Examining water storage variations as a function of meteorology using GRACE and GLDAS

2021 ◽  
Author(s):  
Caleb Kelly ◽  
Nicholas Hamm ◽  
Craig Hancock ◽  
Stephen Grebby ◽  
Stuart Marsh
Keyword(s):  
Surface Water ◽  
Water Availability ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Water Storage ◽  
Meteorological Conditions ◽  
P Value ◽  
Increasing Trend ◽  
Terrestrial Water ◽  
The Impact

<p>The Upper East Region (UER) of Ghana, located between 10.2–11.2°N, 1.6°W–0.03°E, is characterised by a long dry season and annual floods that are exacerbated by the opening of the Bagre Dam in neighbouring Burkina Faso. The UER lies within the Volta Basin, which has been the subject of numerous hydrological studies. The basin spans several jurisdictions with varying meteorological conditions; thus, basin-wide studies may not truly reflect localised dynamics of water storage over the UER. Data from the Gravity Recovery and Climate Experiment (GRACE) mission and hydrological models, e.g., the Global Land Data Assimilation System (GLDAS), have been used for hydrological studies. Nonetheless, GRACE’s resolution may restrict its application to large areas (≥150,000 km<sup>2</sup>) or smaller areas with storage variations of ≥8 km<sup>3</sup>, while GLDAS does not model surface water. With this in mind, this research evaluates GRACE and GLDAS for water storage analysis over the UER (~9000 km<sup>2</sup>).</p><p>We used the latest mass concentration solution from the Centre for Space Research, GLDAS-NOAH, and the Global Precipitation Measurement (GPM) from April 2002 to June 2017. The long-term mean (2004–2009) was removed from GPM and NOAH. The GRACE time series was characterised by an increasing trend in terrestrial water storage anomalies (TWSA) (6.2 mm/yr), annual and semi-annual amplitudes of 99.4 mm and 10.5 mm, and annual and semi-annual phases of 39.1° and 13.6°, respectively. The minimum variation (-150.8 mm, -47.4 km<sup>3</sup>) in TWSA occurred in May 2003, while the maximum (222.3 mm, 69.9 km<sup>3</sup>) occurred in September 2012, both of which are during the rainy season. Rainfall anomalies showed a declining trend at a rate of 0.25 mm/yr. A Pearson correlation coefficient (r) between rainfall and TWSA revealed a low r = 0.30 (p-value << 0.01 ). Conversely, time-lagged r = 0.60, one and two months after rainfall. The largest (r = 0.66) occurred two months  after rainfall. NOAH-based evapotranspiration anomalies (ETA) indicated a slow, but increasing, trend (0.4 mm/yr). Furthermore NOAH-derived TWSA underestimated storage, yielding a rate of decline of 2.1 mm/yr, which could be due to unmodelled surface water. However, NOAH-derived TWSA were comparatively strongly correlated with rainfall (r = 0.69 and 0.87 at lags 0 and 1). As rainfall is the only source of input to the water balance equation and as rates of ETA suggest conditions in the UER support water loss, these results may indicate a strong contribution to TWSA from the yet unmodelled water from the Bagre Dam.</p><p>This study was the first to investigate the impact of meteorological conditions on water availability in the UER using GRACE and GLDAS. The results show that GLDAS-NOAH underestimated storage, and that TWSA increased, although this increase is not entirely explained by rainfall. Subsequent experiments will incorporate the contribution of water from the Bagre Dam as well as other meteorological data (e.g., wind speed, humidity) to better explain the differences in those parameters and fully characterise the impact of meteorological conditions on water availability in the UER. </p>

The Impact of Noah-MP Physical Parameterizations on Modeling Water Availability during Droughts in the Texas-Gulf Region

2021 ◽  
Author(s):  
Wen-Ying Wu ◽  
Zong-Liang Yang ◽  
Michael Barlage
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Water Availability ◽  
Water Storage ◽  
Rooting Depth ◽  
Surface Model ◽  
Terrestrial Water Storage ◽  
Area Index ◽  
Terrestrial Water ◽  
The Impact

