|ISBN: 978-983-3067-34-3||ISBN: 978-983-3067-30-5|
|ISBN: 978-983-3067-31-2||ISBN: 978-983-3067-32-9||ISBN: 978-983-3067-33-6|
Zorkeflee Abu Hasan
Dr. H. Md. Azamathulla
Dr. Lai Sai Hin
The project consists of five volumes as stated below:
River Sand Mining Management Guideline
Volume I: Sungai Muda
Volume II: Sungai Langat
Volume III: Sungai Kurau
The study objective is to develop a sand mining planning and management tool such that DID shall be able to make effective and timely decisions on sand mining applications and operations based on the following:
- To asses the current state of river morphology based on on-site data and determine the capacity of the river to act as natural conveyance to carry both water and sediment;
- To carry out hydraulic/sediment transport modeling study incorporating both the river and its capacity to sustain sediment extraction according to the sediment balance within the catchment;
- To formulate a long term solution encompassing sand mining envelope along the river stretch in terms of both river morphology and hydraulic/sediment transport modelling;
- To establish Geographical Information System for the study area with proper data entry and query features so that the system is useful and practical for planning and managing the morphology of the above said river system.
Scope of Works:
The scope of works shall include but not to be confined to the following:
- Collection and Interpretation of Data and Information
- Site Investigation and Field Inspection
- Engineering Survey and Geotechnical Investigations
- River Morphology
- Hydraulic Modeling
- Planning and Management Tools
- Cost Estimation and Implementation Schedule
- River Database using Geographical Information System (GIS)
USAINS HOLDING Sdn Bhd through River Engineering and Urban Drainage Research Centre (REDAC) has been appointed by Jabatan Pengairan dan Saliran Malaysia to carry out STUDY ON RIVER SAND MINING CAPACITY IN MALAYSIA beginning 21st September 2007 for a period of twelve months.
The Final Report presents eight chapters as follows:
CHAPTER 1 Introduction
Chapter 2 PAST STUDIES
Chapter 3 STUDY AREA
Chapter 4 RIVER MORPHOLOGY
Chapter 5 SEDIMENT TRANSPORT MODELLING
Chapter 6 RIVER SAND MINING ENVELOPE
Chapter 7 RIVER REGISTER DATABASE
CHAPTER 8 SAND MINING GUIDELINE
The present study covers three rivers i.e Sungai Muda, Sungai Langat and Sungai Kurau that have different level of sand mining activities. Sungai Muda has a long history of sand mining activity along the upper reach. Sungai Langat recently has been a major source of sand for construction with the development of Putrajaya. Fewer activities of sand mining are on-going in Sungai Kurau at the upstream of Bukit Merah reservoir.
The objectives of the present study include the assessment of the river morphology, hydrological and sediment transport modelling and development of river register database. Field works on selected sites for the three rivers were made to assess the capacity of the river to convey both water and sediment. Data collection on bed material was made to characterize the physical characteristics of sediment responsible for sediment transport that determines the river response in terms of erosion and deposition. The three rivers clearly have the bed material size in the sand-gravel ranges based on the collected data in the present study.
The replenishment rate as determined from the measured sediment rating curves for the three rivers show that a steeper curve is obtained for Sungai Langat as compared to Sungai Muda and Sungai Kurau. Hence, it is expected that Sungai Langat has a good replenishment rate for the purpose of sand extraction compared to Sungai Muda and Sungai Kurau.
A detailed sediment transport study at six sites for each river was conducted to determine the suitability of existing sediment transport equations for use in the selected sediment transport models. It was found that Yang and Engelund-Hansen equations are able to predict the trend of sediment transport for the three rivers.
Hydraulic and sediment transport modeling study were carried out to determine possible location of deposition along the three rivers in the present study. The depth and volume of deposition will in return determine the viability of sand extraction taking into account the ability of the rivers to replenish the sediment. Three models were used for this purpose: HEC-RAS, FLUVIAL-12 and SWAT.
Proposals on the minimum level or "redline" and maximum level for sand extraction are given based on the HEC-RAS modelling results. It is proposed that the minimum depth of the excavation or redline must be at 1 m deposition above natural channel thalweg elevation while the maximum allowable mining depth is 1.5 m. The extraction is allowed for the whole active channel width after taking into consideration of the required setback to avoid bank erosion, and buffer zone encroachment. Allowing the channel wide extraction will increase the volume of the extraction for a particular site. Hence, few mining sites are allocated for each river which will minimize the disturbance to river equilibrium and environment. Based on the sedimentation trend as predicted by HEC-RAS model and after applying the 1 m redline, it can be concluded that Sungai Langat is viable for sand extraction purpose while Sungai Kurau should be prohibited from any sand extraction activity. Since Sungai Muda is being widened for flood mitigation purpose, it is recommended that deposition should be allowed to occur first after a major flood before any sand extraction activity is allowed in the 40-km lower part of the river.
Comparisons with the existing DID guidelines on sand mining were made based on the modelling results. As a result, a new guideline on river sand mining management is included in this final report that emphasizes the impacts of sand mining and several recommendations for a sustainable sand extraction, including discussions on appropriate extraction methods and sites adopted from overseas experience. Flood plain mining is also proposed as an alternative to in stream mining. Also, Geographical Information System was utilized for the study areas in the development of river register database.
Finally, individual report for each river is provided in three separate volumes:
VOLUME I SUNGAI MUDA
VOLUME II SUNGAI LANGAT
VOLUME III SUNGAI KURAU
Sediment Rating Curve for Sungai Muda
Sediment Rating Curve for Sungai Langat
Sediment Rating Curve for Sungai Kurau
Comparison of Replenishment Rate for three rivers
HEC-RAS Modelling Results for Sungai Kurau
Recommendation: NO SAND MINING ALLOWED
HEC-RAS Modelling Results for Sungai Muda
Recommendation: SAND MINING ALLOWED ONLY AFTER A MAJOR FLOOD OCCURS AT THE COMPLETION
OF THE ON-GOING FLOOD MITIGATION PROJECT
HEC-RAS Modelling Results for Sungai Langat
Recommendation: SAND MINING ALLOWED
Volume of Deposition (tons)
Volume of Deposition (m3)
|1. CH 109715 - CH 97715||4,636,000||3,004,077|
|2. CH 85215 - CH 66000||1,475,000||955,784|
Setback, Redline and Maximum Allowable Mining Depth for In Stream Mining
Floodplain Excavation Pit Geometry
|Berita Harian News on Sand Mining Activity - Jawatankuasa diwujud mantapkan mekanisme pantau aktiviti ambil pasir sungai||<40Kb>|