Long-term and High Temporal Resolution In-situ Monitoring of Potassium, Sodium, and Chloride in a Small Forested Catchment Using Flow Injection Potentiometry

Abstract. Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyse the evolution of the gully network with a high temporal resolution. This study aims at analysing gully morphodynamics over a long timescale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and their contribution to overall sediment dynamics. A gully network of 20 km2 located in southwestern Spain has been analysed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, a minimum of 1.37 km km−2 in 1980, and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall. Land use changes were found to have only a secondary effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956 and 2009, with a mean value of 11.2 t ha−1 yr−1. In the period 2009–2011, characterized by severe winter rainfalls, this value increased significantly to 591 t ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the starting and ending dates greatly underestimates gully contribution during certain years, such as, for example, between 2009 and 2011. This illustrates the importance of the methodology applied using a high temporal resolution of orthophotos.

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High temporal resolution field monitoring of phosphate in the River Frome using flow injection with diode array detection

Analytica Chimica Acta ◽

10.1016/s0003-2670(00)01395-7 ◽

2001 ◽

Vol 440 (1) ◽

pp. 55-62 ◽

Cited By ~ 27

Author(s):

Grady Hanrahan ◽

Martha Gledhill ◽

Philip J Fletcher ◽

Paul J Worsfold

Keyword(s):

Temporal Resolution ◽

Flow Injection ◽

Field Monitoring ◽

High Temporal Resolution ◽

Diode Array ◽

Diode Array Detection ◽

Array Detection

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Long-term in situ monitoring at Dashgil mud volcano, Azerbaijan: a link between seismicity, pore-pressure transients and methane emission

International Journal of Earth Sciences ◽

10.1007/s00531-009-0487-4 ◽

2009 ◽

Vol 99 (S1) ◽

pp. 227-240 ◽

Cited By ~ 18

Author(s):

Achim Kopf ◽

Georg Delisle ◽

Eckhard Faber ◽

Behrouz Panahi ◽

Chingiz S. Aliyev ◽

...

Keyword(s):

Pore Pressure ◽

Methane Emission ◽

In Situ Monitoring ◽

Mud Volcano ◽

Pressure Transients

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Remote sensing of cyanobacterial blooms in Lake Champlain, USA

Water Science & Technology Water Supply ◽

10.2166/ws.2013.114 ◽

2013 ◽

Vol 13 (5) ◽

pp. 1402-1409

Author(s):

Adam Trescott ◽

Elizabeth Isenstein ◽

Mi-Hyun Park

Keyword(s):

Remote Sensing ◽

Satellite Images ◽

Monitoring Program ◽

In Situ Monitoring ◽

Cyanobacterial Blooms ◽

Lake Champlain ◽

Initiation And Propagation ◽

Landsat 7

The objective of this study was to develop cyanobacteria remote sensing models using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) as an alternative to shipboard monitoring efforts in Lake Champlain. The approach allowed for estimation of cyanobacteria directly from satellite images, calibrated and validated with 4 years of in situ monitoring data from Lake Champlain's Long-Term Water Quality and Biological Monitoring Program (LTMP). The resulting stepwise regression model was applied to entire satellite images to provide distribution of cyanobacteria throughout the surface waters of Lake Champlain. The results demonstrate the utility of remote sensing for estimating the distribution of cyanobacteria in inland waters, which can be further used for presenting the initiation and propagation of cyanobacterial blooms in Lake Champlain.

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Diurnal aerosol variations do affect daily averaged radiative forcing under heavy aerosol loading observed in Hefei, China

Atmospheric Measurement Techniques ◽

10.5194/amt-8-2901-2015 ◽

2015 ◽

Vol 8 (7) ◽

pp. 2901-2907 ◽

Cited By ~ 12

Author(s):

Z. Wang ◽

D. Liu ◽

Y. Wang ◽

Z. Wang ◽

G. Shi

Keyword(s):

Temporal Resolution ◽

Radiative Forcing ◽

Single Scattering ◽

High Temporal Resolution ◽

Diurnal Changes ◽

Data Set ◽

Time Resolved ◽

Aerosol Radiative Forcing ◽

Aerosol Loading

Abstract. A strong diurnal variation of aerosol has been observed in many heavily polluted regions in China. This variation could affect the direct aerosol radiative forcing (DARF) evaluation if the daily averaged value is used as normal rather than the time-resolved values. To quantify the effect of using the daily averaged DARF, 196 days of high temporal resolution ground-based data collected in SKYNET Hefei site during the period from 2007 to 2013 is used to perform an assessment. We demonstrate that strong diurnal changes of heavy aerosol loading have an impact on the 24-h averaged DARF when daily averaged optical properties are used to retrieve this quantity. The DARF errors varying from −7.6 to 15.6 W m−2 absolutely and from 0.1 to 28.5 % relatively were found between the calculations using daily average aerosol properties, and those using time-resolved aerosol observations. These errors increase with increasing daily aerosol optical depth (AOD) and decreasing daily single-scattering albedo (SSA), indicating that the high temporal resolution DARF data set should be used in the model instead of the normal daily-averaged one, especially under heavy aerosol loading conditions for regional campaign studies. We also found that statistical errors (0.3 W m−2 absolutely and 11.8 % relatively) will be less, which means that the effect of using the daily averaged DARF can be weakened by using a long-term observational data set.

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In-situ measurements of the ice flow motion at Eqip Sermia Glacier using a remotely controlled UAV

10.5194/gi-2019-6 ◽

2019 ◽

Cited By ~ 1

Author(s):

Guillaume Jouvet ◽

Eef van Dongen ◽

Martin P. Lüthi ◽

Andreas Vieli

Keyword(s):

Remote Sensing ◽

Template Matching ◽

In Situ Measurements ◽

In Situ Monitoring ◽

High Temporal Resolution ◽

Ice Flow ◽

Flow Motion ◽

Remote Sensing Techniques ◽

Matching Techniques

Abstract. Measuring the ice flow motion accurately is essential to better understand the time evolution of glaciers and ice sheets, and therefore to better anticipate the future consequence of climate change in terms of sea-level rise. Although there exist a variety of remote sensing methods to fill this task, in-situ measurements are always needed for validation or to capture high temporal resolution movements. Yet glaciers are in general hostile environments where the installation of instruments might be tedious and risky when not impossible. Here we report the first-ever in-situ measurements of ice flow motion using a remotely controlled Unmanned Aerial Vehicle (UAV). We used a multicopter UAV to land on a highly crevassed area of Eqip Sermia Glacier, West Greenland, to measure the displacement of the glacial surface with the aid of an on-board differential GNSS receiver. Despite the unfortunate loss of the UAV, we measured approximately 70 cm of displacement over 4.36 hours without setting foot onto the glacier – a result validated by applying UAV photogrammetry and template matching techniques. Our study demonstrates that UAVs are promising instruments for in-situ monitoring, and have a great potential for capturing short-term ice flow variations in inaccessible glaciers – a task that remote sensing techniques can hardly achieve.

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