Increase In Minimum Temperature Research Articles

Contrasting hydro-climatic trends and drought dynamics in Ethiopia and South Africa under climate change

Climate change profoundly impacts hydro-climatic systems, altering precipitation, temperature, and drought dynamics. This study investigates contrasting trends in Ethiopia and South Africa under historical and future scenarios (SSP2-4.5, and SSP5-8.5) using CMIP6 datasets. The analysis encompasses national averages and regional clusters to capture both spatial and temporal variability. In Ethiopia, annual precipitation increases by 1.2 mm/year under SSP2-4.5 and 2.5 mm/year under SSP5-8.5, potentially benefiting agriculture but elevating flood risks. Conversely, South Africa experiences decline in precipitation of 0.25 mm/year and 0.32 mm/year under SSP2-4.5 and SSP5-8.5, respectively, likely to exacerbate water scarcity and compromising agricultural resilience. Both countries see substantial increases in potential evapotranspiration (PET) and temperature extremes. Ethiopia’s PET rises by 0.67 mm/year and 0.97 mm/year, while South Africa’s PET increases by 1.14 mm/year and 1.83 mm/year. Temperature increases in Ethiopia are more pronounced in minimum temperatures, while South Africa shows a similar rate of increase in both maximum and minimum temperatures. Drought analysis using SPEI and SPI indices reveals divergent trends: Ethiopia generally experiences decreased drought occurrence, severity and frequency, whereas South Africa faces increased drought occurrences and its properties, particularly under high emissions. These trends vary across clusters, highlighting the need for tailored adaptation strategies in each region. Despite its comprehensive approach, the study acknowledges limitations, including uncertainties in climate model projections and the need for more localized data. Understanding the interplay between hydro-climatic variables and their extremes is essential for effective adaptation. Ethiopia should strengthen flood management and promote soil conservation practices, while South Africa should focus on water conservation. Both nations must integrate climate projections into planning, enhance early warning systems, and foster public–private partnerships for successful adaptation.

Evolution of warm nights in the Canary Islands (1950–2023): evidence for climate change in the Southeastern North Atlantic

Nighttime temperatures have a direct impact on the health and well-being of the population, and are closely linked to the aggravation of certain pathologies and mortality. As global warming acquires extraordinary magnitudes, concepts such as warm night, tropical night or equatorial night, used as indicators to evaluate the evolution of temperatures during the night, are becoming popular. This paper analyses the evolution of nighttime temperatures in the Canary Islands since 1950, identifying a very notable increase in the daily minimum temperature, particularly at the summits, where the rate of increase exceeds 0.2 °C per decade. Overall, the daily minimum temperature easily reaches 20 °C in many parts of the islands, with a statistically significant upward trend in the frequency of tropical nights. In addition, they tend to occur over an increasingly longer season, more consecutively and with greater thermal intensity. Equatorial nights — ≥ 25 °C— are still an eminently summer phenomenon of growing importance in certain areas of the inland of some islands. Torrid nights — ≥ 30 °C—, on the other hand, are associated with extremely warm episodes that affect specific sectors conditioned by local factors.

Climate change impact on water treatment plants: analysis of chlorophyll-a levels and process performance.

Climate change significantly impacts the risk of eutrophication and, consequently, chlorophyll-a (Chl-a) concentrations. Understanding the impact of water flows is a crucial first step in developing insights into future patterns of change and associated risks. In this study, the Statistical DownScaling Model (SDSM)-a widely used daily downscaling method-is implemented to produce downscaled local climate variables, which serve as input for simulating future hydro-climate conditions using a hydrological model. The vulnerability of water quality, particularly Chl-a concentrations in the Latyan Dam and Tehranpars Water Treatment Plant (TWTP) is assessed through six fuzzy regression models under three scenarios: RCP2.6, RCP4.5, and RCP8.5. Projections indicate an increase in minimum temperatures for the Jajrood watershed ranging from 92 to 93%. Seasonal forecasts suggest significant precipitation during the dry season. The HYMOD model predicts increases in streamflow of approximately 97%, 90%, and 92% by 2050 under RCP2.6, RCP4.5, and RCP8.5, respectively, indicating a heightened risk of flooding that poses economic, health, and environmental concerns. Among the six fuzzy regression models, FGR1, FGR3, and FGR4 demonstrated the most favorable results in modeling Chl-a output from the TWTP. In conclusion, while Chl-a concentrations in the effluent of the TWTP are only slightly influenced by climate change, the effects on streamflow patterns are significant. These findings highlight serious future water quality challenges and increased vulnerability of water resources due to climate change.

