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1.
Present-day climatic conditions of the Earth were reached between 5,000 and 8,000 years ago. These are essentially the conditions under which the earliest civilizations arose. Ancient basic water problems were the same as those of today, and remarkable technologies for coping with these problems were developed. Few water technologies, except for water treatment, are modern creations. Dry farming began about 8000 B.C. Irrigation began about 5000 B.C. and became extensive by about 3500 B.C., principally in Mesopotamia, the Nile Valley of Egypt, and the Indus Valley of Pakistan. Ancient irrigators developed ingenious structures for obtaining groundwater without the use of wells or sweeps. One device, the Khanat (a kind of infiltration gallery), is still widely used in the Mediterranean area, southwest Asia and China. The khanat was invented during the First Millenium B.C. Ancient peoples also learned to collect surface runoff in areas of scanty precipitation and to use it for local groundwater recharge. The water was recovered from dug wells and used for domestic supply and stock watering. Damming of rivers began at least by the early part of the First Millenium B.C. in the Arabian Peninsula. Most early dams were for irrigation but some were also for city water supply. Many canals in various areas served the dual purposes of water supply and navigation. Soil and water salinity have been persistent problems throughout the history of irrigation and we still have not solved these problems. Irrigation practices were developed independently in the New World but much later than in the Old. North American Indians in some areas still follow the ancient practices. The chinampa system, still used in Mexico, is one of the most intensive methods of farming ever devised. Ancient peoples in the Old World also developed ingenious methods for conserving and increasing soil moisture and for retarding runoff and erosion. During the time of classical Greece and imperial Rome practical water engineering developed to a high degree. Water tunnels, aqueducts, canals, drainage ditches, and dams become commonplace. Even so, water supply and management came relatively late in Europe, where dependence had been largely on natural supply and distribution until the 19th Century.  相似文献   

2.
The United States and Finland have passed laws to classify and manage Arctic wilderness areas, but their national policies are based on different nature ideologies. Finns tend to perceive wilderness as a human-centered idea, while Americans are inclined to see the same land from a nature-based point of view. Rural residents in the Arctic, and especially indigenous peoples, use motorized vehicles for hunting and gathering in wilderness areas. Attempts of southern-based environmental groups to restrict motor use by imposing a nature-based ideology on rural residents in northern Alaska will result in high levels of political conflict. Alaska land managers need to respect the minority rights of rural residents and a study of wilderness policies in Finnish Lapland is instructive toward this end.  相似文献   

3.
The sustainability of wildlife resources in Africa is threatened by poaching for trophies and meat as well as changes in land use. In order to motivate local people for sustainable wildlife management, efforts to transfer decision-making power as well as benefits from central to local level have been made in several countries. Such efforts have not yet been seen in Kilombero Game Controlled Area, which is the area covered by the present study. The paper documents the importance of wildlife to local people, explores local people's perceptions on wildlife management and identifies constraints to sustainable wildlife management. A total of 177 household interviews in 5 villages and 129 interviews of pupils in schools have been conducted. The majority of pupils reported that their latest meal of meat was from a wild animal, and the most common species was buffalo. Apart from availability of cheap wildlife meat, advantages from living close to wildlife include the use of various parts of animals for, e.g. medical and ritual uses, and various plant products from wildlife habitats. Disadvantages include damages to crops, predation on livestock, and injuries to humans. The estimated loss of yield due to raiding by wildlife amounted to 21.9 and 47.8% of the harvest of rice and maize, respectively. Traditional wildlife management in Kilombero includes few rules to avoid resource depletion, because depletion has traditionally not been a problem due to low hunting technology and low human population. Government management includes strict rules, with hunting quotas as the main instrument, but the government has failed to enforce the rules. Ongoing discussions on new approaches to wildlife management like co-management and community-based management were largely unknown to the villagers in the area. Both poaching and agricultural expansion threaten the sustainability of Kilombero Game Controlled Area. It is suggested that transfers of decision-making power and benefits to local people is necessary in order to achieve sustainable management.  相似文献   

