Search

This paper analyzes the behavior of drought in the face of the impact of climate change and groundwater quality and its implications for agricultural production in a semi-arid area of northeastern Mexico. The pluviometric information of two stations from 1961 to 2020 was analyzed, and the Standardized Precipitation Index was applied in the spring–summer period (SPI-6). Twenty-five samples from the Ahualulco aquifer were collected and analyzed, to which quality indices for agricultural use were applied. The results show that in the last 20 years there have been mild to moderate droughts, which have considerably affected rainfed farmers. The area under irrigation is affected by salinity conditions as the water goes from medium to high conductivities and low to medium sodicity, which indicates a medium sodicity risk but an excessive salinity risk. [ABSTRACT FROM AUTHOR]

Climate change is among the most pressing challenges for human advancement in the twenty-first century. Climate change is having a significant impact on the agricultural sector. The main objective of this study is to evaluate the food security status and sustainability of crop production under different climate change scenarios in the arid and semi-arid zones of Iran. To this end, the Statistical Down-Scaling Model (SDSM) and the outputs of the General Circulation Model (GCM) are employed to project future climate parameters under three climate scenarios. The study then employs the Just and Pope approach by using a panel dataset to evaluate the impact of climate change on crop production. Also, the multi-criteria decision-making (MCDM) technique is used to assess the sustainability of crop production from an economic, social, and environmental perspective in the context of climate change and baseline conditions. The results of the study show that precipitation has a significant favourable effect on crop yield in both zones. Maximum temperature is positively and significantly related to crop yield in the semi-arid area, while the relationship is negative in the arid region. Future projections reveal that under different climate scenarios, the production of irrigated wheat, dryland wheat, irrigated barley, dryland barley, and potato crops will change by a maximum of approximately 7.57%, 35.70%, 62.86%, 15.90%, and 26.88% in the semi-arid zone and − 24.07%, 29.73%, − 31.33%, − 4.80%, and 25.80% in the arid zone, respectively. The findings imply that climate change will decrease the food security index for all crops in the arid zone, while improving the situation for crops in the semi-arid region. The results also indicate that future climate change can have a significant adverse effect on economic water productivity, economic benefits, and the sustainability of strategic crop production in the arid zone compared to the semi-arid zone. Given that a large part of Iran is covered by an arid climate, designing coherent adaptation actions and mitigation policies need to be prioritized to tackle the negative impact of climate change on food production systems. [ABSTRACT FROM AUTHOR]

This paper aims at assess district-wise vulnerability index of the state of Karnataka State, which is predominantly is rainfed and is highly susceptible to climatic variability. Secondary data on relevant indicators were collected to prepare indices viz., crop production losses, exposure, sensitivity and adaptive capacity. Following normalization and using appropriate weights for indicators, these four indices were used for constructing vulnerability index, which can be used a rapid assessment method for prioritizing districts that need measures to moderate the detrimental impact of climate change. It has been observed that Climatic variability caused higher production losses in cereals, pulses and oilseeds in Davangere, Gulbarga and Raichur districts, respectively. Districts like Koppal, Raichur, Bijapur Gulbarga, Gadag, Bagalkote and Bellary were placed under extreme degree of exposure. As per the sensitivity index scores, Kolar district is the most sensitive. Further, Bengaluru (Urban), Dakshin Kannada and Kodagu are ranked first, second and third in terms of adaptive capacity in the state. Overall, vulnerability index scores indicate that Gulbarga, Koppal, Raichur, Bellary, Bagalkote, Bijapur and Belgaum are extremely vulnerable districts in the state. It was also estimated that around 70% of the cultivated area, which supports 60% and 67% of livestock and rural population of the state, respectively are facing ‘extreme to high’ level of vulnerability. The ranking based prioritization of the vulnerable areas calls for a holistic approach for each district or a group of districts to reduce their sensitivity, minimize exposure to rainfall variability through implementation of site-specific and leverage adaptive capacity through better health and education facilities, expansion of employment opportunities in other sectors or reducing over dependence on agriculture. [ABSTRACT FROM AUTHOR]