Climate Change Impact on Hydro-climatic Fluxes in Kantamal Catchmentof the Middle Mahanadi River Basin, India

Climate change is now considered as a newly added threat for natural resource management, which has significant impact on agriculture and allied sectors. Climate change studies play a pivotal role in developing sustainable natural resource management strategies. The present study assesses the effect of climate change on hydro-climatic fluxes in Kantamal catchment of the Mahanadi River basin, India. Utilizing the modified Mann-Kendall test, analysis of long-term climatic variables revealed a decreasing trend in rainfall and increasing trend in temperature. Employing a bias-corrected, multi-model ensemble of three regional climate models (RegCM4-4, RCA4, REMO2009) under the Representative Concentration Pathways (RCPs) of RCP4.5 and RCP8.5 scenarios, a rise in the average maximum temperature of 0.86°C under RCP4.5 and 1.16°C under RCP8.5, as well as an increase in the average minimum temperature of 2.35°C under RCP4.5 and 2.89°C under RCP8.5, by 2099 were projected. Rainfall is projected to decrease by 29.53% (RCP4.5) and 24.34% (RCP8.5), with surface runoff decreasing by 13.91% (RCP4.5) and 9.94% (RCP8.5), actual evapotranspiration declining by 7.81% (RCP4.5) and 7.77% (RCP8.5), soil moisture reducing by 11.17% (RCP4.5) and 9.69% (RCP8.5), and water yield is projected to decline by 39.45% (RCP4.5) and 33.05% (RCP8.5) as compared to the baseline period. Water stress situation is anticipated in the catchment emphasizing the need for planning and management of water resources, and sustainable agriculture.

The climatic impacts on rice yield in the Indian state of Odisha: an application of Just-Pope production function and quantile regression.

The impacts of climate change on Indian agriculture are well documented. However, there is a dearth of research addressing the inter-regional diversities in the impacts. Furthermore, existing studies are mostly restricted to the impacts on mean agricultural yield, overlooking the impacts on yield variability. This study investigates climatic impacts on rice yield in Odisha, a coastal Indian state, employing district-level panel data from 1995 to 2017. This study uses the Feasible Generalized Least Squares (FGLS) and quantile regression approaches to estimate how climatic impacts are realized on mean yield, yield variability, and conditional quantiles of yield distribution. The use of the agro-climatic zone level dummies empowers the study to account for local weather and soil conditions. The results reveal substantial heterogeneity in the climatic impacts across agro-climatic zones. A marginal increase in the maximum temperature reduces rice yield by 279-325kg/ha across different agro-climatic zones, largely constituting the state's coastal region, but increases yield by 340-766kg/ha across the zones lying in the western region. Conversely, an increase in minimum temperature increases rice yield by around 211kg/ha in the coastal region, but reduces by 333-744kg/ha in the western region. In addition, an increase in precipitation reduces yield by 0.318 kg/ha in some parts of the coastal region, but increases yield by 0.268 0.881 kg/ha across other regions. Similar heterogeneity is also identified across conditional quantiles of yield distribution. The heterogeneous impacts call for strategic policy intervention specific to zones and quantiles.

