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1.
Matthew D. Turner 《Geoforum》2009,40(5):746-81
In dryland areas of the Africa, livestock play important economic roles as commodities, wealth stores, producers of products, and agents of environmental change. Conventional depictions of livestock economies in this region have focused (in support or against) on the need for greater engagement of livestock producers with markets supplying meat to urban areas. This paper argues this singular focus has led analysts to ignore two important aspects of livestock economies: livestock as a preferred store of wealth across a wide range of social groups and the need for specialized labor to manage these livestock across open pastures to maintain their productivity and limit their negative environmental impacts. In the West African Sahel, the capital-like nature of livestock wealth has become more clear with a growing fraction of the region’s livestock owned by investors with little connection to livestock husbandry. Livestock investments are maintained on a day-to-day basis by hired herders who facilitate access to ephemeral pastures and water. A particular concern is the changing geographies of livestock ownership and the herding labor in relationship to regional pastures (to economic and environmental ends). This relationship will be explored using the case study of the Maasina region of central Mali - a historically important livestock region, which is now undergoing significant labor emigration. Building from a long-term ethnographic engagement with local livestock owners and herders, the results of ownership surveys of livestock herds across a 14-year period and interviews of urban-based emigrants from the study area about investment decisions will be used to analyze the changing geographies of livestock investment and herding labor in the Maasina. 相似文献
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3.
This paper focuses on the burgeoning application of genetic techniques in livestock agriculture, examining how these are changing livestock breeding knowledge-practices and the representation of animal life. Conventional livestock breeding relies on visual appraisal of animals and maintaining performance records, whereas genetic and genomic techniques offer the potential to assess particular aspects of animals’ genotypes. Advertising and promotional material produced by organisations involved in developing genetic techniques, and reportage and discussion of such techniques in the agricultural media, are used to examine the ways in which the production and value of living bodies in the future is being mapped out in emerging knowledge-practice networks which centre around particular visions and representations of what livestock bodies are and should do or be. The paper argues that bodies should be understood in part in terms of the wider spatial relationships in which they are entangled. A process of’circulating reference’ [Latour, B., 1999. Pandora’s Hope: Essays on the Reality of Science Studies. Harvard University Press, Cambridge, MA] is identified in which rounds of simplification occur in relation to the representation of the genetic qualities of livestock animals. However, these attempts to simplify produce new complexities when livestock breeders attempt to make use of genetic knowledge-practices. Identifying different modes of complexity, the paper discusses their spatiality in terms of differences between genetic abstractions from animal bodies and breeders ‘multi-layered ‘lay’ knowledges of their livestock animals. 相似文献
4.
新疆不同区域牧业雪灾损失时频变化特征 总被引：2，自引：2，他引：0
选用新疆1952-2013年75个县707条雪灾害资料, 采用灰色关联评估模型以县为单位将新疆分为特重雪灾区、 重雪灾区、 一般雪灾区、 小雪灾区. 用气候趋势系数与五阶函数分析各雪灾区牲畜死亡数额的长期变化趋势, 并用morlet小波分析其振荡周期. 结果表明: 全疆及各雪灾区牲畜死亡数额基本都存在23 a左右的长周期, 14～17 a中周期, 10 a左右的小周期, 另外, 还存在5～7 a的小波动, 各区周期振荡的强弱及时间范围不同. 全疆及特重雪灾区牲畜死亡数额长期以来有减少趋势; 而重雪灾区和一般雪灾区牲畜死亡数额长期以来有微弱的增加趋势. 特重雪灾区牲畜死亡数额长期变化趋势决定了新疆雪灾牲畜死亡数额的长期变化趋势, 全疆平均每年因雪灾牲畜死亡数额以0.4%的速率递减, 特重雪灾区每年按上一年度总额1.4%的速率递减. 由于20世纪80年代开始, 新疆有计划、 大规模推行牧民定居工程, 从而大大提高了新疆牧业抗御自然灾害的能力, 以及冬春气温升高的缘故, 使得全疆及各雪灾区牲畜死亡数额大大减少. 因为各牧业区实施牧民定居工程开始的时间不同, 使全疆各雪灾区牲畜死亡数额高值期(年代际与年际尺度振荡的活跃期)进入低值期(少发时期)的临界时间存在差异. 相似文献
5.
