Drought and Drought Mangement

Weather, Climate, and Society, 2019

In the prevailing climate change scenario, to cope with drought, it is necessary to understand the characteristics of meteorological droughts in water-scarce regions to formulate judicial plans for the utilization of water resources. The present investigation, therefore, endeavored to assess the intensity and frequency of droughts over the five semiarid river basins in Maharashtra during the past (1980-2013) and future (2015-50). The study was carried out with the application of standardized precipitation index (SPI) methodology. The agricultural and satellite [normalized difference vegetation index (NDVI)] data were analyzed to understand the effects of meteorological droughts. Although the study area experienced three severe rainfall droughts in 1985/86, 2002/03, and 2011/12, higher frequency of low-intensity droughts is observed, particularly after 2000. The estimation suggests occurrence of moderate, severe, and extreme droughts once in 6, 28, and 50 years, respectively. Among the selected basins, the Agrani, the Karha, and the Man are expected to experience intense droughts and hence require special attention in drought management. The study also highlights that El Niño events considerably retard the monsoon rainfall. However, the occurrence of the positive phase of the Indian Ocean dipole in the El Niño years reduces the intensity of droughts. As agricultural productivity and cropped areas heavily depend on the monsoon rainfall, the meteorological droughts result in agricultural droughts. Moreover, the future warming (by 1.028C) over the study area is very likely to exacerbate the meteorological droughts (estimated to occur in the 2030s) and increase the agricultural water demand, further adding to an already difficult water management challenge in the study basins.

The Handbook of Environmental Chemistry, 2018

Drought by itself cannot be considered a disaster. However, if its impacts on local people, economies and the environment are severe and their ability to cope with and recover from it is difficult, it should be considered as a disaster. Droughts and floods are a recognizable category of natural risk. Hydrological assessments of drought impacts require detailed characteristics. We propose a new conceptual framework for drought identification in landscape with agricultural use. We described hydrological drought characteristics with impacts at the agricultural landscape and food security and the issues related to drought water management. In the past, the Slovak Republic was not considered a country immediately threatened with drought. The situation had changed at the turn of the millennium, especially after the extreme weather conditions in 2014 and also in 2015, when, for example, the historical minima were recorded.

2013

The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

International Journal of Research Studies in Agricultural Sciences

Stress is a change of the normal growth, development and productivity of crop plants and that is outside the normal range of homeostatic control. Among stresses, abiotic stress is caused due to moisture, temperature, mineral (deficiency/toxicity), salinity, soil acidity/soil P H. Drought is the primary cause of crop yield loss among abiotic factors around the world. It is a major problem in world, leading to food shortages and is a challenge for smallholder farmers to produce enough crop grain when rainfall is low and erratic. Climate change is the main cause of biotic and abiotic stresses, which have adverse effects the world's crop production and productivity. Crop production is determined by the existence of sufficient rain fall, especially in areas where crop production is totally relied on rain fall, there is always risk of crop failure or yield loss due to moisture stress. In severe cases, the stress could lead to total crop loss. This day, increasing crop yield is required to meet the needs of increasing population growth, however yield reduction is observed in areas where drought is predominantly devastated crop production. Short duration drought stress mostly reduces grain yield while prolonged drought stress leads to complete death of plant. Drought stress occurs at different stages of growth and adversely affect yield and yield related traits, which lead to reduction in yield. The effect of drought stress is mainly depending on the developmental stage of the plant, degree and duration of the stress, genotypic capacity of species and environmental interactions. Crop plants have adaptation strategies to survive under drought stress by the development of various morphological, physiological and biochemical mechanisms. However, a plant may exhibit more than one strategy to cope with drought stress. Drought resistance is the mechanism(s) causing minimum loss of yield in a drought condition. Drought escape, dehydration avoidance, reduced transpiration or physiological factors are some drought resistance mechanisms. Drought resistant genotypes maintain high photosynthesis under moisture stress condition by restricting transpiration water loss. Finally, the global food security is threatened by climate change and the most challenging in the 21 st century to supply sufficient food for the increasing world population. The use of well adapted and high-yielding varieties with resistance to drought stress is important to reach maximum yield potential as long as possible through minimizing the risk of climate change. Climate-smart agriculture is the only way to reduce the negative impact of climate variations on crop adaptation, before it might affect global crop production drastically.