Evaluation of the effects of climatic variabilities on future hydrological scenarios: application to a coastal basin in Central Chile

ABSTRACT Evaluating the impacts of climate change on coastal basins with a Mediterranean climate represents a significant challenge concerning water security. Consequently, an assessment was conducted on the effects of climate change on hydrological components in a basin within the Coastal Mountain Range of Central Chile. The hydrological model SWAT+ was used, forced by two Shared Socioeconomic Pathways (SSP2-4.5 and SSP5-8.5), incorporating a downscaling process and analyzing both extreme and non-extreme events. Climate projections were made for the following three periods: near (2015–2030), middle (2015–2060), and distant (2015–2100) future. Results indicate a consistent rise in average temperatures across all periods, coupled with decreased precipitation for most of the year. Particularly in the distant future, austral summer stands out as the most impacted season, with projections showing a substantial decrease in precipitation (27 and 54% for SSP2-4.5 and SSP5-8.5, respectively), accompanied by significant increases in both maximum and minimum temperatures. Moreover, the streamflow is anticipated to decline considerably in the austral autumn (−8 and −83% for SSP2-4.5 and SSP5-8.5, respectively). Additionally, as consequences of climate change an increase in droughts (during the dry season) and flooding problems (during the wet season) are expected in the basin, increasing the risk for both extremes.

Impact of climate change on water resources in the Yarmouk River Basin of Jordan

Understanding the impact of climate change on water resources is important for developing regional adaptive water management strategies. This study investigated the impact of climate change on water resources in the Yarmouk River Basin (YRB) of Jordan by analyzing the historical trends and future projections of temperature, precipitation, and streamflow. Simple linear regression was used to analyze temperature and precipitation trends from 1989 to 2017 at Irbid, Mafraq, and Samar stations. The Statistical Downscaling Model (SDSM) was applied to predict changes in temperature and precipitation from 2018 to 2100 under three Representative Concentration Pathway (RCP) scenarios (i.e., RCP2.6, RCP4.5, and RCP8.5), and the Soil and Water Assessment Tool (SWAT) was utilized to estimate their potential impact on streamflow at Addasiyia station. Analysis of data from 1989 to 2017 revealed that mean maximum and minimum temperatures increased at all stations, with average rises of 1.62°C and 1.39°C, respectively. The precipitation trends varied across all stations, showing a significant increase at Mafraq station, an insignificant increase at Irbid station, and an insignificant decrease at Samar station. Historical analysis of streamflow data revealed a decreasing trend with a slope of −0.168. Significant increases in both mean minimum and mean maximum temperatures across all stations suggested that evaporation is the dominant process within the basin, leading to reduced streamflow. Under the RCP scenarios, projections indicated that mean maximum temperatures will increase by 0.32°C to 1.52°C, while precipitation will decrease by 8.5% to 43.0% throughout the 21st century. Future streamflow projections indicated reductions in streamflow ranging from 8.7% to 84.8% over the same period. The mathematical model results showed a 39.4% reduction in streamflow by 2050, nearly double the SWAT model’s estimate under RCP8.5 scenario. This research provides novel insights into the regional impact of climate change on water resources, emphasizing the urgent need to address these environmental challenges to ensure a sustainable water supply in Jordan.

Climate variability and its long-term trends in central Taraba, Nigeria: implications for local ecosystems and rural livelihoods

This study examines the long-term trends of climate variability in Central Taraba, Nigeria, with a focus on analyzing temperature and rainfall patterns from 1980 to 2020. Central Taraba has witnessed notable shifts in climate patterns, characterized by increasing temperatures, erratic rainfall, and prolonged periods of drought and excessive rainfall. These climatic changes pose significant threats to local ecosystems and rural livelihoods, which rely heavily on rain-fed agriculture and natural resources. The research highlights significant fluctuations in both rainfall and temperature, underscoring the challenges posed by climate variability to the region’s ecological and socio-economic systems. The primary objectives of this study are to examine the extent of climate variability on key ecosystem services, assess its impacts on local livelihoods, and identify sustainable management strategies to address these effects. Results show a clear upward trend in both minimum and maximum temperatures across the study area, with some towns experiencing more pronounced increases in minimum temperatures. Rainfall patterns reveal an erratic trend with periods of both drought and excessive rainfall, though a slight but statistically insignificant downward trend in rainfall was observed in most towns. These climatic shifts have profound implications for agriculture, water resources, and rural livelihoods, as communities in the region heavily depend on rain-fed farming and natural ecosystems for sustenance. The study also underscores the pressing need for adaptive strategies such as climate-resilient agriculture and improved water resource management to mitigate the adverse effects of climate variability. Recommendations emphasize strengthening community resilience and integrating climate data into regional development policies to safeguard local livelihoods and ecosystems from future climate-related risks.

