论文标题:秀山县农业旱灾中人为因素的定量分析
Quantitative Analysis of Human Factor on Agricultural Drought in Xiushan County
论文作者 游珍
论文导师 徐刚,论文学位 硕士,论文专业 自然地理学
论文单位 西南师范大学,点击次数 88,论文页数 43页File Size1977k
2002-04-01论文网 http://www.lw23.com/lunwen_679789627/ 农业旱灾;自然因素;人为因素;定量分析;秀山县
Agricultural Drought;Natural Factor;Human Factor;Quantitative Analysis;Xiushan County
本文以秀山县为研究对象，运用定性和定量相结合的方法，分析了农业旱灾的影响因素，并详细讨论了人为因素以及它对农业旱灾的作用。以年代为单位，将建国后50年中各年代的人为因素对农业旱灾的作用相对比，探讨其成因及变化趋势。 全文分为如下四个部分： 第一部分为前言，分析了本文的研究意义及选题背景，结合目前国内外的研究现状，提出自己的思路和方法。 第二部分为秀山县旱灾的成因及机制研究。这一部分首先概述了秀山县的自然条件、社会经济状况和历年来旱灾发生的特点，然后详细分析了农业旱灾的形成机制，指出在农业旱灾的成因中既包括自然因素又包括人为因素，且人为因素主要在水利设施、生态环境、作物及种植结构、土壤改良与水土保持保措施等几个方面影响旱灾。 第三部分为近50年来秀山县农业旱灾中人为因素的定量分析。这一部分分两个步骤。第一步，建立旱灾灾情及旱灾成因的指标体系。对于旱灾灾情，本文采用粮食损失率为指标；对于自然因素则主要根据气象因子的年际和年内变化建立数学模型；对于人为因素，考虑到它的复杂性，采用二级指标，先从水利指标、种植结构易旱指标、生态指标、土壤改良水保指标和政策指标入手，再用权重法，将它们合成为人为因素。计算结果表明，在50年代和60年代，人为因素起加剧旱灾灾情的作用，而在70年代至90年代人为因素起着越来越强的缓解作用。第二步定量分析人为因素对旱灾的影响。在建立数学模型的基础上，从两方面分析这种影响。一方面分析人为因素对旱灾灾情变化的影响程度。结果认为，人为因素对旱灾灾情变化的影响程度较大。与50年代的灾情相比，60年代人为因素对旱灾灾情变化的影响程度为83.9％，且起加剧旱灾的作用。70年代、80年代和90年代人为因素均起缓解旱灾灾情的作用，其对旱灾灾情变化的影响程度分别为61.2％，79.9％和91.9％。 秀山县农业旱灾中人为因素的定量分析另一方面，分析人为因素对旱灾灾情的影响程度。在假设50年代人为因素对旱灾灾情的影响程度为零的前提下，60年代人为因素对旱灾灾情起加剧作用，加剧程度为27．9％，70年代、80年代和 90年代人为因素对旱灾灾情起缓解作用，缓解程度分别为 6．8％，15．3％和 39．4％。 第四部分为结论与讨论。从人为因素对农业旱灾灾情影响的动态变化分析得出，在 50年代和 60年代，由于生态破坏、水利设施不足和不合理的政策导向等，人为因素起着加剧旱灾灾情的作用，而在 70年代、80年代和 90年代山于人们对农业基础设施的投入，抗旱政策的制定等，人为因素开始起着越来越强的缓解旱灾灾情的作用。
Taking Xiushan county as the object and applying qualitative and quantitative analysis, the paper studies the influence factors on agricultural drought, and discusses human factor"s action on agricultural drought. Taking age as unit, the paper compares human factor"s action on agricultural drought in every age since 1950"s, and studies the causes and change tendency.The paper is composed by four parts as follow:The first part is preface. The part analyses the significance and background of this study. Then, combining the current study situation, it poses its own thinking and way.The second part is the study on the cause and mechanism of forming agricultural drought. At first, the part gives a brief account of natural, social and economic condition, and the characteristics of drought in the past in Xiushan county. Then, the part analyses in greater detail the mechanism of forming drought. It thinks the causes of agricultural drought includes human factor as well as natural factor, and human factor acts on agricultural drought in several ways as follow: .water conservancy facilities, ecology environment, crops and plant structure, soil improvement, water and soil conservation etc.The third part is the quantitative analysis about human factor of agricultural drought over last SOyears in Xiushan county. The part is finished by two steps. The first step: it establishes index system about the losses and the causes of agricultural drought. To the losses, the paper takes the rate of loss in grain as index; to natural factor, the paper establishes mathematical model according to the change on meteorological factor in one year and between years ; to human factor, for its complexity ,the paper takes two-gradeindex. Beginning with the water conservancy index, plant structure index, ecology index, soil improvement and water-soil conservation index, policy index, adopting the way of weight, it combines them into human factor. The result indicates human factor aggravated the losses of agricultural drought in 1950"s and 1960"s, but it relieved the losses from 1970"s to 1990"s. The second step: quantitative analyses the influence of human factor on agricultural drought. On the basis of establishing mathematical model, the paper analyses the influence on two sides. On one side ,it analyses the influence of human factor on the change of losses of agricultural drought .The result indicates, comparing with the losses in 1950"s, the influence of human factor on the change of losses of agricultural drought is 83.9% in 1960"s, and human factor aggravated the loss, but in 1970"s, 1980"s and 1990"s, the influence individually is 63.2%, 79.9% and 91.9%, and human factor relieved the losses. On the other side ,it analyses the influence degree of human factor on the losses of agricultural drought. Supposing the influence is zero in 1950"s, the influence aggravated the losses in 1960"s and the influence degree is 27.9%, but in 1970"s, 1980"s and 1990"s, the influence relieved the losses and the influence degree individually is 6.8%, 15.3% and 39.4%.The forth part is conclusion and discussion. From the analysis about human factor, we know because of the destroying to ecology, the lack of water conservancy facilities and unfair policy, human factor aggravated the losses of agricultural drought in 1950"s and 1960"s. But because of the input on agricultural infrastructure and the policy on fighting drought, human factor relived the losses of agricultural drought in 1970"s, 1980"s and 1990"s.
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