对气候变化危机及代际正义问题的哲学思考

为了解决国际气候争端问题,欧美等主要发达国家在其倡导的气候论坛及峰会上主张采用国际限额与交易制度。一方面,国际限额与交易制度难以全面评估和衡量不同国家碳的排放量及其减少排放的能力,正处于现代化进程中的中国据此将需要购买排放权,而代际正义有利于还原碳排放指标分配的公允。另一方面,在代际正义理论的背后,却存在明显的片面性,因为它忽略了现代科技不断进步的可能和社会价值意识水平的提高,其理论仅停留在平面维度上的思考。当前,发展中国家和发达国家应在差异中趋于协同,在看似矛盾冲突的气候谈判与整治格局中逐渐走出僵局。

品种搭配对湖北省玉米–晚稻复种产量及资源效率的影响

玉米–晚稻复种(M–R)能协同口粮与饲料用量生产,近年来开始在长江中游地区发展,其周年丰产高效技术还有待系统研究与完善,而合理的前后季品种搭配是发挥玉–稻产量潜力的重要基础。因此,本研究选取不同的玉米与晚稻品种,于2015年与2017年在湖北省不同区域观测了不同品种搭配模式产量表现与资源利用效率。结果表明,不同热量条件下品种搭配模式对M–R周年产量与资源生产效率影响显著。积温较多时以中熟玉米搭配晚籼稻品种周年产量与光、热、水资源效率具有明显优势;反之则以早熟玉米品种搭配晚籼稻产量与资源生产效率较高。各品种搭配模式对周年有效积温(GDD_(≥10°C))的利用率可达95.6%~100.0%,且前后季积温分配比值(TR)与M–R周年相对产量呈显著的非线性关系;当GDD_(≥10°C)利用率为97.0%~98.5%且TR为1.06~1.08时, M–R可获得较高的周年产量。因此,可依据当地的热量资源条件及合理TR比值,进行玉米、晚稻品种选择搭配。据此,湖北省南部积温较高的区域宜选择生育期125d以内的高产玉米品种与全生育期140d以内的晚稻品种进行搭配;而在积温相对偏少的中北部区域,宜选择生育期120 d以内的高产玉米品种与全生育期130 d以内的晚稻品种进行搭配。

Effect of Water Resources Allocation on Groundwater Environment and Soil Salinity Accumulation under Climate Change

The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People＇s Victory Canal irrigation district was taken as a case, drawing together the irrigation district agriculture water consumption and precipitation from 1954 to 2014 in the People＇s Victory Canal irrigation district, ratios of surface to groundwater irrigation amount, dynamic of groundwater depth and hydrochemical characteristic of groundwater from 2008 to 2014 in the research area, the relationship between groundwater depth and ratio of surface to groundwater irrigation amount was analyzed, in order to ascertain the influence of precipitation on ratios of surface to groundwater irrigation amount and its effect on soil and groundwater environment. The results indicated that positive correlation between the ratios of surface to groundwater irrigation amount and annual precipitation was appeared, affected by climate change, average irrigation amount from surface in the recent 5 years was 2.90 x 108 cubic meters, accounted for 75.52% of total irrigation amount, on the other hand, decreasing tendency of precipitation was obvious, and groundwater depth dynamic in upstream of the branch canals was more dramatic than downstream because of surface water irrigation infiltration, under the unified condition of water use efficiency, ratio of surface to groundwater irrigation amount was negative correlation with area of the groundwater depth beyond 11 m, meanwhile, groundwater depth demonstrated negative correlation with the ratio of surface to groundwater irrigation amount, moreover, alkaline trend of groundwater hydrochemistry during the normal season in the research area was obvious because of phreatic evaporation and the agricultural irrigation from wells, along with irrigation from surface inflow of Yellow River, quality of groundwater hydrochemistry during the dry season was ameliorative greatly. Consequently, it was very important to the agriculture sustainable production that well-canal combined irrigation patterns alleviated extremely alkaline trend of the groundwater hydrochemistry and played a positive role of root layer soil salinity leaching.