Assessing multi-decadal climatic variability and its impact on cardamom cultivation in the Indian Cardamom Hills.

This study examines the multi-decadal variability and trends of surface air temperature and precipitation in the Indian Cardamom Hills (ICH), a degraded tropical rainforest area unique for cardamom cultivation. Utilizing observed long-term climatic data (1958-2017), statistical methods such as the Mann-Kendall test (MKT), Sen's Slope Estimator (SSE), and Incremental Trend Analysis (ITA) were applied to assess the impact of surface air temperature, rainfall, and the number of rainy days on cardamom yield. The analysis revealed a significant decline in annual rainfall by approximately 13.62mm per year, with pronounced seasonal declines 0.87mm for winter, 12.33mm for pre-monsoon, 24.93mm for southwest monsoon, and 18.10mm for post-monsoon. Simultaneously, the number of rainy days dropped by nearly 19.75days over the 40-year period. A noticeable increase in decadal minimum and average temperatures was observed, highlighting potential adverse effects on cardamom yield and irrigation water resources. The findings suggest that excessive rainfall during the southwest monsoon negatively correlates with cardamom yield, while slightly warmer temperatures show a weak positive correlation. The study also emphasizes the need for adaptive agricultural practices and climate-resilient policies to mitigate the effects of changing climatic conditions on cardamom production. This research contributes valuable insights for farmers and other stakeholders as well as policymakers aiming to ensure sustainable cardamom cultivation amidst climate change.

Simulation study on additive-promoted microwave dehydration of lignite

ABSTRACT Microwave dehydration technology has been widely used in coal processing methods due to its unique advantages. Adding additives with high dielectric loss to coal can enhance the microwave absorption capacity of coal, so as to effectively improve the dehydration process. In order to understand the change and distribution of multi-fields in the microwave drying process of lignite under the action of different additives, verify the experiment and reduce the cost and number of experiments, this paper established a multi-field coupling model of electromagnetic field and heat and mass transfer of multiphase porous media based on COMSOL Multiphysics, so as to simulate the microwave drying process of lignite. The results show that the distribution areas of electromagnetic field, temperature field, and vapor in coal are basically the same, while the distribution of liquid water is just the opposite. With the enhancement of additive promotion effect, the parts with strong electromagnetic field strength increase, the hot spots of temperature field increase, the maximum temperature, and minimum temperature increase, and the water content in coal samples decreases. The promotion effect of additives on the microwave dehydration process of lignite is consistent with the experiment.

A century of medical records reveal earlier onset of the malaria season in Haut-Katanga induced by climate change

BackgroundDespite worldwide efforts to eradicate malaria over the past century, the disease remains a significant challenge in the Democratic Republic of the Congo (DRC) today. Climate change is even anticipated...

Model-based analysis of the impact of climate change on hydrology in the Guayas River basin (Ecuador)

ABSTRACT Worldwide climate change will most likely lead to drastic changes in hydrology and food production. In this study, the impact of climate change on the hydrological regime and the fate of pesticides in the Guayas River basin is investigated using the Soil and Water Assessment Tool. Four general circulation models and three representative concentration pathways (RCP 4.5, RCP 6.0 and RCP 8.5) for three future periods were used to assess impact of climate change. Future projections showed a maximum increase in the average monthly precipitation of 40% in June, as well as an increase in an average minimum temperature of 3.85°C for July and an average maximum temperature of 4.5°C for August in 2080s. The model simulations based on RCP 8.5 scenario predict an increase in potential evapotranspiration by 11%, surface runoff of 39% and water yield of 33% in 2080s. The pesticide simulation showed the highest water concentrations during the wet season. Projections of trends in pesticide concentration indicate a similar trend to the current situation given the application rate remains the same. The results can be beneficial for the management and planning of the basin to mitigate flood and water quality-related impacts of food production and climate change.

