan, hakisan permukaan dan hakisan alur di kawasan pertanian di Lembangan Tasik Chini. Kebelakangan, penggunaan USLE telah dipanjangkan sebagai perkakasan serbaguna dalam peramalan kehilangan tanih dan perancangan langkah kawalan dalam kawasan pertanian dengan keberkesanan bersepadu Sistem Maklumat Geografi (GIS) berdasarkan tatacara penganggaran faktor nilai berdasarkan grid lajur. Kajian ini dijalankan untuk meramal resiko hakisan tanih dengan penggunaan kaedah USLE/GIS dalam perancangan penilaian pemuliharaan dalam kawasan kajian. Erosiviti hujan (R), faktor topografi (LS) dan nilai faktor pengurusan litupan permukaan (C) daripada model ini kemudian dikira berdasarkan data hujan, peta topografi dan peta guna tanah. Sampel tanih dianalisis untuk mendapatkan nilai faktor kebolehhakisan (K). Pensampelan tanih terpilih telah dilakukan mewakili sebelas siri tanih di sekitar Tasik Chini. Sebanyak 55 sampel tanih telah dikutip daripada kedalaman (0-20 cm) yang mewakili sebelas siri tanih, iaitu Tebok, Lating, Serdang, Kuala Brang, Kedah, Bungor, Kekura, Malacca, Rasau, Prang dan Gong Chenak. Sifat fizikal tanih seperti taburan saiz butiran, tekstur, kekonduksian hidrolik dan kandungan organik telah dianalisis bertujuan untuk menyokong analisis kadar hakisan. Hasil kajian menunjukkan bahawa lima siri tanih mempunyai kadar kehilangan tanih yang rendah, iaitu: Tebok (purata 0.65 ton/ha/tahun), Lating (purata 0.10 tan/ha/tahun), Bungor (purata 1.61 tan/ha/tahun), Kekura (purata 4.23 tan/ha/tahun) dan Siri Gong Chenak (purata 0.53 tan/ha/tahun). Dua siri tanih mempunyai kadar hakisan tanih sederhana; Serdang, purata 47.41 tan/ha/tahun dan Siri Prang purata 41.10 tan/ha/tahun. Dua siri tanih mempunyai kadar kehilangan tanih sederhana tinggi, iaitu: Kuala Brang, purata 57.16 tan/ha/tahun dan Siri Rasau, purata 57.93 tan/ha/tahun. Siri Malacca mempunyai kadar kehilangan tanih yang tinggi dengan purata 130.26 tan/ha/tahun. Siri Kedah merupakan siri tanih yang terburuk, mempunyai kadar kehilangan tanih yang tertinggi iaitu purata 180.49 tan/ha/tahun. Kadar hakisan yang tinggi diramalkan akan menggalakkan berlakunya proses sedimentasi yang tinggi ke Tasik Chini, akhirnya tasik akan menjadi penuh dan menyebabkan kepupusan tasik.

Kata Kunci: kadar hakisan, penilaian kehilangan tanih, siri tanih, lembangan Tasik Chini

 https://doi.org/10.7186/bgsm56201001