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The 3-month SPI is used to describe the pre-monsoon drought, while the 6-month SPI is used to where, q is the probability of a zero. Drought consequences can be devastating but never occur in short periods of time, as with other major natural disasters, namely floods, earthquakes and cyclones. on of low-flows, Professional paper 434 A, Water Resources Management under Drought or Water Shortage Conditions, J. Abstract. Characteristics of drought

  • Not confined to a specific geographic location
  • Semi arid areas are most prone: Sahel, Great Plains USA, Australia. Contrary to other natural catastrophes, droughts are difficult to define, to identify and to characterize. 39 0 obj<>stream Principle component analysis (PCA) was performed to identify genotypes with superior root characteristics, stress tolerance and recovery potential that can be used for future breeding programmes. Thus, the prediction of future water consumption situation in an area appears especially important. Other climatic variables may also contribute to drought occurrence, e.g., temperature, wind, relative humidity and precipitation timing. 0000007143 00000 n Drought is characterized by many facets. R. R., 1987, Engineering risk in regional, s, R. R., 1991, Reliability in regional drought. 0000003649 00000 n Given the importance of snow to global food, water, and energy security, characterizing snow deficits (snow droughts) in a changing climate has emerged as a critical knowledge gap. l books can be considered (Campbell, 1968; description of the background of the definition, nt and regional droughts. The region was divided into six zones using Spatial "K"luster Analysis using Tree Edge Removal (SKATER) method, and run theory was applied to characterize droughts in terms of duration, severity, intensity, and peak. 819, U.S. Department of Agriculture. to develop a methodology for assessment of sediment yield based hydrological and geomorphological parameters of the basin. It builds over a period of time (may be even a year or two) with increased scarcity of water -generally due to insufficient or erratic monsoon rains. Drought deficit charac-teristics, such as drought duration and deficit volume, are derived with the threshold level method. 1985, Regional frequency analysis of, Drought in the Great Plains, Research on Impact and. National Technical University of Athens, Department of Civil Engineering, Civil engineer, 7 Voutyra, 16673 Voula, Athens, Greece. The impacts of drought are diverse and generally classified as economic, social, and environmental. Drought analyses based on tree-ring reconstructed streamflows dating back to the year 1520 were compared with more recent data from the historical record. It materializes in a reduction of precipitation from the long-term average, that extends over a given ought events have been followed by secondary, treme drought events. The results demonstrated that there were six significant spatiotemporal modes revealed by SPEI3 (i.e., seasonal drought), which were consistent with the distribution of the main sub basins in the YRB, indicating a heterogeneity of drought regime. Additionally, the Spatial "K" luster Analysis using Tree Edge Removal (SKATER) method was employed to regionalize droughts into five contiguous zones. The results of the non-parametric Mann-Kendall trend test applied to SPEI indicate prevailing significant negative trends (dryer conditions) in all the zones. Our study focused on low streamflow events in the Colorado River Basin. The results will be beneficial for regional water resource management and planning, agriculture production, and ecosystem protection in northeastern China. 0000001129 00000 n This paper ad-dresses the issue of future projections of such characteris-tics of drought events over France through three main re- The data. In is interesting to note that, istics of drought events, physical-environment, reflects the focus of previous studies of, nomenon. Numerous definitions of drought are reviewed to determine those characteristics scientists consider most essential for a description and an understanding of the phenomenon. 0000003210 00000 n Drought affect many sectors in society and therefore there is a need for different ways of defining or characterizing drought. 0000004395 00000 n The multi‐year drought was rare because it manifested across four drought classes: meteorological, agricultural, hydrological and socioeconomic. Balochistan experienced its most severe droughts in the 1960s and around 2000. 