Asymmetric Warming of Day and Night Benefits the Early Growth of Acer mono Seedlings More Than Symmetric Warming.

Asymmetric warming refers to the difference between the increase in daytime maximum temperature and the increase in nighttime minimum temperature and has been documented in temperate regions. However, its impacts on seedling growth have been largely ignored. In this study, seedlings of a widely distributed tree species, Acer mono Maxim., were exposed to both symmetric warming (SW) and asymmetric warming scenarios (day warming [DW], night warming [NW] and diurnal asymmetric warming [DAW]). Compared to control, all warming scenarios were found to enhance belowground biomass. DW promoted the seedling growth, while NW reduced the stem biomass. DAW did not impact the total biomass relative to the control. Compared to SW, DAW advanced phenology, increased indole-3-acetic acid content and chlorophyll content, which enhanced total biomass and stored more NSC in the root. Future DAW would be not beneficial to the growth of A. mono seedlings by comparing with the control. This research encourages further exploration of tree growth experiments under asymmetric warming conditions, as most studies tend to underestimate the warming effects on plant growth by focusing on SW. Incorporating the responses of seedling physiology and growth to non-uniform diurnal warming into earth system models is crucial for more accurately predicting carbon and energy balances in a warmer world.

Investigating the Impact of Climate Change Impacts on Direct-seeded Rice Production in Middle Gujarat Using the InfoCrop-rice Model

Rice (Oryza sativa L.) is a global food staple, essential for human nutrition and calorie intake, particularly in low- and middle-income countries. This study assesses the impact of climate change on direct-seeded rice (DSR) production in Middle Gujarat (India) using the InfoCrop-Rice model. The study evaluates potential climate scenarios under Representative Concentration Pathways (RCP) 4.5 and RCP 8.5, focusing on projected changes in temperature, rainfall, and sunshine hours, and their effects on rice yield and phenology. Field data from Kharif 2023 were used to calibrate the model, which projected significant increases in maximum and minimum temperatures, variable changes in rainfall, and consistent reductions in sunshine hours. By 2100, maximum temperatures are expected to rise by up to 6°C under RCP 8.5, and minimum temperatures could increase by as much as 7.5°C. Rainfall projections show high variability, with potential reductions and increases depending on the scenario and time period. Sunshine hours are projected to decline by approximately 6.6% under both RCP scenarios. The model simulations indicate a notable decline in rice yields, with reductions ranging from 18% to 36% by 2100. These results underscore the severe impact of climate change on DSR productivity. The study highlights the need for adaptive strategies, including improved water management, resilient crop varieties, and sustainable agricultural practices, to mitigate the adverse effects of climate change and ensure the sustainability of direct seeded rice production in Middle Gujarat.

Climate Change Trends And Its Effects On The Production Of Selected Food Crops: Evidence From Amaro Kelle District Of Southern Ethiopia

Amaro Kelle district of Southern Ethiopia is a rainfall-based agricultural districts that is vulnerable to the impacts of climate change and risk. This study analyzed climate change trends and effects on the selected food crops production: evidence from the Amaro Kelle district of Southern Ethiopia. Secondary data on climate change trends and food crop production from the Ethiopian national meteorological agency and the Amaro Kelle agricultural and rural development office were used for the study. Microsoft Excel was used to analyze the data on temperature, rainfall and crop production trends. The result on Trend analysis showed an increase in maximum and minimum temperatures at the rate of 0.056 and 0.0787 0C per 32 years, while there is a decrease in annual rainfall at the rate of -7.6012 mm per 32 years. These climatic conditions increased maize and sorghum productivity at the rate of 713.69 and 376.56 tonnes per 12 years, respectively, and decreased productivity of teff and wheat at the rate of -2618.5 and -30.892 tonnes per 12 years, respectively. These findings indicated that climate change positively and negatively affected the district's food crop production and food security. Finally, the study recommends that farmers in the district should focus on the cultivation of those crops that correlate positively with increasing temperature and decreasing rainfall trend in the study area.

