scholarly journals Estimation of Groundwater Depletion in Iran’s Catchments Using Well Data

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 131
Author(s):  
Zohreh Safdari ◽  
Hossein Nahavandchi ◽  
Gholamreza Joodaki
Keyword(s):  
Secular Trend ◽  
Secular Trends ◽  
Negative Trend ◽  
Groundwater Depletion ◽  
Lake Basin ◽  
Observation Well ◽  
The Caspian Sea ◽  
Groundwater Storage ◽  
Central Plateau ◽  
Well Data

Iran is experiencing significant water challenges that have now turned water security into a national priority. By estimating secular trend groundwater storage in Iran between 2002 and 2017, we see that there is an intensive negative trend, even −4400 Mm3 in some areas. These estimations show shifting in the climate and extra extraction from aquifers for agricultural use in some areas in Iran. The secular trend of groundwater storage changes across the whole of Iran inferred from observation well data is −20.08 GT/yr. The secular trends of GWS changes based on observation well data are: −11.55 GT/yr for the Central Plateau basin, −3.60 GT/yr for the Caspian Sea basin, −3.0 GT/yr for the Persian Gulf and Oman Sea basin, −0.53 GT/yr for the Urmieh Lake basin, −0.57 GT/yr for the Eastern Boundary basin, and −0.83 GT/yr for the Gharaghom basin. The most depleted sub-basin (Kavir Markazi) has secular trends of GWS changes of −4.503 GT/yr. This study suggests that groundwater depletion is the largest single contributor to the observed negative trend of groundwater storage changes in Iran, the majority of which occurred after the drought in 2007. The groundwater loss that has been accrued during the study period is particularly alarming for Iran, which is already facing severe water scarcity.

scholarly journals Anthropogenic drought dominates groundwater depletion in Iran

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samaneh Ashraf ◽  
Ali Nazemi ◽  
Amir AghaKouchak
Keyword(s):  
Economic Security ◽  
Groundwater Depletion ◽  
Groundwater Storage ◽  
Rates Of Change ◽  
Level Data ◽  
Basin Scale ◽  
Storage Basin ◽  
Groundwater Reserves ◽  
The Impact ◽  
Hydrological Droughts

AbstractUsing publicly-available average monthly groundwater level data in 478 sub-basins and 30 basins in Iran, we quantify country-wide groundwater depletion in Iran. Natural and anthropogenic elements affecting the dynamics of groundwater storage are taken into account and quantified during the period of 2002–2015. We estimate that the total groundwater depletion in Iran to be ~ 74 km3 during this period with highly localized and variable rates of change at basin and sub-basin scales. The impact of depletion in Iran’s groundwater reserves is already manifested by extreme overdrafts in ~ 77% of Iran’s land area, a growing soil salinity across the entire country, and increasing frequency and extent of land subsidence in Iran’s planes. While meteorological/hydrological droughts act as triggers and intensify the rate of depletion in country-wide groundwater storage, basin-scale groundwater depletions in Iran are mainly caused by extensive human water withdrawals. We warn that continuation of unsustainable groundwater management in Iran can lead to potentially irreversible impacts on land and environment, threatening country’s water, food, socio-economic security.

scholarly journals Groundwater Depletion Signals in the Beqaa Plain, Lebanon: Evidence from GRACE and Sentinel-1 Data

2021 ◽  
Vol 13 (5) ◽  
pp. 915
Author(s):  
Elias C. Massoud ◽  
Zhen Liu ◽  
Amin Shaban ◽  
Mhamad Hage
Keyword(s):  
Snow Water Equivalent ◽  
Water Storage ◽  
Hydrologic Cycle ◽  
Groundwater Depletion ◽  
Satellite Mission ◽  
Groundwater Storage ◽  
Significant Drop ◽  
Monitoring Wells ◽  
High Productivity ◽  
Soil Moisture Storage

Regions with high productivity of agriculture, such as the Beqaa Plain, Lebanon, often rely on groundwater supplies for irrigation demand. Recent reports have indicated that groundwater consumption in this region has been unsustainable, and quantifying rates of groundwater depletion has remained a challenge. Here, we utilize 15 years of data (June 2002–April 2017) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission to show Total Water Storage (TWS) changes in Lebanon’s Beqaa Plain. We then obtain complimentary information on various hydrologic cycle variables, such as soil moisture storage, snow water equivalent, and canopy water storage from the Global Land Data Assimilation System (GLDAS) model, and surface water data from the largest body of water in this region, the Qaraaoun Reservoir, to disentangle the TWS signal and calculate groundwater storage changes. After combining the information from the remaining hydrologic cycle variables, we determine that the majority of the losses in TWS are due to groundwater depletion in the Beqaa Plain. Results show that the rate of groundwater storage change in the West Beqaa is nearly +0.08 cm/year, in the Rashaya District is −0.01 cm/year, and in the Zahle District the level of depletion is roughly −1.10 cm/year. Results are confirmed using Sentinel-1 interferometric synthetic aperture radar (InSAR) data, which provide high-precision measurements of land subsidence changes caused by intense groundwater usage. Furthermore, data from local monitoring wells are utilized to further showcase the significant drop in groundwater level that is occurring through much of the region. For monitoring groundwater storage changes, our recommendation is to combine various data sources, and in areas where groundwater measurements are lacking, we especially recommend the use of data from remote sensing.

