CU e-Journals

Applied Environmental Research (AER)

Applied Environmental Research (AER) publishes fully (double-blinded) peer-reviewed articles in the field of environment. The journal?s focus areas are environment, environmental pollution, hazardous substance and chemical management, natural resources management, climate change, and other interdisciplinary environmental issues.

Current Issue

Applied Environmental Research (AER)
Volume: 43, Issue: 1 (January - April 2021)

	Change in Rainfall Patterns in the Hilly Region of Uttarakhand due to the Impact of Climate Change
	Dilip Kumar, Rajib K. Bhattacharjya
	Page: 1 - 13
	[Abstract] [PDF] Uttarakhand, a Himalayan state of India, may experience an increase in temperature of 1.4°C to 5.8°C by 2100 due to global warming. The rise in temperature may melt the glaciers of the state and may have some significant impact on the rainfall. In this study, we have quantified the changes in the rainfall of the state. Also, an attempt has been made to evaluate the impact of climate change on rainfall. The future rainfall can be estimated by using a global circulation model (GCM). However, due to the very coarse spatial resolution of the different GCM, we cannot use them directly. For matching this spatial inequality between the GCM output and historical precipitation data, we used the statistical downscaling technique. In the present study, we have examined the suitability of the artificial neural network with principal component analysis for downscaling the rainfall for different hilly districts of the state. We usedthe GCM model developed by Canadian Earth System Model, and the Indian metrological department gridded rainfall data. We performed the analysis for the different scenarios to visualize the impact of climate change on rainfall trends for all nine hilly districts of Uttarakhand. Results show that there was a clear indication of climate change in upper Himalayan Districts like Pithoragarh, Rudraprayag, and Chamoli, which was observed from the peak of monthly rainfall. The percentage change of monsoon rainfall in the future may go up to 200 % in the case of RCP8.5, and the change maybe around 180% for RCP4. Also, the volume of rainfall may increase in the case of RCP8.5 from July to September as compared to the historical data, i.e., there may be a shifting of monsoon rainfall in the future.

	Evaluating Water Quality Variation in the Vietnamese Mekong Delta Area Using Cluster and Discriminant Analysis
	Giao Thanh Nguyen, Thi Hong Nhien Huynh
	Page: 14 - 27
	[Abstract] [PDF] The study aims to assess spatial and temporal water quality variations in the upper reaches of the Vietnamese Mekong Delta. Thirty-one water monitoring samples of the two main rivers (Tien and Hau Rivers) and six canals flowing through An Giang Province were collected in thedry season (March) and the rainy season (September) from 2009 to 2019. Seven physicochemicalparameters were analyzed including temperature, pH, dissolved oxygen (DO), biochemical oxygendemand (BOD), total suspended solids (TSS), orthophosphate (P-PO43-), and coliforms. Water quality index (WQI), cluster analysis (CA), and discriminant analysis (DA) were applied to evaluate water quality, spatial and temporal variations, and seasonal discriminant water variables.WQI values (15 - 71) indicated surface water quality was very bad to medium in which the water quality in larger and in smaller rivers in the dry season was less polluted than that in the rainy season due to erosion and runoff water containing waste materials in the wet season. CA groupedthe water quality in the dry and rainy seasons into four clusters mainly due to BOD and coliformsin the dry season; TSS and coliforms in the rainy season. Discriminant analysis revealed that DO, TSS, coliforms, temperature and BOD significantly contributed to seasonal variations in water quality. Therefore, water quality monitoring in the surveyed area could only focus on DO, TSS, coliforms, temperature and BOD to reduce monitoring cost.

	Case Study of Modular Pre-cast Concrete On-Site Stormwater Detention System during Monsoon Season in Southeast Asia
	Darren Y.S. Mah, Johnny O.K. Ngu, Rosmina A. Bustami, Frederik J. Putuhena
	Page: 28 - 40
	[Abstract] [PDF] On-site stormwater detention system within a residential property is meant for an environmental protection device that temporarily stores stormwater within the property lot to mitigate flash flood, particularly during rainy seasons brought by the northeast monsoon. A field test was constructed in a house's car porch with a 4.40 m x 4.70 m x 0.45 m tank filled with precast-concrete modular units with an effective storage volume of 3.97 m3. The system received water from a 95 m2 house roof via 0.1 m diameter pipe, discharged water via 0.05 m diameter pipe. It had recorded six observed storm events coincided with the 2019/2020 monsoon season that consisted 20 - 50 mm peak hourly rainfall, 0.0007 - 0.0018 m3 s-1 inflow, 0.0005 - 0.0012 m3 s-1 outflow and 0.21 - 0.47 m water level. Another four historical storm events coincided with the monsoon from 2015 - 2017 were sourced to augment the analysis. A computer model developed using the storm water management model was calibrated and verified using the six observed events. The Kolmogorov-Smirnov goodness of fit tests between the observed and modelled cumulative distributions had produced 0.01 - 0.14 maximum vertical distances that were lower than the 0.41 - 0.68 critical values indicating close matches. As such, the calibrated and verified model was used to simulate the historical storm events with 40 - 50 mm peak hourly rainfall and produced 0.0010 - 0.0013 m3 s-1 inflow, 0.00072 - 0.00076 m3 s-1 outflow and 0.41 - 0.45 m water level. By combining the field test and computer simulation model, it was found the system was able to contain all stormwaters from northeast monsoon. However, it had a weakness which the system was approaching its maximum capacity once the peak hourly rainfall exceeded 45 mm. With sucha procedure in place, improvement could be carried out.

