## 3 Result and Discussion
The main channel's low sinuosity reflects the substratum's higher slope, whereas the high sinuosity of channels indicates a lower depositional substratum slope. The degree of channel sinuosity can help in inferring the landscape slope during river flow. An abundance of incised tributary valleys develops along the channel at the southwest corner of the study area. The channel shows more sinuosity on the west side and gets less towards the south direction, which is believed to be attributed to the river's pathway geomorphological gradient. At the center of this time slice, we noticed the top of the other high meandering channel extended from the north to south. On the right side of the study area is also a noticeable high sinuosity and meander channel extending from the north-south of the studied area's map-view with some incised tributary valleys. The incised tributary valleys are more visible and concentrate at the west side, while they are less whenever moving towards the downstream in the south direction. This distinguishing feature is considered a result of the lateral lithological differences with assumed sand-laying flat facies associated with point bar sediments and muddy facies, resulting in a mud plug in the channel's last position before being abandoned. Besides, the major compression differences directly across the abandoned channels help define the mud-filled channel systems. In the studied section, most fluvial systems were formed of one-channel zigzaging rivers, which vary widely from less than 100 to 900 m wide (Figure 7). Some minor fluvial systems are tiny and therefore do not display channel belts and bar sediments. The meandering fluvial systems at the TWT of \(-90\), \(-111\), \(-138\), and \(-174\) ms have shown clearly evolved channel belts with widths up to 6 km. The above components are slightly bigger than the Muar River's present shape, which passes through the states of Johor, Negeri Sembilan, and Pahang in Malaysia, and is significant compared with other mainland analogs, like river Ucayali in Peru (Figure 6C1). The southwestern segment of the trunk valley displays well-photographed carved branch valleys that are observed in consecutive time slices, wherein the interflucves were incised to form the tributary valleys (Figure 6(A1,B1)). The uppermost and central part of this fluvial channel displayed slimmer channel-belt sizes with plenty of tributary channels, which correspond with a reduction in sinuosity with fewer tributary channels and an increase in the width at the downstream, as shown in Figure 6(A2,B2). This figure shows that the valley's width can control bar expansion and transition and thus the channel sinuosity. In the southern part of the channel system, a noticeable expansion of the valley can be seen, whereby sinuosity and meander decrease towards the downstream at the south. The eastern segment displays the channel's best image, abandoned channel, bars expansions, and channel belt extended from north to south with a high meandering degree as shown in Figure 6(A3,B3). The slides C1, C2, C3, and C4, are recent analogs with analogous features and similar depositional features: Muar River, Johor, Negeri Sembilan Pahang in Malaysia. A good display in Figure 7 of a 3D block diagram demonstrating the relationship between shape-filled channels in the cross-sections and their chart-view interpretation was noticed at TWT \(-138\) ms. Obviously, the channel's seismic amplitude is quite different from the surrounded point bars' deposits in both the 2D seismic sections and the 3D time slices. The time slice of chart view-imaged Figure 7B represents a well-conserved channel, and channel-belt muddy depositional features, highlighting the channel variation sizes shown in Figure 7B. In the minor channels, there are several of the incised tributary valleys in the single southwest channel: extension surfaces, meander scrolls, abandoned channels, and bar expansions. The 3D amplitude volume reveals the biggest sinuosity channel crosses the Melor field.