AbstractTexas is subject to severe droughts, including the record-breaking one in 2011. To investigate the critical hydrometeorological processes during drought, we use a land surface model, Noah-MP, to simulate water availability and investigate the causes of the record drought. We conduct a series of experiments with runoff schemes, vegetation phenology, and plant rooting depth. Observation-based terrestrial water storage, evapotranspiration, runoff, and leaf area index are used to compare with results from the model. Overall, the results suggest that using different parameterizations can influence the modeled water availability, especially during drought. The drought-induced vegetation responses not only interact with water availability but also affect the ground temperature. Our evaluation shows that Noah-MP with a groundwater scheme produces a better temporal relationship in terrestrial water storage compared with observations. Leaf area index from dynamic vegetation is better simulated in wet years than dry years. Reduction of positive biases in runoff and reduction of negative biases in evapotranspiration are found in simulations with groundwater, dynamic vegetation, and deeper rooting zone depth. Multi-parameterization experiments show the uncertainties of drought monitoring and provide a mechanistic understanding of disparities in dry anomalies.

scholarly journals Simulation of future climate scenarios and the impact on the water availability in southern Brazil

2021 ◽  
Vol 43 ◽  
pp. e56026
Author(s):  
Gabriela Leite Neves ◽  
Jorim Sousa das Virgens Filho ◽  
Maysa de Lima Leite ◽  
Frederico Fabio Mauad
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Water Availability ◽  
Meteorological Data ◽  
Future Climate ◽  
Climate Scenarios ◽  
Southern Brazil ◽  
Climate Data ◽  
Intergovernmental Panel ◽  
The Impact

Water is an essential natural resource that is being impacted by climate change. Thus, knowledge of future water availability conditions around the globe becomes necessary. Based on that, this study aimed to simulate future climate scenarios and evaluate the impact on water balance in southern Brazil. Daily data of rainfall and air temperature (maximum and minimum) were used. The meteorological data were collected in 28 locations over 30 years (1980-2009). For the data simulation, we used the climate data stochastic generator PGECLIMA_R. It was considered two scenarios of the fifth report of the Intergovernmental Panel on Climate Change (IPCC) and a scenario with the historical data trend. The water balance estimates were performed for the current data and the simulated data, through the methodology of Thornthwaite and Mather (1955). The moisture indexes were spatialized by the kriging method. These indexes were chosen as the parameters to represent the water conditions in different situations. The region assessed presented a high variability in water availability among locations; however, it did not present high water deficiency values, even with climate change. Overall, it was observed a reduction of moisture index in most sites and in all scenarios assessed, especially in the northern region when compared to the other regions. The second scenario of the IPCC (the worst situation) promoting higher reductions and dry conditions for the 2099 year. The impacts of climate change on water availability, identified in this study, can affect the general society, therefore, they must be considered in the planning and management of water resources, especially in the regional context

scholarly journals Hydrological Control of Vegetation Greenness Dynamics in Africa: A Multivariate Analysis Using Satellite Observed Soil Moisture, Terrestrial Water Storage and Precipitation

Land ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Sabastine Ugbaje ◽  
Thomas Bishop
Keyword(s):  
Soil Moisture ◽  
Water Availability ◽  
Water Storage ◽  
Important Variable ◽  
Delayed Response ◽  
Terrestrial Water Storage ◽  
Vegetation Greenness ◽  
Vegetation Activity ◽  
Terrestrial Water ◽  
Hydrological Variables

Vegetation activity in many parts of Africa is constrained by dynamics in the hydrologic cycle. Using satellite products, the relative importance of soil moisture, rainfall, and terrestrial water storage (TWS) on vegetation greenness seasonality and anomaly over Africa were assessed for the period between 2003 and 2015. The possible delayed response of vegetation to water availability was considered by including 0–6 and 12 months of the hydrological variables lagged in time prior to the vegetation greenness observations. Except in the drylands, the relationship between vegetation greenness seasonality and the hydrological measures was generally strong across Africa. Contrarily, anomalies in vegetation greenness were generally less coupled to anomalies in water availability, except in some parts of eastern and southern Africa where a moderate relationship was evident. Soil moisture was the most important variable driving vegetation greenness in more than 50% of the areas studied, followed by rainfall when seasonality was considered, and by TWS when the monthly anomalies were used. Soil moisture and TWS were generally concurrent or lagged vegetation by 1 month, whereas precipitation lagged vegetation by 1–2 months. Overall, the results underscore the pre-eminence of soil moisture as an indicator of vegetation greenness among satellite measured hydrological variables.

scholarly journals GRACE water storage estimates for the Middle East and other regions with significant reservoir and lake storage