Advances in Meteorology, 2016

Water, 2020

Water is the most important resource for sustainable agriculture in arid and semi-arid regions, where agriculture is the mainstay for rural societies. By relating the water usage to renewable water resources, we define three stages from sustainable to unsustainable water resources: (1) sustainable, where water use is matched by renewable water capacity, ensuring sustainable water resources; (2) transitional, where water use occasionally exceeds renewable water capacity; and (3) unsustainable, with lack of water resources for agriculture, society, and the environment. Using available drought indicators (standardized precipitation index (SPI) and streamflow drought index (SDI)) and two new indices for agricultural drought (overall agricultural drought index (OADI) and agricultural drought index (ADI)), we evaluated these stages using the example of Fars province in southern Iran in the period 1977-2016. A hyper-arid climate prevailed for an average of 32% of the province's spatio-temporal coverage during the study period. The area increased significantly from 30.6% in the first decade (1977-1986) to 44.4% in the last (2006-2015). The spatiotemporal distribution of meteorological drought showed no significant negative trends in annual precipitation during 1977-2016, but the occurrence of hydrological droughts increased significantly in the period 1997-2016. The expansion of irrigated area, with more than 60% of rainfed agriculture replaced by irrigated agriculture (especially between 1997 and 2006), exerted substantial pressure on surface water and groundwater resources. Together, climate change, reduced river flow, and significant declines in groundwater level in major aquifers led to unsustainable use of water resources, a considerable reduction in irrigated area, and unsustainability in agricultural production in the period 2006-2015. Analysis of causes and effects of meteorological, hydrological, and agricultural drought in the area identified three clear stages: before 1997 being sustainable, 1997-2006 being transitional, and after 2006 being unsustainable.

Drought Frontiers in Rice, 2009

International journal of research studies in agricultural sciences, 2022

A In the development of agricultural crops, biotic and abiotic stresses result in considerable yield losses. One of the main obstacles to agricultural production and global food security is abiotic stress. Stress is a word that refers to several biotic and abiotic environmental factors that prevent crop plants from reaching their full genetic potential. Drought is one of the fundamental issues in the current climatic environment and is one of the most severe abiotic stresses in many areas of the world. Plants experience moisture stress when their evapotranspiration requirements are not met. Drought has a negative impact on plant development and other metabolic processes, making it one of the most significant abiotic stresses and factors restricting the successful production of plant products globally. Drought is caused by a lack of water as a result of erratic rainfall or inadequate irrigation, but it can also be hampered by other elements such as soil salinity, physical characteristics, and excessive air or soil temperatures. Insufficient water supply throughout a crop's life cycle, including precipitation and the capability of the soil to store moisture, limits the crop's potential to produce the highest possible genetic grain yield. The most significant stressor that has a significant impact on crop development and productivity is without a doubt drought. For better management, it is crucial to comprehend the physiological, biochemical, and ecological actions connected to these stresses. It is possible to generalize morphological, physiological, and biochemical responses to a broad range of plant responses to this stress. Due to physical damage, physiological disruptions, and biochemical alterations, inadequate water supplies and abnormal temperatures have a severe impact on crop growth and yields. Drought stress reduces the size of the leaves, stem extension, and root proliferation within the soil; it also disturbs plant water relations and reduces water-use efficiency, which in turn reduces the plant's ability to yield; as a result, breeding for drought resistance is a good approach. This approach combines conventional and molecular methods to develop a drought-tolerant variety. Breeding more drought-tolerant cultivars may be more successful when selection is based on a thorough testing strategy. Practical implications for treatments and management result from a greater understanding of how plants react to this stress. High demand for drought-tolerant types would seem to be a difficult issue for plant breeders, but difficulties are aggravated by the difficulty of crop yield on a genetic and physiological basis. Food security is seriously threatened by drought, which is the main reason for agricultural loss worldwide. Plant biotechnology is currently one of the most promising areas for creating crops that can generate large amounts of food in moisture environments.