scholarly journals Long-term and Two-period Analysis of Hydrologic Conditions of the South Edisto River

2017 ◽  
pp. 13-20
Author(s):  
Rebecca W. Berzinis
Keyword(s):  
South Carolina ◽  
Low Flow ◽  
Mean Flow ◽  
South Fork ◽  
The South ◽  
Period Analysis ◽  
Daily Streamflow ◽  
Low Flows ◽  
Significant Difference

The U.S. Geological Survey (USGS) long-term daily streamflow record at station 02173000 in Bamberg County, South Carolina on the South Fork Edisto River (Latitude 33°23’35”, Longitude 81°08’00” NAD27) spans from 1932 to 2015 and was used for this study. The Nature Conservancy’s Indicators of Hydrologic Alteration (IHA) software was used to analyze the entire record of hydrologic data as ecologically relevant parameters and to categorize the flows. A two-period analysis was conducted to evaluate whether a significant difference could be observed in historic flow data from 1932–1985 (period one) compared to 1986–2015 (period two). An extreme low flow was defined as an initial low flow below 10% of daily flows for the period. Over the entire 76-year period of record, 51 years had at least one occurrence of extreme low flows. A median of 4 days per year had occurrences of extreme flows in period one in contrast to a median of 60 days per year during period two. Annual precipitation totals were not correlated with the number of days per year with extreme low flows. The two-period analysis showed significant differences between period one and period two for monthly mean flow for February, April, May, and August, as well as for 1-day and 30-day minima and maxima values. The analysis calculated the 7Q10 (the lowest stream flow for seven consecutive days that would be expected to occur once in ten years) at 4.4 cubic meters per second (cms), which was -10.9% different from the most recently published estimate. Results presented in this study have shown that spring and summer flows in the South Fork Edisto are statistically significantly lower in period two compared to period one.

Low flow frequency analysis for stream with mixed populations

2015 ◽  
Vol 42 (8) ◽  
pp. 503-509 ◽  
Author(s):  
Mike Hulley ◽  
Colin Clarke ◽  
Ed Watt
Keyword(s):  
Frequency Analysis ◽  
Worked Examples ◽  
Low Flow ◽  
Flow Estimation ◽  
Low Flows ◽  
Record Length ◽  
Mixed Populations ◽  
Flow Frequency ◽  
Recommendations For Assessment

A methodology is developed for the estimation of annual low-flow quantiles for streams with annual low flows occurring in both the summer and winter. Since the low flow generating processes are different in summer and winter, independent seasonal analyses are required. The methodology provides recommendations for assessment of record length, randomness, homogeneity, independence and stationarity, as well as guidelines for distribution selection and fitting for seasonal distributions. The seasonal distributions are then used to develop the combined distribution for annual low flow estimation. Four worked examples of long-term Canadian hydrometric stations are provided.

scholarly journals Changing Low Flow and Streamflow Drought Seasonality in Central European Headwaters

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3575
Author(s):  
Vojtech Vlach ◽  
Ondrej Ledvinka ◽  
Milada Matouskova
Keyword(s):  
Kendall Test ◽  
R Package ◽  
Low Flow ◽  
Headwater Catchments ◽  
Low Flows ◽  
Seasonality Index ◽  
Apparent Shift ◽  
Summer Minimum ◽  
Increasing Temperature

In the context of the ongoing climate warming in Europe, the seasonality and magnitudes of low flows and streamflow droughts are expected to change in the future. Increasing temperature and evaporation rates, stagnating precipitation amounts and decreasing snow cover will probably further intensify the summer streamflow deficits. This study analyzed the long-term variability and seasonality of low flows and streamflow droughts in fifteen headwater catchments of three regions within Central Europe. To quantify the changes in the low flow regime of selected catchments during the 1968–2019 period, we applied the R package lfstat for computing the seasonality ratio (SR), the seasonality index (SI), mean annual minima, as well as for the detection of streamflow drought events along with deficit volumes. Trend analysis of summer minimum discharges was performed using the Mann–Kendall test. Our results showed a substantial increase in the proportion of summer low flows during the analyzed period, accompanied with an apparent shift in the average date of low flow occurrence towards the start of the year. The most pronounced seasonality shifts were found predominantly in catchments with the mean altitude 800–1000 m.a.s.l. in all study regions. In contrast, the regime of low flows in catchments with terrain above 1000 m.a.s.l. remained nearly stable throughout the 1968–2019 period. Moreover, the analysis of mean summer minimum discharges indicated a much-diversified pattern in behavior of long-term trends than it might have been expected. The findings of this study may help identify the potentially most vulnerable near-natural headwater catchments facing worsening summer water scarcity.

