Climate change has become a hot topic in recent years. Flood is one of the most common natural hazards caused from extreme climate change. Scientists have spent a lot of money and time on monitoring ...flood in past decades. The development of Remote Sensing and Geographic Information System (GIS) brings new ways for scientists to analyze, monitor, and predict floods. Remote Sensing provides an alternative method to traditional flood survey with very fine temporal resolution data with much lower cost. Scientists have been utilizing data from MODIS satellite to detect flood in a lot of research. In this paper, flood duration layers are generated with utilizing Remote Sensing based flood data from Dartmouth Flood Observatory. The flood event layers provide detail view of flood events at pixel level. Flood data is currently processed and managed by RFCLASS website which developed by Center for Spatial Information Science and Systems. Few experiments have been designed to explore the possibility of minimizing cloud impact. Result indicated that there is a huge decrease in total events. Flood data generated in this research is ready to serve further research such as crop loss from flood. However, flood data is not fully accurate due to the similarity of spectral pattern between shadow and water surface. Further study is needed in order to remove error caused by shadow.
Based on experimental data and theory, by means of simplified discharge durations in a small flume, the influence of discharge process on channel morphology and channel pattern was analyzed in this ...paper. It was concluded that on the same original channel, different discharge and channel conditions would end with different river morphology, including thalwegs and radius of bends. Different discharge process resulted in two kinds of change: tiny change in the process of "big-small-big" and distinct change in the process of "small-big-small". Flood discharge duration was verified to be the main cause in the discharge process. Proper discharge process will change the morphologies of river, even can led to channel pattern transformation. The influences based on the relationship between the flow and the channel itself, including slope and riverbed constitution. Although not be a main cause, original channel morphology may influence its final channel pattern. Neglecting the influence of channel itself will hamper the understanding of channel patterns.PUBLICATION ABSTRACT
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In the Gemenc floodplain along the river Danube in Southern Hungary, six vegetation zones have been identified. Together with soil and geomorphological data, these vegetation zones are interpreted to ...form a hypothesis of succession for the Gemenc floodplain. As the Gemenc floodplain is comparable with the Dutch floodplains, from a hydrological, geomorphological and floristic point of view, the results can be used in plans for the rehabilitation of the floodplains of the river Rhine in the Netherlands.
Crop production in humid climates is often limited by severe thunderstorms that may leave soil flooded or waterlogged for several days. In 2001, a greenhouse study was initiated to determine the ...tolerance of bush beans (Phaseolus vulgaris L.) to flooding of various durations and at different growth stages. Plants were subjected to eleven flooding treatments lasting from one to eleven days. Flood treatments were initiated when plants reached either early vegetative growth stage (second true leaf open), early reproductive stage (first flower open on the main stem) or late reproductive stage (green seeds fills 1/2 of the pod cavity). In Study 1 flooding during the early vegetative growth stage for one, two and five days resulted in both the number of pods produced and pod fresh weight being statistically similar to that of the non-flooded control. The remaining flood treatments resulted in pod fresh weights 73% or less than the control weight. The number of surviving plants had more influence on the pod fresh weight than did flood duration. The number of pods produced per plant was correlated to pod fresh weight (r2 = 0.90). Only one plant grown to either the early or late reproductive growth stage survived flooding for >24 h. There was a 21% yield reduction for plants flooded for 24 h during the early reproductive growth stage. Flooding for 24 h at the late reproductive stage resulted in a 50% yield reduction. In Study 2 plants flooded during early vegetative growth stage did not flower. Flooding during the late vegetative and flowering growth stages caused a 70% and 49% reduction in yield, respectively. Pod production slowed with increasing flood duration. Yield could be correlated to several plant physical characteristics. We found linear relationships between yield components (pod number and weight) and flood duration, flood timing and leaf area. Greenhouse data indicate that yield reduction can be estimated from changes in plant characteristics resulting from flooding.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
The Okavango basin is shared between the countries of Angola, Namibia and Botswana and terminates in the Kalahari MOZ (Makgadigadi-Okavango-Zambezi) depression as an extensive alluvial fan often ...referred to as a “Delta” (Ringrose et al., 2005a). The upper catchment area receives 1200 mm/year rainfall and flows to the semi-arid Kalahari where the nominal average 460 mm/yr is considered a good rainfall year. Most of the streamflow in the basin is generated within the Angolan upper catchment. After 27 years of civil war, the cease-fire in 2002 may ultimately result in large number of refugees returning to the Angolan headstreams area with anticipated increased demands both for irrigation water and sites for dam construction for electricity generation. As the level of development is not high most of the returning people will be dependent on natural resources. Though the provision of needs to basin inhabitants is undisputed, there are concerns that the resettlement of displaced communities might have downstream environmental impacts (Green Cross International, 2000). Development will however be slow because of the large number of remaining landmines (Mendelsohn and El Obeid, 2004).
Coastal communities are experiencing a gradual increase in flooding. Studies focus on the extent and depth of how coastal flooding will change as sea levels rise and impacts on infrastructure needed ...for risk assessments. However, there is limited information on how the duration of coastal flooding will change; specifically, in a format needed to support risk assessments. Therefore, the objective of this article is to highlight the need for annual exceedance probability curves by examining potential impacts on infrastructure in the city of Norfolk, Virginia. The analysis translates tide data to simulate stationarity and combines it with increments of rising sea levels to represent future tide elevations. The authors use a Poisson probability distribution to calculate flood duration exceedance levels for a specified threshold level and estimate how durations and probabilities could change over time. The article concludes with an assessment of how increasing flood durations can impact infrastructure systems.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