2013 ◽  
Vol 17 (12) ◽  
pp. 4817-4830 ◽  
Author(s):  
L. Longuevergne ◽  
C. R. Wilson ◽  
B. R. Scanlon ◽  
J. F. Crétaux
Keyword(s):  
Spatial Distribution ◽  
Surface Water ◽  
Numerical Experiments ◽  
Water Storage ◽  
Accurate Estimation ◽  
Areal Extent ◽  
Total Water ◽  
Reservoir Storage ◽  
Average Water ◽  
The Impact

Abstract. While GRACE (Gravity Recovery and Climate Experiment) satellites are increasingly being used to monitor total water storage (TWS) changes globally, the impact of spatial distribution of water storage within a basin is generally ignored but may be substantial. In many basins, water is often stored in reservoirs or lakes, flooded areas, small aquifer systems, and other localized regions with areas typically below GRACE resolution (~200 000 km2). The objective of this study was to assess the impact of nonuniform water storage distribution on GRACE estimates of TWS changes as basin-wide averages, focusing on surface water reservoirs and using a priori information on reservoir storage from radar altimetry. Analysis included numerical experiments testing effects of location and areal extent of the localized mass (reservoirs) within a basin on basin-wide average water storage changes, and application to the lower Nile (Lake Nasser) and Tigris–Euphrates basins as examples. Numerical experiments show that by assuming uniform mass distribution, GRACE estimates may under- or overestimate basin-wide average water storage by up to a factor of ~2, depending on reservoir location and areal extent. Although reservoirs generally cover less than 1% of the basin area, and their spatial extent may be unresolved by GRACE, reservoir storage may dominate water storage changes in some basins. For example, reservoir storage accounts for ~95% of seasonal water storage changes in the lower Nile and 10% in the Tigris–Euphrates. Because reservoirs are used to mitigate droughts and buffer against climate extremes, their influence on interannual timescales can be large. For example, TWS decline during the 2007–2009 drought in the Tigris–Euphrates basin measured by GRACE was ~93 km3. Actual reservoir storage from satellite altimetry was limited to 27 km3, but their apparent impact on GRACE reached 45 km3, i.e., 50% of GRACE trend. Therefore, the actual impact of reservoirs would have been greatly underestimated (27 km3) if reservoir storage changes were assumed uniform in the basin. Consequently, estimated groundwater contribution from GRACE would have been largely overestimated in this region if the actual distribution of water was not explicitly taken into account. Effects of point masses on GRACE estimates are not easily accounted for via simple multiplicative scaling, but in many cases independent information may be available to improve estimates. Accurate estimation of the reservoir contribution is critical, especially when separating estimating groundwater storage changes from GRACE total water storage (TWS) changes. Because the influence of spatially concentrated water storage – and more generally water distribution – is significant, GRACE estimates will be improved by combining independent water mass spatial distribution information with GRACE observations, even when reservoir storage is not the dominant mechanism. In this regard, data from the upcoming Surface Water Ocean Topography (SWOT) satellite mission should be an especially important companion to GRACE-FO (Follow-On) observations.

scholarly journals Hydroclimatic regimes: a distributed water-balance framework for hydrologic assessment and classification

2014 ◽  
Vol 11 (3) ◽  
pp. 2933-2965 ◽  
Author(s):  
P. K. Weiskel ◽  
D. M. Wolock ◽  
P. J. Zarriello ◽  
R. M. Vogel ◽  
S. B. Levin ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Balance ◽  
20Th Century ◽  
Water Availability ◽  
Land Surface ◽  
Resource Assessment ◽  
Annual Runoff ◽  
Balance Model ◽  
Equal Weight ◽  
Terrestrial Water