scholarly journals Topography significantly influencing low flows in snow-dominated watersheds

2017 ◽  
Author(s):  
Qiang Li ◽  
Xiaohua Wei ◽  
Xin Yang ◽  
Krysta Giles-Hansen ◽  
Mingfang Zhang ◽  
...  
Keyword(s):  
Regression Models ◽  
Low Flow ◽  
Mean Flow ◽  
Slope Length ◽  
Low Flows ◽  
Slope Length Factor ◽  
High Flows ◽  
Flow Variables ◽  
Characterization Index

Abstract. Watershed topography plays an important role in determining the spatial heterogeneity of ecological, geomorphological, and hydrological processes. Few studies have quantified the role of topography on various flow variables. In this study, 28 watersheds with snow-dominated hydrological regimes were selected with daily flow records from 1989 to 1996. The watersheds are located in the Southern Interior of British Columbia, Canada and range in size from 2.6 to 1,780 km2. For each watershed, 22 topographic indices (TIs) were derived, including those commonly used in hydrology and other environmental fields. Flow variables include annual mean flow (Qmean), Q10%, Q25%, Q50%, Q75%, Q90%, and annual minimum flow (Qmin), where Qx% is defined as flows that at the percentage (x) occurred in any given year. Factor analysis (FA) was first adopted to exclude some redundant or repetitive TIs. Then, stepwise regression models were employed to quantify the relative contributions of TIs to each flow variable in each year. Our results show that topography plays a more important role in low flows than high flows. However, the effects of TIs on flow variables are not consistent. Our analysis also determines five significant TIs including perimeter, surface area, openness, terrain characterization index, and slope length factor, which can be used to compare watersheds when low flow assessments are conducted, especially in snow-dominated regions.

Long-term patterns of fruit production in five forest types of the South Carolina upper coastal plain

2012 ◽  
Vol 76 (5) ◽  
pp. 1036-1046 ◽  
Author(s):  
Cathryn H. Greenberg ◽  
Douglas J. Levey ◽  
Charles Kwit ◽  
John P. Mccarty ◽  
Scott F. Pearson ◽  
...  
Keyword(s):  
South Carolina ◽  
Coastal Plain ◽  
Fruit Production ◽  
Forest Types ◽  
The South

Climate elasticity of low-flows: the long-term impact of droughts

2020 ◽  
Author(s):  
Vazken Andréassian ◽  
Alban de Lavenne
Keyword(s):  
Low Flow ◽  
Long Term Memory ◽  
Term Memory ◽  
Climate Elasticity ◽  
Climate Anomalies ◽  
Linear Dependency ◽  
Low Flows ◽  
Model Free ◽  
Hydrogeological Characteristics

<p>The long-term memory of catchments (carried by their hydrogeological characteristics) has a considerable impact on low-flow dynamics. Here, we present an exploratory study on a large French dataset to characterize the climate elasticity of low-flows and understand its long-term dependency. The climate elasticity of catchments is a simple concept (almost model-free) that allows analyzing the linear dependency of streamflow anomalies to climate anomalies (Andréassian et al., 2016). Widely-used for average annual streamflow, we propose to extend this concept to annual minimum monthly flow anomalies (QMNA) in order to characterize the climate dependency of QMNAs. By introducing progressively the linear dependency to the climatic anomalies of previous years, we further characterize the long-term memory of low-flows for the catchments of our set.</p><p><strong>References</strong></p><p>Andréassian, V., Coron, L., Lerat, J., and Le Moine, N. 2016. Climate elasticity of streamflow revisited – an elasticity index based on long-term hydrometeorological records, Hydrol. Earth Syst. Sci., 20, 4503-4524.</p><p> </p>

Evaluation of the south carolina comr/cunity long-term care medicaid waiver for the elderly and disabled

1996 ◽  
Vol 19 (8) ◽  
pp. 1335-1361
Author(s):  
Carleen H. Stoskopf ◽  
Samuel L. Baker ◽  
James R. Ciesla ◽  
Donna L. Richter ◽  
Elizabeth D. Schulman
Keyword(s):  
South Carolina ◽  
Long Term Care ◽  
The Elderly ◽  
The South ◽  
Term Care

LONG-TERM SURFACE WEATHERING ALONG A ROCK GLACIER IN THE SOUTH FORK OF WRIGHT VALLEY, EAST ANTARCTICA

2016 ◽  
Author(s):  
Kelsey Winsor ◽  
◽  
Kate M. Swanger ◽  
Rachel D. Valletta ◽  
James L. Dickson ◽  
...  
Keyword(s):  
East Antarctica ◽  
South Fork ◽  
The South ◽  
Rock Glacier

scholarly journals Climate change alters low flows in Europe under global warming of 1.5, 2, and 3 °C

