scholarly journals An Integrated Hydrological-Hydraulic Model for Simulating Surface Water Flows of a Shallow Lake Surrounded by Large Floodplains

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1213 ◽  
Author(s):  
Tomohiro Tanaka ◽  
Hidekazu Yoshioka ◽  
Sokly Siev ◽  
Hideto Fujii ◽  
Yoichi Fujihara ◽  
...  
Keyword(s):  
Surface Water ◽  
Remote Sensing Data ◽  
Hydraulic Model ◽  
Water Dynamics ◽  
Roughness Coefficient ◽  
Time Step ◽  
Data Set ◽  
Water Flows ◽  
Tonle Sap ◽  
Numerical Stability Analysis

An integrated hydrological-hydraulic model employing the 2-D local inertial equation as the core is established for effective numerical simulation of surface water flows in a great lake and its floodplain. The model is a cascade of validated hydrological and hydraulic sub-models. The model was applied to simulating the surface water flows of the Tonle Sap Lake and its floodplain in Cambodia using the roughness coefficient value calibrated comparing with a remote-sensing data set. The resulting model reasonably handles backwater flows during the rainy season and simulates the propagations of wet and dry interfaces without numerical instability, owing to a proper setting of time step supported by a novel numerical stability analysis. Sensitivity analysis of the surface water dynamics focusing on the setting of roughness coefficient and the backwater effect was also carried out. Overall, utilizing the 2-D local inertial equation in the assessment of lake water dynamics is a new modelling approach, which turns out to be an efficient simulation tool.

scholarly journals Monitoring monthly surface water dynamics of Dongting Lake using Sentinal-1 data at 10 m

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4992 ◽  
Author(s):  
Liwei Xing ◽  
Xinming Tang ◽  
Huabin Wang ◽  
Wenfeng Fan ◽  
Guanghui Wang
Keyword(s):  
Surface Water ◽  
Water Distribution ◽  
Remote Sensing Data ◽  
Water Area ◽  
Dongting Lake ◽  
Water Dynamics ◽  
High Temporal Resolution ◽  
Backscattering Coefficient ◽  
Distribution Maps ◽  
Lower Accuracy

High temporal resolution water distribution maps are essential for surface water monitoring because surface water exhibits significant inner-annual variation. Therefore, high-frequency remote sensing data are needed for surface water mapping. Dongting Lake, the second-largest freshwater lake in China, is famous for the seasonal fluctuations of its inundation extents in the middle reaches of the Yangtze River. It is also greatly affected by the Three Gorges Project. In this study, we used Sentinel-1 data to generate surface water maps of Dongting Lake at 10 m resolution. First, we generated the Sentinal-1 time series backscattering coefficient for VH and VV polarizations at 10 m resolution by using a monthly composition method. Second, we generated the thresholds for mapping surface water at 10 m resolution with monthly frequencies using Sentinel-1 data. Then, we derived the monthly surface water distribution product of Dongting Lake in 2016, and finally, we analyzed the inner-annual surface water dynamics. The results showed that: (1) The thresholds were −21.56 and −15.82 dB for the backscattering coefficients for VH and VV, respectively, and the overall accuracy and Kappa coefficients were above 95.50% and 0.90, respectively, for the VH backscattering coefficient, and above 94.50% and 0.88, respectively, for the VV backscattering coefficient. The VV backscattering coefficient achieved lower accuracy due to the effect of the wind causing roughness on the surface of the water. (2) The maximum and minimum areas of surface water were 2040.33 km2in July, and 738.89 km2in December. The surface water area of Dongting Lake varied most significantly in April and August. The permanent water acreage in 2016 was 556.35 km2, accounting for 19.65% of the total area of Dongting Lake, and the acreage of seasonal water was 1525.21 km2. This study proposed a method to automatically generate monthly surface water at 10 m resolution, which may contribute to monitoring surface water in a timely manner.

scholarly journals Development and Evaluation of a Multi-Year Fractional Surface Water Data Set Derived from Active/Passive Microwave Remote Sensing Data

2015 ◽  
Vol 7 (12) ◽  
pp. 16688-16732 ◽  
Author(s):  
Ronny Schroeder ◽  
Kyle McDonald ◽  
Bruce Chapman ◽  
Katherine Jensen ◽  
Erika Podest ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Remote Sensing Data ◽  
Microwave Remote Sensing ◽  
Passive Microwave ◽  
Data Set ◽  
Passive Microwave Remote Sensing ◽  
Sensing Data ◽  
Fractional Surface

scholarly journals Evaluation of surface water dynamics for water-food security in seasonal wetlands, north-central Namibia

2014 ◽  
Vol 364 ◽  
pp. 380-385 ◽  
Author(s):  
T. Hiyama ◽  
T. Suzuki ◽  
M. Hanamura ◽  
H. Mizuochi ◽  
J. R. Kambatuku ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Food Security ◽  
Surface Water ◽  
Satellite Remote Sensing ◽  
Cropping Systems ◽  
Remote Sensing Data ◽  
Water Dynamics ◽  
Mixed Cropping ◽  
North Central ◽  
Seasonal Wetlands

Abstract. Agricultural use of wetlands is important for food security in various regions. However, land-use changes in wetland areas could alter the water cycle and the ecosystem. To conserve the water environments of wetlands, care is needed when introducing new cropping systems. This study is the first attempt to evaluate the water dynamics in the case of the introduction of rice-millet mixed-cropping systems to the Cuvelai system seasonal wetlands (CSSWs) in north-central Namibia. We first investigated seasonal changes in surface water coverage by using satellite remote sensing data. We also assessed the effect of the introduction of rice-millet mixed-cropping systems on evapotranspiration in the CSSWs region. For the former investigation, we used MODIS and AMSR-E satellite remote sensing data. These data showed that at the beginning of the wet season, surface water appears from the southern (lower) part and then expands to the northern (higher) part of the CSSWs. For the latter investigation, we used data obtained by the classical Bowen ratio-energy balance (BREB) method at an experimental field site established in September 2012 on the Ogongo campus, University of Namibia. This analysis showed the importance of water and vegetation conditions when introducing mixed-cropping to the region.