Abstract. Runoff-based indicators of terrestrial water availability are appropriate for humid regions, but have tended to limit our basic hydrologic understanding of drylands – the dry-sub-humid, semi-arid, and arid regions which presently cover nearly half of the global land surface. In response, we introduce an indicator framework that gives equal weight to humid and dryland regions, accounting fully for both vertical (precipitation + evapotranspiration) and horizontal (groundwater + surface-water) components of the hydrologic cycle in any given location – as well as fluxes into and out of landscape storage. We apply the framework to a diverse hydroclimatic region (the conterminous USA), using a distributed water-balance model consisting of 53 400 networked landscape hydrologic units. Our model simulations indicate that about 21% of the conterminous USA either generated no runoff or consumed runoff from upgradient sources on a mean-annual basis during the 20th century. Vertical fluxes exceeded horizontal fluxes across 76% of the conterminous area. Long-term average total water availability (TWA) during the 20th century, defined here as the total influx to a landscape hydrologic unit from precipitation, groundwater, and surface water, varied spatially by about 400 000-fold, a range of variation ~100 times larger than that for mean-annual runoff across the same area. The framework includes, but is not limited to classical, runoff-based approaches to water-resource assessment. It also incorporates and re-interprets the green-blue water perspective now gaining international acceptance. Implications of the new framework for hydrologic assessment and classification are explored.

scholarly journals Quality of life in epilepsy

2017 ◽  
Vol 5 (2) ◽  
pp. 452 ◽  
Author(s):  
Prem Singh ◽  
Achyut Kumar Pandey
Keyword(s):  
Quality Of Life ◽  
Pearson Correlation ◽  
Tertiary Care ◽  
P Value ◽  
Care Hospital ◽  
Lower Education Level ◽  
One Year ◽  
Patients With Epilepsy ◽  
The Impact

Background: The quality of life (QOL) evaluation is a relatively new measure to evaluate the outcome of epilepsy. Many factors influence the quality of life of people with epilepsy, including seizure severity, stigma, fear, and the presence of cognitive or psychiatric problems. QOL is influenced by biological factors as well as cultural, social and religious beliefs and values. This study was planned to find out the impact of epilepsy on quality of life of epileptic patients.Methods: The study was conducted in the epilepsy clinic of department of neurology at a tertiary care hospital over a period of one year.101 patients were included after fulfilling the inclusion criteria. All the patients seeking treatment in the OPD were screened, assessed and then all procedures were fully explained to them. History regarding name, age sex, socio-demographic profile and detailed history regarding seizure disorder was taken from both the patient and the reliable informant. Bengali version of QOLIE-9 was used to assess the quality of life.Results: One hundred and one patients with epilepsy consisting of 70 men (69.3%) and 31 women (30.7%) were included. Their ages ranged from 15 to 52, the mean age being 26.17 (SD = 7.84). Out of the 101 patients, 65 patients (64.4%) were suffering from partial epilepsies and 36 patients (35.6%) were suffering from generalized epilepsies. Mean QOLIE-9 total scores were 16.66, 19.74, 20.13 and 24.00 in married, widows, unmarried and separated individuals respectively. The differences in the means were statistically significant on ANOVA (p value 0.002). Mean QOLIE-9 total scores were 27.75, 19.64, 19.65, 18.14 and 18.00 in primary, secondary, higher secondary, graduate and postgraduate individuals respectively. The differences were highly significant statistically on ANOVA (p value<0.001). Frequency of seizures per month was positively correlated with QOLIE-9 total scores (Pearson Correlation 0.622) and was highly statistically significant (p value<0.001).Conclusions: Frequent seizures, lower education level and single status are associated with lower quality of life in persons with epilepsy.

scholarly journals Assessment of impacts of climate change on surface water availability using coupled SWAT and WEAP models: case of upper Pangani River Basin, Tanzania

2018 ◽  
Vol 378 ◽  
pp. 23-27 ◽  
Author(s):  
Peter Kishiwa ◽  
Joel Nobert ◽  
Victor Kongo ◽  
Preksedis Ndomba
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
River Basin ◽  
Water Use ◽  
Water Availability ◽  
Swat Model ◽  
Economic Activities ◽  
Peak Flows ◽  
Global Circulation Models ◽  
The Impact