Future trends in the occurrence of heat waves (HW) over Pakistan have been presented using three regional climate models (RCMs), forced by three different global climate models (GCMs) runs under RCP8.5 scenarios. The results of RCMs are obtained from CORDEX (Coordinated Regional climate Downscaling EXperiment) database. Two different approaches for the assessment of HWs are defined, namely Fixed and Relative approaches. Fixed approach is defined for a life-threatening extreme event in which the temperature can reach more than 45 °C for a continuous stretch of several days; however, Relative approach events may not be directly life-threatening, but may cause snow/ice melt flooding and impact on food security of the country in summer and winter seasons, respectively. The results indicate a consistent increase in the occurrence of HWs for both approaches. For the Fixed approach, the increase is evident in the eastern areas of Pakistan, particularly plains of Punjab and Sindh provinces which host many big cities of the country. It is argued that the effect of HWs may also be exacerbated in future due to urban heat island effect. Moreover, summer time HWs for Relative approach is most likely to increase over northern areas of the country which hosts reservoirs of snow and glacier, which may result in events like glacial lake outburst flood and snow/ice melt flooding. Furthermore, the increase in winter time HWs for Relative approach may affect negatively on the wheat production, which in turn can distress the overall food productivity and livelihoods of the country. It is concluded that this study may be a useful document for future planning in order to better adapt to these threats due to climate change. 相似文献
6.
Monitoring of regional groundwater levels provides important information for quantifying groundwater depletion and assessing impacts on the environment Historically,groundwater level monitoring wells in Beijing Plain,China,were installed for assessing groundwater resources and for monitoring the cone of depression.Monitoring wells are clustered around well fields and urban areas.There is urgent need to upgrade the existing monitoring wells to a regional groundwater level monitoring network to acquire information for integrated water resources management.A new method was proposed for designing a regional groundwater level monitoring network.The method is based on groundwater regime zone mapping.Groundwater regime zone map delineates distinct areas of possible different groundwater level variations and is useful for locating groundwater monitoring wells.This method was applied to Beijing Plain to upgrade a regional groundwater level monitoring network. 相似文献
7.
Mongolian pastoral husbandry is subject to various climate hazards such as dzud (Mongolian for “severe winter conditions”). Dzud in the 2009/2010 winter affected 80.9% of the country and killed more than 10 million livestock (23.4% of the total). To understand the natural and man-made mechanisms of this dzud, we examined the contributions of dzud-causing factors such as climate hazards (cold temperatures and heavy snow) and winter–spring livestock grazing (measured as overgrazing rate), which created a distinct regional pattern of high livestock mortality using a regression tree method. The regression tree model accounted for 58% of the total spatial variation of the mortality and identified various types of dzud in each region. Results showed that during the 2009/2010 winter, almost all of Mongolia experienced extreme cold temperatures, with abnormally large amounts of snow. In addition, more than half of the territory was overgrazed because of the lower pasture biomass resulting from summer drought and livestock overpopulation. At the regional scale, high livestock mortalities occurred in moderately to heavily overgrazed regions in south-central and western Mongolia, resulting from the combination of these factors. Conversely, areas with lower livestock mortalities (or non-dzud) coincided with sufficient pasture capacity in the north and east, even under extreme cold and snow. This indicates the importance of controlling the number of livestock to below the pasture carrying capacity regardless of an inter-annually varying climate. Moreover, we identified critical thresholds of each factor across which serious disasters occurred. These thresholds are practically useful for future livestock management of pasture land. 相似文献
8.