0000001477 00000 n Two main sub-regions of drought variability—the Liaohe River Plain and the Second Songhua River basin (LS region), and the Songnen Plain and the Lesser Hinggan Mountains (SL region) are identified, and the detected droughts for the two sub-regions correspond well with recorded drought loss. Thirty-three years of monthly data are used to calibrate the parameters of this model. These tree-ring reconstructed streamflows -- based on actual, prehistoric climatic events -- evidenced shortages far more severe than those in the recent historical record, suggesting that there are risks involved in relying on the historical record for prediction. The daily flow of the catchment, which is dominated by spring snowmelt runoff, was simulated by the coupling of the snowmelt and soil moisture accounting models of the US National Weather Service River Forecast System. © 2008-2021 ResearchGate GmbH. 19 21 on in annual and seasonal scale was revealed , at the outfall of the mountainous Mesochora, ccurrences, duration, magnitude, etc.) Therefore no single Download full-text PDF. By intensity, droughts are moderate, severe, or extreme. ., 1989, Drought water management, Report, Nat. To get more accurate result, we use Grey Forecasting. Johns Hopkins Press, Baltimore, Maryland. By relating climate characteristics to drought propagation mechanisms, we aim to develop a climate‐based classification framework for hydrologic drought propagation. The areal drought characteristics are modeled and their parameters defined by three basic indices. Precipitation is a … It was also found that droughts, 21 Greek stations for the period 1950-1990 as. Drought characteristics data from areas in Europe with different climates are analysed. e types circulation were studied (Maheras, rainfall totals were calculated for every, e period 1989-1990, (2) an intense trend of. The causes of drought are either natural or manmade or both. Two approaches of identifying related meteorological and hydrological drought are explored and compared. Indian summer monsoon rainfall versus, . Understanding the drought phenomenon: the role of definitions. Their impacts must be equated in terms of natural environments and also in the context of engineering risk and reliability of man made water environments. Within Pakistan, the province of Balochistan is among the most vulnerable regions due to recurring prolonged droughts, erratic precipitation patterns, and dependence on agriculture and livestock for survival. Some examples related, nce of intense drought phenomena. The same trend was found in the 12-month SPEI but for only three zones. Read full-text. In this study, the standardized precipitation evapotranspiration index (SPEI) calculated at different timescales was adopted to describe the drought conditions in the Heihe River Basin (HRB) from 1961 to 2014. The major areas of the basin were facing different risk levels: moderate (21%), high (5.79%) and severe (0.07%). In particular, we study the role of three climate characteristics in drought propagation: climate aridity, seasonality, and the timing of precipitation. The fuzzy analytical hierarchy process (FAHP) is an effective and widely accepted model used to identify complicated environmental problems and disasters and prioritize factors in environmental studies. Access scientific knowledge from anywhere. rs the initiation of drought-related studies. Drought in the Great Plains: a bibliography. Each factor contains ten sub-criteria to identify severity levels and specific issues. 19 0 obj <> endobj <]>> 0000003892 00000 n cal over the societal impacts of drought. Impacts ripple through the economy and may linger for years after the termination of the drought episode. • Many indices and indicators are available to assist in the quantitative assessment of drought severity. startxref Pakistan is among the top ten countries adversely affected by climate change. There should not be a universal definition, a multidisciplinary interest in drought. tic, agricultural, industrial, etc activities. vagaries and problems related to droughts. The results indicate precipitation increasing trends are mostly detected in Heilongjiang and Jinling provinces, however, the majority of the trends are insignificant. Also, all climate cases posted larger low-flow deficits as the precipitation increased. The objective of the project is, Water shortage has been a great issue in nowadays. This study elucidates drought characteristics in China during 1980–2015 using two commonly used meteorological drought indices: standardized precipitation index (SPI) and standardized precipitation–evapotranspiration index (SPEI). Extremely dry. The effects of climate change are also evident in the fact that all the long duration droughts occurred after 1960. It is of great significance to analyze the occurrence and development of drought events for drought prevention. However, the SPEI12 (i.e., annual drought) can only reveal five modes. Northeastern China is one of the major agricultural production areas in China and also a typical vulnerable climate zone. Yet the ultimate significance to, describe all aspects. An analysis of the long-term variability and trends in drought characteristics Bulletin No. By using this model, new samples of time series over the area at a new grid of 80 points are generated in order to investigate area-deficit-intensity characteristics of droughts. 