Development and evaluation of indices to assess the ecological health of the Pahang River, Malaysia

Water is the essential need for life and all living things need water for living. Recently, the demand for clean and portable water has increased tremendously due to the rapid development and population growth. Since Malaysia has transformed from agriculture country to industrial based country, we are grappling with so many problems such as the increasing of waste, deterioration of water quality, and so on. Due to inadequate technical knowledge, we are not capable to handle and manage the increasing amount of waste. As a result, increasing amount of waste has polluted the water, degraded the habitat as well as caused a massive mortality of fish. Practically in Malaysia, assessment methods were focusing only on certain perspectives, e.g. chemical and physical parameters of water. The integrated assessment (combination between physical, chemical and biological component) to evaluate the health of aquatic environment is scarce. Furthermore, no specific and comprehensive assessment approach was established. For instance, water quality assessment is normally solely based on chemical and physical factors, while biological factor is neglected. This method only provides a partial perspective of water degradation. Moreover, it does not provide any information regarding biota status which becomes one of the main limitations of this method. The main focus of present dissertation is the development of assessment method that could show more sensitivity towards the biological assemblage and at the same time it also could provide additional information to decision maker prior initiating any restoration works. Understanding the effects only from physicochemical parameters is not adequate to evaluate the condition of water environment because it involved the biota. At present, few studies were conducted in this river to evaluate the environment condition of this river, however, none of them focused on the developing of bio-assessment method to evaluate the biotic and abiotic condition in the river. Thus, the present study was designed to investigate the fish composition, assess the water and habitat quality, and integrate this information to develop comprehensive assessment method that is reliable, rapid manner and the results can be easily deliver and present to public. In addition, the development of this assessment is crucial for monitoring and managing our water environment where the threats of biodiversity are tremendously increased especially this river

Fluvial Erosion Process and Field Measurement Techniques: An Overview

Fluvial erosion is the detachment of soil particles from the riverbank or bed by the action of numerous factors including land use, vegetation geomorphology, soil properties and climate change. There are various techniques currently available for measuring riverbank erosion at broad range spatial and temporal scales. Riverbank erosion measurements are vital in the documentation of riverbank erosion and deposition. Measurement of riverbank erosion could provide several important information that could be used for various functions, especially in river corridor management. Various measuring techniques have been implemented with varying degrees of success. This paper highlights and discusses different methods, emphasising on their operating principle, merits, and demerits as well as their field application. The measuring techniques include erosion pin, survey, erosion painting, photo electronic erosion pin (PEEP), photogrammetry, and lidar technology. The selected methods discussed in this chapter could help researchers and or practitioners in predicting or evaluating riverbank erosion of a given study area

HEC-RAS hydraulic model for floodplain area in Sembrong river

The study of floodplain is significant to human life and social economy. It can be seen that by using most computer models, locations of structures affected by floodwaters, such as bridges and roads cannot be effectively compared to the floodplain location in stream floodplain analysis. The purpose of this study is to develop an output of Hydrologic Engineering Center’s River Analysis System (HEC-RAS) hydraulic model and to enable one dimensional steady flow analysis. This study is applied to Sembrong river catchment area, located in Batu Pahat. Floodplain data features such as length of streams, bank position, streamline and cross-sections were used to produce river flow and its cross-sectional shape for each station along the study area. Total of 7 flow rate values were used to indicate an increase in the water level in order to accommodate the additional amount of water that flow into river. The results show that water will overflow into the floodplain at maximum flow rate of 24 m3 /s. The hydraulic model had indicated that 33 out of 65 stations were unable to accommodate the maximum flow rate and thus will led to flooding. By developing the hydraulic model, it clearly shows that the results are more reliable and the affected area can be easily identified. The developed flood model can be a very useful tool in flood management of Sembrong river in terms of river development planning, flood mitigation measures, flood evacuation planning and addressing public awareness. This study proved that HEC-RAS is one of effective instrument for analysis and modeling

Morphological Adjustment of Kahang River Consequent to Construction of Kahang Dam

In a tropical country like Malaysia, the availability of research works to monitor channel changes as a response to situating a dam over an observation period may help to establish new management strategies. These investigations will constitute a vital approach in assessing the changes to channel morphology downstream due to the presence of a dam and its operations. In the present study, the effects of Kahang Dam on Kahang River morphology, in particular, the downstream section was investigated and analyzed between January 2017 to January 2018. The rainfall pattern of the study period, the flow regime concerning the period, and geomorphological channel adjustments were carried out during the field surveys over a 400 meters reach. Different responses were leading to high flow and low flow regimes during periods with and without any interference due to dam operations. Similarly, the river channel was characterized by adjustments and realignments, causing modifications to the river morphology. Changes in cross-sectional area and local incision were also noticed as a direct response to sediment deficit and bank erosion process

Artificial neural network application in sediment prediction: a review

The development of an accurate sediment prediction model is a priority for all hydrological researchers. Several conventional approaches showed an inability to predict suspended sediment correctly. These approaches fall short in understanding the transport of sediments behaviour in rivers because of its complex, non-stationary, and non-linear nature. There have been important advances in the theoretical understanding of Artificial Neural Network (ANN) over the last few decades, as well as algorithmic techniques for their implementation and applications of the approach to hydrological and practical problems. ANN and other machine learning models have been used in predicting complex non-linear relationships and patterns of large input parameters to achieve the desired output. This chapter reviews several relevant works of literature on sediment transport prediction while focusing on a wide range of ANN applications. ANN sediment transport models have increasingly attracted several researchers over the past years. Therefore, the need to acquire in-depth knowledge about their theory and modelling approaches. Besides, this chapter provides an overview of the ANN approach and other emerging machine learning hybrid models, which have yielded satisfactory results. Also, provided in this review are several examples of successful applicability of ANN in sediment prediction

