scholarly journals Unsustainability Syndrome—From Meteorological to Agricultural Drought in Arid and Semi-Arid Regions

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 838 ◽  
Author(s):  
Ali Torabi Haghighi ◽  
Nizar Abou Zaki ◽  
Pekka M. Rossi ◽  
Roohollah Noori ◽  
Ali Akbar Hekmatzadeh ◽  
...  

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.

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 632
Author(s):  
Weinan Lu ◽  
Wenxin Liu ◽  
Mengyang Hou ◽  
Yuanjie Deng ◽  
Yue Deng ◽  
...  

Improving agricultural water use efficiency (AWUE) is an important way to solve the shortage of water resources in arid and semi-arid regions. This study used the Super-DEA (data envelopment analysis) to measure the AWUE of 52 cities in Northwest China from 2000 to 2018. Based on spatial and temporal perspectives, it applied Exploratory Spatial Data Analysis (ESDA) to explore the dynamic evolution and regional differences of AWUE. A spatial econometric model was then used to analyze the main factors that influence the AWUE in Northwest China. The results showed firstly that the overall AWUE in Northwest China from 2000 to 2018 presented a steady upward trend. However, only a few cities achieved effective agricultural water usage by 2018, and the differences among cities were obvious. Secondly, AWUE showed an obvious spatial autocorrelation in Northwest China and showed significant high–high and low–low agglomeration characteristics. Thirdly, economic growth, urbanization development, and effective irrigation have significant, positive effects on AWUE, while per capita water resource has a significant, negative influence. Finally, when improving the AWUE in arid and semi-arid regions, plans should be formulated according to local conditions. The results of this study can provide new ideas on the study of AWUE in arid and semi-arid regions and provide references for the formulation of regional agricultural water resource utilization policies as well.


2020 ◽  
Vol 12 (16) ◽  
pp. 2587
Author(s):  
Yan Nie ◽  
Ying Tan ◽  
Yuqin Deng ◽  
Jing Yu

As a basic agricultural parameter in the formation, transformation, and consumption of surface water resources, soil moisture has a very important influence on the vegetation growth, agricultural production, and healthy operation of regional ecosystems. The Aksu river basin is a typical semi-arid agricultural area which seasonally suffers from water shortage. Due to the lack of knowledge on soil moisture change, the water management and decision-making processes have been a difficult issue for local government. Therefore, soil moisture monitoring by remote sensing became a reasonable way to schedule crop irrigation and evaluate the irrigation efficiency. Compared to in situ measurements, the use of remote sensing for the monitoring of soil water content is convenient and can be repetitively applied over a large area. To verify the applicability of the typical drought index to the rapid acquisition of soil moisture in arid and semi-arid regions, this study simulated, compared, and validated the effectiveness of soil moisture inversion. GF-1 WFV images, Landsat 8 OLI images, and the measured soil moisture data were used to determine the Perpendicular Drought Index (PDI), the Modified Perpendicular Drought Index (MPDI), and the Vegetation Adjusted Perpendicular Drought Index (VAPDI). First, the determination coefficients of the correlation analyses on the PDI, MPDI, VAPDI, and measured soil moisture in the 0–10, 10–20, and 20–30 cm depth layers based on the GF-1 WFV and Landsat 8 OLI images were good. Notably, in the 0–10 cm depth layers, the average determination coefficient was 0.68; all models met the accuracy requirements of soil moisture inversion. Both indicated that the drought indices based on the Near Infrared (NIR)-Red spectral space derived from the optical remote sensing images are more sensitive to soil moisture near the surface layer; however, the accuracy of retrieving the soil moisture in deep layers was slightly lower in the study area. Second, in areas of vegetation coverage, MPDI and VAPDI had a higher inversion accuracy than PDI. To a certain extent, they overcame the influence of mixed pixels on the soil moisture spectral information. VAPDI modified by Perpendicular Vegetation Index (PVI) was not susceptible to vegetation saturation and, thus, had a higher inversion accuracy, which makes it performs better than MPDI’s in vegetated areas. Third, the spatial heterogeneity of the soil moisture retrieved by the GF-1 WFV and Landsat 8 OLI image were similar. However, the GF-1 WFV images were more sensitive to changes in the soil moisture, which reflected the actual soil moisture level covered by different vegetation. These results provide a practical reference for the dynamic monitoring of surface soil moisture, obtaining agricultural information and agricultural condition parameters in arid and semi-arid regions.