Assessing the impact of climate change on agricultural production in central Afghanistan

Afghanistan has faced extreme climatic crises such as drought, rising temperature, and scarce precipitation, and these crises will likely worsen in the future. Reduction in crop yield can affect food security in Afghanistan, where the majority of population and economy are completely dependent on agriculture. This study assessed the interaction between climate change and crop yield in Kabul of Afghanistan during the reference (1990–2020) and future (2025–2100) periods. Climate data (1990–2020) were collected from four meteorological stations and three local organizations, and wheat yield data (1990–2020) were acquired from the United States Agriculture Department. Data during the reference period (1990–2020) were used for the validation and calibration of the statistical downscaling models such as the Statistical Downscaling Model (SDSM) and Long Ashton Research Station Weather Generator (LARS-WG). Furthermore, the auto-regression model was used for trend analysis. The results showed that an increase in the average annual temperature of 2.15°C, 2.89°C, and 4.13°C will lead to a reduction in the wheat yield of 9.14%, 10.20%, and 12.00% under Representative Concentration Pathway (RCP)2.6, RCP4.5, and RCP8.5 during the future period (2025–2100), respectively. Moreover, an increase in the annual maximum temperature of 1.79°C, 2.48°C, and 3.74°C also causes a significant reduction in the wheat yield of 2.60%, 3.60%, and 10.50% under RCP2.6, RCP4.5, and RCP8.5, respectively. Furthermore, an increase in the annual minimum temperature of 2.98°C, 2.23°C, and 4.30°C can result in an increase in the wheat yield of 6.50%, 4.80%, and 9.30% under RCP2.6, RCP4.5, and RCP8.5, respectively. According to the SDSM, the decrease of the average monthly precipitation of 4.34%, 4.10%, and 5.13% results in a decrease in the wheat yield of 2.60%, 2.36%, and 3.18% under RCP2.6, RCP4.5, and RCP8.5, respectively. This study suggests that adaptation strategies can be applied to minimize the consequences of climate change on agricultural production.

The Abrupt Change in Potential Evapotranspiration and Its Climatic Attribution over the Past 50 Years in the Sichuan–Chongqing Region, China

Potential evapotranspiration (PET), as an indicator of atmospheric evaporative demand, is a critical hydrological and meteorological factor to reflect regional and global hydrological cycles and environmental change. Understanding these nuanced responses of PET to environmental changes is important for agricultural production and water demand estimation. This study rigorously evaluated fluctuations in PET using the Penman–Monteith model over a 50-year span from 1970 to 2020 in the Sichuan–Chongqing region, an area notably susceptible to climate change. The changing characteristics of PET and local meteorological factors were detected by integrating the Mann–Kendall method and Pettitt test. Furthermore, the contribution and sensitivity of key meteorological variables to the observed variation in PET were also thoroughly investigated. Breakpoint analysis revealed that abrupt changes appeared in 1996 for annual PET. The detrending method indicated that substantial decreases in net radiation and wind speed (p < 0.01) were responsible for the decrease in annual PET from 1970 to 1996. Marked increases in minimum temperature and wind speed were the driving forces behind the uptick in annual PET in 1997–2020. At seasonal scales, wind speed and net radiation predominantly influenced PET in 1970–1996 in general. However, from 1997 to 2020, the factors controlling PET fluctuations displayed considerable seasonal variation. Sensitivity analysis showed that Ws and Tmin were the second-most sensitive factors. By exploring the impacts of PET changes and shifts, attention must be paid when allocating water resources reasonably under the background of ongoing climate change and likelihood of future drought.