2018 ◽  
Vol 22 (2) ◽  
pp. 1017-1032 ◽  
Author(s):  
Andreas Marx ◽  
Rohini Kumar ◽  
Stephan Thober ◽  
Oldrich Rakovec ◽  
Niko Wanders ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
General Circulation ◽  
Snow Accumulation ◽  
Low Flow ◽  
Model Ensemble ◽  
Daily Streamflow ◽  
Low Flows ◽  
Future Global Warming ◽  
The Mediterranean

Abstract. There is growing evidence that climate change will alter water availability in Europe. Here, we investigate how hydrological low flows are affected under different levels of future global warming (i.e. 1.5, 2, and 3 K with respect to the pre-industrial period) in rivers with a contributing area of more than 1000 km2. The analysis is based on a multi-model ensemble of 45 hydrological simulations based on three representative concentration pathways (RCP2.6, RCP6.0, RCP8.5), five Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs: GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC-ESM-CHEM, NorESM1-M) and three state-of-the-art hydrological models (HMs: mHM, Noah-MP, and PCR-GLOBWB). High-resolution model results are available at a spatial resolution of 5 km across the pan-European domain at a daily temporal resolution. Low river flow is described as the percentile of daily streamflow that is exceeded 90 % of the time. It is determined separately for each GCM/HM combination and warming scenario. The results show that the low-flow change signal amplifies with increasing warming levels. Low flows decrease in the Mediterranean region, while they increase in the Alpine and Northern regions. In the Mediterranean, the level of warming amplifies the signal from −12 % under 1.5 K, compared to the baseline period 1971–2000, to −35 % under global warming of 3 K, largely due to the projected decreases in annual precipitation. In contrast, the signal is amplified from +22 (1.5 K) to +45 % (3 K) in the Alpine region due to changes in snow accumulation. The changes in low flows are significant for regions with relatively large change signals and under higher levels of warming. However, it is not possible to distinguish climate-induced differences in low flows between 1.5 and 2 K warming because of (1) the large inter-annual variability which prevents distinguishing statistical estimates of period-averaged changes for a given GCM/HM combination, and (2) the uncertainty in the multi-model ensemble expressed by the signal-to-noise ratio. The contribution by the GCMs to the uncertainty in the model results is generally higher than the one by the HMs. However, the uncertainty due to HMs cannot be neglected. In the Alpine, Northern, and Mediterranean regions, the uncertainty contribution by the HMs is partly higher than those by the GCMs due to different representations of processes such as snow, soil moisture and evapotranspiration. Based on the analysis results, it is recommended (1) to use multiple HMs in climate impact studies and (2) to embrace uncertainty information on the multi-model ensemble as well as its single members in the adaptation process.

scholarly journals Zmienność przepływów niżówkowych w wybranych zlewniach pogórskich i beskidzkich w latach 1988‑2017 = Variability of low flow in Polish Carpathians (foothills and Beskidy Mountains) catchments in the period 1988‑2017

2021 ◽  
Vol 93 (1) ◽  
pp. 5-25
Author(s):  
Witold Bochenek ◽  
Małgorzata Kijowska-Strugała
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Arable Land ◽  
Low Flow ◽  
Soil Permeability ◽  
Low Flows ◽  
Polish Carpathians ◽  
Continental Climate

Water flow in the Polish Carpathians was exemplified by long-term (1988‑2017) analysis of two foothill catchments (of the Skawinka and Stobnica) and two catchments in the Beskidy Mountains (of the Soła and Osława). The work allowed for the determination of the duration of low flows and outflow deficits in relation to changes in thermal and precipitation conditions, as well as land use and land cover. In the selected catchments, the 30-year period brought a decrease in the area of arable land and an increase in the area of grassland and forest. In addition built-up areas increased by 495% between 1990 and 2018. A greater susceptibility to the occurrence of total drought was noted for the Beskidy Mountains catchments, in which the duration of low flows and outflow deficit was greater than in the foothill catchments. At the same time, the mountain catchments proved less susceptible to the emergence of deep drought, on account of their higher levels of forest cover and levels of soil permeability. In regional terms, the durations of low flows and outflow deficits were greater in the catchments located in the eastern part of the Carpathians (those of the Stobnica and Osława), in line with this area’s intensified features of a continental climate.

Sign in / Sign up

Export Citation Format

Share Document