Chap.3 Geophysical of Kajang

This study is about the geophysical attributes in Bandar Kajang, Selangor covering the three main subtopics which are Integrated Environment Pollution, River Intervention, and Flood Issues.

This section is about integrated environment pollution. Prestige Group reported several studies on river conditions. A study by Juahir et al. (2011) on spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques. The study investigates the spatial water quality pattern of seven stations located along the main Langat River. Juahir et al. (2011) used environmentric method to classify and analyse water quality and found the method meaningful on the spatial variability of a large and complex river water quality data.

Another is by Chin and Ng (2015) who investigate the issue of river pollution in Malaysia, and the different factors affecting it. Chin and Ng (2015) found that a lack of public awareness regarding pollution and its effects needs to be addressed through education. Also, there is a need for clarity and honesty from authorities on the state of rivers and ongoing plans. The statistics showed that 81.7% of people are unaware of river conditions, which shows a clear dysconnectivity and desensitization, and hence increases the likelihood of pedestrians littering and polluting rivers around Malaysia. The survey conducted also showed a large portion of people believed it was not the population’s fault or responsibility to restore rivers, but rather the governments and NGO’s.

However, Juahir et al. (2011) limited his study to research about the water pollution and factor only while Chin and Ng (2015) study is lacking some insights to how different socioeconomic classes and education levels play into these numbers. Therefore, the study recommended to collect some data from local people or employer to study the effects of water pollution at Langat River. Another recommendation is to understand how the cultural, economic, and educational background could change the perception of climatic and environmental issues and develop a more efficient method for educating them on the matter.

This section is about river intervention. According to heart Group, Roche et al., (2020) mentioned that global biodiversity is threatened by habitat loss, climate change, and biological invasion. However, predictions of impacts on native fauna are hampered by an inadequate knowledge of how these factors interact and how climate change will affect the distribution, abundance, and behavior of both native and invasive species, not least as most predictions are based on the long-term effects of temperature alone. Arlettaz et al., (2011) found many river revitalization projects are currently under development, but still lack proper assessments of their effects on biodiversity, especially regarding non-aquatic vertebrates. Wang (2012) highlighted the urban river pollution control where the author had probed deeper into the remediation.

Roche et al., (2020) presented a case study illustrating how local-scale climate change impacts (such as increased temperature, reduced rainfall, and shifts in peak rainfall) affected the hydrology of a channelized lowland European river (such as reduced flow, reduction in flood events, increased siltation, and macrophyte growth), allowing native fish species to recolonize the bankside zone and reducing the density of invasive round goby Neogobius melanostomus by removing its preferred habitat. While most studies predict long-term negative impacts on global fish populations, some suggest potential direct and indirect benefits at a local scale. We are of the opinion that, at a local scale, climate change impacts on fish will be more complex than long-term predictions suggest. While impacts on fish will differ between regions and/or continents, depending on the specific impacts of climate change, identification of positive effects will be essential in clarifying long-range forecasts and identifying management procedures for mitigating overall negative impacts.

Arlettaz et al., (2011) analyzed the progressive changes in habitat mosaics, and the demographic response of two rare species of wading birds along a Swiss section of the Rhone River over a period of three decades. He mentioned during the period preceding revitalization, the diversity of the habitat mosaic had been steadily declining. This impoverishment could, however, be reverted after 1994, when the revitalization was initiated. In 2006, the re-established habitat matrix was more diverse than at any time during the previous 27 years. The formerly channelized stream underwent radical transformation as it mutated into a heterogeneous braided river boosting pioneer riverine habitats. This has led the two wading bird species to establish significantly more territories than before the revitalization operations. The population size of Actitis Hypoleucos and Charadrius Dubius had increased by 83% and 20%, respectively, between 1995 and 2007. During the same period, A. hypoleucos declined dramatically in Switzerland as a whole, whilst C. dubius showed no distinct population trend. The response of the two waders may have resulted from an increase in the number of lateral arms of the river, where the availability of productive temporary ponds provides excellent foraging opportunities. A significant proportion of these habitats was created by a targeted extraction of sediments with the objective to promote biodiversity while maintaining economic activity and improving security against floods. This suggests that gravel exploitation is not incompatible with efficient river restoration.

Wang (2012) presented then situation of urban river pollution where he discussed about river pollution control and its remediation. After comparing different techniques and concepts of bioremediation technology, the study found the potential of biological ecological remediation as the primary technique with physical and chemical remediation as the supplementary means in river pollution remediation. Based on Roche et al., (2020), their study recommends to focus and emphasize the impact of fish to a specific river and nearby communities which would raise awareness on the riverbank. According to Arlettaz et al. (2011), their study recommends involving the relationship between other living organisms as well in order to have an overview of the balance of ecosystem. It is critical to Wang (2012) who recommends obtaining community consensus on river remediation activism.

In summary, proper assessments on river revitalization must involve balancing its fragile ecosystems. To do so, understanding the impact of aqua lives would enhance awareness on managing the riverbank. Moreso, the need to understand how river pollution is causing habitat loss, climate change, and biological invasion. Biological ecological remediations are recommended as primary technique is highly pursued.

