scholarly journals Evaluation of Annual Sediment Load Production in Kenyir Lake Reservoir, Malaysia

2018 ◽  
Vol 7 (3.14) ◽  
pp. 55
Author(s):  
Mohd Khairul Amri Kamarudin ◽  
Noorjima Abd. Wahab ◽  
Ahmad Fadhli Mamat ◽  
Hafizan Juahir ◽  
Mohd Ekhwan Toriman ◽  
...  

Kenyir Lake’s natural environment experienced significant changes over the past 20 years. Pressure from anthropogenic activities such as deforestation, construction, and sand mining around Sungai Terengganu, tourism, farming and agricultural has creating imbalance between environmental processes and response in Kenyir Lake. The aim of the study is to estimate the production of sediment yield (Muatan Sedimen) (MS) (tonnes/km2/year) in Kenyir Lake Basin. 21 sampling stations were chosen along Kenyir Lake to represent the upstream and downstream. The statistical analysis proved that the correlation and regression relationship between Total Suspended Solid (TSS), MS and area of catchment. MS showed a weak correlation and insignificant relationship of regression caused by the anthropogenic factors and uncertain climate changes. These sedimentation problems due to unsustainable land use changes, river bank erosion problems and active construction activity around the Kenyir Lake Basin. This study suggests the sedimentation management methods including land use settlement, cliff erosion problems, settlement and negotiable of uncontrolled development operations in Kenyir Lake and the integrated of river and lake management methods based on Integrated River Basin Management (IRBM) in Kenyir Lake Basin is recommended.  

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1636
Author(s):  
Thanh N. Le ◽  
Duy X. Tran ◽  
Thuong V. Tran ◽  
Sangay Gyeltshen ◽  
Tan V. Lam ◽  
...  

Saltwater intrusion risk assessment is a foundational step for preventing and controlling salinization in coastal regions. The Vietnamese Mekong Delta (VMD) is highly affected by drought and salinization threats, especially severe under the impacts of global climate change and the rapid development of an upstream hydropower dam system. This study aimed to apply a modified DRASTIC model, which combines the generic DRASTIC model with hydrological and anthropogenic factors (i.e., river catchment and land use), to examine seawater intrusion vulnerability in the soil-water-bearing layer in the Ben Tre province, located in the VMD. One hundred and fifty hand-auger samples for total dissolved solids (TDS) measurements, one of the reflected salinity parameters, were used to validate the results obtained with both the DRASTIC and modified DRASTIC models. The spatial analysis tools in the ArcGIS software (i.e., Kriging and data classification tools) were used to interpolate, classify, and map the input factors and salinization susceptibility in the study area. The results show that the vulnerability index values obtained from the DRASTIC and modified DRASTIC models were 36–128 and 55–163, respectively. The vulnerable indices increased from inland districts to coastal areas. The Ba Tri and Binh Dai districts were recorded as having very high vulnerability to salinization, while the Chau Thanh and Cho Lach districts were at a low vulnerability level. From the comparative analysis of the two models, it is obvious that the modified DRASTIC model with the inclusion of a river or canal network and agricultural practices factors enables better performance than the generic DRASTIC model. This enhancement is explained by the significant impact of anthropogenic activities on the salinization of soil water content. This study’s results can be used as scientific implications for planners and decision-makers in river catchment and land-use management practices.


2017 ◽  
Vol 122 (3) ◽  
pp. 690-707 ◽  
Author(s):  
Xibao Xu ◽  
Guishan Yang ◽  
Yan Tan ◽  
Xuguang Tang ◽  
Hong Jiang ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2493 ◽  
Author(s):  
Meena Kumari Kolli ◽  
Christian Opp ◽  
Daniel Karthe ◽  
Michael Groll

