scholarly journals Continuous Monitoring of the Spatio-Temporal Patterns of Surface Water in Response to Land Use and Land Cover Types in a Mediterranean Lagoon Complex

2019 ◽  
Vol 11 (12) ◽  
pp. 1425 ◽  
Author(s):  
Zhichao Li ◽  
Yujie Feng ◽  
Nadine Dessay ◽  
Eric Delaitre ◽  
Helen Gurgel ◽  
...  
Keyword(s):  
Surface Water ◽  
Human Activities ◽  
Coastal Wetlands ◽  
Annual Variation ◽  
Coastal Lagoons ◽  
Sand Beach ◽  
Mediterranean Lagoon ◽  
Potential Link ◽  
Spatio Temporal ◽  
The Impact

Mediterranean coastal lagoons and their peripheral areas often provide a collection of habitats for many species, and they often face significant threats from anthropogenic activities. Diverse human activities in such areas directly affect the spatio-temporal dynamic of surface water and its ecological characteristics. Monitoring the surface water dynamic, and understanding the impact of human activities are of great significance for coastal lagoon conservation. The Regional Natural Park of Narbonne includes a typical Mediterranean lagoon complex where surface water dynamic and its potential link with local diverse human activities has not yet been studied. In this context, based on all the available Landsat images covering the study area during 2002–2016, this study identified the water and non-water classes for each satellite observation by comparing three widely used spectral indices (i.e., NDVI, NDWI and MNDWI) and using the Otsu method. The yearly water frequency index was then computed to present the spatio-temporal dynamic of surface water for each year, and three water dynamic scenarios were also identified for each year: permanent water (PW), non-permanent water (NPW) and non-water (NW). The spatial and inter-annual variation in the patterns of the three water scenarios were characterized by computing the landscape metrics at scenario-level quantifying area/edge, shape, aggregation and fragmentation. Finally, the quantitative link between different land use and land cover (LULC) types derived from the LULC maps of 2003, 2012 and 2015 and the surface water dynamic scenarios was established in each of the 300 m × 300 m grid cells covering the study area to determine the potential impact of human activities on the surface water dynamic. In terms of the inter-annual variation during 2002–2016, PW presented an overall stability, and NPW occupied only a small part of the water surface in each year and presented an inter-annual fluctuation. NPW had a smaller patch size, with lower connectivity degree and higher fragmentation degree. In terms of spatial variation during 2002–2016, NPW often occurred around PW, and its configurational features varied from place to place. Moreover, PW mostly corresponded to the natural lagoon, and salt marsh (as a part of lagoons), and NPW had a strong link with arable land (agricultural irrigation) and salt marsh (salt production), sand beach/dune, coastal wetlands and lagoon for the LULC maps of 2003, 2012 and 2015. However, more in-depth analysis is required for understanding the impact of sand beach/dune, coastal wetlands and lagoon on surface water dynamics. This study covers the long-term variations of surface water patterns in a Mediterranean lagoon complex having intense and diverse human activities, and the potential link between LULC types and the water dynamic scenarios was investigated on different dates. The results of the study should be useful for environmental management and protection of coastal lagoons.

scholarly journals Continuous Monitoring of the Spatio-Temporal Patterns of Surface Water in Response to Land Use and Land Cover Types in a Mediterranean Lagoon Complex

2019 ◽  
Author(s):  
Zhichao Li ◽  
Yujie Feng ◽  
Nadine Dessay ◽  
Eric Delaitre ◽  
Helen Gurgel ◽  
...  
Keyword(s):  
Surface Water ◽  
Human Activities ◽  
Coastal Wetlands ◽  
Annual Variation ◽  
Coastal Lagoons ◽  
Sand Beach ◽  
Mediterranean Lagoon ◽  
Potential Link ◽  
Spatio Temporal ◽  
The Impact

