scholarly journals Monthly and Seasonal Drought Characterization Using GRACE-Based Groundwater Drought Index and Its Link to Teleconnections across South Indian River Basins

Climate ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 56
Author(s):  
K Satish Kumar ◽  
P AnandRaj ◽  
K Sreelatha ◽  
Deepak Singh Bisht ◽  
Venkataramana Sridhar

Traditional drought monitoring is based on observed data from both meteorological and hydrological stations. Due to the scarcity of station observation data, it is difficult to obtain accurate drought distribution characteristics, and also tedious to replicate the large-scale information of drought. Thus, Gravity Recovery and Climate Experiment (GRACE) data are utilized in monitoring and characterizing regional droughts where ground station data is limited. In this study, we analyzed and assessed the drought characteristics utilizing the GRACE Groundwater Drought Index (GGDI) over four major river basins in India during the period of 2003–2016. The spatial distribution, temporal evolution of drought, and trend characteristics were analyzed using GGDI. Then, the relationship between GGDI and climate factors were evaluated by the method of wavelet coherence. The results indicate the following points: GRACE’s quantitative results were consistent and robust for drought assessment; out of the four basins, severe drought was noticed in the Cauvery river basin between 2012 and 2015, with severity of −27 and duration of 42 months; other than Godavari river basin, the remaining three basins displayed significant negative trends at monthly and seasonal scales; the wavelet coherence method revealed that climate factors had a substantial effect on GGDI, and the impact of Southern Oscillation Index (SOI) on drought was significantly high, followed by Sea Surface Temperature (SST) Index (namely, NINO3.4) and Multivariate El Niño–Southern Oscillation Index (MEI) in all the basins. This study provides reliable and robust quantitative result of GRACE water storage variations that shares new insights for further drought investigation.

2020 ◽  
Vol 9 (2) ◽  
pp. 73
Author(s):  
Majid Dehghani ◽  
Somayeh Salehi ◽  
Amir Mosavi ◽  
Narjes Nabipour ◽  
Shahaboddin Shamshirband ◽  
...  

Temporary changes in precipitation may lead to sustained and severe drought or massive floods in different parts of the world. Knowing the variation in precipitation can effectively help the water resources decision-makers in water resources management. Large-scale circulation drivers have a considerable impact on precipitation in different parts of the world. In this research, the impact of El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO) on seasonal precipitation over Iran was investigated. For this purpose, 103 synoptic stations with at least 30 years of data were utilized. The Spearman correlation coefficient between the indices in the previous 12 months with seasonal precipitation was calculated, and the meaningful correlations were extracted. Then, the month in which each of these indices has the highest correlation with seasonal precipitation was determined. Finally, the overall amount of increase or decrease in seasonal precipitation due to each of these indices was calculated. Results indicate the Southern Oscillation Index (SOI), NAO, and PDO have the most impact on seasonal precipitation, respectively. Additionally, these indices have the highest impact on the precipitation in winter, autumn, spring, and summer, respectively. SOI has a diverse impact on winter precipitation compared to the PDO and NAO, while in the other seasons, each index has its special impact on seasonal precipitation. Generally, all indices in different phases may decrease the seasonal precipitation up to 100%. However, the seasonal precipitation may increase more than 100% in different seasons due to the impact of these indices. The results of this study can be used effectively in water resources management and especially in dam operation.


Author(s):  
Majid Dehghani ◽  
Somayeh Salehi ◽  
Amir Mosavi ◽  
Narjes Nabipour ◽  
Shahab Shamshirband ◽  
...  

Temporary changes in precipitation may lead to sustained and severe drought or massive floods in different parts of the world. Knowing variation in precipitation can effectively help the water resources decision-makers in water resources management. Large-scale circulation drivers have a considerable impact on precipitation in different parts of the world. In this research, the impact of El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO) on seasonal precipitation over Iran was investigated. For this purpose, 103 synoptic stations with at least 30 years of data were utilized. The Spearman correlation coefficient between the indices in the previous 12 months with seasonal precipitation was calculated, and the meaningful correlations were extracted. Then the month in which each of these indices has the highest correlation with seasonal precipitation was determined. Finally, the overall amount of increase or decrease in seasonal precipitation due to each of these indices was calculated. Results indicate the Southern Oscillation Index (SOI), NAO, and PDO have the most impact on seasonal precipitation, respectively. Also, these indices have the highest impact on the precipitation in winter, autumn, spring, and summer, respectively. SOI has a diverse impact on winter precipitation compared to the PDO and NAO, while in the other seasons, each index has its special impact on seasonal precipitation. Generally, all indices in different phases may decrease the seasonal precipitation up to 100%. However, the seasonal precipitation may increase more than 100% in different seasons due to the impact of these indices. The results of this study can be used effectively in water resources management and especially in dam operation.