Muhammad Imran Ather Ashraf Ateeq Ur Rehman 《Journal of the Geological Society of India》2016,88(6):711-717
Quality of soil data is vital to formulate agricultural policies at different scales. Current agricultural applications in Pakistan depend however, on average values of soil estimates over larger areas. In this work, model-based ordinary kriging (OK) and Bayesian kriging (BK) to interpolate soil data is used. The aim is to compare the two different methods for the accuracy of soil data prediction. For this soils were sampled for Electrical Conductivity (EC, dS m –1) at 759 different locations in the rural agricultural areas of Qasur Tehsil, Pakistan. Cross validation was used to compare the performance of OK and BK. Our results show strong skewness and spatial dependency of soil EC values in heterogeneous regions. Box-Cox transformation successfully reduced the level of skewness in the soil EC data (from 14.1 to 0.11). Contrary to OK, under-estimation of soil EC values was not evident in the BK interpolation. Mean square prediction error for BK (1.45) was significantly reduced as compared to that for OK (6.1). Considering these findings, BK is a better model to explain the sub-regional soil EC variability and estimating strategies for sustainable agricultural planning in Pakistan. 相似文献
9.
安徽江淮地区土壤微量元素分布特征及成因分析 总被引：2，自引：0，他引：2
多目标区域地球化学调查作为生态地球化学调查的基础工作,以快速查明表层土壤及其背景地球化学元素分布为目的.本文以安徽江淮地区多目标区域地球化学调查结果为基础,对安徽江淮地区耕地土壤及其母质中主要元素分布特征及其成因进行了分析研究,结果得出:(1)大多数地区表层土壤微量元素含量与深层具有一致性和继承性;(2)各地土壤微量元素分布特征主要受成土母质类型控制,说明其成因与成土母质和成土过程等因素有关;(3)耕地土壤微量元素含量的变异受施肥、灌溉和耕作方式等人为因素影响较大,且存在较大的地区差异性. 相似文献
10.
Development of regional pollution export coefficients based on artificial rainfall experiments and its application in North China 总被引：1，自引：1，他引：0
R. Liu W. Yu J. Shi J. Wang F. Xu Z. Shen 《International Journal of Environmental Science and Technology》2017,14(4):823-832
The Export Coefficient Model (ECM) has been widely used to estimate nonpoint source (NPS) pollution loads due to its ease of application. Accurate pollution export coefficients are crucial for reducing uncertainties in load estimation. By integrating artificial simulated rainfall experiments with field survey data, we have developed a new method that estimates regional pollution export coefficients. Results showed that the export coefficients calculated using this new method accurately express the regional rainfall–runoff characteristics, as the simulation precision of this method had grown by 30% than the results with traditional ECM and export coefficients which surveyed from the literature. Based on the calculated regional pollutant export coefficient, the annual loads of TN and TP in the plains area of the Baiyangdian basin in 2010 were 25,967.13 t and 4349.29 t, respectively. Among different types of sources, rural livestock had the greatest contribution (over 60%), whereas rural domestic waste represented the smallest contribution (approximately 10%). Of the different sources, pigs contributed almost half of all NPS pollution from livestock, rural residential areas were the main land use pollution source, and rural living garbage was the main source of rural domestic waste. Spatially, NPS was mainly distributed in the Zhulong and Juma watersheds. Other watersheds only contributed approximately 5% NPS per watershed. However, the per-area loads of these lower load watersheds were larger or nearly equal to that of the Zhulong watershed. Therefore, the lower load watersheds should be addressed for the control of NPS pollution. 相似文献
11.
Ergs 总被引：1，自引：0，他引：1
I.G. Wilson 《Sedimentary Geology》1973,10(2):77-106
Ergs (areas of aeolian sand deposits) invariably have bed forms usually with a 3-order hierarchy of ripples, dunes and draas (large sandy bed forms). Ergs may occur in any relatively vegetation-free area with an adequate sand supply. The virtual absence of ergs from highland areas is attributed largely to acceleration and divergence of the winds which makes the sandflow undersaturated. Ergs with thick sand deposits and draa development in the Sahara, Arabia and Asia are contrasted with thinner dune ergs in Australia which lack draa development. Sand thickness, proportion of sand-cover, bed-form height, spacing and orientation vary in a significant way with position within the Algerian ergs. This may partly be due to regional variations in the wind regime but more probably to regional grain-size variations which, because they determine the threshold velocity of sand movement, control the effective wind regime in an area. Grain-size variations can be interpreted from aerial photographs to a large extent because of their effect on the size and shape of the bed form. A study of the northern Algerian ergs shows that regional patterns of sandflow may vary according to the grain size considered and that there is no simple relation between wind directions and the draa trends in any area even although the latter are maintained consistently for large distances. 相似文献
12.