Mediterranean coastal lagoons and their peripheral areas often provide a collection of habitats for many species, and they often face significant threats from anthropogenic activities. Diverse human activities in such areas directly affect the spatio-temporal dynamic of surface water and its ecological characteristics. Monitoring the surface water dynamic, and understanding the impact of human activities are of great significance for coastal lagoon conservation. The Regional Natural Park of Narbonne includes a typical Mediterranean lagoon complex where surface water dynamic and its potential link with local diverse human activities has not yet been studied. In this context, based on all the available Landsat images covering the study area during 2002-2016, this study identified the water and non-water classes for each satellite observation by comparing three widely used water indices (i.e., NDVI, NDWI and MNDWI) and using the Otsu method. The yearly water frequency index was then computed to present the spatio-temporal dynamic of surface water for each year, and three water dynamic scenarios were also identified for each year: permanent water (PW), non-permanent water (NPW) and non-water (NW). The spatial and inter-annual variation in the patterns of the three water scenarios were characterized by computing the landscape metrics at scenario-level quantifying area/edge, shape, aggregation and fragmentation. Finally, the quantitative link between different land use and land cover (LULC) types derived from the LULC maps of 2003, 2012 and 2015 and the surface water dynamic scenarios was established in each of the 300 m x 300 m grid cells covering the study area to determine the potential impact of human activities on the surface water dynamic. In terms of the inter-annual variation during 2002-2016, PW presented an overall stability, and NPW occupied only a small part of the water surface in each year and presented an inter-annual fluctuation. NPW had a smaller patch size, with lower connectivity degree and higher fragmentation degree. In terms of spatial variation during 2002-2016, NPW often occurred around PW, and its configurational features varied from place to place. Moreover, PW mostly corresponded to natural lagoon, and salt marsh (as a part of lagoons), and NPW had a strong link with arable land (agricultural irrigation) and salt marsh (salt production), sand beach/dune, coastal wetlands and lagoon for the LULC maps of 2003, 2012 and 2015. However, more in-depth analysis is required for understanding the impact of sand beach/dune, coastal wetlands and lagoon on surface water dynamics. This study covers the long-term variations of surface water patterns in a Mediterranean lagoon complex having intense and diverse human activities, and the potential link between LULC types and the water dynamic scenarios was investigated on different dates. The results of the study should be useful for environmental management and protection of coastal lagoons.

scholarly journals Spatio-temporal changes in evapotranspiration over China using GLEAM_V3.0a products (1980–2014)

2018 ◽  
Vol 49 (5) ◽  
pp. 1330-1348 ◽  
Author(s):  
Xiuqin Yang ◽  
Bin Yong ◽  
Yixing Yin ◽  
Yuqing Zhang
Keyword(s):  
River Basin ◽  
Spatial Patterns ◽  
Seasonal Variations ◽  
Annual Variation ◽  
Southern China ◽  
Global Land ◽  
Southwest Region ◽  
The Mean ◽  
Spatio Temporal ◽  
The Impact

Abstract This study used land evapotranspiration (ET) values from 61 ChinaFLUX eddy covariance (EC) sites and water-balanced derived ET in ten basins to investigate the performance of Global Land Evaporation Amsterdam Model (GLEAM) V3.0a ET estimates (i.e., ETG) over China. We quantified the spatio-temporal characteristics of ETG and the impact of precipitation (P) and potential ET (ETP) on ETG. ETG was appropriate for estimating daily, seasonal, and annual ET rates. The mean annual ETG increased progressively from the northwest to southeast of China. Domain-averaged annual ETG over China was 421.90 mm year−1 during 1980 to 2014. The spatial patterns of ETG were in accordance with those of annual precipitation. Low ETG values occurred in the Northwest River Basin, and relatively high ET values were found across southern China. ETG showed the highest annual variation in the Northwest River Basin and low variation in the southwest region, which captured seasonal variations with maxima in summer and minima in winter. The inter-annual variation of annual ETG and ETP differed significantly from 1980 to 2014, yielding prominent spatial variability around −16.50 to 9.10 mm year−2 and −1.90 to 4.70 mm year−2, respectively. Annual ETG is correlated well with P and ETP at each site.