4.
The Hponkanrazi Wildlife Sanctuary, North Myanmar and three contiguous protected areas, comprise some of the largest expanses of natural forest remaining in the region. Demand for wildlife products has resulted in unsustainable exploitation of commercially valuable species resulting in local extirpation of vulnerable species. Camera trap, track and sign, and questionnaire-based surveys were used to examine (a) wildlife species targeted by hunters, (b) the importance of wild meat for household consumption, and (c) the significance of hunting as a livelihood activity for resident villages. Certain commercially valuable species highly preferred by hunters were either completely absent from hunt records (tiger, musk deer and otter) or infrequently obtained during actual hunts (bear, pangolin). Species obtained by hunters were commonly occurring species such as muntjacs with low commercial value and not highly preferred by hunters. Fifty eight percent of respondents (n = 84) indicated trade, 27% listed subsistence use and 14% listed human-wildlife conflict as the main reason for hunting (n = 84). Average amount of wild meat consumed per month is not significantly higher during the hunting season compared to the planting season (paired t-test, P > 0.05). Throughout the year, the average amount of fish consumed per month was higher than livestock or wild meat (Friedman test, P < 0.0001). Hunting is driven largely by trade and wild meat, while not a critical source of food for a large number of families could potentially be an important, indirect source of access to food for hunting families. Findings and trends from this study are potentially useful in helping design effective conservation strategies to address globally prevalent problems of declining wildlife populations and dependent human communities. The study provides recommendations to reduce illegal hunting and protect vulnerable species by strengthening park management through enforcement, increasing the opportunity costs of poaching, establishing no-take zones and research to determine the economic significance of hunting for livelihoods.  相似文献   

5.
Wild game management for hunting in Western society has become increasingly complex as stakeholders have multiplied and as ‘sustainability’ influences the contemporary debate. This paper questions whether the current legal framework for game management, which has evolved from early European civilisations to focus on ‘hunting rights’, is relevant to regulate the contemporary environmental, social and economic dimensions of wild game and their management. Employing a narrative analysis to focus on deer, the study identifies key legislative tenets and highlights the pertinence of historical laws to contemporary conflicts. The analysis suggests that current legislation is increasingly divergent from contemporary trends and has created inertia with respect to sustainable deer management. The paper offers four options to redress this: state intervention; voluntary collaboration; financial incentives; and establishing a legal responsibility for management. It is concluded that significant innovation is required in one or more of these four areas to facilitate the contemporary sustainable management of wild deer in Britain.  相似文献   

6.
Our immense national water quality control program has been launched on a wholly empirical basis, much as our ancestors initiated early navigation improvements and flood control. Not only has there been no effort to determine the benefits of water quality control; the theoretical groundwork for optimization has not been developed. Three main national objectives for consideration are national economic efficiency, preserving and improving the national environment for man's use and development (conservation), and regional development. Although popular at present, the regional development objective is not particularly useful from an economic viewpoint. Efficiency objectives other than environmental can be evaluated but are apt to be minor. Other water quality benefits can be broken down appropriately into four main categories: (a) man's recreational environment; (b) man's home environment; (c) man's working environment; (d) intangibles related to scientific, historic, health and cultural values. In management of water quality, various technical relationships must be considered, particularly as to quantity of water needed for waste disposal, and relationship of this use to water supply withdrawals. Advanced waste treatment must be compared with other alternatives, not only of flow augmentation, but also technological process changes, distribution of effluents, and artificial river aeration.  相似文献   