India’s largest freshwater ecosystem of the Kolleru Lake has experienced severe threats by land-use changes, including the construction of illegal fishponds around the lake area over the past five decades. Despite efforts to protect and restore the lake and its riparian zones, environmental pressures have increased over time. The present study provides a synthesis of human activities through major land-use changes around Kolleru Lake both before and after restoration measures. For this purpose, archives of all Landsat imageries from the last three decades were used to detect land cover changes. Using the Google Earth Engine cloud platform, three different land-use scenarios were classified for the year before restoration (1999), for 2008 immediately after the restoration, and for 2018, i.e., the current situation of the lake one decade afterward. Additionally, the NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) indices were used to identify land cover dynamics. The results show that the restoration was successful; consequently, after a decade, the lake was transformed into the previous state of restoration (i.e., 1999 situation). In 1999, 29.7% of the Kolleru Lake ecosystem was occupied by fishponds, and, after a decade of sustainable restoration, 27.7% of the area was fishponds, almost reaching the extent of the 1999 situation. On the one hand, aquaculture is one of the most promising sources of income, but there is also limited awareness of its negative environmental impacts among local residents. On the other hand, political commitment to protect the lake is weak, and integrated approaches considering all stakeholders are lacking. Nevertheless, alterations of land and water use, increasing nutrient concentrations, and sediment inputs from the lake basin have reached a level at which they threaten the biodiversity and functionality of India’s largest wetland ecosystem to the degree that immediate action is necessary to prevent irreversible degradation.


2020 ◽  
Vol 32 (4) ◽  
pp. 827-834
Author(s):  
Muhammad Towhid Moula ◽  
Ranjit K. Nath ◽  
Mh. Mosfeka Chowdhury ◽  
Md. Abu Bakar Siddique

Halda is an important river of Bangladesh, is now polluted in different ways through industrial, agricultural, domestic and sewage disposal. Increased anthropogenic activities have increased the potential pollution of the river and excessive pollutants may be toxic to humans and aquatic fauna. Presence of heavy metals in the river water causes perilous impact on the aquatic organisms. Hence, regular monitoring of pollution levels in the river is indispensable. In this study, we discuss about physico-chemical assessments of water quality parameters viz. pH, dissolve oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total solid (TS), total suspended solid (TSS), total dissolved substance (TDS), total alkalinity, turbidity, salinity, electrical conductivity (EC), hardness, chloride and heavy metals in the water of Halda river during rainy and winter seasons, at different points; sources of pollutants in water and their effects given starting from the early research until the current research.


2017 ◽  
Vol 63 (No. 6) ◽  
pp. 245-253 ◽  
Author(s):  
Khaleghi Mohammad Reza

In recent decades, due to rapid human population increases and in its results, destructive effects of anthropogenic activities on natural resources have become a great challenge. Land use and vegetation are important factors in soil erosion and runoff generation. This study was performed to assess the effects of different amounts of forest cover on the control of runoff and soil loss in the Talar basin, which is located in Mazandaran province, using a runoffrainfall model, geographical information system (GIS) and remote sensing (RS) to determine the hydrologic effects of deforestation on the Talar watershed (north of Iran). A runoff-rainfall model has been presented using GIS (HECGeoHMS) and hydrologic model (HEC-HMS). Land use changes (deforestation) and anthropogenic activities (roads and impervious surfaces development) were evaluated using RS techniques and satellite images. We used the Soil Conservation Service and Curve Number methods for hydrograph simulation and runoff estimation, respectively. First, a model was performed and optimized. Afterward, the optimized model was evaluated by other six events of floods (model validation). According to the obtained results, the runoff generation potential has been increased in the Talar watershed due to deforestation during the last forty years. Land use changes cause an increase in runoff volume and flood peak discharge.


2019 ◽  
Vol 11 (2) ◽  
pp. 35
Author(s):  
Peter Nkashi AGAN

Land use is the utilization and reordering of land cover for human comfort. This process disrupts the pristine state of the environment reducing the quality of environmental receptors like water, air, vegetation etc. Air pollution is introduced into the environment as a result of anthropogenic activities from commercial, industrial and residential areas. These activities are burning of fossil fuels for power generation, transport of goods and services, valorization of raw materials into finished products, bush burning, use of gas cookers, generators and electric stove etc. The introduction of pollutants into the planetary layer of the atmosphere has impacted negatively on the quality of the environment posing threat to humans and the survival of the ecosystem. In Lagos metropolis, commercial activities and high population densities have caused elevated levels of pollution in the city. This study aimed to investigate the spatial distribution of pollutant in Lagos metropolis with a view to revealing the marked spatial/temporal difference in pollutants levels over residential, commercial and industrial land uses. Commercial and industrial land uses revealed higher levels of pollutants than the residential areas. Pearson product moment correlation coefficients revealed strong positive relationship between land use and air quality in the city.