Secular trends of sustained remission in rheumatoid arthritis, a nationwide study in Sweden

Rheumatology ◽  
2019 ◽  
Author(s):  
Jon T Einarsson ◽  
Minna Willim ◽  
Tore Saxne ◽  
Pierre Geborek ◽  
Meliha C Kapetanovic
Keyword(s):  
Symptom Onset ◽  
Secular Trend ◽  
Secular Trends ◽  
Treat To Target ◽  
Sustained Remission ◽  
Life Table Analysis ◽  
Treatment Start ◽  
Quality Register ◽  
Table Analysis ◽  
The One

Abstract Objectives The aim of this study of patients with RA in Sweden was to investigate secular trends in achieving sustained remission (SR), i.e. DAS28 <2.6 on at least two consecutive occasions and lasting for at least 6 months. Methods All adult RA patients registered in the Swedish Rheumatology Quality register through 2012, with at least three registered visits were eligible, a total of 29 084 patients. Year of symptom onset ranged from 1955, but for parts of the analysis only patients with symptom onset between 1994 and 2009 were studied. In total, 95% of patients fulfilled the ACR 1987 classification criteria for RA. Odds of reaching SR for each decade compared with the one before were calculated with logistic regression and individual years of symptom onset were compared with life table analysis. Results Of patients with symptom onset in the 1980s, 1990s and 2000s, 35.0, 43.0 and 45.6% reached SR, respectively (P < 0.001 for each increment), and the odds of SR were higher in every decade compared with the one before. The hazard ratio for reaching SR was 1.15 (95% CI 1.14, 1.15) for each year from 1994 to 2009 compared with the year before. Five years after symptom onset in 2009, 45.3% of patients had reached SR compared with 15.9% in 1999. Conclusion There is a clear secular trend towards increased incidence of SR in patients with RA in Sweden. This trend most likely reflects earlier diagnosis and treatment start, and adherence to national and international guidelines recommending the treat to target approach.

scholarly journals Indications for Protracted Groundwater Depletion after Drought over the Central Valley of California*,+

2016 ◽  
Vol 17 (3) ◽  
pp. 947-955 ◽  
Author(s):  
S.-Y. Simon Wang ◽  
Yen-Heng Lin ◽  
Robert R. Gillies ◽  
Kirsti Hakala
Keyword(s):  
El Nino ◽  
Central Valley ◽  
The State ◽  
First Century ◽  
Groundwater Depletion ◽  
Groundwater Storage ◽  
Twenty First Century ◽  
Agricultural Regions ◽  
California's Central Valley ◽  
California’S Central Valley

Abstract Ongoing (2014–16) drought in the state of California has played a major role in the depletion of groundwater. Within California’s Central Valley, home to one of the world’s most productive agricultural regions, drought and increased groundwater depletion occurs almost hand in hand, but this relationship appears to have changed over the last decade. Data derived from 497 wells have revealed a continued depletion of groundwater lasting a full year after drought, a phenomenon that was not observed in earlier records before the twenty-first century. Possible causes include 1) lengthening of drought associated with amplification in the 4–6-yr drought and El Niño frequency since the late 1990s and 2) intensification of drought and increased pumping that enhances depletion. Altogether, the implication is that current groundwater storage in the Central Valley will likely continue to diminish even further in 2016, regardless of the drought status.

