scholarly journals Extreme Droughts Change in the Mekong River Basin: A Multidisciplinary Analysis Based on Satellite Data

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2682
Author(s):  
Vo Tuong ◽  
Thanh-Van Hoang ◽  
Tien-Yin Chou ◽  
Yao-Min Fang ◽  
Chun-Tse Wang ◽  
...  

This study evaluates droughts in the Mekong River Basin (MKB) based on a multidisciplinary method, mainly using the Standardized Precipitation Index (SPI) and Mann–Kendall (MK) test. Precipitation data corresponding to the seasonality of the regional climate were retrieved from Integrated Multi-satellitE Retrievals for Global Precipitation Measurement from 2001 to 2020, at a monthly temporal scale and 0.1 degree spatial resolution. Drought events and their average interval, duration, and severity were determined based on Run theory. Our results revealed the most extreme drought period was in January 2014, at the time the lowest precipitation occurred. Spatial extreme drought results indicated that Zone 2 in the upstream MKB has the highest frequency of drought, with 44 events observed during 19 years, and experiences the most severe droughts, whereas Zone 24 in the downstream MKB has the most prolonged drought duration of seven months. The periods and locations of extreme drought were identified using the SPI, corresponding to historic droughts of the MKB. Furthermore, the MK test shows an increasing trend of droughts in the lower MKB and the cluster analysis identified six clusters of times series. Overall, our study provides essential findings for international and national water resource stakeholders in identifying trends of extreme drought in the MKB.

2021 ◽  
Vol 3 ◽  
Author(s):  
Hsin-Fu Yeh

In recent years, Taiwan has been facing severe water shortages due to extreme drought. In addition, changes in rainfall patterns have resulted in an increasingly notable drought phenomenon, which affects the management and utilization of water resources. Therefore, this work examines basins in Central Taiwan. Long-term records from 13 rainfall and 17 groundwater stations were selected. The Standardized Precipitation Index (SPI) and Standardized Groundwater Level Index (SGI) were used to analyze the drought characteristics of this region. The rainfall and groundwater level data from basins in Central Taiwan were analyzed in this study. The results show that the year 2015 experienced extreme drought conditions due to a correlation with SPI and SGI signals. In addition, with regard to groundwater drought, more drought events occurred in the Da'an River basin; however, the duration and intensity of these events were relatively low, in contrast to those of the Wu River basin. Finally, the correlation between SPI and SGI was observed to vary in different basins, but a certain degree of correlation was observed in all basins. The results show that drought intensity increases with longer drought durations. Moreover, severe droughts caused by rainfall tend to occur at a greater frequency than those caused by groundwater.


2011 ◽  
Vol 14 (1) ◽  
pp. 221-235 ◽  
Author(s):  
Nan Zhang ◽  
Ziqiang Xia ◽  
Shaofeng Zhang ◽  
Hong Jiang

Drought is one of the most harmful natural hazards in the Upper Reaches of the Yangtze River basin (URYR) in the mid-west part of China. Alterations in precipitation will affect the severity of drought. The nonparametric Mann–Kendall (MK) test was used in this paper to examine the trend of precipitation and the standardized precipitation index (SPI) was adopted to analyze the spatial–temporal variations of meteorological drought over different time scales in the last 50 years. The MK test value of precipitation indicated that, for most of the URYR showed an increasing trend of precipitation in the months of January, February, March and June, mainly in the Min-Tuojiang, Jialingjiang and Wujiang sub-basins and a decreasing trend was observed in August to December. The most obvious decreasing trend of precipitation occurred in the Jialingjiang, upper mainstream and Wujiang sub-basins in September, with a rate ranging from –7.89mm/10 years to –39.36mm/10 years. The results show that the SPI is applicable in the URYR basin. The number of severe droughts differed among the six sub-basins, i.e., a more obvious 3-month drought takes place in the middle of the upper mainstream, Wujiang sub-basins and the southeast of Jialingjiang sub-basin and other droughts in 6, 9 and 12 month timescales have the same effect in these three sub-basins. The outcomes of the paper could provide references for droughts mitigation, local water resources management and agriculture decision making.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 413 ◽  
Author(s):  
Coleen Fox ◽  
Christopher Sneddon