Flood Modelling Studies Using River Analysis System (HEC-RAS) For Flood Plain Area in Muar City

Floods are the most frequent type of natural disaster and occur when heavy precipitation for days or even weeks. Floods will cause extensive destruction, resulting in loss of life and disruption to personal property and vital infrastructure for public health. In this study, HEC-RAS model was used to identify the flood prone area and to determine cross section at floodplain area along the stream network. The study was conducted in the area Muar, Johor. The methodology involved collection of parameters such as length of stream, lateral & elevation of coordinates, streamline and flow data to perform a hydraulic simulation. Different value of flowrate had been used by using the manning equation to estimate the drainage or channel capability to manage the flowrate. The number of station for each cross section need to locate in order to simulate the cross section along the river or channel. Meanwhile, the result outcome will show the cross section for each station. From the result, the analysis of the cross section include with the affected area of floodplain was identified. According to the hydraulic model generated by HEC-RAS software, 7 of 20 stations found will be flood for the 10 years return period since they were unable to accommodate the water flow. By doing this research, the flood model will be developed and HEC-RAS software is one of the tool that can analyse and model for the floodplain area. In a meantime, the government can control and give an early warning about the flood incident

Flood Modelling Studies Using River Analysis System (HEC-RAS) For Flood Plain Area in Muar City

Floods are the most frequent type of natural disaster and occur when heavy precipitation for days or even weeks. Floods will cause extensive destruction, resulting in loss of life and disruption to personal property and vital infrastructure for public health. In this study, HEC-RAS model was used to identify the flood prone area and to determine cross section at floodplain area along the stream network. The study was conducted in the area Muar, Johor. The methodology involved collection of parameters such as length of stream, lateral & elevation of coordinates, streamline and flow data to perform a hydraulic simulation. Different value of flowrate had been used by using the manning equation to estimate the drainage or channel capability to manage the flowrate. The number of station for each cross section need to locate in order to simulate the cross section along the river or channel. Meanwhile, the result outcome will show the cross section for each station. From the result, the analysis of the cross section include with the affected area of floodplain was identified. According to the hydraulic model generated by HEC-RAS software, 7 of 20 stations found will be flood for the 10 years return period since they were unable to accommodate the water flow. By doing this research, the flood model will be developed and HEC-RAS software is one of the tool that can analyse and model for the floodplain area. In a meantime, the government can control and give an early warning about the flood incident

A Review on the Causes, Effects and Mitigation of Climate Changes on the Environmental Aspects

Abstract Climate change is often used interchangeably with the term global warming but, it is a much broader term which includes global warming and some other climate changes that are observed on our planet over the last few decades. In recent time climate change impacts are being felt, the average global temperature is on the rise every decade since the 1970s. Sea ice and glaciers are disappearing, rising sea levels, species are becoming extinct, droughts that render landscape more susceptible to wildfires, changing seasons and severe weather events are becoming more common. These are problems primarily caused by the emission of greenhouse gases into the environment that results to rise in global temperature. There seems to be a consensus among scientist, researchers and all other stakeholders that climate change is already happening and primarily caused by human activities, a few disagree with this view and attribute climate change as a natural phenomenon. The objective of this paper is to (i) introduce climate change in our world today, (ii) enumerate significant causes of climate change in our environment, as well as the effects (iii), suggest ways the impact of climate change due to GHG emissions and other contributors can be mitigated

Field performance of a constructed litter trap with oil and grease filter using low-cost materials

The current study was conducted to develop a litter trap by using crushed clay as an adsorbent media filter to reduce oil and grease (O&G) contents in residential wastewater and then to prevent the degradation of the environment and natural water bodies. Clay acts as a magnet, drawing the oil molecules out of the water and causing them to attach to the surfaces of the clay. The trap was built using Polyvinyl chloride (PVC) pipe and bamboo and installed at site-specific discharge points of storm water for removal of O&G. A total of twenty-four (24) wastewater samples were collected before and after the filtration The design achieved 94% of O&G removal. However, the removal efficiency deepened on the rainfall intensity, the increasing of rainfall effect negatively on the removal percentage of O&G. Nonetheless, the designed system exhibited a potential to remove O&G from the residential wastewater

Field Performance of a Constructed Litter Trap with Oil and Grease Filter using Low-cost Materials

The current study was conducted to develop a litter trap by using crushed clay as an adsorbent media filter to reduce oil and grease (O&G) contents in residential wastewater and then to prevent the degradation of the environment and natural water bodies. Clay acts as a magnet, drawing the oil molecules out of the water and causing them to attach to the surfaces of the clay. The trap was built using Polyvinyl chloride (PVC) pipe and bamboo and installed at site-specific discharge points of storm water for removal of O&G. A total of twenty-four (24) wastewater samples were collected before and after the filtration The design achieved 94% of O&G removal. However, the removal efficiency deepened on the rainfall intensity, the increasing of rainfall effect negatively on the removal percentage of O&G. Nonetheless, the designed system exhibited a potential to remove O&G from the residential wastewater