山西省干旱灾害风险评估与区划

[目的]分析山西省干旱灾害风险的关键作用因子,并进行风险评估和区划,对于提升该地干旱灾害风险管理和决策水平、减轻干旱损失具有重要指导意义。[方法]文章利用改进的相对湿润度指数、DEM资料、地形坡度资料和1990—2016年以县(市)为单元的行政区域的人口密度、GDP、人均GDP、耕地面积等社会经济数据来定量化评价山西干旱风险,从干旱灾害致灾因子的危险性、孕灾环境的脆弱性、承灾体的易损性和防灾减灾能力4个方面选取因子,构建相应的指数模型并分析其空间分布状况,在此基础上进一步构建山西省干旱灾害风险综合评估模型,并基于GIS绘制山西省干旱灾害风险区划图。[结果]山西省干旱致灾因子危险性呈北高南低的趋势,大同、朔州、忻州北部和西部、太原南部的干旱致灾因子危险性最强;孕灾环境脆弱性呈东西两侧高、中间低的趋势,而承灾体易损性和防灾减灾能力均呈东西两侧低、中间高的趋势;从干旱灾害风险区划图可以看出,山西省干旱风险总体呈北高南低,从西北向东南递减的趋势。高风险区主要分布在大同、朔州东部,较高风险区包括朔州西部、忻州中西部、太原大部,吕梁大部、晋中西部、临汾中部、运城西部为中风险区,临汾西部、晋中大部、长治东北部为较低风险区,临汾东部、运城东部、晋城大部、长治西部和南部风险最低。[结论]山西省干旱灾害的精细化风险区划,可为相关区域有效地开展抗旱活动提供定量化依据,增强干旱灾害防御的科学性、实用性和可操作性。     

DROUGHT AND POPULATION MOBILITY IN RURAL ETHIOPIA

Significant attention has focused on the possibility that climate change will displace large populations in the developing world, but few multivariate studies have investigated climate-induced migration. We use event history methods and a unique longitudinal dataset from the rural Ethiopian highlands to investigate the effects of drought on population mobility over a ten-year period. The results indicate that men's labor migration increases with drought and that land-poor households are most vulnerable. However, marriage-related moves by women also decrease with drought. These findings suggest a hybrid narrative of environmentally-induced migration that recognizes multiple dimensions of adaptation to environmental change.     

Droughts and farms’ financial performance: a farm‐level study in New Zealand

We quantify the impacts of droughts in New Zealand on the profitability of dairy, sheep and beef farms using a comprehensive administrative database of all farms in New Zealand. For dairy farms, we found that drought events have positive impacts on dairy farms’ revenue and profit in the year of the drought. This effect is most likely attributable to drought‐induced increases in the export price of milk solids, as New Zealand is the market maker in this global market and almost all domestic dairy production is exported. All of these quantified impacts, however, are not very large, suggesting that, at this point in time, droughts have a fairly moderate impact on New Zealand dairy and sheep–beef businesses.     

宁夏玉米和小麦干旱风险评价研究

[目的]分析宁夏23年(1993—2016年)玉米和小麦干旱时空分布格局及演变趋势,探讨各县玉米和小麦的干旱风险成因及关键作用因子,以期为宁夏县级作物防旱抗灾工作提供科学依据。[方法]本文基于成灾综合评价法,从干旱对玉米和小麦种植的危险性、玉米和小麦在干旱环境下的暴露性、玉米和小麦种植在干旱胁迫下的脆弱性和区域农业抗旱能力4个方面选取指标构建作物干旱风险模型,利用1981—2016年气象数据资料及玉米、小麦生育期资料、玉米小麦产量和面积等数据,分析计算宁夏各地区的玉米和小麦的干旱风险。[结果] 23年间(1993—2016年)宁夏玉米和小麦干旱风险整体上呈逐步上升趋势,玉米干旱风险上升趋势明显,最高达到45%。而小麦干旱风险趋势较平缓,干旱风险水平在30%～40%之间。品种间的差异主要在于干旱危险性指数和暴露性指数间差异较大,玉米干旱暴露度高,生育期较长,潜在蒸散量大,降水无法供应生育期内的需水量,因而玉米干旱风险较大。从空间分布来看,小麦干旱风险高值区分布范围较广,由于小麦生育期在雨季初期,降水量较少,且种植面积大,因而受旱面积较大。各县(市)玉米和小麦危险性、暴露性指数权重均在0. 3以上,是导致玉米和小麦干旱风险较高的主要原因。[结论]因此调整种植比例,减少小麦的种植面积,加强农村脱贫,增加农民收入,是减少干旱危害的有效措施。     