Abstract. This study was designed to investigate the dynamics of current and future surface water availability for different water users in the upper Pangani River Basin under changing climate. A multi-tier modeling technique was used in the study, by coupling the Soil and Water Assessment Tool (SWAT) and Water Evaluation And Planning (WEAP) models, to simulate streamflows under climate change and assess scenarios of future water availability to different socio-economic activities by year 2060. Six common Global Circulation Models (GCMs) from WCRP-CMIP3 with emissions Scenario A2 were selected. These are HadCM3, HadGEM1, ECHAM5, MIROC3.2MED, GFDLCM2.1 and CSIROMK3. They were downscaled by using LARS-WG to station scale. The SWAT model was calibrated with observed data and utilized the LARS-WG outputs to generate future streamflows before being used as input to WEAP model to assess future water availability to different socio-economic activities. GCMs results show future rainfall increase in upper Pangani River Basin between 16–18 % in 2050s relative to 1980–1999 periods. Temperature is projected to increase by an average of 2 ∘C in 2050s, relative to baseline period. Long-term mean streamflows is expected to increase by approximately 10 %. However, future peak flows are estimated to be lower than the prevailing average peak flows. Nevertheless, the overall annual water demand in Pangani basin will increase from 1879.73 Mm3 at present (2011) to 3249.69 Mm3 in the future (2060s), resulting to unmet demand of 1673.8 Mm3 (51.5 %). The impact of future shortage will be more severe in irrigation where 71.12 % of its future demand will be unmet. Future water demands of Hydropower and Livestock will be unmet by 27.47 and 1.41 % respectively. However, future domestic water use will have no shortage. This calls for planning of current and future surface water use in the upper Pangani River Basin.

Regional analysis of winter wheat yields under different ecological conditions in Hungary and Croatia

2011 ◽  
Vol 59 (1) ◽  
pp. 23-33 ◽  
Author(s):  
P. Pepó ◽  
V. Kovačević
Keyword(s):  
Winter Wheat ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Regional Analysis ◽  
Crop Protection ◽  
Weather Conditions ◽  
Water Shortage ◽  
Spring Temperature ◽  
Temperature Regimes ◽  
The Impact

Wheat is the second most important field crop on arable lands in Hungary and Croatia. Yield variations between years are high in both countries. In the short term these variations are mainly the result of the weather parameters specific to individual growing seasons. The aim of this study was to compare variations in winter wheat yields over years in four counties in Hungary and five in Croatia, with the emphasis on the impact of rainfall and mean air temperature regimes. The results showed that rainfall in spring was most decisive for winter wheat yields. The highest winter wheat yields were obtained when the rainfall in the winter half-year ranged from 230–260 mm and the spring rainfall from 180–230 mm. The precipitation in the growing season is much higher in eastern Croatia than in eastern Hungary, so water shortage is a more pronounced environmental problem for wheat in Hungary. This is probably why wheat yields were lower in eastern Hungary than in eastern Croatia in the period tested. Pearson correlation analysis on the yields and meteorological data between 1990 and 2009 revealed a positive correlation between spring rainfall and the yield, and a negative correlation between spring temperature and the yield. The results proved that yields were determined not only by weather conditions, but by many other factors (crop rotation, tillage, fertilization, variety, crop protection, etc.).

scholarly journals Global partitioning of runoff generation mechanisms using remote sensing data

2020 ◽  
Vol 24 (3) ◽  
pp. 1415-1427
Author(s):  
Joseph T. D. Lucey ◽  
John T. Reager ◽  
Sonya R. Lopez
Keyword(s):  
Quality Control ◽  
Surface Water ◽  
Time Lag ◽  
Water Storage ◽  
Time Lags ◽  
Terrestrial Water Storage ◽  
Total Water ◽  
Runoff Generation ◽  
Terrestrial Water ◽  
Water Inundation

Abstract. A set of complex processes contribute to generate river runoff, which in the hydrological sciences are typically divided into two major categories: surface runoff, sometimes called Hortonian flow, and baseflow-driven runoff or Dunne flow. In this study, we examine the covariance of global satellite-based surface water inundation (SWI) observations with two remotely sensed hydrological variables, precipitation, and terrestrial water storage, to better understand how apparent runoff generation responds to these two dominant forcing mechanisms in different regions of the world. Terrestrial water storage observations come from NASA’s Gravity Recovery and Climate Experiment (GRACE) mission, while precipitation comes from the Global Precipitation Climatology Project (GPCP) combined product, and surface inundation levels from the NASA Surface WAter Microwave Product Series (SWAMPS) product. We evaluate the statistical relationship between surface water inundation, total water storage anomalies (TWS; TWSAs), and precipitation values under different time lag and quality control adjustments between the data products. We find that the global estimation of surface inundation improves when considering a quality control threshold of 50 % reliability for the SWAMPS data and after applying time lags ranging from 1 to 5 months. Precipitation and total water storage equally control the majority of surface inundation developments across the globe. The model tends to underestimate and overestimate at locations with high interannual variability and with low inundation measurements, respectively.

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