Adaptation to future climate change with limited water resources is a major global challenge to sustainable and sufficient crop production. However, the large-scale responses of the crop water footprint and its associated benchmarks under various irrigation regimes to future climate change scenarios remain unclear. The present study quantified the responses of the maize and wheat water footprint (WF) per unit yield (m 3 t -1) as well as the corresponding WF benchmarks under two Representative Concentration Pathway (RCP) scenarios, RCP2.6 and RCP8.5, in the 2030s, 2050s, and 2080s at a 5 arcmin grid level in China. The AquaCrop model with the outputs of six global climate models from Phase 5 of the Coupled Model Intercomparison Project (CMIP5) as its input data was used to simulate the WFs of maize and wheat. The differences among rain-fed wheat and maize and furrow-, micro-, and sprinkler-irrigated wheat and maize were identified. Compared with the baseline year (2013), the maize WF will increase under both RCP2.6 and RCP8.5 (by 17 % and 13 %, respectively) until the 2080s. The wheat WF will increase under RCP2.6 (by 12 % until the 2080s) and decrease (by 12 %) under RCP8.5 until the 2080s, with a higher increase in the wheat yield and a decrease in the wheat WF due to the higher CO 2 concentration in 2080s under RCP8.5. The WF will increase the most for rain-fed crops. Relative to rain-fed crops, micro-irrigation and sprinkler irrigation result in the smallest increases in the WF for maize and wheat, respectively. These water-saving management techniques will mitigate the negative impact of climate change more effectively. The WF benchmarks for maize and wheat in the humid zone (an approximate overall average of 680 m 3 t -1 for maize and 873 m 3 t -1 for wheat at the 20th percentile) are 13 %–32 % higher than those in the arid zone (which experiences an overall average of 601 m 3 t -1 for maize and 753 m 3 t -1 for wheat). The differences in the WF benchmarks among various irrigation regimes are more significant in the arid zone, where they can be as high as 57 % for the 20th percentile: WF benchmarks of 1020 m 3 t -1 for sprinkler-irrigated wheat and 648 m 3 t -1 for micro-irrigated wheat. Nevertheless, the WF benchmarks will not respond to climate changes as dramatically as the WF in the same area, especially in areas with limited agricultural development. The present study demonstrated that the observed different responses to climate change in terms of crop water consumption, water use efficiency, and WF benchmarks under different irrigation regimes cannot be ignored. It also lays the foundation for future investigations into the influences of irrigation methods, RCPs, and crop types on the WF and its benchmarks in response to climate change in all agricultural regions worldwide. [ABSTRACT FROM AUTHOR]

The frequency of drought events in the Mediterranean region has increased significantly in recent years, along with a substantial increase in their spatial and temporal extent. These events are associated with high temperatures and low precipitation. Our study presents a vision on the impact of temperature on agricultural drought frequency, severity, and temporal extent under future scenarios over seven vast plains located in the semi-arid region of the Mediterranean basin. A multivariate frequency analysis of both meteorological and agricultural drought characteristics is based using the copula theory. The return periods of past and future drought events are determined using the two drought indices standardized precipitation index and standardized precipitation evapotranspiration index. The projected drought events are determined based on climate simulations (monthly precipitations and temperatures) from the RCA4-MPI-ESM-LR model, and the projection period was forced by the two representative concentration pathway scenarios RCP4.5 and RCP8.5. Results showed that the frequency of drought events is much higher if only precipitation (SPI) is taken into account than if overall climate (precipitation and temperature, SPEI) is considered while their severity and duration are more intense using SPEI. The risk of drought is best estimated by multivariate frequency analysis where the unvaried return periods, considering the duration or severity, underestimate the recurrence of events. Drought events in the plains are likely to be more severe and to last longer, particularly during the hot season (between May and September) between 2021 and 2071 according to the two future scenarios. In addition, agricultural production is threatened by a spring agricultural drought (between February and April) between 2050 and 2100 under the RCP4.5 scenario, which can have serious consequences on agricultural income as well as food security. [ABSTRACT FROM AUTHOR]