2021 ◽  
Vol 17 (2) ◽  
pp. 111-124
Author(s):  
Safrudin Nor Aripbilah ◽  
Heri Suprapto

El Nino and La Nina in Indonesia are one of the reasons that caused climate changes, which has possibility of drought and flood disasters. Sragen Regency wherethe dry season occurs, drought happened meanwhile other areas experience floods and landslides. A study on drought needs to be carried out so as to reduce the risk of losses due to the drought hazard. This study is to determine the drought index in Sragen Regency based on several methods and the correlation of each methods and its suitability to the Southern Oscillation Index (SOI) and rainfall. Drought was analyzed using several methods such as Palmer Drought Severity Index (PDSI), Thornthwaite-Matter, and Standardized Precipitation Index (SPI) then correlated with SOI to determine the most suitable method for SOI. The variables are applied in this method are rainfall, temperature, and evapotranspiration. The results showed that the drought potential of the Palmer method is only in Near Normal conditions, which is 1%, Severe drought conditions are 29% for the Thornthwaite-Matter method, and Extreme Dry conditions only reach 1,11% for the SPI method. The PDSI and SPI methods are inversely proportional to the Thornthwaite-Matter method and the most suitable method for SOI values or rainfall is the SPI method. These three methods can be identified the potential for drought with only a few variables so that they could be applied if they only have those data.Keywords: Drought, PDSI, Thornthwaite-Matter, SPI, SOI


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3113
Author(s):  
Michaela Danáčová ◽  
Gabriel Földes ◽  
Marija Mihaela Labat ◽  
Silvia Kohnová ◽  
Kamila Hlavčová

The paper aims to assess the impact of deforestation due to windstorms on runoff in small mountain river basins. In the Boca and Ipoltica River basins, changes in forested areas were assessed from available historical and current digital map data. Significant forest losses occurred between 2004 and 2012. During the whole period of 1990–2018, forested areas in the Boca river decreased from 83% to 47% and in the Ipoltica River basin from 80% to 70%. Changes in runoff conditions were assessed based on an assessment of changes in the measured time series of the hydrometeorological data for the years 1981–2016. An empirical hydrological model was used to determine the design peak discharges before and after significant windstorms were estimated for different rain intensities and return periods. The regional climate scenario for the period 2070–2100 was used to assess the current impact of climate change and river basin deforestation on predicted changes in design floods in the coming decades. The effect of deforestation became evident in the extreme discharges, especially in future decades. In the Boca River basin, the estimated design floods increased by 59%, and in the Ipoltica River basin by 172% in the case of the 100-year return period.


2020 ◽  
Vol 12 (17) ◽  
pp. 7023 ◽  
Author(s):  
Netrananda Sahu ◽  
Atul Saini ◽  
Swadhin Behera ◽  
Takahiro Sayama ◽  
Sridhara Nayak ◽  
...  

The impact of Indo-Pacific climate variability in the South Asian region is very pronounced and their impact on agriculture is very important for the Indian subcontinent. In this study, rice productivity, climatic factors (Rainfall, Temperature and Soil Moisture) and associated major Indo-Pacific climate indices in Bihar were investigated. Bihar is one of the major rice-producing states of India and the role of climate variability and prevailing climate indices in six events (between 1991–2014) with severer than −10% rice productivity are analyzed. The Five-year moving average, Pearson’s Product Moment Correlation, Partial Correlation, Linear Regression Model, Mann Kendall Test, Sen’s Slope and some other important statistical techniques were used to understand the association between climatic variables and rice productivity. Pearson’s Product Moment Correlation provided an overview of the significant correlation between climate indices and rice productivity. Whereas, Partial Correlation provided the most refined results on it and among all the climate indices, Niño 3, Ocean Niño Index and Southern Oscillation Index are found highly associated with years having severer than −10% decline in rice productivity. Rainfall, temperature and soil moisture anomalies are analyzed to observe the importance of climate factors in rice productivity. Along with the lack of rainfall, lack of soil moisture and persistent above normal temperature (especially maximum temperature) are found to be the important factors in cases of severe loss in rice productivity. Observation of the dynamics of ocean-atmosphere coupling through the composite map shows the Pacific warming signals during the event years. The analysis revealed a negative (positive) correlation of rice productivity with the Niño 3 and Ocean Niño Index (Southern Oscillation Index).