Nativa ◽  
2018 ◽  
Vol 6 (6) ◽  
pp. 613 ◽  
Author(s):  
Daniel Soares Ferreira ◽  
Wilian Rodrigues Ribeiro ◽  
Morgana Scaramussa Gonçalves ◽  
Andre Alves Pinheiro ◽  
Ramon Amaro Sales ◽  
...  

A agricultura irrigada no Brasil cresceu mais de 40% nos últimos 20 anos, representando uma área de 4,4 milhões de ha, com a região Sudeste representando 47% deste total. O método de irrigação por pivô é o que mais cresce, com os estados de Minas Gerais, Goiás, Bahia e São Paulo concentrando cerca de 80% da área ocupada pela tecnologia. Neste cenário, a atualização das informações torna-se fundamentais pois criarão bases de conhecimento que irão ajudar estabelecer diretrizes para adoção e planejamento de políticas públicas que venham a contribuir para o uso estratégico dos recursos hídricos. Foi realizado fotointerpretação na escala de 1:1000, em imagens satélite da plataforma Google EarthTM Pro, para identificação do equipamento e obtenção de sua área de ocupação. Com os dados coletados realizou-se análises em função dos municípios, microrregiões e bacias hidrográficas. Atualmente, estima-se uma área irrigada de 134.741,11 hectares e 2.301 pivôs centrais. Os municípios de Rio Paranaíba (302), Perdizes (164), Santa Juliana (135), Uberaba (120) e Patos de Minas (111) destacam-se em maior número de equipamentos. A Microrregião de Araxá abrange a maior concentração de pivôs, 694, com 40.728,94 hectares irrigados. Na Bacia do Rio Paranaíba concentra-se 85,75% dos pivôs.Palavras-chave: sensoriamento remoto, sistema de irrigação, recursos hídricos. SCENARIO OF THE AREA IRRIGATED BY CENTRAL PIVOT IN THE TRIÂNGULOMINEIRO, IN THE STATE OF MINAS GERAIS, BRAZIL ABSTRACT: Irrigated agriculture in Brazil has grown over 40% in the last 20 years, representing an area of 4.4 million ha, with the Southeast region representing 47% of this total. The pivot irrigation method is the fastest growing, with the states of Minas Gerais, Goiás, Bahia and São Paulo concentrating around 80% of the area occupied by technology. In this scenario, updating the information becomes fundamental because it will create knowledge bases that will help establish guidelines for the adoption and planning of public policies that will contribute to the strategic use of water resources. It was realized photointerpretation in scale of 1: 1000, in satellite images of the platform Google EarthTM Pro, for identification of the equipment and obtaining of its area of occupation. With the data collected, analyzes were performed according to the municipalities, microregions and river basins. Currently, an irrigated area of 134,741.11 hectares and 2,301 central pivots is estimated. The municipalities of Rio Paranaíba (302), Perdizes (164), Santa Juliana (135), Uberaba (120) and Patos de Minas (111) stand out in more equipment. The Araxá Microregion encompasses the highest concentration of pivots, 694, with 40,728.94 irrigated hectares. In the Paranaíba River Basin, 85.75% of the pivots are concentrated.Keywords: remote sensing, irrigation system, water resources.