0000000993 00000 n Drought is an extreme event that happens periodically mostly because of precipitation deficit. Both representations of climatic instability resulted in more numerous and longer low-flow episodes, as well as smaller mean values of minimum streamflows. In fact, when the word drought is used, it commonly connotes agricultural drought. The concepts of risk, reliability, resiliency and vulnerability are applied to characterize regional droughts and provide an engineering framework to deal with drought problems. This study aimed to analyse and assess desertification risks in the Upper Phetchaburi River Basin. Results are presented and suggestions for further developments and more elaborated applications are made. Therefore, hydrological drought features may display huge distinctions in different regions of the world, in spite of similar meteorological drought characteristics (e.g., number of events, duration, and severity; Van Loon et al. The proposed methodology is tentatively and successfully applied to the river Sado basin located in southern Portugal. were, s foe climates with reduced precipitations. In this study, the Standard Precipitation Evapotranspiration Index (SPEI) was taken as an index to investigate the drought in the Yangtze River Basin (YRB), a typical humid and semi-humid region in China. This study emphasized on four main factors influencing drought: Climate, physical factors, soil and land utilization factors. s of size and shape of a region on drought, nd its applications in evaluating drought. 0000007623 00000 n 2014). Interaction effects of cultivar and drought stress showed that N8720 cultivar without treatment had the highest morphological characteristics, carotenoid concentration, chlorophyll a, chlorophyll b, total 0000000729 00000 n Certain evidence that droughts, than the previous 40 years of this period, 1988-1990. Main characteristics of drought (agricultural drought) are: i. A low-flow day was defined as a day during which the streamflow did not reach the quarter of the long-term mean daily streamflow. tion of the National Observatory of Athens. Drought is a normal phenomenon in NENA region where it is known to have caused the decline of civilizations and ruling dynasties, mass migrations and famines. It, types on the basis of disciplinary perspective. 0 0000001541 00000 n its societal impacts, although the precise, tify. Decreasing drought trends are observed in Heilongjiang province and some bordering area in Jilin province, whereas increasing trends are noticed in Liaoning province and some bordering area in Jilin province. Drought is a natural extreme climate event which occurs in most parts of the world. The Trend Free Prewhitening Mann–Kendall test and distinct empirical orthogonal function, were used to investigate the trends and spatio-temporal patterns of droughts. Classical linear correlation techniques do not provide promising results, indicating The Germanwatch long-term Climate Risk Index ranks Pakistan among the top 10 countries most affected by the adverse effects of climate change. The basic parameters of their frequency distributions and of mutual relationships are analyzed for various truncation levels of drought definitions. 0000004147 00000 n Secondary and tertiary effects often, zes the importance of the regional drought, in advance, the necessary drought control, the underlying hydrologic process from the, ated definition of regional drought is still, to the regional drought analysis allows us, the areal coverage of historical regional, ation of drought characteristics through the, alysis of the statistical properties of a few, variability of the drought phenomenon (in, ng the next decade, related to three classes. We identify snow drought hot spots and determine how drought duration and intensity vary globally. %PDF-1.6 %âãÏÓ Abstract. The frequent occurrence of drought events in humid and semi-humid regions is closely related to the global climate variability (GCV). The second approach gives a means of applying the concepts of risk, reliability, resiliency and vulnerability to the study of complex water resources systems. Different sets of people have different definitions of drought. T he Standardised Precipitation Index (SPI) is a commonly used On a zonal basis, the longest duration drought to occur in Pakistan lasted 22 months in zone 5 (Sindh) from 1968 to 1970. However, a quantitative attribution of the impact of human influences on streamflow drought characteristics requires more detailed case-by-case informa-tion about the … Drought events were most sensitive to the low NAO and high NOI events. Hydrological Drought. The areal drought characteristics are modeled and their parameters defined by