关键词： Irrigation water demand   Climate change   Water price   Agro-economic supply model  

摘要： Pressures on resources and climate change are likely to strongly impact the availability of water, which directly affects agricultural systems. To estimate these impacts, we develop a prospective approach combining an agricultural supply side economic model and a crop model. We extend previous work by incorporating water resource constraints and apply our model to a large part of the French agricultural sector under three climate scenarios over 2010-2010. Results indicate that, at a given water price, potential change in irrigation water demand would differ strongly according to the region concerned and the scenario applied. In France as a whole, irrigation increases in all scenarios, by 60% under the intermediate scenario, by 40% under the least extreme scenario, and by 20% under the toughest scenario. Differentiating the northern and southern regions, the relative increase is more pronounced in the north, while demand in the south significantly increases under the intermediate scenario and decreases under the toughest scenario. When considering autonomous adaptation of farming systems to climate change, agricultural income in northern regions is likely to be negatively affected to a greater extent than in southern regions.

关键词： Environmental changes   Climate change   Land use change   Water resources   Water deficits   Small catchment  

摘要： The aims of this study are: i) to better understand the coupled interactions between land use changes, climate change and the aquatic ecosystem in a small agricultural catchment (<100 km(2)) with a long observation history (1963-2018) and a known land use history, and ii) to test available approaches to separate land use and climate change impacts on water resources in such a small catchment. The pre- and post-change periods have been separated based on change points and the known land use history. Next, conceptual and analytical approaches were applied to quantify and to distinguish between the impacts of climate and land use changes on annual runoff for these two periods. Over the observation period, both land use changes (increase in forest areas) as well as climate change (a temperature rise and a decrease in annual precipitation) occurred. These changes contributed to a decrease in the average annual runoff by 51.9 mm (49% of the long-term average) during the observation period. The quantified contributions of climate and land use changes to the decrease in the mean annual runoff amount to between 60% and 80% and between 40% and 20%, respectively. (i) The results obtained from different methods were consistent - a change in runoff was primarily caused by shifts in climatic variables. (ii) However, the quantified contributions varied depending on the method applied and the form of the Budyko curve. (iii) Thus, special care should be taken in relation to the selection of the Budyko curve for quantifying these changes. (iv) Knowledge of the water deficit sources can result in better planning of water resources management in such small catchments.

关键词： greenhouse gas   the Denitrification-Decomposition model (DNDC)   water demand   planting structure   climate change  

摘要： The agriculture sector is one of the largest users of water and a significant source of greenhouse gas (GHG) emissions. The development of low-GHG-emission and water-conserving agriculture will inevitably be the trend in the future. Because of the physiological differences among crops and their response efficiency to external changes, changes in planting structure, climate and input of production factors will have an impact on regional agricultural water use and GHG emissions. This paper systematically analyzed the spatial-temporal evolution characteristics of crop planting structure, climate, and production factor inputs in Heilongjiang Province, the main grain-producing region of China, from 2000 to 2015, and quantified the regional agricultural water use and GHG emissions characteristics under different scenarios by using the Penman-Monteith formula and the Denitrification-Decomposition (DNDC) model. The results showed that the global warming potential (GWP) increased by 15% due to the change in planting structure. A large increase in the proportion of rice and corn sown was the main reason. During the study period, regional climate change had a positive impact on the water-saving and emission reduction of the agricultural industry. The annual water demand per unit area decreased by 19%, and the GWP decreased by 12% compared with that in 2000. The input of fertilizer and other means of production will have a significant impact on GHG emissions from farmlands. The increase in N fertilizer input significantly increased N2O emissions, with a 5% increase in GWP. Agricultural water consumption and carbon emissions are affected by changes in climate, input of means of production, and planting structure. Therefore, multiple regulatory measures should be taken in combination with regional characteristics to realize a new layout of planting structure with low emissions, water conservation, and sustainability.

关键词： Anthropogenic climate change   Plant biostimulants   Drought   Salinity   Cropping systems  

摘要： Anthropogenic climate change, namely climate alterations induced by human activities, is causing some issues to agricultural systems for their vulnerability to extreme events. Forecasts predict a global population increase in the near years that will exacerbate this situation, elevating the global demand for food. It will pose severe concerns in terms of natural resource usage and availability. Agriculture is one of the anthropogenic activities that will be more affected in the future. Climate extremes menace to affect the quantity and quality of crop production severely. Drought, water and soil salinity are considered among the most problematic factors that anthropogenic climate change will increase. This complex and worrying scenario requires the urgent implementation of sustainable measures which are capable of improving crop yield and quality, fostering the robustness and resilience of cropping systems. Among the more current methodology, the use of natural plant biostimulants (PBs) has been proposed to improve plant resistance to abiotic environmental stresses. The advantage of using these substances is due to their effectiveness in improving crop productivity and quality. Therefore, in this review, the most recent researches dealing with the use of natural PBs for improving plant resistance to drought and salinity, in an anthropogenic climate change scenario, have been reported and critically discussed. (C) 2020 Elsevier B.V. All rights reserved.

