摘要
泾河流域是农业旱灾的多发地区,但是对该地农业旱灾的发生规律、旱灾影响及旱灾恢复和准备措施方面开展的研究还较少。本文根据自然灾害风险评估的理论框架,建立了1km栅格精度的泾河流域农业旱灾风险空间评估模型,并对农业旱灾致灾因子危险性及农业承险体脆弱性进行评估,最后综合评估该地区农业旱灾风险。在此基础上,分析研究区农业旱灾危险性、承险体脆弱性及风险的空间特征。本研究采用Z指数方法评估泾河流域农业旱灾致灾因子的强度,选取农作物生长季缺水率、土壤有效含水量、有效灌溉面积比及坡度4个指标评估研究区1km空间尺度的农业旱灾脆弱性。农业旱灾风险综合评估的结果表明,泾河流域农业旱灾风险的高风险区位于该地区北部,低风险区位于该地区南部,且不同等级风险区呈现自东向西、自南向北逐渐降低的总体趋势,但不同等级风险区呈现间隔分布的趋势。
Though drought is a recurrent phenomenon in the Jinghe watershed,very little attention has been paid to the mitigation and preparedness of droughts in this area.Current research on risk or vulnerability of agricultural drought are mostly based on administrative units and ignore the interior differences between administrative units.This paper presents a method for the spatial assessment of agricultural risk in the Jinghe watershed of western China at a 1km grid scale.A conceptual framework which emphasizes the combined roles of hazard and vulnerability in defining risk was used,and the Z index method in a GIS environment was used to map the spatial extent of drought severity hazard using monthly precipitation data between 1957-2009 from the China Meteorological Data Sharing Service System.The key social and physical factors that define agricultural drought vulnerability in the context of the Jinghe watershed are climate,soil,irrigation and topography,respectively indicated by seasonal crop water deficiency（SCWD）,available water capacity（AWC）,irrigation percentage of the whole area of county-level and slope.Agricultural risk was computed by the integration of drought severity and vulnerability.The agricultural severity calculation results showed that 10.8% of the total Jinghe watershed was grouped into the high severity class,71.8% into the moderate class and 17.4% into the low class.Vulnerability calculation results showed that 35.3% of the total arable land area falls into the high vulnerable class,and 51.7% into the moderate vulnerable class and 13.0% into the low vulnerable class.Agricultural drought risk calculations indicated that 40.5% of the total arable area suffered high risk and 32.2% and 27.3% was grouped into moderate and low risk classes.Generally,the northern Jinghe watershed falls into high risk class,the middle part into moderate risk,and the southern part into low risk;however,spatial variation occurred across the eastern part of the study area as there were scattered spots classified as low risk here.
出处
《资源科学》
CSSCI
CSCD
北大核心
2012年第11期2197-2205,共9页
Resources Science
基金
国家科技支撑计划课题:"中国重大自然灾害风险等级综合评估技术研究"(编号:2008BAK50B05)
国家重点基础研究发展计划:"中国主要陆地生态系统服务功能与生态安全"(编号:2009CB421106)
中国科学院知识创新项目:"生态服务功能的阶梯消耗与环境响应"(编号:KZCX2-EW-306)
关键词
农业旱灾
自然灾害
脆弱性
风险评估
泾河流域
Agriculture drought
Natural hazard
Vulnerability
Risk assessment
Jinghe watershed
