Malaysia mempunyai tanggungjawab mendepositkan koordinat-koordinat titik-titik pangkal yang digunakan untuk mengukur lebar batas laut wilayah dan sempadan zon-zon maritim yang lain kepada Setiausaha Agung, Pertubuhan Bangsa-Bangsa Bersatu (PBB). Titik-titik pangkal adalah asas kepada penetapan bagi zon-zon maritim, perundangan batas maritim dan perlaksanaan penguatkuasaan. Kertas ini menghuraikan bagaimana dua parameter penting iaitu kecerunan pesisir depan dan datum carta boleh menyebabkan ketidakpastian terhadap posisi titik-titik pangkal. Hubungkait trigonometri antara parameter membuktikan sisihan datum sebanyak 0.2 m dan kecerunan pesisir depan sebanyak 0.1º menyebabkan ketidakpastian posisi mendatar sebanyak 114.6 m. Ketidakpastian kedudukan titik pangkal menjadi signifikan apabila sisihan antara datum carta meningkat dan kecerunan pesisir depan semakin landai. Hasil prosesan kedudukan titik-titik pangkal melalui perisian “CARIS” mendapati perbezaan kedudukan titik-titik pangkal sebanyak 108 m, 169 m dan 107 m. Kesimpulannya, ketidakpastian ini boleh menyebabkan negara kerugian kawasan maritim.
Malaysia has a long coastline stretching over 4,809 km where more than 1,300 km of beaches are experiencing erosion.
Coastal erosion is recognised as the permanent loss of land and habitats along the shoreline resulting in the changes
of the coast. Thus, it is important to detect and monitor shoreline changes especially in Pahang coast by identifying the
rate of shoreline erosion and accretion. This study used temporal data and high spatial resolution imagery (SPOT 5) using
remote sensing and GIS techniques to monitor shoreline changes along 10 study locations, which is from Cherating to
Pekan of the Pahang coast. The total length of shoreline changes is about 14 km (14035.10 m) where all these areas are
very likely to experience erosion ranging from 0.1 to 94.7 ha. On the other hand, these coastal areas found a minimal
accretion with increased sediment from 0.1 to 2.8 ha. Overall, the coastal areas are exposed to higher erosion process
than accretion with a very high vulnerability of erosion rate from 1.8 to 20.9 meter per year. The findings on monitoring
shoreline changes and identifying vulnerable erosion areas might be useful in the policy and decision making for
sustainable coastal management.
Penggunaan tanah boleh mengakibatkan perubahan fungsi dari masa ke masa, sesuai dengan tujuan pembangunan. Kawasan Bandar Pekanbaru terdiri daripada 12 sub-kawasan persekutuan dengan jumlah keluasan kira-kira 632.26 km2. Tujuan kajian adalah untuk menganalisis perubahan guna tanah daripada aspek ruang dan masa. Data guna tanah yang diambil kira dalam analisis ini adalah peta guna tanah 1992 dan 2004. Hasil analisis dengan menggunakan perisian ArcView GIS versi 3.2 mendapati bahawa telah berlaku penurunan guna tanah signifikan, iaitu jenis perkebunan dan hutan tahun 2004. Peningkatan jenis lain-lain, penggunaan tanah seperti permukiman dan tumbuhan/semak tahun 2004 telah berlaku. Perubahan ini merupakan pengaruh daripada pembangunan bandar. Sebaliknya, pembangunan bandar boleh memberi impak negatif terhadap sekitaran jika pola perubahan guna tanah dirancang tanpa pengurusan yang baik.
This study investigates the relationship between land use types and sedimentary characteristics of fluvial bed at three
rivers in Selangor, Malaysia; namely Sungai Tengi, Selangor and Langat. The diversity in population density and land
development at the adjacent river banks gives associated dominant land use type as forest, agriculture and urban for
Tengi, Selangor and Langat, respectively. Field sampling was conducted at consistent spatial locations for Tengi and
Selangor, whereas for Langat, the bed sediment was taken at non-uniform spatial points due to limited access. Statistical
analysis of the sediment bed mixture shows that forest dominated land gives finer bed sediment size at < 200 µm.
Agriculture-type of land use increases the mean sediment size to medium sand, whereas bed material near to urbanized
areas has coarser sediment size with > 650 µm. Correlation analysis proved that there is a relationship between types
of land use with the mean sediment size. No distinctive correlation can be observed for sorting, skewness and kurtosis
of the sediment with the types of land use.