关键词： 农业干旱   干旱影响强度   干旱成灾强度   气候变化  

摘要： 基于1951-2018年各省(自治区)农作物播种面积、干旱受灾面积、干旱成灾面积等数据,构建了干旱影响强度和干旱成灾强度特征指标,并分析近70a各省(自治区)空间尺度的农业干旱灾害的分布、发生次数、变化趋势和气候变暖背景下的阶段性变化特点。研究表明:(1)内蒙古自治区、山西省和河北省等省(自治区)的干旱受灾面积、干旱成灾面积、干旱影响强度和干旱成灾强度的多年平均值均位于前列;(2)中度及以上干旱等级发生次数最多的前10位均为北方省份(自治区),总次数均≥25次,其中内蒙古自治区、山西省和陕西省位居农业干旱发生次数最多前三位;(3)16省(自治区)的干旱受灾面积和干旱影响强度存在减小趋势,但大部分地区即23个省(自治区)的干旱成灾面积和27个省(自治区)的干旱成灾强度存在增加趋势;(4)受气候变化影响,各省(自治区)在气候较冷的I阶段(1951-1984年)农业干旱较轻,在气候增暖明显的II阶段(1985-1997年)农业干旱大幅加重,在气候增暖趋缓的III阶段(1998-2018年)农业干旱受灾面积、成灾面积和干旱影响强度普遍减小,但其成灾强度在加重。总之,农业干旱具有明显的南轻北重特征,且北方农业干旱更加频繁,因此北方地区仍需加强防御,减轻重大干旱对农业的影响。

关键词： 气候变化   气温   降水量   农业气象灾害   赣州市  

摘要： 统计江西省赣州地区2000-2019年的气温与降水量等气象观测资料,分析该地区气候变化特征,探析该地区主要农业气象灾害及防御措施,以期能够为合理利用当地气候资源、做好防灾减灾工作、保障当地民众日常生产生活安全等提供参考。

关键词： Wetland   Climate change   Adaptation strategies   Economic-hydrological-behavioral modelling  

摘要： Water resources at the basin level are affected by climate change in the form of available water scarcity and multiple droughts leading to conflicts among different water users, especially between the agricultural sector and wetland services. However, owing to the multidimensional and multi-scalar nature of water management and climate change, it is needed to integrate tools to analyze impacts and adaptation. Accordingly, the current study presents an economic-hydrological-behavioral modeling to evaluate potential effects of climate change and adaptation strategies on irrigated agriculture and to manage water resources conflicts among different water users and uses in basins. This model has an iterative framework between a farm-based multi-objectives optimization model, a water evaluating and planning model (WEAP), and an agent-based model, which can represent socio-economic, hydrologic, agronomic and behavioral systems covering all dimensions and scales related to climate change. For this purpose, the economic-hydrological-behavioral modelling was applied in a case study in the Halilrud Basin in Kerman Province, Iran. Results revealed that adoption of suitable adaptive strategies and measures could mitigate the effects of climate change and provide more water to restore the Jazmourian Wetland in this basin. Additionally, the results indicated that different forms of rigidity in the individual behavior of farmers slowed down the adaptation of the agricultural sector, so that implementation of adaptive strategies led to only 14% less water consumption.

关键词： drought   climate change impacts   Titicaca basin   Andes   Altiplano  

摘要： The impact of climate change on droughts in the Lake Titicaca, Desaguadero River, and Lake Poopo basins (TDPS system) within the Altiplano region was evaluated by comparing projected 2034-2064 and observed 1984-2014 hydroclimate time series. The study used bias-corrected monthly climate projections from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), under the Representative Concentration Pathway 8.5 (RCP8.5) emission scenarios. Meteorological, agricultural, and hydrological droughts were analyzed from the standardized precipitation, standardized soil moisture, and standardized runoff indices, respectively, the latter two estimated from a hydrological model. Under scenarios of mean temperature increases up to 3 degrees C and spatially diverse precipitation changes, our results indicate that meteorological, agricultural, and hydrological droughts will become more intense, frequent, and prolonged in most of the TDPS. A significant increase in the frequency of short-term agricultural and hydrological droughts (duration of 1-2 months) is also projected. The expected decline in annual rainfall and the larger evapotranspiration increase in the southern TDPS combine to yield larger projected rises in the frequency and intensity of agricultural and hydrological droughts in this region.

关键词： Climate change   Vulnerability   Agriculture and adaptation  

摘要： Climate variability and change pose ever-growing challenges in the semiarid tropics, where majority of the population depend on climate-dependent activities such as agriculture. This has rendered these countries more vulnerable to climate change-induced variability. In spite of the uncertainties about anticipated magnitude of climate change on regional scale, an assessment of the possible changes in key climatic elements to identify most vulnerable locations becomes important for formulating adaptation strategies. This study compiles the existing knowledge about observed climate and projections of future change in Telangana state of India. The agriculture in this semiarid state has to adapt to changes in mean climate variables to increased variability with greater risk of extreme weather events, such as prolonged dry spells. Based on climatic vulnerability assessment, we found that the number of vulnerable mandals (currently 28%) will be increased to 45% during early century and to 59% by mid-century. As per the climate exposure index scores, Jogulamba-Gadwal district was found to be most sensitive. Overall, vulnerability index scores indicated that Adilabad, Nagarkurnool, Nalgonda, Peddapalli, Suryapet, Wanaparthy, and Yadadri are extremely vulnerable districts in the state. The ranking of vulnerable mandals in each district envisages the need for a holistic approach for each mandal or a group of mandals to reduce their sensitivity though implementation of site-specific adaptation strategies to minimize climate-related shocks not only in agriculture but also in other sectors.