The Mekong River Basin of mainland Southeast Asia is confronting a series of intertwined social, political, and biophysical crises. The ongoing construction of major hydroelectric dams on the river’s main channel and tributary systems—particularly in the basin’s lower and more populated reaches—is leading to significant socioecological changes. Multiple scientific studies have suggested that proceeding with the planned dam construction will disrupt the region’s incredibly productive fisheries and threaten the livelihoods of millions of basin residents. These effects will almost certainly be exacerbated by global and regional climate change. Yet increased understanding of the adverse consequences of dams for the Mekong’s hydrological and ecological processes is having minimal impact on decision-making around hydropower development. While local communities, non-governmental organizations (NGOs), and certain scientists draw on this knowledge to oppose or question accelerated dam building, state officials and hydropower developers have turned to the expertise of engineering and technological assessments in order to justify dam construction. Drawing on work in political geography, political ecology, and science and technology studies (STS), we ask two primary questions. First, why does engineering/technological knowledge retain so much legitimacy and authority in the face of mounting scientific knowledge about ecological change? Secondly, how are narratives of progress deployed and co-produced in the contested epistemologies of large dams as development? We conclude with some examples of how contestations over dams seem to be shifting epistemological boundaries in meaningful ways, creating new spaces for knowledge production and transfer. To answer these questions, we focus on three contested dams that are at various stages of construction in the basin: the nearly complete Xayaburi Dam, the under-construction Don Sahong Dam, and the planned Pak Beng Dam. The research advances understandings of the politics of contested knowledges as they become manifest in the conceptualization and governance of large dams in transboundary basins.


Author(s):  
Senna Bouabdelli ◽  
Ayoub Zeroual ◽  
Mohamed Meddi ◽  
Fateh Djelloul ◽  
Ramdane Alkama

Abstract. In last decades, the impact of climate change started to appear in the semi-arid regions of the Mediterranean Basin. The severity and frequency of drought events in Northwestern Algeria have affected water resources availability and agriculture. This study aims to evaluate the temporal evolution of drought events characteristics, such as drought duration, frequency and severity, of the Beni Bahdel Dam catchment, Northwestern Algeria. Drought characteristics have been derived from the Standardized precipitation index (SPI) computed for the period from 1941 to 2100 using precipitation data from observations and simulations of the regional climate model RCA4 (Rossby Centre Atmosphere model, version 4). The RCA4 model was forced by the global circulation model MPI-ESM-LR under two Representative Concentration Pathways (RCPs) scenarios. The ability of the model simulations was firstly assessed to reproduce the drought characteristics from observed data (1951–2005). Then, future changes in drought characteristics over the twenty-first century were investigated under the two scenarios (RCP4.5 and RCP8.5). Results show an amplification of drought frequencies and durations in the future under the RCP8.5 scenario.


2012 ◽  
Vol 12 (5) ◽  
pp. 1561-1572 ◽  
Author(s):  
S. Kavalieratou ◽  
D. K. Karpouzos ◽  
C. Babajimopoulos

Abstract. A combined regional drought analysis and forecast is elaborated and applied to the Aison River Basin (Greece). The historical frequency, duration and severity were estimated using the standardized precipitation index (SPI) computed on variable time scales, while short-term drought forecast was investigated by means of 3-D loglinear models. A quasi-association model with homogenous diagonal effect was proposed to fit the observed frequencies of class transitions of the SPI values computed on the 12-month time scale. Then, an adapted submodel was selected for each data set through the backward elimination method. The analysis and forecast of the drought class transition probabilities were based on the odds of the expected frequencies, estimated by these submodels, and the respective confidence intervals of these odds. The parsimonious forecast models fitted adequately the observed data. Results gave a comprehensive insight on drought behavior, highlighting a dominant drought period (1988–1991) with extreme drought events and revealing, in most cases, smooth drought class transitions. The proposed approach can be an efficient tool in regional water resources management and short-term drought warning, especially in irrigated districts.


2021 ◽  
Vol 765 ◽  
pp. 144494
Author(s):  
He Chen ◽  
Junguo Liu ◽  
Ganquan Mao ◽  
Zifeng Wang ◽  
Zhenzhong Zeng ◽  
...  

2021 ◽  
Vol 36 ◽  
pp. 100873
Author(s):  
Yishan Li ◽  
Hui Lu ◽  
Kun Yang ◽  
Wei Wang ◽  
Qiuhong Tang ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 303
Author(s):  
Shi Hu ◽  
Xingguo Mo

Using the Global Land Surface Satellite (GLASS) leaf area index (LAI), the actual evapotranspiration (ETa) and available water resources in the Mekong River Basin were estimated with the Remote Sensing-Based Vegetation Interface Processes Model (VIP-RS). The relative contributions of climate variables and vegetation greening to ETa were estimated with numerical experiments. The results show that the average ETa in the entire basin increased at a rate of 1.16 mm year−2 from 1980 to 2012 (36.7% of the area met the 95% significance level). Vegetation greening contributed 54.1% of the annual ETa trend, slightly higher than that of climate change. The contributions of air temperature, precipitation and the LAI were positive, whereas contributions of solar radiation and vapor pressure were negative. The effects of water supply and energy availability were equivalent on the variation of ETa throughout most of the basin, except the upper reach and downstream Mekong Delta. In the upper reach, climate warming played a critical role in the ETa variability, while the warming effect was offset by reduced solar radiation in the Mekong Delta (an energy-limited region). For the entire basin, the available water resources showed an increasing trend due to intensified precipitation; however, in downstream areas, additional pressure on available water resources is exerted due to cropland expansion with enhanced agricultural water consumption. The results provide scientific basis for practices of integrated catchment management and water resources allocation.


Sign in / Sign up

Export Citation Format

Share Document