scholarly journals Riparian-Buffer Loss and Pesticide Incidence in Freshwater Matrices of Ikpoba River (Nigeria): Policy Recommendations for the Protection of Tropical River Basins

2021 ◽  
Author(s):  
Azubuike Victor Chukwuka ◽  
Ozekeke Ogbeide
Keyword(s):  
Surface Water ◽  
Vegetation Index ◽  
Principal Component ◽  
River Basins ◽  
Riparian Buffer ◽  
Fish Populations ◽  
Benthic Fish ◽  
Regulatory Guidance ◽  
Buffer Width

The unregulated use of watersheds for agriculture negatively impacts the quality of river basins. In particular, the reduced quality of surface-waters, have been attributed to absence or poorly-decided riparian-buffer specifications in environmental laws. To demonstrate suitable buffer-width for protection of surface water, sediment and benthic fish populations, five riparian areas with different vegetation richness and buffer-width were selected within an organochlorine pesticide (OCP)-impacted watershed using the Normalized Differential Vegetation Index (NDVI) and multiple buffer analysis respectively. Mean OCP levels in surface water, sediment and fish sampled at each riparian stations showed site-specific differences with markedly higher levels of α-BHC, β-BHC, δ-BHC, p,p′-DDD and total pesticide residues at stations with least riparian cover. The principal component analysis further revealed more OCPs associating with sediment and fish from stations having smaller buffer-width and sparse riparian vegetation. Stations with wider buffer-width of at least 120 m provided greater protection to adjacent surface water and benthic fish populations. While this study recommends riparian buffer-widths for a typical tropical environment, further research which assesses other contaminant types in aquatic matrices adjacent to different riparian environments would be valuable and informative for regulatory guidance and strategic protection of ecosystem services.

scholarly journals CONSTRUCTION AND APPLICATION OF ENHANCED REMOTE SENSING ECOLOGICAL INDEX

2018 ◽  
Vol XLII-3 ◽  
pp. 1809-1813
Author(s):  
X. Wang ◽  
C. Liu ◽  
Q. Fu ◽  
B. Yin
Keyword(s):  
Remote Sensing ◽  
Natural Disasters ◽  
Vegetation Index ◽  
Principal Component ◽  
Hainan Island ◽  
Weight Coefficient ◽  
Ecological Environment ◽  
Ecological Index ◽  
Environment Quality

In order to monitor the change of regional ecological environment quality, this paper use MODIS and DMSP / OLS remote sensing data, from the production capacity, external disturbance changes and human socio-economic development of the three main factors affecting the quality of ecosystems, select the net primary productivity, vegetation index and light index, using the principal component analysis method to automatically determine the weight coefficient, construction of the formation of enhanced remote sensing ecological index, and the ecological environment quality of Hainan Island from 2001 to 2013 was monitored and analyzed. The enhanced remote sensing ecological index combines the effects of the natural environment and human activities on ecosystems, and according to the contribution of each principal component automatically determine the weight coefficient, avoid the design of the weight of the parameters caused by the calculation of the human error, which provides a new method for the operational operation of regional macro ecological environment quality monitoring. During the period from 2001 to 2013, the ecological environment quality of Hainan Island showed the characteristics of decend first and then rise, the ecological environment in 2005 was affected by severe natural disasters, and the quality of ecological environment dropped sharply. Compared with 2001, in 2013 about 20000 square kilometers regional ecological environmental quality has improved, about 8760 square kilometers regional ecological environment quality is relatively stable, about 5272 square kilometers regional ecological environment quality has decreased. On the whole, the quality of ecological environment in the study area is good, the frequent occurrence of natural disasters, on the quality of the ecological environment to a certain extent.

scholarly journals Analisis Komparasi Metode Pemetaan Ekosistem Mangrove Menggunakan Penginderaan Jauh dan Sistem Informasi Geografis