7.
Sensors and enabling technologies are becoming increasingly important tools for water quality monitoring and associated water resource management decisions. In particular, nutrient sensors are of interest because of the well‐known adverse effects of nutrient enrichment on coastal hypoxia, harmful algal blooms, and impacts to human health. Accurate and timely information on nutrient concentrations and loads is integral to strategies designed to minimize risk to humans and manage the underlying drivers of water quality impairment. Using nitrate sensors as the primary example, we highlight the types of applications in freshwater and coastal environments that are likely to benefit from continuous, real‐time nutrient data. The concurrent emergence of new tools to integrate, manage, and share large datasets is critical to the successful use of nutrient sensors and has made it possible for the field of continuous monitoring to rapidly move forward. We highlight several near‐term opportunities for federal agencies, as well as the broader scientific and management community, that will help accelerate sensor development, build and leverage sites within a national network, and develop open data standards and data management protocols that are key to realizing the benefits of a large‐scale, integrated monitoring network. Investing in these opportunities will provide new information to guide management and policies designed to protect and restore our nation's water resources.  相似文献   

8.
In the Southwestern United States, increasing demand for firewood has quickly promoted pinyon-juniper woodlands to commercial status. Slow recovery rates for pinyon and juniper and inadequate mensuration data present significant obstacles to predictive management efforts. Many National Forest districts have witnessed continued fuel use for at least the past 100 years. To explore the need for long-term analysis at the district level, we have developed FORMAN I, a computer simulation written in FORTRAN IV that models prolonged fuel harvesting and its impact on pinyon-juniper woodlands. The technique is well-suited for historical analyses and we comply with an initial application that involves the suggested impact of prehistoric peoples on a marginal woodland in Chaco Canyon, New Mexico. To accentuate the significance of the simulation, we have deliberately overestimated woodland parameters while maintaining conservative annual rates for firewood procurement. A low-density woodland (less than 14.8 cords/ha) is completely depleted within 200 years when subjected to tenth-through-twelfth century estimates of human demography for the canyon. Interesting conclusions are drawn from the lack of pinyon-juniper recovery at Chaco over the past millennium. Traditional assumptions, such as the pristine state of Southwestern vegetation prior to historic settlement and subsequent invasion of marginal grasslands by pinyon and juniper, are questioned.  相似文献   

9.
There is a general lack of information on the impact of forest plantations and the presence of urban settlements on populations of resource-demanding species such as large felids. To partially address this problem, a project study was conducted to find out whether mosaics of forest plantations and native vegetation can function as an adequate habitat for pumas (Puma concolor) in southern Brazil. The study was conducted within a 1255-km2 area, managed for planted stands of Pinus spp. and Eucalyptus spp. Individual identification of pumas was carried out using a combination of track-matching analysis (discriminant analysis) and camera-trapping. Both techniques recorded closely similar numbers of individual pumas, either total (9–10 individuals) or resident (5–6 individuals). A new approach, developed during this study, was used to individualize pumas by their markings around the muzzle. The estimated density varied from 6.2 to 6.9 individuals/100 km2, ranking among the highest across the entire puma range and indicating a potential total population of up to 87 individuals in the study site. In spite of the availability of extensive areas without human disturbance, a radio-tracked female used a core home range that included forest plantations, an urbanized village, and a two-lane paved road with regular vehicular traffic. The high density of pumas and the species’ intensive use of modified landscapes are interpreted here as deriving from conditions rarely found near human settlements: mutual tolerance by pumas and humans and an adequate habitat (regardless of plantations) largely due to the inhibition of invasions and hunting and maintenance of sizable extents of native forest patches. More widely, it suggests the potential of careful management in forestry operations to provide habitat conditions for resource-demanding species such as the puma. Furthermore, it highlights the importance of curbing invasions and hunting, in this case provided by the presence of company employees, for the maintenance of wildlife populations.  相似文献   