Remote sensing of groundwater storage change - past, present and future

2020 ◽  
Author(s):  
Susanna Werth ◽  
Manoochehr Shirzaei ◽  
Grace Carlson ◽  
Chandrakanta Ojha
Keyword(s):  
High Resolution ◽  
Surface Deformation ◽  
Central Valley ◽  
Groundwater Depletion ◽  
High Temporal Resolution ◽  
Hydrological Models ◽  
Groundwater Storage ◽  
Aquifer System ◽  
Vertical Land Motion ◽  
The Impact

&lt;p&gt;Groundwater remains one of the least comprehensively monitored storage components in the hydrological cycle, because it's flow and storage processes are strongly linked to geology of the underground and because direct observations from well sites provide only point observations of complex and partly deep aquifer systems.&lt;/p&gt;&lt;p&gt;In recent years, geodetic methods have become increasingly available to complement ground-based observations and to expand investigations of the impact of climate extremes or human water use on groundwater storage variability. Satellite gravimetry from the Gravity Recovery And Climate Experiment (GRACE/FO) has been shown to be sensitive to groundwater depletion at large spatial scales (&gt; 300km) and relatively high temporal resolution (monthly). These data provide a valuable boundary condition for regional studies, and they have been applied widely to improve parameter and structure of hydrological models.&lt;/p&gt;&lt;p&gt;Moreover, changes in groundwater stocks cause surface deformation associated with regional elastic loading of the Earth&amp;#8217;s crust and localized poroelastic compaction of the aquifer skeleton, which are detectable by GPS and InSAR. The loading signal is typically much smaller than the land subsidence due to poroelastic compaction and thus masks out the loading signal adjacent to the aquifer system. However, the poroelastic signal can be used to estimate groundwater volume change in confined aquifer units and provides insight into the mechanical properties of the aquifer system. Also, the deformation sensors provide spatial resolutions of tens of meters (e.g., InSAR) to several kilometers (e.g., GPS) that can be used to solve for the volume of fluid removed from the aquifer system.&lt;/p&gt;&lt;p&gt;In this presentation, we demonstrate and discuss the applicability of poroelastic modeling, by applying GPS and InSAR based observations of vertical land motion, to quantify groundwater storage changes. Using the Central Valley in California as an example, we will show when this approach is applicable and when it is not, depending on the type of aquifer and observed deformation compared to water level changes. Using a 1-D poroelastic calculation based on deformation data, we find a groundwater loss of 21.3&amp;#177;7.2 km&lt;sup&gt;3&lt;/sup&gt; for the entire Central Valley during 2007-2010 and of 29.3&amp;#177;8.7 km&lt;sup&gt;3&lt;/sup&gt; for the San Joaquin Valley during 2012-2015. These loss estimates during drought are consistent with that of GRACE-based estimates considering uncertainty ranges.&lt;/p&gt;&lt;p&gt;Finally, we will discuss the increased availability of high-resolution radar data from Sentinel 1A/B as well as the upcoming radar mission NASA-ISRO SAR Mission (NISAR), to be launched in 2022, and how this will allow for high-resolution monitoring of vertical land motion and with that of compaction in confined aquifers around the world. The availability of these datasets increases the capability of geodetic methods for groundwater monitoring at higher spatial resolution than GRACE data, hence, providing the potential to apply these datasets to further improve parameterization and formulation of groundwater routines in regional to large-scale hydrological models.&lt;/p&gt;

scholarly journals Secular change in atmospheric Ar∕N<sub>2</sub> and its implications for ocean heat uptake and Brewer–Dobson circulation

2021 ◽  
Vol 21 (2) ◽  
pp. 1357-1373
Author(s):  
Shigeyuki Ishidoya ◽  
Satoshi Sugawara ◽  
Yasunori Tohjima ◽  
Daisuke Goto ◽  
Kentaro Ishijima ◽  
...  
Keyword(s):  
Secular Trend ◽  
Heat Content ◽  
Secular Trends ◽  
Global Ocean ◽  
Secular Change ◽  
Seasonal Cycles ◽  
Interannual Variations ◽  
Ocean Heat Uptake ◽  
Increasing Trends ◽  
D Model