Multi-Site Bundling of Drought Tolerant Maize Varieties and Index Insurance

Drought Tolerant Maize Varieties (DTMV) and Rainfall Index Insurance (RII) are potential complements, though with limited empirical basis. We employ a multivariate spatial framework to investigate the potential for bundling DTMV with a simulated multi-site and multi-environment RII, designed to insure against mild, moderate and severe drought risk. We use yield data from on-farm trials conducted by the International Maize and Wheat Improvement Center (CIMMYT) and partners over 49 locations in Eastern and Southern Africa spanning 8 countries and 5 mega-environments (dry lowland, dry mid altitude, wet lower mid altitude, low wetland and wet upper mid altitude) in which 19 different improved maize varieties including DTMV were tested at each location. Spatially correlated daily rainfall data are generated from a first-order two-state Markov chain process and used to calibrate the index and predict yields with a hierarchical Bayes multivariate spatial model. Results show high variation in the performance and benefits of different bundles which depend on the maize variety, the risk layer insured, and the type of environment, with high chances of selecting a sub-optimal and unattractive contract. We find that complementing RII with a specific DTMV produces contracts with lower premiums and higher guaranteed returns especially in dry lowland increasing the chances of scaling up RII within this environment.     

农业干旱灾害研究进展

［目的］文章阐述了基于不同数据源开展的农业干旱灾害研究，为明确农业干旱灾害研究的概况，便于把握农业干旱灾害研究的关键技术与问题。［方法］通过气象、遥感、统计3类数据，以使用数据源作为索引，对我国农业干旱灾害监测、评价及预警、灾害时空格局等内容进行分析。［结果］通过统计文献，了解农业干旱灾害研究的概况，分析农业干旱的基础和困境，明确国内农业干旱灾害的发展过程和最新进展，阐述未来农业干旱的研究重点。［结论］基于气象数据的农业干旱灾害研究最为系统，时间序列跨度长、空间分布范围广，在监测、预警、评价和格局分析等方面都有细致的研究； 基于遥感数据的农业干旱灾害研究主要以监测和灾害评价为主； 基于统计数据开展农业干旱灾害的研究主要集中在灾害损失评价方面； 基于多源数据的农业干旱灾害研究在逐渐增多，在监测、预警、评价等方面也有所突破。农业干旱研究的关键技术，以及研究的系统性、研究内容和发生机理等方面仍有待加强。     

秦淮河石臼湖跨流域抗旱调水对沿线水体及水域功能的影响

根据2011年秦淮河石臼湖跨流域抗旱调水前后调水沿线水体水质资料,分析调水对沿线水体水质及石臼湖南京高淳、溧水渔业、工业用水区水域功能的影响。结果表明:抗旱调水成效明显,调水结束后,调水沿线秦淮河水质有所改善,水质类别与调水前相比均呈上升趋势,各超标项目超标倍数随时间均呈下降趋势;石臼湖需水量得到了补给,石臼湖旱情得到缓解,水质能够满足淡水养殖用水和农田灌溉用水需求。     

河北省水旱灾害发生情况统计分析

河北省历史上水旱灾害频繁,对河北省的水旱灾害进行了统计分析,探讨了水旱灾害在时间和空间上的分布规律,结果表明该省涝灾减轻,旱灾是该省的一种主要自然灾害,为今后的防灾抗灾提供了科学依据。     

The productivity impact of climate change: Evidence from Australia's Millennium drought

The economic impact of climate change has usually been estimated based on changes in average weather condition and is often measured in terms of immediate loss of output or profit. Yet little is known about the impact of extreme weather event, in particular its impact on productivity in the medium to long term. Using Australia's Millennium drought as a case of extreme weather event and applying the synthetic control method, we show that severe droughts occurred between 2002 and 2010 has brought down agricultural total factor productivity by about 18 percent in Australia over the period, contributing significantly to the country's long-term slowdown of agricultural total factor productivity growth. Our results highlight the significance of productivity impact of extreme weather events that has been overlooked when accessing the economic impact of climate change.     

模拟道路种植环境对银杏生长的影响

城市下垫面性质的改变，压缩了行道树生长的环 境空间，阻碍了土壤水分的移动与循环，增加了行道树生长 的难度。探究街道种植环境对行道树生长的限制因子，是完 善行道树种植设计与栽培管理技术，改善城市街道形象，提 升城市绿化水平，增强城市生态系统弹性的有效途径。利用 模拟道路立地环境试验站，通过对移植后的银杏生长势的评 估、叶性状参数的测定、生理指标的定期观测得出，行道树 生长受硬质铺装等人工覆盖面的显著影响，生长量普遍降低 了50%；渗透性铺装能有效改善行道树的生存环境；为行道 树提供充足的水分供给和有效的降水补充通道，是道路建设 和行道树栽植所需要考虑的主要因素；在移栽初期，采取提 高土壤保水力和养分水平、增大树池体积的方式对银杏行道 树的生长有较好的促进作用。