In-depth Exploration of Temperature Trends in Morocco: Combining Traditional Methods of Mann Kendall with Innovative ITA and IPTA Approaches

This study examines trends in minimum and maximum temperatures at various climate stations located in different regions of Morocco for a period of five decades (1970 to 2019). Mann–Kendall, Sen’s estimator, Innovative Trend Analysis (ITA) and Innovative Polygon Trend Analysis (IPTA) were used in the analysis. The results show significant fluctuations, at different time scales, between minimum and maximum temperatures at all stations. In coastal areas, such as Rabat Sale, minimum temperatures fell during January and February while other months saw increases. Average minimum temperatures in Rabat Sale tend to fall by 0.5 °C. On the other hand, maximum temperatures in Rabat Sale rose by 0.2 °C. A decrease of 0.4 °C for Tmin and 1.6 °C for Tmax were observed in higher continental regions, such as Meknes. Other stations, such as Fez Sais (0.6 °C Tmin and 2.6 °C Tmax) and Taza (1.1 °C Tmin and 2.6 °C Tmax) showed an upward trend. Trends also vary, with notable increases in minimum and maximum temperatures, indicating different climatic dynamics according to altitude and locality. In particular, the ITA highlights a significant increase in annual maximum temperatures, with a P-value < 0.05 and trend slopes ranging from 0.0015 °C per year in Rabat Sale to 0.0076 °C per year in Taza. In addition, the IPTA results confirm diversity of upward and downward trends on monthly and seasonal scales, highlighting impact of geographical factors such as proximity to sea, topography, and continentality that contribute to formation of regional microclimates. The results highlight significant impact of climate change in Morocco.

The Effect of Climate Change on the Water Requirements of Wheat Crops in Al-Qurna District for the Periods (1950-1961) and (2011-2022)

Climate is one of the fundamental factors influencing various human activities, including agriculture. Climatic conditions impact the type of crops that can be grown and their water requirements, which is especially important in arid regions like the study area. Understanding these requirements helps determine the amount of irrigation water needed for crops to avoid overuse, as well as the agricultural area that can be irrigated and the water needs of wheat crops. Water consumption refers to the amount used by a crop during its growth period over a specified area to build plant tissues within a specific timeframe. The study shows that climatic elements such as solar radiation, various temperature types (mean, maximum, and minimum), wind, relative humidity, rainfall, and evaporation affect the water requirements of wheat crops in the study area. When examining the climate element changes between the periods 1950-1961 and 2011-2022, whether the change direction is positive (increase) or negative (decrease), it was observed that there were increases in solar radiation, mean temperature, maximum and minimum temperatures, and evaporation. Meanwhile, there were decreases in relative humidity, rainfall, and wind speed, with an increase in water demand for all wheat planting months, especially in October, March, and April during the 2011-2022 period. This is due to higher evaporation resulting from increased temperatures, unlike the 1950-1961 period , during which the water demand for most months was lower due to moderate climate elements.

The simultaneous prediction of yield and maturity date for wheat-maize by combining satellite images with crop model.

The simultaneous prediction of yield and maturity date has an important impact on ensuring food security. However, few studies have focused on simultaneous prediction of yield and maturity date for wheat-maize in the North China Plain (NCP). In this study, we developed the prediction model of maturity date and yield (PMMY) for wheat-maize using multi-source satellite images, an Agricultural Production Systems sIMulator (APSIM) model and a random forest (RF) algorithm. The results showed that the PMMY model using peak leaf area index (LAI) and accumulated evapotranspiration (ET) has the optimal performance in the prediction of maturity date and yield. The accuracy of the PMMY model using peak LAI and accumulated ET was higher than that of the PMMY model using only peak LAI or accumulated ET. In a single year, the PMMY model had good performance in the prediction of maturity date and yield. The latitude variation in spatial distribution of maturity date for WM was obvious. The spatial heterogeneity for yield of wheat-maize was not prominent. Compared with 2001-2005, the maturity date of the two crops in 2016-2020 advanced 1-2 days, while yield increased 659-706 kg ha-1. The increase in minimum temperature was the main meteorological factor for advance in the maturity date for wheat-maize. Precipitation was mainly positively correlated with maize yield, while the increase in minimum temperature and solar radiation was crucial to the increase in yield. The simultaneous prediction of yield and maturity can be used to guide agricultural production and ensure food security. © 2024 Society of Chemical Industry.