Spontaneous resettlement after drought: An Ethiopian example*

Based upon two recent periods of fieldwork among a spontaneously resettled population of cattle herders in southwestern Ethiopia, this paper is an attempt to illustrate, by a particular case, the general proposition that external aid, if it is not to be counter-productive, must meet people's needs as they themselves define them. The people in question, the Mursi, have experienced, since 1970, their worst period of drought and hunger in living memory. They have responded to this experience with resilience and inventiveness and largely without external assistance. The paper concentrates on a recent, drought induced, migration of Mursi to higher land, outside their traditional territory, and shows how the migrants are adapting to a new way of life which brings them into direct conflict with some of their most cherished cultural traditions.     

旱涝灾害的一些基本问题初探

首先就旱涝灾害对人类的作用进行了分析，认为它影响范围最大，危害程度最深．其次．对旱涝灾害的成因、确定旱涝灾害的定量指标以及评估旱涝灾害的指标体系进行分析探讨；最后对国内防御旱涝灾害的能力做了总体评价，并对其所采取的预防，救抗灾措施等进行分析．     

减轻旱灾,谋求旱区可持续发展的综合途径与措施

运用旱区环境社会学的观点和方法，从旱灾、旱区环境与人类行为交互作用的角度分析旱灾，提出减轻旱灾、谋求旱区可持续发展的综合途径、措施与对策。对策的重点是非技术措施与方法，如调适人类开发利用生态资源的观念、方法及群体行为，改善旱区的社会格局、加强旱区人类行为评估和移民管理等。同时提出减轻旱灾，必须强化旱灾的社会学研究。     

气象卫星遥感在干旱监测中的应用

本文根据ＮＯＡＡ极轨气象卫星ＡＶＨＲＲ资料计算生成植被指数相对距平图用于旱情监测，并在江苏省１９９４年特大干旱中进行了应用服务     

黑龙江省旱涝灾害农业气候指标及地理分布区划

作者根据水分平衡原理，在考虑水分供应和植物蒸散的基础上，研究了符合黑龙江省实际的农作物旱涝灾动态指标，提出用月气象资料计算旱涝起止日期的模型和计算公式，并制作了黑龙江省春旱区划、春涝区划、夏涝区划和综合旱涝区划。     

Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst)

The effects of experimentally elevated O₃ on soil respiration rates, standing fine-root biomass, fine-root production and δ¹³C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O₃ under beech and spruce, and was related to O₃-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O₃ on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O₃ regime. δ¹³C signature of newly formed fine-roots was consistent with the differing g_s of beech and spruce, and indicated stomatal limitation by O₃ in beech and by drought in spruce. Our study showed that drought can override the stimulating O₃ effects on fine-root dynamics and soil respiration in mature beech and spruce forests.     

The continuing conundrum of the LEA proteins

Research into late embryogenesis abundant (LEA) proteins has been ongoing for more than 20 years but, although there is a strong association of LEA proteins with abiotic stress tolerance particularly dehydration and cold stress, for most of that time, their function has been entirely obscure. After their initial discovery in plant seeds, three major groups (numbered 1, 2 and 3) of LEA proteins have been described in a range of different plants and plant tissues. Homologues of groups 1 and 3 proteins have also been found in bacteria and in certain invertebrates. In this review, we present some new data, survey the biochemistry, biophysics and bioinformatics of the LEA proteins and highlight several possible functions. These include roles as antioxidants and as membrane and protein stabilisers during water stress, either by direct interaction or by acting as molecular shields. Along with other hydrophilic proteins and compatible solutes, LEA proteins might also serve as “space fillers” to prevent cellular collapse at low water activities. This multifunctional capacity of the LEA proteins is probably attributable in part to their structural plasticity, as they are largely lacking in secondary structure in the fully hydrated state, but can become more folded during water stress and/or through association with membrane surfaces. The challenge now facing researchers investigating these enigmatic proteins is to make sense of the various in vitro defined functions in the living cell: Are the LEA proteins truly multi-talented, or are they still just misunderstood?     

DROUGHT INDICATED IN CARBON-13/CARBON-12 RATIOS OF SOUTHWESTERN TREE RINGS1

ABSTRACT: Stomatal closure during periods of moisture deficiency should theoretically lead to elevated ¹³C/¹²C ratios as reduction of available CO₂ leads to diminished photosynthetic discrimination against ¹³C in favor of ¹²C. Stable-carbon isotope ratio chronologies developed from 5-yr tree-ring groups at 17 sites in six southwestern states were tested for a drought relationship by first fitting a spline curve to each chronology to remove the long-term trend and calculating indices as the ratio of actual to spline curve value. The time series of “Del Indices” so developed are significantly correlated with 5-yr mean Palmer Hydrological Drought Indices (post-1930 period) and reconstructed July Palmer Drought Severity Indices from respective areas. Overall, in the period since 1790, the driest pentads were 1900–04 and 1960–64, whereas the wettest were 1980–84 and 1915–19. Maps of drought represented for two pentads seem to be reasonable representations, although spatial correlations of Del Indices with PHDI were generally not significant. These Del Index drought reconstructions may provide a useful measure of past physiological response to drought (stomatal closure), although the present cost of analysis would prevent this from being a routine method.     

THE PALMER DROUGHT SEVERITY INDEX AS A MEASURE OF HYDROLOGIC DROUGHT1

ABSTRACT: The Palmer Drought Severity Index (PDSI) is perhaps the most widely used regional drought index. However, there is considerable ambiguity about its value as a measure of hydrologic drought. In this paper the PDSI for climatic divisions in New Jersey is compared to the occurrence within each climatic division of streamflows in their lower quartile for the month (streamflow index), and ground-water levels in their lower quartile for the month (ground-water index). These indices are found to have distinct properties. It is not uncommon for PDSI values to indicate “severe” or “extreme” drought at times when the streamflow or groundwater index is above its lower quartile at many stations within the climatic division. The PDSI values and groundwater index indicate more persistent subnormal conditions than the streamflow index for truncation levels yielding the same total duration of drought over a period. The ground-water index tends to indicate a later beginning to droughts and of the three indices is the most conservative indicator of a drought's end. Drought timing and duration properties for the ground-water index are found to be highly influenced by the average depth to water in the well. Overall, the three indices of drought can provide three very different characterizations of drought. In particular, the results indicate that considerable caution should be exercised in drawing conclusions about hydrologic drought from the PDSI.     

西南地区1959—1961年三年自然灾害分析

该文以丰富而翔实的资料就西南地区１９５９～１９６１年三年自然灾害，特别是旱灾的灾情、灾情特点、灾害损失、灾害原因及其经验教训进行了论述．