Pakistan, being an agro-based economy, is considered most vulnerable to the impacts of climate change. The country is susceptible to many natural catastrophes and climate-induced events due to intra-geographical and intra-topographical disparities. This paper is an attempt to measure the relative vulnerability of diverse topographies in rural areas of Pakistan using vulnerability and capacity index tool. The results are based on the findings of primary survey data (350 households from 17 rural communities). Accordingly, and as expected, the key relative differences are attributed to topographical conditions besides the basic quandary of rural areas of Pakistan. The topographical attributes are largely linked to the nature of hazards and relative impacts. While the other aspects of vulnerability in all topographies stem out of inappropriate infrastructure, low education, and institutional factors. The absence of multi-sectoral and productive economic opportunities also poses an adverse impact on the resilience of households in rural areas. The women and households headed by females are found relatively more vulnerable than male-headed households.
相似文献13.
Population increases, land-use changes and marketing opportunities are important factors affecting crop-livestock integration
particularly with respect to their effect on soil fertility and feed supply for ruminant livestock. As the human population
density rises, crop farmers and grazers are finding it profitable to establish contracts for paddocking, and they are reaching
agreement on equitable ways to make use of crop residues and take care of livestocks. As the processes of intensification
proceed, mixed crop-livestock systems are evolving as the viable and dominant farming system, allowing smallholder farmers
to capitalize on the complementarity between crops and livestock. Strategies directed to raise the productivity of specific
crop-livestock systems need to consider the stage of development of the target area in relation to intensification and the
nature of crop-livestock interactions. Information related to crop and livestock systems in West Africa is currently available
from various sources e.g., household surveys, aerial surveys, rural appraisal, experimental etc., and held by different agencies.
The approach used in this study shows how such data (biophysical and socioeconomic) can be integrated within a GIS environment
and synthesized to identify the evolution of systems across environments and also to identify constraints and potential of
the systems. Potential for integrated crop-livestock systems remains untapped and/or knowledge of its existence is unknown
for large parts of Nigeria. Using data from 36 case studies and georeferenced data on cropping intensities and livestock population
for the entire country, it was possible to predict emerging crop-livestock systems using GIS. Indeed, depending on availability
of data, it is now possible to extend a similar approach in other African countries. The potential contribution of this technology
is largely unknown in West and Central Africa, where few operational programs use them. Major technological innovations and
appropriate government policies have potential to shift the balance in regional developments, if targeted carefully at areas
where the right conditions exist. Further research could then target specific areas thus ensuring efficient allocation of
resources while policy makers can achieve development goals by directing policies and resources to domains that have the greatest
potential.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Natural Hazards - The Murree region in Pakistan is frequently affected by landslides and causes damages to lands, houses, life lines and even loss of livestock and human life. We have attempted in... 相似文献
15.