2021 ◽  
Vol 13 (24) ◽  
pp. 5081
Author(s):  
Yiming Wang ◽  
Zengxin Zhang ◽  
Xi Chen

Understanding the driving mechanism of vegetation changes is essential for vegetation restoration and management. Vegetation coverage in the Poyang Lake basin (PYLB) has changed dramatically under the context of climate change and human activities in recent decades. It remains challenging to quantify the relative contribution of natural and anthropogenic factors to vegetation change due to their complicated interaction effects. In this study, we selected the Normalized Difference Vegetation Index (NDVI) as an indicator of vegetation growth and used trend analysis and the Mann-Kendall test to analyze its spatiotemporal change in the PYLB from 2000 to 2020. Then we applied the Geodetector model, a novel spatial analysis method, to quantify the effects of natural and anthropogenic factors on vegetation change. The results showed that most regions of the basin were experiencing vegetation restoration and the overall average NDVI value in the basin increased from 0.756 to 0.809 with an upward yearly trend of +0.0026. Land-use type exerted the greatest influence on vegetation change, followed by slope, elevation, and soil types. Except for conversions to construction land, most types of land use conversion induced an increase in NDVI in the basin. The influence of one factor on vegetation NDVI was always enhanced when interacting with another. The interaction effect of land use types and population density was the largest, which could explain 45.6% of the vegetation change, indicating that human activities dominated vegetation change in the PYLB. Moreover, we determined the ranges or types of factors most suitable for vegetation growth, which can be helpful for decision-makers to optimize the implementation of ecological projects in the PYLB in the future. The results of this study could improve the understanding of the driving mechanisms of vegetation change and provide a valuable reference for ecological restoration in subtropical humid regions.


2021 ◽  
Vol 934 (1) ◽  
pp. 012059
Author(s):  
A M S Hertika ◽  
D Arfiati ◽  
E D Lusiana ◽  
R B D S Putra ◽  
D R N Wasti

Abstract Anthropogenic activities along watershed area are often causing river pollution. This will affect the sustainability of aquatic resources, such as fish. One of the fish species in Brantas River that can be employed as bioindicator of water pollution is Wader fish (Puntius, sp.). The aim of this research was to analyze the health of Wader fish based on tits hematological profile. This study utilized descriptive method and conducted in three sites of Brantas River that located in Malang city, Indonesia. We took water quality parameters data to obtain Pollution Index of the river and blood samples to evaluate the hematological profile of wader fish caught in research area. Further analysis to evaluate relationship between water quality factors and hematological profile of Wader fish was performed by using Canonical Correspondence Analysis (CCA) with the support of PAST software version 4.06. The results showed that pH, temperature, dissolved oxygen (DO), ammonia and total suspended solid (TSS) of the study area were within the normal range, while the biological oxygen demand (BOD) value was above the standard. In addition, Pollution Index of this research suggested that Brantas River condition was low polluted. Meanwhile, the analysis of hematological profile of wader fish in terms of erythrocytes and hemoglobin were below than the recommended value, leukocytes were normal, and micronuclei were above the standard.


2016 ◽  
Vol 47 (S1) ◽  
pp. 84-101 ◽  
Author(s):  
Renhua Yan ◽  
Junfeng Gao ◽  
Lingling Li

Hydrological processes in lowland polders, especially those for paddy rice planting, are affected by complicated factors. The improved Wageningen Lowland Runoff Simulator (WALRUS) model incorporates an irrigation and drainage scheme, and a new stage–discharge relationship to account for hydrological processes in multi-land-use polder with paddy fields and pumping stations. Here, this model was applied to assess how climate and land use changes affected the runoff of a Chinese polder in Poyang Lake basin in the past two decades. Simulated results showed that the runoff in the autumn–winter transition and midsummer months increased significantly, whereas those in the other months decreased slightly during the period of 1996–2005, primarily affected by climate change. For the period of 2006–2014, the runoff in the autumn–winter transition and midsummer increased, while that in the other months declined, affected by both climate and land use/cover changes. The land use/cover change resulting from the conversion of rice–wheat rotation to dominantly double-rice cropping and the expansion of residential area, increased the runoff during this period by demanding more irrigation water from the outside basin.


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