	The Spatial Variability of Soil Physical Properties of Different Sized-gap in a Subtropical Forest, China
	Supaporn Buajan, Jinfu Liu, Zhongsheng He
	Page: 41 - 55
	[Abstract] [PDF] Gap areas create heterogeneity in the spatial environment, which is important to plant regeneration and diversity. Soil physical properties (SPP) are factors that affect plant growth. This study aims to assess the spatial variability of SPP in different gap sizes and to determine the effect of gap size on SPP. We used geostatistical analysis to illustrate the spatial patterns of SPP variability within 9 gaps, classified into three sizes (small, medium, and large) and under the canopy at the Castanopsis kawakamii natural reserve forest, the soil samples were collected entire gap area at 20 cm depth with the grid system (resolution: 3 m × 3 m). The following SPPs were determined using soil cores: soil bulk density (SBD), soil water mass content (SWMC), soil volumetric moisture content (SVMC), maximum moisture capacity (MMC), capillary water capacity (CWC), minimum water-holding capacity (MWHC), soil capillary porosity (SCP), and soil total porosity (STP). We found that every SPP, except SCP and STP, significantly differed with gap size. Gap sizes generally improved the SPPs, especially in the small and large gaps, indicating that the soil there was more suitable for plant growth than the soil under the canopy. The highest spatial variability of SPPs was observed in the large gaps. Gap size affected SPP and its spatial variability. The results from this study will be useful for work on forest gapregeneration and conservation, especially around the study site.

	Ecosystem Service Value of the Mixed Land Use Pattern in Asia: Thailand's Experience
	Nararuk Boonyanam, Somskaow Bejranonda
	Page: 56 - 72
	[Abstract] [PDF] The rapid increase in economic development and urbanisation along the Eastern Economic Corridor (EEC) of Thailand has accelerated the change in its ecosystem service value (ESV), leading to the demand for related analysis to ensure sustainable growth in the area. The aim of this study is to: (1) evaluate the land use change in Chonburi Province; the most urbanised city in the EEC of Thailand between 2006 and 2016, and (2) assess the land use change impact on ESV. Secondary data from land use maps for 2006 and 2016 was used to evaluate land use change and its impact on ESV using the land use transition matrix, land use dynamic degree, and the benefit transfer method. Urban and built-up land use were found to dominate other use types. The top three highest annual rates of land use change were found in water bodies, rangeland, and urban and built-up land. The ESV in 2016 was found to be 1.31% higher than for 2006. The ecosystem service functions (ESFs) contributing to the increase in ESV were waste treatment, hydrological regulation, climate regulation and recreation and service culture. Future land use planning should focus on increasing wetlands and protecting agricultural land in the study area since these contribute to the highest ESV. In addition, it is essential to balance economic development with ecological enhancement.

	Effect of Modified Septic Tank on Groundwater Quality around Federal University of Agriculture, Abeokuta, South-west Nigeria
	Kofoworola Olatunde, Modupe Sarumi, Sadiq Abdulsalaam, Babatunde Bada, Funmilola Oyebanji
	Page: 73 - 89
	[Abstract] [PDF] Groundwater forms a very important part of the water supply chain and its quality can be affected by improperly constructed septic tanks used by homeowners in peri-urban locations such as Abeokuta in recent times. Sixty groundwater samples collected from hand-dug wells ≤15m from septic tanks were analysed for physicochemical and bacteriological parameters using standard procedures. Results were integrated with multivariate and hydrogeochemical analyses to assess the effect improperly built septic tanks have on groundwater quality around the Federal University of Agriculture, Abeokuta. The range of values for the measured parameters include: pH (6.26 - 8.66), EC (83 - 1035 μS cm-1), TDS (42 - 621 mg L-1), Mg2+(2 - 60 mg L-1), NO3- (5.09 - 17 mg L-1), Fe (-.04 - 5.32 mg L-1), BOD (0.1 - 13.2) and E. Coli (ND - 41×10 cfu mL-1). The abundance of major ions are in the order Ca2+˃Mg2+˃K+˃Na+ and Cl-˃SO42- >HCO3- >NO3-˃PO42-. The piper trilinear plot shows that the dominant hydrochemical facies in the study area is the Ca2+ - Cl- type. A correlation analysis and a principal component analysis both reflect intrusions from biological wastes such as surrounding septic tanks or municipal waste disposals as well as dissolutions from basal rocks. The possibility of infiltration from sewage into groundwater is confirmed by the numberof samples with high BOD, NO3-, and E.coliconcentrations. Contamination of groundwater with sewage exposes the populace to acute excreta-related illness. This therefore calls for stringent monitoring and management measures to be put in place by relevant regulatory authorities to safeguard the human health and environment within the study area.

	Tourism Density Effect on Environmental Performance Index: Evidence in ASEAN Countries
	Jain Yassin, Sarma Aralas, Danie E.K. Basa
	Page: 90 - 101
	[Abstract] [PDF] The purpose of this current study is to assess the effect of tourism density on the environmentalperformance index on 10 ASEAN countries from 2002 to 2017. This study adopted panel data regressions with the Driscoll and Kraay standard. This method accounts for cross-sectionaldependence, heteroskedasticity, autocorrelation, and the possible correlation between countries when observing the environmental performance index and tourism density. Empirical results found a statistically significant and negative relationship between the tourism density index and the environmental performance index in 10 ASEAN countries. This result implied that an increasein the tourism density index will deteriorate the environmental performance index. The results ofthis study underline the need for sustainable tourism policies and practices in tourism destinations to be executed by the local stakeholders and policymaker to accelerating the Sustainable Development Goals (SDGs) in ASEAN countries. In addition, this study offers justification for the policymaker to give careful attention to the carrying capacity of a tourist destination.

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