2012 ◽  
Vol 9 (3) ◽  
pp. 2717-2762 ◽  
Author(s):  
L. E. Flint ◽  
A. L. Flint ◽  
B. J. Stolp ◽  
W. R. Danskin

Abstract. The coastal-plain aquifer that underlies the San Diego City metropolitan area in southern California is a groundwater resource. The understanding of the region-wide water balance and the recharge of water from the high elevation mountains to the east needs to be improved to quantify the subsurface inflows to the coastal plain in order to develop the groundwater as a long term resource. This study is intended to enhance the conceptual understanding of the water balance and related recharge processes in this arid environment by developing a regional model of the San Diego region and all watersheds adjacent or draining to the coastal plain, including the Tijuana River basin. This model was used to quantify the various components of the water balance, including semi-quantitative estimates of subsurface groundwater flow to the coastal plain. Other approaches relying on independent data were used to test or constrain the scoping estimates of recharge and runoff, including a reconnaissance-level groundwater model of the San Diego River basin, one of three main rivers draining to the coastal plain. Estimates of subsurface flow delivered to the coastal plain from the river basins ranged from 12.3 to 28.8 million m3 yr−1 from the San Diego River basin for the calibration period (1982–2009) to 48.8 million m3 yr−1 from all major river basins for the entire coastal plain for the long-term period 1940–2009. This range of scoping estimates represents the impact of climatic variability and realistically bounds the likely groundwater availability, while falling well within the variable estimates of regional recharge. However, the scarcity of physical and hydrologic data in this region hinders the exercise to narrow the range and reduce the uncertainty.


2019 ◽  
Vol 13 (1) ◽  
pp. 129-136
Author(s):  
Andreea-Violeta Tudorache

Abstract The present paper analyzes the extreme variabilities of rainfall and runoff regime within vulnerable hydrographic river basins, focused on a case study: Elan river basin, year 2016. This year, due to excess rainfall, the Elan River basin was affected by torrential rainfall, warned against by orange and red code hydrological forecasts. For this reason, this study makes an analysis of the spatial and temporal variability of the surface runoff also considering the main flood events occurring in this river basin. The impact of liquid precipitation on the surface runoff will be highlighted by a statistical analysis of the relationship between monthly average flows and the sum of monthly precipitation in the river basin. The monthly flows series from the Murgeni and Poșta Elan hydrometric stations were capitalized through appropriate statistical analyses. Maximum flows were reported to the thresholds values corresponding to the Defense Levels.


Author(s):  
N. I. Koronkevich ◽  
K. S. Melnik

Global urban landscapes were growing rapidly during last decades. The impact of this growth on annual river runoff of foreign European and Russian river basins was shown in this article. Calculations for Moscow river basin were taken as a basis for computations. The performed calculations show, that 1% of urbanization area increase also enhances total river runoff at 1%. At the same time 1% growth of watertight territories (included in urbanized landscapes) leads to an increase in runoff by 2–3%. The growth of urbanized areas led to a smaller increase in runoff (2–3 times) in the past (in comparison with current period) due to a less established system of diversion from urbanized landscapes. Calculations were made for Spree, Thames, Seine river basins in comparison Moscow River basin. Impact of capitals landscapes (Berlin, London, Paris, and Moscow) on river runoff was estimated initially, and then the influence of other urbanized areas located in river basins. As a result, the general influence of all urbanized territories was defined. According to results of conducted calculations, modern urbanized areas led to an increase of annual river runoff by more than 9% in Spree river basin, more than 20% of the Thames, over 11% of the Seine and 10% in the basin of Moscow River in comparison with changes during the period of norm calculation (from the end of 19th century till the beginning of the 1960s of the 20th century). According to the results of conducted calculations, modern total annual runoff increase is 2.2–4.5% for Europe and 0.2–0.3% for the Russian Federation in comparison with changes during the period of norm calculation, and in relation to the runoff from the most populated their parts is 3.5-6.9% and 1-2%, respectively. In addition, it can be expressed in km3 with following values: 44.9–89.8 (for foreign Europe) and 7.2–14.3 (for the Russian Federation). For the whole Europe (including European territory of Russia), the runoff increases by 50–100 km3 (or by 2–4%) per year. Actually, this is not so much in percentage terms, though in terms of volume – these values are close to annual runoff of such river as Neva.


2021 ◽  
Author(s):  
Erwin Rottler ◽  
Klaus Vormoor ◽  
Till Francke ◽  
Michael Warscher ◽  
Ulrich Strasser ◽  
...  

Abstract In snow-dominated river basins, floods often occur during early summer, when snowmelt-induced runoff superimposes with rainfall-induced runoff. An earlier onset of seasonal snowmelt as a consequence of a warming climate is often expected to shift snowmelt contribution to river runoff and potential flooding to an earlier date. Against this background, we assess the impact of rising temperatures on seasonal snowpacks and quantify changes in timing, magnitude and elevation of snowmelt. We analyse in situ snow measurements, conduct snow simulations and examine changes in river runoff at key gauging stations. With regard to snowmelt, we detect a threefold effect of rising temperatures: snowmelt becomes weaker, occurs earlier and forms at higher elevations. Due to the wide range of elevations in the catchment, snowmelt does not occur simultaneously at all elevations. Results indicate that elevation bands melt together in blocks. We hypothesise that in a warmer world with similar sequences of weather conditions, snowmelt is moved upward to higher elevation. The movement upward the elevation range makes snowmelt in individual elevation bands occur earlier, although the timing of the snowmelt-induced runoff stays the same. Meltwater from higher elevations, at least partly, replaces meltwater from elevations below.


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