A NEW TECHNIQUE ESTIMATING LOCATION OF MEAN JOINT CENTERS OF ROTATION WITH ASSOCIATED DISPERSIONS AND ASSESSING TO FUNCTIONAL COORDINATE SYSTEM OF MOVING LIMB SEGMENTS

2006 ◽  
Vol 06 (04) ◽  
pp. 373-384
Author(s):  
ERIC BERTHONNAUD ◽  
JOANNÈS DIMNET
Keyword(s):  
Numerical Technique ◽  
New Technique ◽  
Helical Axis ◽  
Joint Movement ◽  
Time Step ◽  
Data Set ◽  
Minimization Procedure ◽  
A New Technique ◽  
Joint Center

Joint centers are obtained from data treatment of a set of markers placed on the skin of moving limb segments. Finite helical axis (FHA) parameters are calculated between time step increments. Artifacts associated with nonrigid body movements of markers entail ill-determination of FHA parameters. Mean centers of rotation may be calculated over the whole movement, when human articulations are likened to spherical joints. They are obtained using numerical technique, defining point with minimal amplitude, during joint movement. A new technique is presented. Hip, knee, and ankle mean centers of rotation are calculated. Their locations depend on the application of two constraints. The joint center must be located next to the estimated geometric joint center. The geometric joint center may migrate inside a cube of possible location. This cube of error is located with respect to the marker coordinate systems of the two limb segments adjacent to the joint. Its position depends on the joint and the patient height, and is obtained from a stereoradiographic study with specimen. The mean position of joint center and corresponding dispersion are obtained through a minimization procedure. The location of mean joint center is compared with the position of FHA calculated between different sequential steps: time sequential step, and rotation sequential step where a minimal rotation amplitude is imposed between two joint positions. Sticks are drawn connecting adjacent mean centers. The animation of stick diagrams allows clinical users to estimate the displacements of long bones (femur and tibia) from the whole data set.

scholarly journals Characteristics of surface-water flows in the ridge and slough landscape of Everglades National Park: implications for particulate transport

Hydrobiologia ◽  
2006 ◽  
Vol 569 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Lynn Leonard ◽  
Alexander Croft ◽  
Daniel Childers ◽  
Sherry Mitchell-Bruker ◽  
Helena Solo-Gabriele ◽  
...  
Keyword(s):  
Surface Water ◽  
National Park ◽  
Everglades National Park ◽  
Water Flows ◽  
Particulate Transport ◽  
Ridge And Slough

scholarly journals Groundwater stable isotope profile of the Etosha National Park, Namibia

Koedoe ◽  
2016 ◽  
Vol 58 (1) ◽  
Author(s):  
Edward S. Riddell ◽  
Werner Kilian ◽  
Wilferd Versfeld ◽  
Martin Kosoana
Keyword(s):  
Surface Water ◽  
National Park ◽  
Terrestrial Ecosystem ◽  
Hydrological Process ◽  
Data Set ◽  
Research Attention ◽  
Tightly Coupled ◽  
Isotope Profile ◽  
Rainfall Recharge ◽  
Large Protected Area

The Etosha National Park (ENP) is a large protected area in northern Namibia. While the ENP has received a lot of research attention in terms of terrestrial ecosystem process understanding in recent decades, aquatic and hydrological research has to date been limited to a descriptive form. This study provides a baseline hydrological data set of the spatial representation of Oand H-isotope ratios in the groundwater at a park scale, with a focus on three water point types utilised by game, namely natural artesian and contact springs as well as artificial boreholes. The data are used to infer broad-scale hydrological process from groundwater recharge mechanisms dominated by direct rainfall recharge in the west of the ENP to evaporative controls on surface water recharge pathways in the east of the ENP close to Fishers Pan. The findings are used to recommend further targeted research and monitoring to aid management of water resources in the ENP.Conservation implications: The terrestrial ecosystem, particularly large game, are tightly coupled to the distribution of available surface water in the ENP, notably contact and artesian springs. Within the ENP there is a perceived desiccation of these springs. This study provides a baseline upon which more comprehensive studies should be undertaken to differentiate natural from anthropogenic causes for this phenomenon.

Using Satellite Imagery to Examine the Relationship between Surface-Water Dynamics of the Salt Lakes of Western Texas and Ogallala Aquifer Depletion

Wetlands ◽  
2017 ◽  
Vol 37 (6) ◽  
pp. 1055-1065 ◽  
Author(s):  
L. J. Heintzman ◽  
S. M. Starr ◽  
K. R. Mulligan ◽  
L. S. Barbato ◽  
N. E. McIntyre
Keyword(s):  
Surface Water ◽  
Satellite Imagery ◽  
Water Dynamics ◽  
Salt Lakes ◽  
Ogallala Aquifer ◽  
Aquifer Depletion ◽  
The Relationship
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