Spatial and Temporal Pattern Assessment of Agricultural Drought Sensitivity and its Potential Impact on Economic Crops in Nakhon Ratchasima, Thailand

Climate change impacts on meteorological, agricultural and hydrological droughts in China

Thailand frequently suffers from rainfall shortages and ensuing droughts and the northeast region is especially vulnerable. The effects of climate change on water resources are further directly related to agricultural drought vulnerability. The objectives of the study were (1) to assess the spatial and temporal patterns of agricultural drought vulnerability based on agricultural drought exposure, agricultural drought sensitivity, and adaptive capacity and (2) to assess the potential impact of agricultural drought vulnerability on economic crops. To do so, this study integrated drought exposure, drought sensitivity and adaptive capacity for assessing spatial and temporal patterns of agricultural drought vulnerability and their potential impacts on economic crops at both the district and subdistrict levels in Thailand’s northeastern Nakhon Ratchasima Province. Our results showed that the spatial and temporal patterns of agricultural drought vulnerability in two periods (6m10 and 12m) varied from one region to another. Levels of severity were established, and moderate, high and very high levels were found in 10 districts and 96 subdistricts in the 6m10 period (May to October). They further occurred in 17 districts and 166 subdistricts in the 12m period (January to December). Districts and subdistricts with identical potential impact in both periods included 3 districts and 48 subdistricts. The potential impact of agricultural drought vulnerability on economic crops further was higher in the 12m duration than for 6m10. The highest potential impact was found to be on cassava (2023). In conclusion, the results of the study can be used as basic information for government agencies to monitor and mitigate agricultural drought in Nakhon Ratchasima. The government should further consider implementing a feasibility study for groundwater use in local agriculture, to better mitigate the impact of drought on important vulnerable economic crops.

Purpose: This paper discusses theoretical, policy and practical issues concerning the problem of ‘agrochemical dependency’ in Thailand, including roles that public extension services play in advocacy or mitigation of agrochemical use.Methodology/Approach: Our research aimed to better understand department of agricultural extension (DOAE) institutional and officials’ perceptions of contributing factors to agrochemical dependency as well as strategies for mitigating agrochemical use. We reviewed relevant policies, web materials and technical cooperation agreements. We supplemented theoretical and document analysis with interviews totalling15 DOAE managers or senior officers comparing Bangkok headquarters and Nan Province perspectives. We refer to relevant secondary literatures for explanatory context.Findings: Results showed differences as well as similarities between views of DOAE officials in Bangkok headquarters and those from one province (Nan) about DOAE priorities, responsibilities and perceived reasons why farmers overuse agrochemicals or do not adopt organic agriculture (OA). A national policy encouraged ‘safe use’ of agrochemicals but not (necessarily or effectively) mitigation while the DOAE still (to a much lesser extent) promoted self-sufficiency and OA alternatives. Interviews and documentary evidence revealed DOAE public–private partnerships with corporate advice, technical support, human resources and learning activities that encouraged or normalized agrochemical use and dependency.Practical Implications: Study results should be useful for governments, donors, international agencies and department officials in policy development, program planning, training design, budgeting and delivery.Originality/Value: This study is unique for: better understanding implications of agrochemical dependency and privatization of public extension services; analyzing factors inhibiting OA adoption; and examining contentious policies, partnerships, and training activities.

<span>Frequency and intensity of drought have troubled sustainable agriculture and worsened food insecurity of Ethiopians. This study aimed to investigate climate change-induced agricultural drought over the moist-cool and moist-warm climatic zones, using historical precipitation and temperature data recorded in the crop growing months for 35 years. The changes of temperatures and precipitation were analyzed using Mann Kendall trend test. Agricultural drought indices were analyzed using R-model by withdrawing potential evapotranspiration from precipitation to determine the existing water balance. The values of drought indices were used to characterize the duration, severity, intensity and trends of agricultural drought. Results showed that the changes in maximum and minimum temperatures and precipitation were significantly stronger in the Ale Woreda (P<0.05). However, minimum temperature and precipitation in Adami-Tulu did not noticeably change. The spatial drought events occurred more widely in Ale than in Adami Tulu. The events occurred 12 and 17 times with cumulative severity indices of 41.95 and 48.22 in Ale and Adami-Tulu, respectively. Agricultural drought intensities of the two districts were labeled as “severe” and “moderate dry”, for Ale and Adami-Tulu, respectively. The intensity of drought in Ale district significantly increased (P<0.05) and that in Adami-Tulu negligibly changed. Therefore, the study explicitly showed that more changes in temperature and precipitation aggravated agricultural drought in Ale than in Adami-Tulu more intensely and it is suggested that more attention shall be paid to Ale Woreda.</span>