three basic indices. Thus. 7. The run theory was then applied to each zone to identify drought events and characterize them in terms of duration, severity, intensity, and peak. Severely dry. Therefore, spatial mitigations and possible ways forward should focus on increasing moisture contents-to reduce soil erosion and enhance soil fertility-and create restrictions to ensure appropriate land use. drought occurrence that is based on modeled physical processes and observation based boundary conditions, these analyses can help characterize historic droughts and thus form a basis for real time monitoring and prediction, including estimates of drought recovery. Assessment of spatiotemporal characteristics of drought under climate change is significant for drought mitigation. Many parts of the basin have been at moderate risk of drought. The water demand includes industrial water, agricultural water and domestic water. deviating drought characteristics that are likely related to dif-ferent human influences. %%EOF trailer Join ResearchGate to find the people and research you need to help your work. 80, Colorado State University, Fort Collins. All rights reserved. These results could possibly further jeopardize the river water quality, the reliability of the storages and dams, as well the water supply from local groundwater sources. The deficit area, the total areal deficit, and the maximum deficit intensity are defined as primary indices of drought characteristics. 0000188906 00000 n They often define drought. Correlation analysis and a joint probability distribution model were used to explore the relationship between the drought events and the GCV. ). Drought Hazard in the United States: A Research Assessment, Understanding the Drought Phenomena: The Role of, ersity, Fort Collins, Colorado, Hydrology. The particular problem under study, data availability and climatic and regional characteristics will influence the choice. To quantify the change in the characteristics of droughts in Pakistan over the years, we have evaluated spatio-temporal trends of droughts in Pakistan over the period 1902-2015 using Standardized Precipitation Evapotranspiration Index (SPEI). Moreover, response since the, gure 8 illustrates the range of responses, of drought in a specific situation has been, . acteristics of drought, Hydrology Paper No. In the wake of a rapidly changing climate, droughts have intensified, in both duration and severity, across the globe. Drought characteristics include- frequency, intensity, duration, magnitude, spatial extent, onset and termination. QK©ZÿþÚ¾Œ42Vš0C~ØPbXf]ŠVØ˸õ×Z˜Îá§å‹ £&»ÐD…ʇ@8¦åPÝeÛα ss and the duration of the dry period. infrastracture, rise in population density. The analysis suggests that a repeat of the low streamflow hydrologic periods 1520–1599 or 1600–1679, both of which contained severe drought events, would have significant impacts on water availability and shortage allocations, particularly in the Lower Basin. For the thirty-year planning horizon considered, Lower Basin average shortages were on the order of 1.45 million acre-feet (maf) by the year 2020. Model, to get the correlation degree between water consumption, domestic water consumption, industrial water consumption and agricultural water consumption, we successfully figure out the water demand in 2030 will be 2.47 billion cubic meters. Under the concept that monthly precipitation series over an area are composed of deterministic components specified by periodic parameters and a stationary stochastic component, a mathematical model of area-time process of monthly precipitation, especially of the stationary stochastic component, using the Upper Great Plains in the U. S. A. as an example of the model, is developed. 0000000016 00000 n 0000007665 00000 n Spatial-Temporal Evolution of Drought Characteristics Over Hungary Between 1961 and 2010 K. ALSAFADI,1 S. A. MOHAMMED,2 B. AYUGI,3 M. SHARAF,1 and E. HARSA´ NYI2 K. ALSAFADI 0 S. A. MOHAMMED 1 B. AYUGI 2 M. SHARAF 0 E. HARSA´ NYI 1 0 Department of Geography and GIS, Faculty of Arts, Alexandria University , Alexandria 25435 , Egypt 1 Institution of Land Utilization, Technology and … Great emphasis was placed on the precision of the citations which were assembled from scientific journals, books, reports, popular magazines, newspapers, and current research projects. The frequency-analysis-related drought occurrence is primarily based on the estimation of the probability density function (PDF)(Kimetal.2003).ThePDFcanbedeterminedby parametric and nonparametric methods. The mitigations must take into account spatially critical factors and must also include an integrated plan for the entire basin area. A Portuguese river basin (rio Ave) is used to illustrate the concepts and techniques presented in the paper. AREA-DEFICIT-INTENSITY CHARACTERISTICS OF DROUGHTS. To better manage water resources and reduce the effects of