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Accueil du site → Doctorat → Chine → 2007 → Risk Assessment and Risk Management of Agricultural Drought and Flood in Hengyang

Hunan Agricultural University (2007)

Risk Assessment and Risk Management of Agricultural Drought and Flood in Hengyang

Liu Lan Fang

Titre : Risk Assessment and Risk Management of Agricultural Drought and Flood in Hengyang

Auteur : Liu Lan Fang

Grade : Doctoral Dissertation 2007

Université : Hunan Agricultural University

Résumé
Natural disaster is increasingly frequent and agriculture is threatened bya variety of natural hazard t as a result of global environment changing and theeconomical development. The disaster risk assessment and the risk management havebeen concerned highly by the government department and the academic circles.Hengyang is one of the most important agricultural production bases in HunanProvince. The high frequency occurrence of drought and flood disaster here hasalready restricted severely the sustainable development of agricultural economyand people’s life. On the basis of the research achievements at home and abroadand the latest principle of catastrophology this paper made use of the historicaldisaster data of long period, statistical data and pertinent maps to analysis therisk of drought and flood disaster under the technique of GIS and fuzzy evaluationin Hengyang. The risk management system of the agricultural flood and drought hasbeen proposed so as to provide the rationale for the agriculture flood preventiondrought-resistant in Hengyang. As well as it is beneficial to losses reductionof drought and flood in moist south local of our country.From the system angle, the article pointed out that the content of riskassessment about the agricultural flood and drought disaster is consisted of hazardanalysis of drought and the flooding, vulnerability assessment of the agriculturalflood and drought disaster and loss appraises of the agricultural flood and droughtdisaster. Based content of risk assessment about the agricultural flood and droughtdisaster, the content of risk management about agricultural flood and droughtdisaster involves to hazard management of the drought and the flood, theagricultural flood and drought disaster vulnerability management as well asagricultural exposition management. Therefore this agricultural risk managementsystem of flood and drought disaster is constituted by three systems:countermeasures of controlling hazard of the drought and the flood, measures ofreducing the agricultural disaster vulnerability as well as method of making overagricultural losses.By using the historical disaster material statistics : The result indicatedthat the agricultural drought hazard is higher than the agricultural flood hazardin Hengyang ; that the agricultural flood often occurs in the spring summer season and the agriculture drought appears much in the summer and fall season ; that theagricultural drought hazard is bigger in south than in north ; that the agriculturaldrought hazard is biggest in middle of Hengyang ; that the agricultural flood hazardis bigger in north than in south ; that it is bigger in the Xiangjiang River thanin east mountainous region and middle rough terrain ; that the frequency ofagricultural great drought is approximately four time in ten years and thefrequency of agricultural big flood is approximately three time in ten years.Carrying fuzzy assessment on vulnerability of agricultural flood, the resultis that five counties belong to I (highly degree vulnerability), that twocounties belong toⅡ(medium degree vulnerability), that one county belongs toⅢ(lower degree vulnerability). By assessment on vulnerability of agriculturaldrought, The result is that the vulnerability of agricultural drought is thebiggest, is 0.57, in Hengnan county and that the vulnerability of agriculturaldrought is 0.39 in Changning county, that vulnerability of agricultural droughtis higher in middle part of Hengyang than in east and west part of Hengyang.In this article, by estimating on the losses of agricultural drought and flood,the result is that the agricultural drought risk degree is biggest in Hengnancounty and is smallest in Changning county, The agricultural flood risk degreeis the highest in Hengshan county and it is the smallest in Hengnan county. Ina word the risk degree of agricultural losses is higher in the north than in thesouth of Hengyang.Taking case study of big drought in 2003 and big swollen mountain streamdisaster in Leiyang, the formation mechanism of huge disaster is studied in thisarticle. It is the compound of disaster chain to enlarge a function and agriculturalvulnerability to respond to an effect.In the last part the countermeasures of risk management about agriculturaldrought and flood are put forward to develop the agriculture system according tothe principle of the sustainable development.There are innovations of researching methodology on risk assessment and riskmanagement about agricultural drought asking for help the modern technique of theGIS、GPS by selecting a case study of Hengyang from the south moist district.There is innovation of researching methodology which the paper has showed interaction and merge of natural science and economic science by studying theformation of a huge disaster risk from the compound of disaster chain and peasanthousehold to respond to behavior. Therefore they contribute to comprehensivedevelopment of the disaster theories.

Mots clés : agricultural flood and drought risk assessment risk management Hengyang

Présentation (Dissertationtopic )

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