This section is about flood issues. According to Millenium Group, Tehrany et al. (2014) highlighted that flood susceptibility mapping method to produce flood susceptibility maps of Busan City. Another study by N. Kang, S. Kim, Y. Kim et al. (2016) aims to improve the urban drainage system to facilitate climate change adaptation. Lourenco et al. (2020) highlighted a framework to support flood prevention and mitigation in the landscape and urban planning process regarding water dynamics where the authors seeking for future urban solution. Tehrany et al. (2014) stated that the main aim of this research was to overcome the weakness of logistic regression regarding bivariate probability capabilities.

A flood inventory map with a total of 160 flood locations was extracted from various sources. The impact of each independent variable on flooding was evaluated by analysing each independent variable with the dependent flood layer. The validation dataset, was used to evaluate the flood susceptibility map using the prediction rate method. N. Kang, S. Kim, Y. Kim et al. (2016) stated a methodology, and a series of mitigation strategies are presented to efficiently improve the urban drainage system in light of climate change. In addition, they assessed the impact of climate change and predicted the scale of potential future flood damage by applying the methodology and mitigation strategies to urban areas. An urban flood prevention measures for Gyeyang-gu (Province), Incheon, Korea, was established and validated by the economic feasibility of the projects to reduce flood damage.

Lourenco et al. (2020) examine a possible analytical framework for urban planning and design of flood control alternatives, using a multifunctional open space system that incorporates water dynamics into current and future urban solutions. This framework starts with a diagnosis of the current situation, analysing three main aspects: urban floods and their consequences; urban plans and legal environmental constraints; and available open spaces and multifunctional opportunities. Then, a set of guidelines is proposed to articulate urban needs with environmental limits, intending to help in the design of urban flood control alternatives, while increasing environmental value and retrofitting urban vicinity. These guidelines include multi- scale solutions in the watershed context, using sustainable urban drainage concepts in multifunctional open spaces, which can also act as environmental connections and protective fluvial parks. In view of weaknesses regarding the above approaches, this study proposes increasing the frequency of flood data observations and focusing on selective problematic type of building drainage system in order for buildings to adapt with flood situations such as in Kajang.

Kajang can benefit with the use of green infrastructure to improve urban air quality through planting vegetation. Such infrastructure can influence how the city can reduce residents too pollution exposure to pollution whether by air or river. One way is to exercise biological ecological remediation in order for river revitalization at Langat River and giving residents access to green urban linkages in the form of jogging paths or cycling paths. Community participations can be encouraged by having social nodes in the form of pocket parks along the green urban linkages and alongside the river. Implementing a framework to support flood prevention and mitigation through the landscape and urban planning process in Kajang is also called for. This is due to current inadequate systematic urban drainage system. Moreover, Kajang could benefit by having its own flood inventory map for forecasting flash flooding. The significants of the above recommendations could be amplified with awareness and education programmes to promote better water consumption and conservation by consumers.

Juahir, Hafizan, Sharifuddin M. Zain, Mohd Kamil Yusoff, T. I. Tengk. Hanidza, A. S. Moh. Armi, Mohd Ekhwan Toriman, and Mazlin Mokhtar. 2011. “Spatial Water Quality Assessment of Langat River Basin (Malaysia) Using Environmetric Techniques.” Environmental Monitoring and Assessment 173(1–4):625–41. doi: 10.1007/s10661-010-1411-x.

Chin, C. M. M., Ng, Y. J. (2015). A Perspective Study on the Urban River Pollution in Malaysia. Chemical Engineering Transactions, 45. DOI: 10.3303/CET1545125

Roche, K., Jurajda, P., Šlapanský, L., & White, S. M. (2020). Turning back the tide? Local-scale impacts of climate change may have positive effects by restoring natural riverine habitat and reducing invasive fish density. Freshwater Biology, 65(11), 2010–2020. https://doi.org/10.1111/fwb.13604

Arlettaz, R., Lugon, A., Sierro, A., Werner, P., Kéry, M., & Oggier, P. A. (2011). River bed restoration boosts habitat mosaics and the demography of two rare non-aquatic vertebrates. Biological Conservation, 144(8), 2126–2132. https://doi.org/10.1016/j.biocon.2011.05.003

Wang, J., Liu, X. D., & Lu, J. (2012). Urban River Pollution Control and Remediation. Procedia Environmental Sciences, 13(2011), 1856–1862. https://doi.org/10.1016/j.proenv.2012.01.179

Tehrany, M. S., M. J. Lee, B. Pradhan, M. N. Jebur, and S. Lee. 2014. “Flood Susceptibility Mapping Using Integrated Bivariate and Multivariate Statistical Models.” Environmental Earth Sciences 72(10):4001-15. doi: 10.1007/s12665-014-3289-3.

Kang, N., Kim, S., Kim, Y., Noh, H., Hong, S. J., & Kim, H. S. (2016). Urban drainage system improvement for climate change adaptation. Water, 8(7), 268.

Lourenço, I. B., de Oliveira, A. K. B., Marques, L. S., Barbosa, A. A. Q., Veról, A. P., Magalhães, P. C., & Miguez, M. G. (2020). A framework to support flood prevention and mitigation in the landscape and urban planning process regarding water dynamics. Journal of Cleaner Production, 277, 122983.