2017 ◽  
Vol 17 (5) ◽  
pp. 1278-1286 ◽  
Author(s):  
Larry W. Mays

There are many people on Earth today that live with severe water shortages and severe lack of sanitation, particularly among the poor. These people for the most part do not understand the knowledge base of methodologies of harvesting and conveying water and sanitation methods that have been around for thousands of years. A survey of ancient water technologies used in semi-arid and arid regions is presented in this paper. The survey will include methodologies used by Mesopotamians, the Persians, the Egyptians, and the Nabataeans. The attempt here is to explore how these traditional methods developed by the ancients in semi-arid and arid regions of the world could possibly be used to help solve the present-day water resources sustainability problems, especially in developing parts of the world. The advantages of the traditional knowledge of ancient water technologies are explored with the goal of determining ways to help poor people with water shortages and sanitation.


polemica ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 072-086
Author(s):  
Sandra Sereide Ferreira da Silva ◽  
Vera Lúcia Antunes De Lima ◽  
Ângela Maria Cavalcanti Ramalho ◽  
Allan Carlos Alves

Resumo: A escassez da água em regiões áridas e semiáridas tem sido tema de debates, políticas e pesquisas com o objetivo principal de subsidiar as ações capazes de permitir o seu aproveitamento racional, permitindo a convivência da população com os períodos de seca ou reduzida precipitação. Assim, a escassez de água tem conduzido à implantação de projetos de desenvolvimento, que têm como desafio a busca de alternativas de convivência com a seca que conduzam a melhorias sociais. Com base nesse contexto, este estudo tem como objetivo propor a criação de um modelo de construção de cenários para viabilidade do reúso de água para ser utilizado como elemento mitigador das implicações da seca em regiões semiáridas. O modelo de construção de cenários é um importante instrumento de gerenciamento de recursos naturais, neste caso específico, recursos hídricos, pois permite envolver um grande número de participantes, tem a possibilidade de orientar o debate público para a construção estratégica coletiva de um futuro almejado, contribui para um eficaz processo de aprendizagem organizacional no âmbito do Sistema Nacional de Gerenciamento de Recursos Hídricos visando um melhor entendimento, tanto dos aspectos ambientais quanto dos aspectos sociais e institucionais relacionados aos recursos hídricos no País, em especial, nas regiões semiáridas. Como se trabalham e convivem com a incerteza, os cenários procuram analisar e sistematizar as diversas probabilidades dos eventos e dos processos por meio da exploração dos pontos de mudança e das grandes tendências, de modo que as alternativas mais prováveis sejam antecipadas.Palavras-chaves: Recursos Hídricos. Reúso de Água. Regiões Semiáridas. Construção de Cenários.Abstract: Water scarcity in arid and semi-arid regions has been the subject of debates, policies and research with the main objective of subsidizing actions capable of allowing their rational use, allowing the population to coexist with periods of drought or reduced precipitation. Thus, water scarcity has led to the implementation of development projects, which challenge the search for alternatives to coexistence with drought that lead to social improvements. Based on this context, this study aims to propose the creation of a model for the construction of scenarios for the feasibility of water reuse to be used as a mitigating element of the drought implications in semi-arid regions. The scenario building model is an important tool for managing natural resources, in this specific case, water resources, since it allows a large number of participants to be involved, it has the possibility of guiding the public debate towards the collective strategic construction of a desired future, contributes to an effective organizational learning process within the National Water Resources Management System aiming at a better understanding of both the environmental aspects and the social and institutional aspects related to the water resources in the Country, especially in the semi-arid regions. As they work and coexist with uncertainty, the scenarios seek to analyze and systematize the various probabilities of events and processes by exploring the points of change and the major trends, so that the most likely alternatives are anticipated.Keywords: Water Resources. Water reuse. Semi-Arid Regions. Construction of Scenarios.