2020 ◽  
Vol 17 (2) ◽  
pp. 49-55
Author(s):  
Isma Yulia Rahma
Keyword(s):  
Forest Canopy ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Principal Component ◽  
Mangrove Ecosystem ◽  
Forest Canopy Density ◽  
Distribution Mapping ◽  
Information System Technology ◽  
The Right

The use of tools and methods in mapping mangrove ecosystem continues to change.Nowday's trend in mapping is to use remote sensing and digital geographic Information system technology. There are several commonly used methods for mapping the mangrove ecosystem, but we should be aware that choosing the right method of analysis will greatly support the quality of research. The research method is literature review from various books and accredited scientific journals. Subsequently conducted analysis of application methods of mapping mangrove ecosystem of various case studies and research needs. Based on research, there are five methods and analysis used i.e.manual interpretation with Mirror stereoscope, NDVI (Normalized Difference Vegetation Index) as the most common analysis for mangrove distribution mapping. Multivariat PCA (Principal Component Analysis), FCD (Forest Canopy Density) model, and copmpare methods to mapping the extensive changes of mangrove ecosystems. Therefore, this article can be an input for the prospective mangrove ecosystem researchers in determining the preciese method of analysis.  

scholarly journals Using Principal Components Analysis and IDW Interpolation to Determine Spatial and Temporal Changes of Surface Water Quality of Xin’anjiang River in Huangshan, China

2020 ◽  
Vol 17 (8) ◽  
pp. 2942 ◽  
Author(s):  
Wenjie Yang ◽  
Yue Zhao ◽  
Dong Wang ◽  
Huihui Wu ◽  
Aijun Lin ◽  
...  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Surface Water ◽  
Safety Management ◽  
Temporal Distribution ◽  
Surface Water Quality ◽  
Principal Component ◽  
Organic Pollution ◽  
Sampling Point

This study was aimed at assessing the spatial and temporal distribution of surface water quality variables of the Xin’anjiang River (Huangshan). For this purpose, 960 water samples were collected monthly along the Xin’anjiang River from 2008 to 2017. Twenty-four water quality indicators, according to the environmental quality standards for surface water (GB 3838-2002), were detected to evaluate the water quality of the Xin’anjiang River over the past 10 years. Principal component analysis (PCA) was used to comprehensively evaluate the water quality across eight monitoring stations and analyze the sources of water pollution. The results showed that all samples could be analyzed by three main components, which accounted for 87.24% of the total variance. PCA technology identified important water quality parameters and revealed that nutrient pollution and organic pollution are major latent factors which influence the water quality of Xin’anjiang River. It also showed that agricultural activities, erosion, domestic, and industrial discharges are fundamental causes of water pollution in the study area. It is of great significance for water quality safety management and pollution control of the Xin’anjiang River. Meanwhile, the inverse distance weighted (IDW) method was used to interpolate the PCA comprehensive score. Based on this, the temporal and spatial structure and changing characteristics of water quality in the Xin’anjiang River were analyzed. We found that the overall water quality of Xin’anjiang River (Huangshan) was stable from 2008 to 2017, but the pollution of the Pukou sampling point was of great concern. The results of IDW helped us to identify key areas requiring control in the Xin’anjiang River, which pointed the way for further delicacy management of the river. This study proved that the combination of PCA and IDW interpolation is an effective tool for determining surface water quality. It was of great significance for the control of water pollution in Xin’anjiang River and the reduction of eutrophication pressure in Thousand Island Lake.

Environmental Water Stress in Transboundary River Basins

2017 ◽  
Author(s):  
Tales Carvalho-Resende
Keyword(s):  
Water Stress ◽  
Surface Water ◽  
Environmental Water ◽  
River Basins ◽  
Water Quantity ◽  
Natural Flow Regime ◽  
Transboundary River ◽  
Transboundary River Basins ◽  
Natural Flow ◽  
Water Uses

The Environmental Water Stress in Transboundary River Basins indicator focuses on the water quantity aspect and considers hydrological alterations from monthly dynamics of the natural flow regime due to anthropogenic water uses and dam operations. For more information, visit: http://twap-rivers.org/ Basin Stress Surface water Transboundary

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