scholarly journals Use of Machine Learning in Evaluation of Drought Perception in Irrigated Agriculture: The Case of an Irrigated Perimeter in Brazil

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1546 ◽  
Author(s):  
Louise Caroline Peixoto Xavier ◽  
Samiria Maria Oliveira da Silva ◽  
Taís Maria Nunes Carvalho ◽  
João Dehon Pontes Filho ◽  
Francisco de Assis de Souza Filho
Keyword(s):  
Management Practices ◽  
Standardized Precipitation Index ◽  
Adaptation Strategy ◽  
Irrigated Agriculture ◽  
Drought Duration ◽  
Drought Period ◽  
Agriculture Sector ◽  
Proactive Management ◽  
Allocation Process ◽  
Irrigated Perimeter

This study aimed to understand the perception of drought among farmers, in order to support decision-making in the water allocation process. This study was carried out in the Tabuleiro de Russas irrigated perimeter, in northeast Brazil, over the drought period of 2012–2018. Two analyses were conducted: (i) drought characterization, using the Standardized Precipitation Index (SPI) based on drought duration and frequency criteria; and (ii) analysis of farmers’ perceptions of drought via selection of explanatory variables using the Random Forest (RF) and the Decision Tree (DT) methods. The 2012–2018 drought period was defined as a meteorological phenomenon by local farmers; however, an SPI evaluation indicated that the drought was of a hydrological nature. According to the RF analysis, four of the nine study variables were more statistically important than the others in influencing farmers’ perception of drought: number of cultivated land plots, farmer’s age, years of experience in the agriculture sector, and education level. These results were confirmed using DT analysis. Understanding the relationship between these variables and farmers’ perception of drought could aid in the development of an adaptation strategy to water deficit scenarios. Farmers’ perception can be beneficial in reducing conflicts, adopting proactive management practices, and developing a holistic and efficient early warning drought system.

scholarly journals Dealing with Water Scarcity and Salinity: Adoption of Water Efficient Technologies and Management Practices by California Avocado Growers

2020 ◽  
Vol 12 (9) ◽  
pp. 3555
Author(s):  
Julie Reints ◽  
Ariel Dinar ◽  
David Crowley
Keyword(s):  
Water Scarcity ◽  
Management Practices ◽  
Crop Yields ◽  
Saline Water ◽  
Primary Data ◽  
Irrigated Agriculture ◽  
Water Supplies ◽  
Self Organizing Maps ◽  
Agriculture Sector ◽  
Elevated Salinity

The irrigated agriculture sector has been facing an increased scarcity of good quality water worldwide. Consequently, the sustainability of water intensive crops, such as avocado, is threatened when water becomes scarce and expensive, or when growers must use saline water supplies that reduce crop yields. A variety of irrigation technologies and water management practices are now recommended to help growers through times of limited water supplies and elevated salinity levels. To examine how growers adopt different practices and combinations of practices, we collected data from a sample of avocado growers in California. We used Kohonen self-organizing maps, and developed logit models to identify the most common bundles of technologies and management practices that growers are using to deal with water scarcity. We test the validity of the proposed bundles and factors affecting their adoption, using primary data obtained from a survey of California avocado growers at the height of the drought during 2012–2013. Results show that farm location, share of income from agricultural production, use of cooperative extension advice, and farmer characteristics, such as age and education, all play important roles in grower adoption of individual and bundled methods to adapt to water scarcity.

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 ◽  
...  
Keyword(s):  
River Basin ◽  
Regional Climate ◽  
Standardized Precipitation Index ◽  
Extreme Drought ◽  
Mekong River ◽  
Drought Duration ◽  
Mekong River Basin ◽  
Drought Period ◽  
Mk Test ◽  
The Standardized Precipitation Index

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.

scholarly journals An Assessment of Drought Stress in Tea Estates Using Optical and Thermal Remote Sensing

2021 ◽  
Vol 13 (14) ◽  
pp. 2730
Author(s):  
Animesh Chandra Das ◽  
Ryozo Noguchi ◽  
Tofael Ahamed
Keyword(s):  
Remote Sensing ◽  
Drought Stress ◽  
Land Surface ◽  
Climatic Factors ◽  
Standardized Precipitation Index ◽  
Landsat 8 ◽  
Drought Frequency ◽  
Moisture Index ◽  
Area Index ◽  
Drought Period