In recent years, the intensity and frequency of droughts have been increasing with the advent of the climate crisis. Agricultural droughts have a significant economic and social impact. Agricultural drought is not only a natural disaster but also leads to food security threats and reduced economic activities, such as decreased productivity. Therefore, it is very important to specify the scale of agricultural drought and quantitatively estimate the economic damage. In this study, we developed an analytical methodology to quantitatively assess the economic damage of agricultural drought and estimated the damage of agricultural drought in 2018 and 2019 for the Republic of Korea. The 2018 agricultural drought was estimated to have caused USD 4.438 million in damage cost and USD 5.180 million in recovery cost. The 2019 drought was less damaging than the previous year, with an estimated damage cost of USD 286,000 and recovery costs of USD 218,000. The results suggest that the economic impact of agricultural drought varies by region depending on the frequency and intensity of the drought and confirm the importance of regional strategies for effective drought management and response. The impacts of agricultural drought go beyond short-term agricultural losses and lead to long-term economic burdens. Therefore, the results of this study are expected to be used as a basis for understanding the impacts of agricultural drought on national economies and for developing policies and strategies to minimize impacts.

Exploring the influence of climate change-induced drought propagation on wetlands

ABSTRACTIt has been broadly reported that future climate change will most likely affect the spatio‐temporal distribution of water resources and consequently droughts. There is a prevailing notion that an increase in temperature and frequency of heat waves are expected to result in more intense droughts in the coming years. In this study, we aimed to evaluate the effect of the potential evapotranspiration (PET) method selection on future drought projections over Poland. In our study, simulations of the Soil and Water Assessment Tool (SWAT) model were conducted, utilising an ensemble of six EURO‐CORDEX projections, spanning the period from 2006 to 2100 under the RCP8.5 scenario. Two model setups with two different PET methods (Penman‐Monteith—PM and Hargreaves—HAR) were used. For drought conditions evaluation we selected the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for meteorological drought, Standardized Streamflow Index (SSI) for hydrological drought, and Standardized Soil Moisture Index (SMI) for agricultural drought. The meteorological and hydrological droughts were calculated using a 12‐month time aggregation window, while agricultural drought was calculated using a 3‐month window. Climate projections revealed that by 2080s annual mean temperature and precipitation increase is expected by up to +3.4°C and +10.3% respectively. Under future climate conditions duration and severity of meteorological droughts are projected to decrease. PM method leads to a higher PET increases (1.35 mm year−1) than the HAR method (1.1 mm year−1) throughout the century which entail diverging signal of change for agricultural and hydrological droughts. PM‐ and HAR‐based simulations indicate increase in the total duration and cumulative severity of agricultural droughts, buthowever, for HAR‐based projections, the increase is much less. For hydrological droughts the signal of change is similar for both PET methods, but considerably distinct in magnitude. Considering the entire simulation period, by the end of the century cumulative severity of hydrological droughts is projected to decrease, with a much more pronounced decline for HAR (70% reduction) than for the PM method (35% reduction). Our study demonstrated that methodological choices are crucial to the assessment of future drought risk under climate change.

Comprehensive consideration of physical forms of meteorological and agricultural drought is necessary for the development of robust monitoring and assessment of droughts. This consideration facilitated the development and analyze an integrated weighted drought index (IWDI) by using the AHP (analytical hierarchy process) technique that takes into account all possible variables relevant to different types of drought such as meteorological, agriculture, and soil moisture drought indices. Heilongjiang northeastern province of China had suffered frequent droughts due to the changing climate. Droughts affected agricultural production and caused a decrease in total yield due to less water availability, particularly in summer which is the only growing season in the area. In this study, an integrated index was developed to examine its applicability and to assess the impact of drought on rice yield using eight different drought indices included meteorological, remote sensing multi-sensor, soil moisture conditions, and climate variables. The results showed that IWDI had a significant correlation with meteorological and agricultural drought indices. Detailed analysis revealed that, compared to a single meteorological or an agricultural drought index, IWDI achieved good results for agriculture drought monitoring. Results showed that IWDI captured a significant impact of drought on rice yield and its variation in the area which was from 17 to 75% at different stations. This study also concluded that integration of different indices may be a better option for policymakers and economists in understanding and monitoring agricultural droughts losses.