Climate change has caused a shift in aridity, particularly in the world's dry regions, affecting several sectors, predominantly the agricultural and water resources. This research examined the climate change effects on crop water demand (CWD) in Syria during 1951–2010. Given the lack of observed data, this analysis relied on Global Precipitation Climatology Center (GPCC) precipitation and Climatic Research Unit (CRU) temperature. Potential evapotranspiration (PET) at each grid was estimated using the Penman–Monteith model and the CWD using the FAO-56 method. The analysis revealed that CWD in Syria increased during 1981 − 2010 compared to that during 1951 − 1980. The increase in CWD was found for grapes, tobacco, barley, and cotton, whereas the maximum changes were during April and May. The most remarkable changes in CWD were for barley, between − 20 and 40 mm. It showed a decreased CWD in the south and a rise in the north (0 − 40 mm). The CWD for wheat showed a decline in most parts of the country, except in the north. The increase in CWD for barley and wheat caused an increase in agricultural water stress in the region. Agriculture planning needs to be developed according to the expected future climate changes to maintain the agricultural production in the region. [ABSTRACT FROM AUTHOR]

Climate variability and change coupled with small landholdings, low land productivity and water scarcity in arid and semi-arid regions contribute to environmental degradation, reduced agricultural productivity, and increased vulnerability to the rural communities. With the aid of the fuzzy cognitive maps constructed by 427 community groups with 4–5 members in each group, drawn from 96 villages in 12 districts of arid and semi-arid India, the paper evaluates the effectiveness of various adaptation pathways. The ongoing adaptations in arid and semi-arid India face adaptation deficits. The FCM-based simulations revealed that integrated adaptation measures that embrace nature-based solutions, including integrated water resource management, natural farming-assisted soil rejuvenation, and improved agricultural productivity are most likely to enhance the resilience of small and marginalised farming communities to climate variability and change. Facilitation of such adaptation measures requires inclusive and adaptive local institutions, sufficient financial assistance, and climate information services. Besides, gender-nuanced, inclusive, and adaptive governance and processes would be helpful for the implementation of appropriate adaptation interventions in arid and semi-arid drylands worldwide. Hence policy-makers must enable polycentric and adaptive governance, and inclusive institutions and processes. The emphasis on multiple factors in a socio-ecological system often makes it difficult to understand the critical role of a particular factor. However, the FCM-based simulations in this study helped us overcome such limitations. Image 1 • FCM-based simulations used to examine the effectiveness of current adaptations. • Current adaptations face adaptation deficit and provide limited resilience. • Integrated adaptations embracing nature-based solutions could provide resilience. • Lack of finance, technology, and locally relevant information are the key barriers. • Polycentric-adaptive governance and inclusive institutions & processes are crucial. [ABSTRACT FROM AUTHOR]

Currently, an important scientific challenge that researchers are facing is to gain a better understanding of climate change at the regional scale, which can be especially challenging in an area with low and highly variable precipitation amounts such as Iran. Trend analysis of the medium-term change using ground station observations of meteorological variables can enhance our knowledge of the dominant processes in an area and contribute to the analysis of future climate projections. Generally, studies focus on the long-term variability of temperature and precipitation and to a lesser extent on other important parameters such as moisture indices. In this study the recent 50-year trends (1955-2005) of precipitation (P), potential evapotranspiration (PET), and aridity index (AI) in monthly time scale were studied over 14 synoptic stations in three large Iran basins using the Mann-Kendall non-parametric test. Additionally, an analysis of the monthly, seasonal and annual trend of each parameter was performed. Results showed no significant trends in the monthly time series. However, PET showed significant, mostly decreasing trends, for the seasonal values, which resulted in a significant negative trend in annual PET at five stations. Significant negative trends in seasonal P values were only found at a number of stations in spring and summer and no station showed significant negative trends in annual P. Due to the varied positive and negative trends in annual P and to a lesser extent PET, almost as many stations with negative as positive trends in annual AI were found, indicating that both drying and wetting trends occurred in Iran. Overall, the northern part of the study area showed an increasing trend in annual AI which meant that the region became wetter, while the south showed decreasing trends in AI. [ABSTRACT FROM AUTHOR]