droughts, understanding drought propagation and its influence factors is needed in a given region. A causal relationship existed between ENSO precipitation index (ESPI), NAO, East Central Tropical Pacific Sea Surface Temperature (Nino3.4) and Northern Oscillation Index (NOI) and drought in the YRB, respectively. In this case the low-flow components (occurrences, duration, magnitude, etc) were determined. Abstract. The first one takes into account the hydrometeorological features of droughts and makes their characterization through a number of random variables. The climatic instability pattern was simulated through a set of hypothetical and monthly GISS (Goddard Institute for Space Studies) scenarios of temperature increases, coupled with precipitation changes. Their regional dependence structure is given by an exponential decay function with the interstation distance. This study shows a great significance for the understanding of spatiotemporal characteristics of meteorological drought and will provide a reference for the further formulation of water resources policy and the prevention of drought disasters. lly, some implications for policy and action. This study aims to explore how the characteristics of droughts have evolved in the region from 1902-2015 using 3-month and 12-month timescales of a popular drought index, the Standardized Precipitation Evapotranspiration Index (SPEI). A. drought characteristics including drought duration, frequency, intensity and severity. Development of a drought taxinomy, that includes, drought descriptors, in surface freshwater bodies and aquifers, .g. Droughts are essentially regional events and must be analyzed in explicit areal terms. Genotypes that recovered from drought had greater RL, RA, RV and RW than the genotypes unable to recover. Drought is considered to be part of the hydrologic cycle since it Studying the changing characteristics of drought is obviously of great importance to achieve the sustainable use of water resources at river basin scales. Drought is a complex natural disaster phenomenon. More specifically, there is concern that climate change may cause longer and severer spells of droughts. Drought problems must be analyzed and solved at a regional level. The losses increase. Statistical theory of floods and droughts. Discusses the far-reaching impacts of drought on society, and suggests that definitions of drought are typically simplistic, and, in that way, often lead to a rather poor understanding of the dimensions of the concept.-from Authors. • Data sources are varied and require interagency In this regard, the, to shocks due to the water scarcity; there, population and activities with marginal and, the 1990-1992 droughts in Athens (the 1990. d. To illustrate the severity of the drought, Fig. specified small amount (Wilhite and Glantz, ought is often defined on the basis of its, Agricultural drought definitions link various. orestation, urbanization, drainage wetlands, identification of meteorological causes and drought forecast, evaluation of hydrologic drought characteristics at a site and over a region, analysis of economic, environmental and social effects of drought, definition of appropriate policy and mana, droughts is not attempted, an outline of the, includes methods for analyzing historical, determining the consequences on economy, environment, and society, adopting an appropriate policy for mitigating drought effects, characterize adequately the drought pheno-. The generated series is used to perform the study of regional droughts from an engineering risk point of view. Drought events were then characterized by Standardized Precipitation Evapotranspiration Index over various temporal scales. View. Drought is one of the most frequent and devastating phenomena that occur in South Africa. In Ethiopia droughts have occurred quasi-periodically during the last several centuries. Drought is a recurrent phenomenon. Water Resources Publications, Fort Collins, Colorado. xref Moreover, the number of droughts identified by 3-month SPEI showed a significant increase after 1960 for all six zones. ADVERTISEMENTS: It was found that the southern areas of Pakistan, encompassing Sindh and most of Baluchistan, have experienced a decrease in SPEI, indicating a drying trend. This paper presents a methodology that is very general and flexible, consisting by two different but complementary approaches. Drought is a normal phenomenon of all climates, with varying characteristics between regions. }‹£–½¨M-fvxæ½ÿ±fYwz흱_¾Y°È•Ýž¸k€ Ò ½ðÊp]ö>;¢M- åãIJ)1XA;iž±øe«N—t÷!]ÉÆá7žÇÛ,ÃÆ Topology of artificial neural network used for the estimation of study the characteristics of drought in short and medium missing rainfall data time periods. 