Precipitation and vegetation transpiration variations dominate the dynamics of agricultural drought characteristics in China

Agricultural drought is closely related to meteorological drought in which the agricultural drought is an impact of meteorological drought. This study aim to understand the duration, spatial extent, severity and lag time of meteorological and agricultural drought during El Niño years. The data used in this study are monthly data of CHIPRS and MODIS. Meteorological drought and agricultural drought are intensified in the El Niño years. The duration of meteorological drought is different in each region but generally occurs during June to November. Agricultural drought mostly occurs from August to November. Spatially, meteorological drought and agricultural drought in 2015 has wider extent and higher severity (SPI <-2 and VHI <10) than in 2002. Agricultural drought generally intensified in areas that have monsoonal rainfall type such as Java, Bali, Nusa Tenggara, Lampung, southern part of Kalimantan, and southern part of Sulawesi. We found that VHI is significantly correlated with SPI-3 reach 58% of the total area of Indonesia. It means rainfall deficit during three months has a significant impact on agricultural drought in Indonesia. In general, SPI-3 and VHI clearly explain the relationship between meteorological drought and agricultural drought in Indonesia.

This study investigates the impacts of climate change and water management including agricultural irrigation, water withdrawal, and reservoir regulation on future meteorological, agricultural, and hydrological droughts and their connections. The analysis is based on the simulations from four global hydrological models forced with the projections from five global climate models for historical period 1971–2000 and future period 2070–2099 with and without water management. Three unified drought indices, the standardized precipitation index, standardized soil moisture index, and standardized streamflow index, are adopted to represent the meteorological, agricultural, and hydrological droughts, respectively. The analysis suggests that the climate‐induced drought changes in all three types of droughts are enhanced but in different directions, while water‐management‐induced changes in agricultural and hydrological droughts are more consistent across space and simulations. Overall, water management activities reduce both the duration and intensity of agricultural droughts by roughly 1 order of magnitude, while increase those of hydrological droughts by up to 50%. Basin‐scale analysis reveals that the higher is the intensity of irrigation, the larger will be the water‐management‐induced drought changes. Due to water management activities at some regions, the return periods of extreme agricultural droughts (in terms of severity) can change from 100 to 300 years or even longer, while typical 100‐year hydrological droughts are likely to occur more often for the regions located in 25°N–40°N and 15°S–50°S. This study provides a global view on drought modification in the Anthropocene, which will help improve adaptation strategies for future droughts.

Meteorological drought indicators are commonly used for agricultural drought contingency planning in Ethiopia. Agricultural droughts arise due to soil moisture deficits. While these deficits may be caused by meteorological droughts, the timing and duration of agricultural droughts need not coincide with the onset of meteorological droughts due to soil moisture buffering. Similarly, agricultural droughts can persist, even after the cessation of meteorological droughts, due to delayed hydrologic processes. Understanding the relationship between meteorological and agricultural droughts is therefore crucial. An evaluation framework was developed to compare meteorological- and agriculture-related drought indicators using a suite of exploratory and confirmatory tools. Receiver operator characteristics (ROC) was used to understand the covariation of meteorological and agricultural droughts. Comparisons were carried out between SPI-2, SPEI-2, and Palmer Z-index to assess intraseasonal droughts, and between SPI-6, SPEI-6, and PDSI for full-season evaluations. SPI was seen to correlate well with selected agriculture-related drought indicators, but did not explain all the variability noted in them. The correlation between meteorological and agricultural droughts exhibited spatial variability which varied across indicators. SPI is better suited to predict non-agricultural drought states than agricultural drought states. Differences between agricultural and meteorological droughts must be accounted for in order to devise better drought-preparedness planning.