Abstract. Systematic measurements of the atmospheric Ar∕N2 ratio have been made at ground-based stations in Japan and Antarctica since 2012. Clear seasonal cycles of the Ar∕N2 ratio with summertime maxima were found at middle- to high-latitude stations, with seasonal amplitudes increasing with increasing latitude. Eight years of the observed Ar∕N2 ratio at Tsukuba (TKB) and Hateruma (HAT), Japan, showed interannual variations in phase with the observed variations in the global ocean heat content (OHC). We calculated secularly increasing trends of 0.75 ± 0.30 and 0.89 ± 0.60 per meg per year from the Ar∕N2 ratio observed at TKB and HAT, respectively, although these trend values are influenced by large interannual variations. In order to examine the possibility of the secular trend in the surface Ar∕N2 ratio being modified significantly by the gravitational separation in the stratosphere, two-dimensional model simulations were carried out by arbitrarily modifying the mass stream function in the model to simulate either a weakening or an enhancement of the Brewer–Dobson circulation (BDC). The secular trend of the Ar∕N2 ratio at TKB, corrected for gravitational separation under the assumption of weakening (enhancement) of BDC simulated by the 2-D model, was 0.60 ± 0.30 (0.88 ± 0.30) per meg per year. By using a conversion factor of 3.5 × 10−23 per meg per joule by assuming a one-box ocean with a temperature of 3.5 ∘C, average OHC increase rates of 17.1 ± 8.6 ZJ yr−1 and 25.1 ± 8.6 ZJ yr−1 for the period 2012–2019 were estimated from the corrected secular trends of the Ar∕N2 ratio for the weakened- and enhanced-BDC conditions, respectively. Both OHC increase rates from the uncorrected- and weakened-BDC secular trends of the Ar∕N2 ratio are consistent with 12.2 ± 1.2 ZJ yr−1 reported by ocean temperature measurements, while that from the enhanced-BDC is outside of the range of the uncertainties. Although the effect of the actual atmospheric circulation on the Ar∕N2 ratio is still unclear and longer-term observations are needed to reduce uncertainty of the secular trend of the surface Ar∕N2 ratio, the analytical results obtained in the present study imply that the surface Ar∕N2 ratio is an important tracer for detecting spatiotemporally integrated changes in OHC and BDC.

scholarly journals Secular Trends in Height, Body Mass and Mean Menarche Age in Romanian Children and Adolescents, 1936–2016

2021 ◽  
Vol 18 (2) ◽  
pp. 490
Author(s):  
Raluca-Monica Pop ◽  
Arava Tenenboum ◽  
Marian Pop
Keyword(s):  
Children And Adolescents ◽  
Body Mass ◽  
Secular Trend ◽  
Age Groups ◽  
Secular Trends ◽  
Age At Menarche ◽  
Data Sets ◽  
Anthropometric Parameters ◽  
Data Set ◽  
Menarche Age

Secular trends in anthropometric parameters have been documented in most European countries, but no data is available regarding Romanian. The aim of the study was to calculate secular trend in height, body mass and mean menarche age for Romanian children and adolescents. Methods: A secondary data analysis was performed using ten data sets for urban and eight data sets for rural boys and girls, age 5–15 years, covering 80 years (1936 to 2016). Secular trend in height (cm/decade), body mass(kg/decade) and mean menarche age (years) were calculated. Results: Overall, there was a positive secular trend for height in both genders, which parallels the gross domestic product (GDP)/capita difference, more pronounced in boys, across all age-groups, with a maximum for 15 years-old boys (~3 cm/decade) and 13 years-old girls (~2 cm/decade). Body mass trend was also positive, more accentuated in the rural population. Mean age at menarche was higher in rural compared to urban girls, had a negative trend with the disappearance of the difference in the latest available data set (2013). Conclusion: In summary, an overall positive and ongoing secular trend in height and body mass was documented in Romanian children and adolescents, especially for the pubertal age-range, in concordance to other western countries, but out of phase by approximately 20 years.

scholarly journals The correlation between solar and geomagnetic activity – Part 2: Long-term trends

2011 ◽  
Vol 29 (8) ◽  
pp. 1341-1348 ◽  
Author(s):  
Z. L. Du
Keyword(s):  
Secular Trend ◽  
Time Window ◽  
Function Analysis ◽  
Lag Time ◽  
Secular Trends ◽  
Dynamical Process ◽  
Term Evolution ◽  
Increasing Trend ◽  
Long Term Trends

Abstract. Using lag-correlation function analysis, the correlation coefficient at zero lag (r0), the maximum (rm) and the corresponding lag time (Lm) between solar (Rz) and geomagnetic (aa) activity for a 528-month (44-year) running time window are shown to vary in a declining, declining and rising secular trend, respectively, before 1958. However, these trends changed since 1958 with a rising secular trend in both r0 and rm and without a significant trend in Lm, probably related to a periodicity longer than 140 years. An odd-numbered solar cycle tends to show a higher correlation and a shorter lag time between Rz and aa than the previous even-numbered one, suggesting a 2-cycle periodicity superimposed on secular trends. An even-numbered Hale cycle tends to show a higher correlation and a shorter lag time between Rz and aa than the previous odd-numbered one, suggesting a 4-cycle periodicity superimposed on secular trends. The variations in the correlations may be related to the non-linearity between Rz and aa, and the decreasing trend in the correlation (r0) is not exclusively caused by the increasing trend in the lag time of aa to Rz. These results represent an observational constraint on solar-dynamo models and can help us gain a better understanding of the long-term evolution of solar activities. In applications, therefore, cautions must be taken when using the correlation for molding the dynamical process of the Sun and for predicting solar activities.

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