Mohamed Ismail Siddiqi Dr. 《GeoJournal》1985,10(1):83-89
Conclusion Population growth in Pakistan is alarming. The long and continuing shortage of foodgrains at intervals and increasing competition for land use have resulted in deterioration in yield per hectare, and low reproduction of livestock, although hard struggle is going on for self sufficiency. The margin in food supply has arrived even in those areas where the production has been abundant, and vulnerable to crop failure and other emergency causes. Provision against these dangers call for the maintenance of adequate national reserves, which can be brought into action at an early stage of the emergency.The area under agriculture can be increased through improved programmes of soil conservation and development of barani (rain fed areas) with cost-benefit consideration. Several million hectares of barani areas have fertile soils and are suitable for agricultural development. It has been estimated that 45 billion m3 of river water flows into the Arabian Sea. A part of the water sources is properly harnessed and could possibly change the economic conditions of the barani region. A number of regions are covered by hard texture of the soil, mechanization will have to be introduced in these areas to increase production much beyond the level of margin. Soil conservation measures have already been initiated and in some cases demonstrated to farmers, but the reclaimed virgin lands up to 1973 were very little, just 46.5 ha of virgin lands and 72 ha of cultivated area from the Soan and Potwar uplands. It is expected that 300,000 ha of cultivated area, 10,000 ha of gullied land will be reclaimed through soil conservation methods in the current Fifth Year Plan.Pakistan has great water potential. The remedy lies in wise judicious and scientific water management. Inadequate natural and artificial drainage systems are causing water-logging and salinity. An accelerated programme for recovering lost land is already in operation. Many land reforms were introduced from time to time, but the production result is not of great significance. Restrictions were imposed on consolidated holdings. The economic level of such holding above subsistence have not yet been taken into consideration. It is, therefore, necessary, to make a thorough analysis of agricultural problems, particularly with the foodgrain crops, with reference to population growth, the efforts should continue till the food supply occupies the supreme position by increasing production and reducing the rate of population growth by adopting socio-economic methods. 相似文献
16.
<正>This study attempts to acquire information on tectonic activity in western China from land surface temperature(LST) field data.On the basis of the established relationship between heat and strain,we analyzed the LST distribution in western China using the satellite data product MODIS/Terra.Our results show that:1. There are departures from annual changes of LST in some areas,and that these changes are associated with the activity of some active tectonic zones.2.When annual-change background values caused by climate factors are removed,the long-period component(LST_(LOW)) of temperature residual(△T) of the LST is able to serve as an indicator for tectonic activity.We have found that a major earthquake can produce different effects on the LST fields of surrounding areas.These effects are characterized by both rises and drops in temperature.For example, there was a noteworthy temperature decline associated with the Sumatran M9 earthquake of 2004 in the Bayan Har-Songpan block of central Tibetan Plateau.3.On the other hand,the LST field of a single area may respond differently to major shocks occurring in different areas in the regions surrounding China.For instance,the Kunlun M 8.1 event made the LST on the Longmen Mountains fault zone increase,whereas the Zaisan Lake M 7.9 quake of 2003,and the Sumatran M9 event of 2004.caused decreases in the same area's LST.4.The variations of land surface temperature(LST) over time are different in different tectonic areas.These phenomena may provide clues for the study of tectonic deformation processes.On the basis of these phenomena,we use a combination of temperature data obtained at varied depths,regional seismicity and strain results obtained with GPS measurements,to test the information related to tectonic activity derived from variations of the LST field,and discuss its implications to the creation of models of regional tectonic deformation. 相似文献
17.
Rural diversification in Croatia is well advanced because many rural families have been able to find work in secondary and
tertiary activities without the need to migrate to the towns. Many rural settlements have now attained an urban character
although there are regional variations, including a contrast between the continental zone with a relatively high level of
commitment to agriculture and the coastal areas, with pronounced ‘deagrarisation’ where the ports and tourist resorts are
well developed and the natural resource conditions for agriculture are poor. These variations are examined at the municipality
level with reference to two key indicators: the share of nonagricultural population and the share of workers in the total
active population. Four categories of socio-economic transformation are recognised: more urbanised, urbanised, less urbanised
and rural. The main regional differences between the continental and coastal areas are confirmed with the latter showing a
relatively high level of socio-economic transformation through the prominence of more highly urbanised municipalities.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
F. Carrasco D. Sánchez I. Vadillo B. Andreo C. Martínez L. Fernández 《Environmental Geology》2008,54(3):575-585
The water framework directive (WFD) is applied within the Guadalhorce river basin, a Western Mediterranean basin in the Málaga
province (South Spain). Criteria defining different surface and groundwater bodies are described. The basic hydrographic network
is constituted of low-mountain and low-altitude Mediterranean mineralized rivers. Heavily modified surface water bodies correspond
(1) to areas where dams regulate the main watercourses, (2) to areas downstream of reservoirs, where river flow is reduced,
and (3) to the coastal sector of the river where artificial channelling has caused morphological variations. Groundwater bodies
are related to carbonate and porous aquifers and, locally, to aquifers influenced by dissolution of evaporites. The main impacts
to water bodies are irrigated lands and livestock farming. There are also point sources of pollution, such as wastewater,
landfills, golf courses, industrial zones, quarries and petrol stations. In addition, groundwater is frequently pumped for
human supply and irrigation. Qualitative status of groundwater bodies was done by chemical analysis of samples from a monitoring
network and the quantitative status by examining variations in piezometric levels. Both revealed the existence of water bodies
at risk of not meeting the environmental objectives of the WFD. The main indicators of pollution are nitrates related to agricultural
activities, and total organic carbon (TOC), PO43− and NH4+ in relation to wastewater. 相似文献
19.