<sec><p indent="0mm">Agricultural droughts, causing 9%–10% loss in global crop yield, seriously threaten food security and sustainable socio-economic development at regional and global scales. Based on impact-based early warning, the threats from agricultural drought hazards can be effectively prevented and drought loss can be significantly mitigated, and thus it is a hot and cutting-edge scientific topic presently. In this article, we aimed at the impact-based early warning of agricultural drought, and focused on its three important issues: agricultural drought impact data, agricultural drought indices, and methods for determining agricultural drought thresholds, respectively. Our objective is to provide a comprehensive review of the current research progress and future prospects in this field. </sec><sec> The key to impact-based early warning of agricultural drought is to establish the relationship between actual agricultural drought impacts and agricultural drought indicators. However, low spatiotemporal resolution of existing agricultural drought impact data cannot meet the needs of agricultural drought early warning at local scales, especially when facing diverse agricultural conditions. Thus, it is required to apply high-resolution meteorological, hydrological, and vegetation spectral data, and also generate high-resolution agricultural drought impact dataset through suitable downscaling approaches. A large number of indices have been proposed and developed for characterizing agricultural drought and describing its spatiotemporal variability. </sec><sec> These indices include single variable-based drought indices and multiple variables-based composite drought indices. Among them, vegetation indices, which exhibit a strong correlation with crop yields and are sensitive to water deficit conditions, have much better application potential for impact-based early warning of agricultural drought, than other types of widely used drought indices. Agricultural drought thresholds, linking the critical states of water deficit with actual drought impacts, are crucial for early warning of agricultural droughts. Particularly, the thresholds of vegetation indices can accurately capture the abrupt changes in crop physiological traits caused by water deficit conditions. The absolute threshold method has been widely used for the determination of agricultural drought thresholds. However, it fails to reflect the inherent spatial heterogeneity of vegetation conditions in specific regions, resulting in the biased assessment of agricultural drought impacts as well as its early warning. Alternatively, it would be more reasonable to evaluate the agricultural drought degrees using the “relative threshold method”. The core of relative threshold method is to estimate the relative changes of actual agricultural drought condition compared to its own baseline, based on which different agricultural drought degrees can be reasonably quantified. The relative threshold method enhances the spatial applicability of agricultural drought thresholds, and thus can be a more adaptive approach for the impact-based early warning of agricultural droughts. </sec><sec> Currently, the impact-based early warning of agricultural droughts is still a big research gap, and its development is challenging. In order to promote the research on impact-based early warning of agricultural droughts, we suggest that more reliable agricultural drought impact dataset with high resolution should be generated by applying both statistical and dynamic downscaling methods, and the relative threshold method should be further improved by verifying its reasonableness and applicability. Meanwhile, more efforts should focus on establishing synthetic agricultural drought early warning system by coupling physical models and artificial intelligence methods, and multi-dimensional influencing factors and their cascading impacts on socio-economic developments should be considered together. Then, it can be expected that the uncertainties of agricultural drought forecasting and early warning can be reduced, and agricultural drought hazards can be more effectively prevented. </sec>

Droughts have more impact on crops than any other natural disaster. Therefore, drought risk assessments, especially quantitative drought risk assessments, are significant in order to understand and reduce the negative impacts associated with droughts, and a quantitative risk assessment includes estimating the probability and consequences of hazards. In order to achieve this goal, we built a model based on the three-dimensional (3D) Copula function for the assessment of the proportion of affected farmland areas (PAFA) based on the idea of internally combining the drought duration, drought intensity, and drought impact. This model achieves the “internal combination” of drought characteristics and drought impacts rather than an “external combination.” The results of this model are not only able to provide the impacts at different levels that a drought event (drought duration and drought intensity) may cause, but are also able to show the occurrence probability of impact at each particular level. We took Huize County and Mengzi County in Yunnan Province as application examples based on the meteorological drought index (SPI), and the results showed that the PAFAs obtained by the method proposed in this paper were basically consistent with the actual PAFAs in the two counties. Moreover, due to the meteorological drought always occurring before an agricultural drought, we can get SPI predictions for the next month or months and can further obtain more abundant information on a drought warning and its impact. Therefore, the method proposed in this paper has values both on theory and practice.

The research aims to identify the reality of the extension services provided to workers in the vegetable production in the farms of Imam Hussein and Al-Abbas’s shrines by the agricultural and extension departments in the holy Karbala governorate. The research included the vegetable farms belonging to Imam Hussein and Al-Abbas’s holy shrines, as well as the agricultural extension departments that provided extension services to those farms. The research sample was chosen from all the agricultural extension agents in the agricultural extension departments in Karbala governorate, totaling (36) agricultural extension agents. In order to achieve the objectives of the research, the researcher prepared a questionnaire to collect data related to the research topic. It contained a 4-point scale for the reality of extension services provided to workers in vegetable production in the shrine’s farms, which includes (82) paragraphs, to measure the axes of extension services. The research concluded that there are few activities and extension services provided by extension agents in agricultural extension departments. The researcher recommends that the vegetable farms of the two shrines be included in the annual plans to provide activities and extension services by the extension organizations in the governorate. Besides that, these activities should be planned and targeted..