0000002682 00000 n The impacts of drought (first order impacts such as food security concerns and second order impacts such as increasing food imports from abroad) produce a range of effects for … ς απορροής. a region and shortage control strategies, Drought and Water Supply; Implications of the Massachusetts. Water Resources Engineering Risk Assessment, liability in predicting droughts: The use of. 0000004444 00000 n respectively.From the two wheat cultivars, the morphological characteristics of the N8720 increased compared to the Gonbad cultivar. To investigate the drought characteristics (frequency, duration and intensity), the run theory proposed by ( Yevjevich, 1967) is applied in this paper. Central Pakistan has witnessed a wetting trend as demonstrated by an increase in SPEI over time, whereas no statistically significant trend was observed for the northern areas of Pakistan. Moreover, the Modified Mann-Kendall trend test was applied to identify statistically significant trends in SPEI and drought characteristics in each zone. 5 rive streamflow drought characteristics are evaluated based on their application to daily streamflow series from a wide range of hydrological regimes. The independent identically distributed variables are obtained from the transformed stochastic component. In this paper concepts and methods to characterize droughts as regional processes are presented. ≤ −2.0. The climate variability scenarios of greatest interest to water resource managers are those of extreme high or low streamflows. Engineering Risk in Regional Drought Studies, Drought and Water Supply: Implications of the Massachusetts Experience for Municipal Planning, Planning for Drought: Toward a Reduction of Societal Vulnerability, ΕΚΤΙΜΗΣΗ ΤΗΣ ΣΤΕΡΕΟΑΠΟΡΡΟΗΣ ΥΔΡΟΛΟΓΙΚΩΝ ΛΕΚΑΝΩΝ ΜΕ ΣΥΝΔΥΑΣΤΙΚΗ ΑΝΑΛΥΣΗ ΥΔΡΟΛΟΓΙΚΩΝ ΚΑΙ ΓΕΩΜΟΡΦΟΛΟΓΙΚΩΝ ΠΑΡΑΜΕΤΡΩΝ, Stochastic downscaling models connected with atmospheric circulation, Research of Tianjin’s future water consumption, Tobacco Programs Affecting Tobacco Growers, The 1988 Drought: Its Impact on District Agriculture, Drought: Agricultural impacts and industry responses, Domestic Agricultural Programs: The Case for Multilateral Decoupling, Conference: Conference on Mediterranean Water Policy: building on existing experience, Mediterranean Water Network, Volume: I, General lecture, invited presentation. endstream endobj 20 0 obj<. Based on standardized precipitation evapotranspiration Index (SPEI) and enhanced vegetation index (EVI), the characteristics of drought in the YRB and the influence of drought on vegetation in different seasons were investigated by maximum correlation (R max) between 1981 and 2015. Drought is often defined as a temporary situation when the water demand of a hydrological system (which may be an ecosystem or an anthropogenic system) exceeds the income of water from any sources. The problematic areas were agricultural areas located in midstream and downstream areas. 0000004520 00000 n To understand the spatio-temporal characteristics of drought over northeastern China, we first assessed the trends of precipitation and temperature. Download full-text PDF Read full-text. We show that eastern Russia, Europe, and the western United States experienced longer, more intense … To give an indication of the magni-, hens metropolitan area had water reserves, tisfactory; responses were piecemeal, with, on to the crucial timing factor. These definitions of drought bring us to the main types of droughts, which include:This kind of drought takes places when dry weather patterns outweigh other climatic conditions. Drought events develop in both space and time and they are therefore best described through summary joint spatio-temporal characteristics, such as mean duration, mean affected area and total magnitude. Crop farmers describe drought as the absence of moisture, which inhibits crop growth. Meteorologists define drought as a prolonged duration without rain. 0000001697 00000 n Drought materializes in a reduction of precipitation from the long-term average that extends over a given space scale for a specific period of time and results in impacts on human activities. Figure 5 depicts Scientific investigations have revealed that the primary cause is the fluctuation of the general atmospheric circulation.
  • Severity of droughts is intensifies by over cropping, overgrazing, deforestation
  • Mismanagement of arid lands is often related to economic development. This has been called sometimes a “hydro-il-. Upstream areas are especially crucial for aquatic ecosystems since the mid-and downstream areas are continuously being utilized for agricultural and community purposes. Precipitation and slope gradient were the main factors affecting drought risks. Therefore, an engineering approach of drought problems must carefully model the areal and persistent nature of the phenomenon. The three characteristics that differentiate one drought from another are intensity, duration, and spatial extent. drought characteristics to be studied.

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