《Applied Geochemistry》2006,21(3):492-514
Geochemical mapping of northern Honshu in the Northeast Japan Arc was carried out using stream sediments at a sampling density of one sample per 130 km2. More than 50 elements were determined in 395 stream sediment samples (<0.18 mm fraction). In geochemical maps, areas with especially low concentrations of large ion lithophile elements (LILE), Be and Li widely overlap with the distribution of Quaternary volcanic rocks along the volcanic front. The areas rich in mafic elements are associated with mafic rocks in many cases. On a regional scale, Ni, Cr and Cu contents are higher in the eastern Paleozoic–Mesozoic basement zone, Pb and Tl tend to be higher on the western zones, and Zn and Cd are high in the western back-arc zone. The areas especially rich in Cu, Zn, Cd, Pb, Bi and Tl coincide with the distribution of large mineral deposits. High concentrations related to Kuroko, hydrothermal-vein, and skarn-type deposits are recognized. High values of As and Sb are related to active geothermal areas near volcanoes and ore deposits. Chemical variations of K, Ce, Th and Sn in the stream sediments are concordant with chemical variations in major rocks. The median and mean concentrations for the stream sediments in northern Honshu, showing arc signatures, are lower in Rb, Cs, Th, Li, K, Be, Ta, LREE, Ni, Hg and Sn, and higher in Sc, Ca and Cd relative to the whole area of Japan, largely because of the contribution of Cenozoic island-arc volcanic rocks that are generally poor in incompatible elements. The averaged chemical compositions of the stream sediments for the geologic zones show systematic variations of many elements. The contrasting variations of LREE and Th contents, which are lower in the zones of Cenozoic rocks relative to the zones of pre-Neogene basements, reflect the regional variations in the main rocks, and also reflect the change of geological settings of the studied area from the continental margin to an island arc during the Cenozoic. 相似文献
20.
Nebkha development and its relationship to environmental change in the Alaxa Plateau,China 总被引：2，自引：0，他引：2
Xunming Wang Honglang Xiao Jinchang Li Mingrui Qiang Zhizu Su 《Environmental Geology》2008,56(2):359-365
Extensive nebkha areas develop mainly under the control of aeolian processes, and their sediments record information on regional
environmental changes during different periods. Such areas have developed on the dry riverbeds and deserted arable lands of
China’s Alaxa Plateau, Taklimakan, and Kumutage deserts. In this paper, we studied nebkhas that had developed in the Heicheng–Juyan
region to determine their CaCO3 contents, particle size distributions, and creation dates. Extensive human activities have occurred in this region since
at least in the late Tang Dynasty (618–907 ad). Although historical records show that most of the region’s rivers dried up around 1372, surface water persisted in some
areas until the early Qing Dynasty (1644–1911 ad). After the 1600s, extensive nebkhas began to develop due to drying of the region’s rivers. The early stages of nebkha development
were controlled by both the sediment supply and the regional wind regime, whereas late stages were controlled primarily by
variations in wind activity. In the Alaxa Plateau, it took about 100 years for arable lands and riverbeds to evolve into gobi
deserts, and during this time, several phases occurred with different levels of wind activity. The land degradation processes
in this region are mainly controlled by surface water resources, and the impact of human activities such as reclamation on
land degradation appear to have been overestimated in previous studies. 相似文献