Drought is one of the detrimental climatic factors that affects the productivity and quality of tea by limiting the growth and development of the plants. The aim of this research was to determine drought stress in tea estates using a remote sensing technique with the standardized precipitation index (SPI). Landsat 8 OLI/TIRS images were processed to measure the land surface temperature (LST) and soil moisture index (SMI). Maps for the normalized difference moisture index (NDMI), normalized difference vegetation index (NDVI), and leaf area index (LAI), as well as yield maps, were developed from Sentinel-2 satellite images. The drought frequency was calculated from the classification of droughts utilizing the SPI. The results of this study show that the drought frequency for the Sylhet station was 38.46% for near-normal, 35.90% for normal, and 25.64% for moderately dry months. In contrast, the Sreemangal station demonstrated frequencies of 28.21%, 41.02%, and 30.77% for near-normal, normal, and moderately dry months, respectively. The correlation coefficients between the SMI and NDMI were 0.84, 0.77, and 0.79 for the drought periods of 2018–2019, 2019–2020 and 2020–2021, respectively, indicating a strong relationship between soil and plant canopy moisture. The results of yield prediction with respect to drought stress in tea estates demonstrate that 61%, 60%, and 60% of estates in the study area had lower yields than the actual yield during the drought period, which accounted for 7.72%, 11.92%, and 12.52% yield losses in 2018, 2019, and 2020, respectively. This research suggests that satellite remote sensing with the SPI could be a valuable tool for land use planners, policy makers, and scientists to measure drought stress in tea estates.

scholarly journals Assessment of the Dissimilarities of EDI and SPI Measures for Drought Determination in South Africa

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Omolola M. Adisa ◽  
Muthoni Masinde ◽  
Joel O. Botai
Keyword(s):  
South Africa ◽  
South African ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Standardized Precipitation Index ◽  
Drought Monitoring ◽  
Drought Indices ◽  
Drought Severity ◽  
Pearson Correlation Coefficient ◽  
Drought Duration

This study examines the (dis)similarity of two commonly used indices Standardized Precipitation Index (SPI) computed over accumulation periods 1-month, 3-month, 6-month, and 12-month (hereafter SPI-1, SPI-3, SPI-6, and SPI-12, respectively) and Effective Drought Index (EDI). The analysis is based on two drought monitoring indicators (derived from SPI and EDI), namely, the Drought Duration (DD) and Drought Severity (DS) across the 93 South African Weather Service’s delineated rainfall districts over South Africa from 1980 to 2019. In the study, the Pearson correlation coefficient dissimilarity and periodogram dissimilarity estimates were used. The results indicate a positive correlation for the Pearson correlation coefficient dissimilarity and a positive value for periodogram of dissimilarity in both the DD and DS. With the Pearson correlation coefficient dissimilarity, the study demonstrates that the values of the SPI-1/EDI pair and the SPI-3/EDI pair exhibit the highest similar values for DD, while the SPI-6/EDI pair shows the highest similar values for DS. Moreover, dissimilarities are more obvious in SPI-12/EDI pair for DD and DS. When a periodogram of dissimilarity is used, the values of the SPI-1/EDI pair and SPI-6/EDI pair exhibit the highest similar values for DD, while SPI-1/EDI displayed the highest similar values for DS. Overall, the two measures show that the highest similarity is obtained in the SPI-1/EDI pair for DS. The results obtainable in this study contribute towards an in-depth knowledge of deviation between the EDI and SPI values for South Africa, depicting that these two drought indices values are replaceable in some rainfall districts of South Africa for drought monitoring and prediction, and this is a step towards the selection of the appropriate drought indices.

scholarly journals Spatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transfer

2012 ◽  
Vol 9 (1) ◽  
pp. 57-70 ◽  
Author(s):  
L. Lassaletta ◽  
E. Romero ◽  
G. Billen ◽  
J. Garnier ◽  
H. García-Gómez ◽  
...  
Keyword(s):  
River Basin ◽  
Management Practices ◽  
N Fertilization ◽  
Irrigated Agriculture ◽  
N Budget ◽  
Ebro River ◽  
N Retention ◽  
Management Measures ◽  
Mediterranean Regions ◽  
Food And Feed

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.

scholarly journals Caractérisation à l’aide du SPI de la Sécheresse climatique dans le bassin versant de Ziz (Sud-Est, Maroc)

2018 ◽  
Vol 14 (21) ◽  
pp. 177 ◽  
Author(s):  
Radouan Mehdaoui ◽  
El-Mostafa Mili ◽  
Aziz Seghir
Keyword(s):  
Temporal Variability ◽  
Standardized Precipitation Index ◽  
Winter Season ◽  
Spatial And Temporal Variability ◽  
Drought Period ◽  
North Eastern ◽  
Edge Part ◽  
The Standardized Precipitation Index ◽  
Bassin Versant ◽  
Eastern Edge

This paper analyzes the spatial and temporal variability of drought in winter season in an arid geographical gradient located in the eastern edge part of the Moroccan High Atlas especially at the Ziz watershed. Drought period between 1975 and 2013 were analyzed using the Standardized Precipitation Index (SPI) over 12 months for a 38-year scale. The results indicate that the most important drought by intensity and duration occurred during the 1982/84, 1983/84, 2000/01, and 2004/05 periods are generalized on all stations of the basin with a minimum SPI reached -2.77 at the Taous station. The results indicate that drought in winter have been tied to the dominance of dry circulation with the exception of the frequency of thermodynamic and north-eastern disturbances which are considered unstable aerological conditions. Which occur frequently between February and April of each year for the Errachidia station, Hassan Adakhil Dam, Foum Zaabal, Tillicht, M'Zizl, Arfoud and Taouz.