scholarly journals EVALUATION OF THE HEAVY METALS CONTAMINATION OF THE WATER OF THE MOULOUYA MEDIUM

2021 ◽  
Vol XLVI-4/W5-2021 ◽  
pp. 193-196
Author(s):  
H. Ech-Chafay ◽  
M. Najy ◽  
A. El Ghazouany ◽  
O. Akkaoui ◽  
M. Lachhab ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Surface Water ◽  
Surface Waters ◽  
Concentration Gradient ◽  
Human Activities ◽  
Anthropogenic Impact ◽  
Heavy Metals Contamination ◽  
The Impact ◽  
Metallic Pollution

Abstract. This work is part of a program to study and monitor the impact of human activities in the cities of Missour and Outat El Haj on the quality of the surface waters of the average Moulouya (Morocco).The aim of this study is to evaluate in time and space, the degree of metallic pollution of surface water of the average Moulouya during the period (September 2014, January, April and July 2015). The results of this study suggest that the waters of the ten stations in the study area are relatively contaminated with heavy metals. The contents of the analyzed metals are high and variable in the wastewater of the cities of Missour and Outat El Haj and in the waters of the Moulouya average.The anthropogenic impact on the ecosystems selected for this work is highlighted by: the high metallic contamination of the water of the stations located downstream of wastewater discharges of the cities of Missour and Outat El Haj, and the variation of the contents according to an increasing concentration gradient from station M1 to M9.

scholarly journals Swath altimetry measurements of the mainstem Amazon River: measurement errors and hydraulic implications

2014 ◽  
Vol 11 (8) ◽  
pp. 9399-9434
Author(s):  
M. D. Wilson ◽  
M. Durand ◽  
H. C. Jung ◽  
D. Alsdorf
Keyword(s):  
Surface Water ◽  
Measurement Errors ◽  
Water Surface ◽  
Hydraulic Model ◽  
Two Dimensions ◽  
Temporal Sampling ◽  
Dimensional Measurements ◽  
Spatio Temporal ◽  
Ocean Topography ◽  
The Impact

Abstract. The Surface Water and Ocean Topography (SWOT) mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water surface elevations. In this paper, we aimed to (i) characterize and illustrate in two-dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii) simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii) assess the impact of each of these on estimates of water surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a "virtual mission" for a 300 km reach of the central Amazon (Solimões) River at its confluence with the Purus River, using a hydraulic model to provide water surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimension height error spectrum derived from the SWOT design requirements. We thereby obtained water surface elevation measurements for the Amazon mainstem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths of greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-section averaging and 20 km reach lengths, results show Nash–Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1% average overall error in discharge, respectively.

The landscape pattern characteristics of coastal wetlands in Jiaozhou Bay Under The Impact Of Human Activities

2006 ◽  
Vol 124 (1-3) ◽  
pp. 361-370 ◽  
Author(s):  
Dongqi Gu ◽  
Yuanzhi Zhang ◽  
Jun Fu ◽  
Xuliang Zhang
Keyword(s):  
Landscape Pattern ◽  
Human Activities ◽  
Coastal Wetlands ◽  
Jiaozhou Bay ◽  
The Impact

scholarly journals MONITORING THE SPATIO-TEMPORAL TRAJECTORY OF URBAN AREA HOTSPOTS IN WUHAN, CHINA USING TIME-SERIES NIGHTTIME LIGHT IMAGES

2019 ◽  
Vol XLII-4/W20 ◽  
pp. 71-76
Author(s):  
Y. L. Ruan ◽  
Y. H. Zou
Keyword(s):  
Urban Area ◽  
Human Activities ◽  
Urban Expansion ◽  
Data Sets ◽  
Threshold Method ◽  
Expansion Pattern ◽  
Nighttime Light ◽  
Spatio Temporal ◽  
Urban Extent ◽  
The Impact

