Predicting water quality by relating secchi-disk transparency and chlorophyll a measurements to Landsat satellite imagery for Michigan inland lakes, 2001-2006

Fact Sheet ◽  
2007 ◽  
Author(s):  
L.M. Fuller ◽  
R.J. Minnerick
Keyword(s):  
Water Quality ◽  
Satellite Imagery ◽  
Secchi Disk ◽  
Secchi Disk Transparency ◽  
Inland Lakes ◽  
Landsat Satellite

scholarly journals Water Quality Parameters and Bird Diversity in Jagdishpur Reservoir, Nepal

2013 ◽  
Vol 13 (1) ◽  
pp. 143-155 ◽  
Author(s):  
Jham Bahadur Thapa ◽  
Tej Bahadur Saund
Keyword(s):  
Water Quality ◽  
Species Richness ◽  
Threatened Species ◽  
Bird Species ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Total Alkalinity ◽  
Secchi Disk ◽  
Positive Correlation ◽  
Secchi Disk Transparency

Water quality parameters were analyzed seasonally to examine relationships with bird numbers and species richness in Jagdishpur reservoir. This wetland is a Ramsar site and an important bird area (IBA) of Nepal. The trophic status of the reservoir was categorized as eutrophic as assessed by Secchi disk transparency (1.45 ± 0.53 m), total alkalinity (220.94 ± 85.52 mg/l) and total nitrogen (884.19 ± 291.61 ?g/l) concentrations. Direct count method detected a total of 77 bird species belonging to 8 orders and 31 families of which 40 species were resident and 37 migrants. Species richness ranged from 21(summer) to 74 species (winter). Secchi disk transparency showed a significant positive correlation with bird numbers ((r = 1.00, p < 0.01) whereas significant negative correlation was found between water temperature and species richness (r = - 0.97, p < 0.05). Absolute positive correlation between species richness and seasons was established (r = 0.74). The seasonal distribution pattern showed two peaks of species richness, Shannon diversity, equitability and evenness index, one in winter and the other in autumn. Fulica atra (30.53%), Dendrocygna javanica (15.88%) and Anas strepera (9.58%) were the three most dominant bird species. Fourteen CITES species, 8 globally and 14 nationally threatened species were recorded. Conservation action plan for threatened species that focuses on population monitoring, protecting key habitats and habitat enhancement is urgently needed. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 143-155 DOI: http://dx.doi.org/10.3126/njst.v13i1.7453

Predicting chlorophyll-a concentrations in two temperate reservoirs with different trophic states using Principal Component Regression (PCR)

2018 ◽  
Vol 47 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kemal Çelik
Keyword(s):  
Water Quality ◽  
Linear Regression Analysis ◽  
Oxygen Demand ◽  
Principal Component Regression ◽  
Principal Component ◽  
Multiple Linear Regression Analysis ◽  
Ammonium Nitrogen ◽  
Secchi Disk ◽  
Secchi Disk Transparency ◽  
Water Quality Variables

Abstract Relationships between chlorophyll-a (chl-a) concentrations and 16 physicochemical variables in temperate eutrophic Çygören and mesotrophic Ikizcetepeler reservoirs (Turkey) were determined using Principal Component Analysis (PCA). PCA was used to simplify the complexity of relationships between water quality variables. Principal component scores (PCs) were used as independent variables in the multiple linear regression analysis (MLR) to predict chl-a in both reservoirs. This procedure is called Principal Component Regression (PCR). In the eutrophic Çygören Reservoir, chl-a was significantly (p < 0.05) correlated with nitrite-nitrogen (NO2), ammonium-nitrogen (NH4), phosphate (PO4), total suspended solids (TSS), pH, Secchi disk transparency, total dissolved solids (TDS) and total phosphorus (TP). In the mesotrophic Ikizcetepeler Reservoir, chl-a was significantly (p < 0.05) correlated with TSS, NO2, chemical oxygen demand (COD), sulfate (SO4), TDS, pH and the Secchi disk. In the eutrophic Çaygören Reservoir, six PCs explained 71% of the total variation in the water quality, while in the mesotrophic Ikizcetepeler Reservoir, six PCs explained 75% of the variation. This study has shown that PCR is a more robust tool than direct MLR to simplify the relationships between water quality variables and to predict chl-a concentrations in temperate reservoirs with different trophic states.

scholarly journals Mapping and Monitoring Erosion-Accretion in an Alluvial River Using Satellite Imagery – The River Bank Changes of the Padma River in Bangladesh

2018 ◽  
Vol 37 (3) ◽  
pp. 87-95 ◽  
Author(s):  
Mohammad Maruf Billah
Keyword(s):  
Satellite Imagery ◽  
Bank Erosion ◽  
River Bank ◽  
River Bank Erosion ◽  
Island Area ◽  
River Bed ◽  
Drastic Increase ◽  
Padma River ◽  
Landsat Satellite ◽  
The Right

Abstract The Padma river is widely known for its dynamic and disastrous behaviour, and the river has been experiencing intense and frequent bank erosion and deposition leading to the changes and shifting of bank line. In this paper, a time series of Landsat satellite imagery MSS, TM and OLI and TIRS images and are used to detect river bank erosion-accretion and bank line shifting during the study period 1975–2015. This study exhibits a drastic increase of erosion and accretion of land along the Padma river. The results show that from 1975 to 2015, the total amount of river bank erosion is 49,951 ha of land, at a rate of 1,249 ha a−1 and the total amount of accretion is 83,333 ha of land, at a rate of 2,083 ha a−1. Throughout the monitoring period, erosion-accretion was more pronounced in the right part of the river and bank line had been shifting towards the southern direction. The paper also reveals that the total area of islands had been increased significantly, in 2015 there was about 50,967 ha of island area increased from 20,533 ha of island area in 1975, and the results evidence consistency of sedimentation in the river bed.

scholarly journals Monitoring scrub weed change in the Canterbury region using satellite imagery

2007 ◽  
Vol 60 ◽  
pp. 137-140 ◽  
Author(s):  
J.D. Shepherd ◽  
J.R. Dymond ◽  
J.R.I. Cuff
Keyword(s):  
Satellite Imagery ◽  
Vegetation Cover ◽  
Satellite Image ◽  
Visual Assessment ◽  
Woody Vegetation ◽  
Spatial Change ◽  
Valid Data ◽  
Woody Cover ◽  
Landsat Satellite ◽  
Thematic Data

The spatial change of woody vegetation in the Canterbury region was automatically mapped between 1990 and 2001 using Landsat satellite image mosaics The intersection of valid data from these mosaics gave coverage of 84 of the Canterbury region Changes in woody cover greater than 5 ha were identified Of the 5 ha areas of woody change only those that were likely to have been a scrub change were selected using ancillary thematic data for current vegetation cover (eg afforestation and deforestation were excluded) This resulted in 2466 polygons of potential scrub change These polygons were rapidly checked by visual assessment of the satellite imagery and assigned to exotic or indigenous scrub change categories Between 1990 and 2001 the total scrub weed area in the Canterbury region increased by 3600 400 ha and indigenous scrub increased by 2300 400 ha

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