Soil sodicity in Victoria

Soil Research ◽  
1993 ◽  
Vol 31 (6) ◽  
pp. 869 ◽  
Author(s):  
GW Ford ◽  
JJ Martin ◽  
P Rengasamy ◽  
SC Boucher ◽  
A Ellington
Keyword(s):  
Land Degradation ◽  
Management Practices ◽  
Agricultural Land ◽  
Current Knowledge ◽  
Relevant Information ◽  
Irrigated Agriculture ◽  
Future Research ◽  
Sodic Soils ◽  
Diverse Range ◽  
Key Issues

This paper gives a broad overview of the distribution and agricultural importance of sodic soils in Victoria. Sodic soils are estimated to occupy at least 13.4 Mha, representing at least 73% of Victoria's agricultural land. Most of this land is used for dryland farming; about 85% of the cropped land and 66% of the land sown to dryland pastures occurs on sodic soils. The largest sodicity class is 'alkaline sodic', dominated by a diverse range of soils (red duplex, yellow duplex, calcareous earths and self-mulching cracking clays). Alkaline sodic soils comprise half of the total agricultural land area, or about 24% of the area of land currently used for dryland cropping and 21% of the land under sown pasture. Land degradation problems are recognized as affecting most agricultural land in Victoria, and to be substantially limiting its productivity. The nature, extent and severity of the various forms of land degradation are a consequence of both intrinsic soil properties and of management practices. There is an urgent need to improve current farming practices to prevent further deterioration of the soil resource. Existing knowledge of the behaviour of sodic soils under both dryland and irrigated agriculture is reviewed. It is concluded that substantial gains in productivity are possible, but will require effective collaboration between soil scientists, agronomists, and land managers. Collation and integration of current knowledge on the properties and management of sodic soils in Victoria, and the acquisition of additional relevant information by targeted long-term research is required. Key issues for future research are identified.

Support Irrigation Water Management of Cereals Using Optical Remote Sensing and Modeling in a Semi-Arid Region

2019 ◽  
pp. 124-145 ◽  
Author(s):  
Tarik Benabdelouahab ◽  
Hayat Lionboui ◽  
Rachid Hadria ◽  
Riad Balaghi ◽  
Abdelghani Boudhar ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
Near Infrared ◽  
Irrigated Agriculture ◽  
Optical Remote Sensing ◽  
Crop Modeling ◽  
Management Tools ◽  
Irrigated Perimeter ◽  
Semi Arid Region ◽  
Semi Arid

Irrigated agriculture is an important strategic sector for Morocco, contributing to food security and employment. Nowadays, irrigation scheme managers shall ensure that water is optimally used. The main objective was to support the irrigation monitoring and management of wheat in the irrigated perimeter using optical remote sensing and crop modeling. The potential of spectral indices derived from SPOT-5 images was explored for quantifying and mapping surface water content changes at large scale. Indices were computed using the reflectance in red, near infrared, and shortwave infrared bands. A field crop model (AquaCrop) was adjusted and tested to simulate the grain yield and the temporal evolution of soil moisture status. This research aimed at providing a scientific and technical approach to assist policymakers and stakeholders to improve monitoring irrigation and mitigating wheat water stress at field and irrigation perimeter levels in semi-arid areas. The approach could lead to operational management tools for an efficient irrigation at field and regional levels.

Irrigation Management and Water Pricing in Turkey

2012 ◽  
pp. 73-86
Author(s):  
Erol H. Cakmak
Keyword(s):  
Irrigation Water ◽  
Management Practices ◽  
Global Climate ◽  
Irrigation Management ◽  
Water Pricing ◽  
Irrigated Agriculture ◽  
Water Users ◽  
Total Water Consumption ◽  
Water Charges ◽  
Almost All

Irrigated agriculture in Turkey currently consumes 75 percent of the total water consumption, which corresponds to about 30 percent of the renewable water supply. Unfavorable future global climate and economic conditions will increase the stress in the water sector. The operation and maintenance (O&M) of almost all large surface irrigation schemes developed by the state has been transferred to irrigation associations governed by the farmers. The purpose of this paper is to provide an overview of irrigation management practices and an evaluation of irrigation water pricing after the transfer using price data at the association level since 1999. Results indicate that both irrigation water charges and collection rates increased following the transfer. However, the recuperation of investment costs for irrigation development from the users has remained minimal. The price of the irrigation water continued to be on per hectare basis, and farmers using pumping water face 2.5 times higher water charge per hectare then the gravity water users. The uptake of more efficient water application technology accompanied by pricing mechanisms reflecting scarcity value of water will certainly ease the adjustment burden of the irrigation sector in the future.

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