Abstract. Urban area hotspots can be considered as an ideal representation of spatial heterogeneity of human activities within a city, which is susceptible to regional urban expansion pattern pattern. However, in previous studies most researchers focused on extracting urban extent, leaving the interior variation of nighttime radiance intensity poorly explored. With the help of multi-source data sets such as DMSP/OLS (NTL), LST and NDVI, we proposed an applicable framework to identify and monitor the spatiotemporal trajectory of polycentric urban area hotspots. Firstly, the original NTL dataset were calibrated to reduce inconsistency and discontinuity. And we integrated NTL, LST as well as NDVI and established an urban index TVANUI capturing the approximate urban extents. Secondly, multi-resolution segmentation algorithm, neighborhood statistics analysis and a local-optimized threshold method were employed to get more precise urban extent with an overall accuracy above 85% and a Kappa above 0.70. Thirdly, the urban extents were utilized as masks to get corresponding radiance intensity from calibrated NTL. Finally, we established the Gaussian volume model for each cluster and the resulting parameters were used to quantitatively depict hotspot features (i.e., intensity, morphology and centroid dynamics). All the identified urban hotspot showed our framework could successfully capture polycentric urban hotspots, whose fitting coefficients were over 0.7. The spatiotemporal trajectory of hotspot powerfully revealed the impact of the regional urban growth pattern and planning strategies on human activities in the city of Wuhan. This study provides important insights for further studies on the relationship between the regional urbanization and human activities.

scholarly journals Swath-altimetry measurements of the main stem Amazon River: measurement errors and hydraulic implications

2015 ◽  
Vol 19 (4) ◽  
pp. 1943-1959 ◽  
Author(s):  
M. D. Wilson ◽  
M. Durand ◽  
H. C. Jung ◽  
D. Alsdorf
Keyword(s):  
Surface Water ◽  
Water Surface ◽  
Hydraulic Model ◽  
Two Dimensions ◽  
Main Stem ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Temporal Sampling ◽  
Spatio Temporal ◽  
The Impact

Abstract. The Surface Water and Ocean Topography (SWOT) mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface-water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water-surface elevations. In this paper, we aimed to (i) characterise and illustrate in two dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii) simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii) assess the impact of each of these on estimates of water-surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a virtual mission for a ~260 km reach of the central Amazon (Solimões) River, using a hydraulic model to provide water-surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimensional height error spectrum derived from the SWOT design requirements. We thereby obtained water-surface elevation measurements for the Amazon main stem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-sectional averaging and 20 km reach lengths, results show Nash–Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1 % average overall error in discharge, respectively. We extend the results to other rivers worldwide and infer that SWOT-derived discharge estimates may be more accurate for rivers with larger channel widths (permitting a greater level of cross-sectional averaging and the use of shorter reach lengths) and higher water-surface slopes (reducing the proportional impact of slope errors on discharge calculation).

ASSESSING THE IMPACT OF GROUNDWATER CONTAMINATION ON STREAM WATER QUALITY BY MULTIPLE APPROACHES AT THE GROUNDWATER-SURFACE WATER INTERFACE

2017 ◽  
Author(s):  
Poul L. Bjerg ◽  
◽  
Vinni Rønde ◽  
Nicola Balbarini ◽  
Anne Th. Sonne ◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Groundwater Contamination ◽  
Stream Water ◽  
Water Interface ◽  
Stream Water Quality ◽  
The Impact

The impact of the Russian oil industry on surface water quality (a case study of the Agan River catchment, West Siberia)

2020 ◽  
Vol 79 (14) ◽  
Author(s):  
Dmitriy V. Moskovchenko ◽  
Aleksey G. Babushkin ◽  
Andrey A. Yurtaev
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Surface Water Quality ◽  
Oil Industry ◽  
West Siberia ◽  
River Catchment ◽  
The Impact
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