2020 ◽  
Vol 163 (3) ◽  
pp. 1247-1266 ◽  
Author(s):  
Hagen Koch ◽  
Ana Lígia Chaves Silva ◽  
Stefan Liersch ◽  
José Roberto Gonçalves de Azevedo ◽  
Fred Fokko Hattermann

AbstractSemi-arid regions are known for erratic precipitation patterns with significant effects on the hydrological cycle and water resources availability. High temporal and spatial variation in precipitation causes large variability in runoff over short durations. Due to low soil water storage capacity, base flow is often missing and rivers fall dry for long periods. Because of its climatic characteristics, the semi-arid north-eastern region of Brazil is prone to droughts. To counter these, reservoirs were built to ensure water supply during dry months. This paper describes problems and solutions when calibrating and validating the eco-hydrological model SWIM for semi-arid regions on the example of the Pajeú watershed in north-eastern Brazil. The model was calibrated to river discharge data before the year 1983, with no or little effects of water management, applying a simple and an enhanced approach. Uncertainties result mainly from the meteorological data and observed river discharges. After model calibration water management was included in the simulations. Observed and simulated reservoir volumes and river discharges are compared. The calibrated and validated models were used to simulate the impacts of climate change on hydrological processes and water resources management using data of two representative concentration pathways (RCP) and five earth system models (ESM). The differences in changes in natural and managed mean discharges are negligible (< 5%) under RCP8.5 but notable (> 5%) under RCP2.6 for the ESM ensemble mean. In semi-arid catchments, the enhanced approach should be preferred, because in addition to discharge, a second variable, here evapotranspiration, is considered for model validation.


2020 ◽  
Vol 63 (3) ◽  
pp. 703-729 ◽  
Author(s):  
Steven R. Evett ◽  
Paul D. Colaizzi ◽  
Freddie R. Lamm ◽  
Susan A. O’Shaughnessy ◽  
Derek M. Heeren ◽  
...  

Highlights Irrigation is key to the productivity of Great Plains agriculture but is threatened by water scarcity. The irrigated area grew to &gt;9 million ha since 1870, mostly since 1950, but is likely to decline. Changes in climate, water availability, irrigated area, and policy will affect productivity. Adaptation and innovation, hallmarks of Great Plains populations, will ensure future success. Abstract. Motivated by the need for sustainable water management and technology for next-generation crop production, the future of irrigation on the U.S. Great Plains was examined through the lenses of past changes in water supply, historical changes in irrigated area, and innovations in irrigation technology, management, and agronomy. We analyzed the history of irrigated agriculture through the 1900s to the present day. We focused particularly on the efficiency and water productivity of irrigation systems (application efficiency, crop water productivity, and irrigation water use productivity) as a connection between water resource management and agricultural production. Technology innovations have greatly increased the efficiency of water application, the productivity of water use, and the agricultural productivity of the Great Plains. We also examined the changes in water stored in the High Plains aquifer, which is the region’s principle supply for irrigation water. Relative to other states, the aquifer has been less impacted in Nebraska, despite large increases in irrigated area. Greatly increased irrigation efficiency has played a role in this, but so have regulations and the recharge to the aquifer from the Nebraska Sand Hills and from rivers crossing the state. The outlook for irrigation is less positive in western Kansas, eastern Colorado, and the Oklahoma and Texas Panhandles. The aquifer in these regions is recharged at rates much less than current pumping, and the aquifer is declining as a result. Improvements in irrigation technology and management plus changes in crops grown have made irrigation ever more efficient and allowed irrigation to continue. There is good reason to expect that future research and development efforts by federal and state researchers, extension specialists, and industry, often in concert, will continue to improve the efficiency and productivity of irrigated agriculture. Public policy changes will also play a role in regulating consumption and motivating on-farm efficiency improvements. Water supplies, while finite, will be stretched much further than projected by some who look only at past rates of consumption. Thus, irrigation will continue to be important economically for an extended period. Sustaining irrigation is crucial to sustained productivity of the Great Plains “bread basket” because on average irrigation doubles the efficiency with which water is turned into crop yields compared with what can be attained in this region with precipitation alone. Lessons learned from the Great Plains are relevant to irrigation in semi-arid and subhumid areas worldwide. Keywords: Center pivot, Crop water productivity, History, Sprinkler irrigation, Subsurface drip irrigation, Water use efficiency.


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