10.
Agricultural change has transformed large areas of traditional farming landscapes, leading to important changes in the species community assemblages in most European countries. We suspect that the drastic changes in land-use that have occurred in Andalusia (southern Spain) over recent decades, may have affected the distribution and abundance of game species in this region. This article compares the distribution of the main game species in Andalusia during the 1960s and 1990s, using data from maps available from the Mainland Spanish Fish, Game and National Parks Service and from recent datasets on hunting yield distributions, respectively. Big-game and small-game species were significantly segregated in southern Spain during the 1990s, as two clearly independent chorotypes (groups of species whose abundances are similarly distributed) were obtained from the classification analysis. In contrast, big-game and small-game species were not significantly segregated several decades ago, when there was only one chorotype consisting of small-game species and wild boar. The other three ungulates did not constitute a significant chorotype, as they showed positive correlations with some species in the group mentioned above. These changes seem to be a consequence of the transformations that have occurred in the Iberian Mediterranean landscape over the last few decades. The abandoning of traditional activities, and the consequent formation of dense scrubland and woodland, has led to an expansion of big-game species, and a decrease of small-game species in mountain areas. Moreover, agricultural intensification has apparently depleted small-game species populations in some agricultural areas. On the other hand, the increasingly intensive hunting management could be artificially boosting this segregation between small-game and big-game species. Our results suggest that the conservation and regeneration of traditional agricultural landscapes (like those predominating in the 1960s) should be a priority for the conservation of small-game species.  相似文献   

11.
Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production—the most widespread and long-running commercial use of public lands—can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates.  相似文献   

12.
Water availability, use and quality in a rural watershed of the Colombian Andes were investigated through participatory research involving local youth. Research included the quantification of disaggregated water use at the household level; comparison of water use with availability; monitoring water quality of streams, community water intakes and household faucets; and the determination of land use – water quality interactions. Youth were involved in all aspects of the research from design to implementation, dissemination of results and remediation options. Quantification of domestic and on-farm water use, and water availability indicated that water availability was sufficient during the study period, but that only an 8% decrease in dry season supply would result in shortages. Elevated conductivity levels in the headwaters were related to “natural” bank erosion, while downstream high conductivity and coliform levels were associated with discharges from livestock stalls and poorly maintained septic tanks in the stream buffer zone. Through the involvement of youth as co-investigators, the knowledge generated by the research was appropriated at the local level. Community workshops led by local youth promoted water conservation and water quality protection practices based on research, and resulted in broader community participation in water management. The approach involving youth in research stimulated improved management of both land and water resources, and could be applied in small rural watersheds in developed or developing countries.  相似文献   

13.
The flow records of the Rivers Bure, Nar and Wensum in eastern England have been examined with the aim of identifying long-term changes in flow behaviour relating to variations in rainfall amount, land use, land drainage intensity and water resources use. In the study area, and since 1931, there is no evidence of long-term change in rainfall amount or distribution, on either an annual or seasonal basis. Despite changes in water resources use and catchment characteristics since the beginning of the century, such as the ending of water milling and increased land drainage and arable farming, rainfall-runoff modelling over the period 1964-1992 showed that the relationship between rainfall and runoff has remained essentially unchanged in the three study rivers. A catchment resource model used to 'naturalise' the historic flow records for the period 1971-1992 to account for the net effect of water supply abstractions and discharges revealed that mean river flows have been altered by surface water and groundwater abstractions, although the average losses to mean weekly flows due to net abstractions for all water uses was no greater than 3%. Greater losses occurred during drought periods as a result of increased consumptive use of water for spray irrigation and amounted to a maximum loss of 24% in the Nar catchment. In lowland areas such as eastern England that are prone to summer dry weather and periodic drought conditions, an integrated approach to river basin management, as advocated by the EU Framework Directive, is recommended for future management of surface and groundwater resources for public water supplies, river regulation purposes and industrial and agricultural demands.  相似文献   

14.
In California, the growing popularity of urban agriculture (UA) has unfolded against a backdrop of historic drought. While UA is often celebrated as an urban sustainability strategy, it must be able to persist during drought if it is to perform these functions. Using Santa Clara County – the geographic core of Silicon Valley – as a case study, we use interviews and surveys to explore the implications of drought for UA. We show how developing an understanding of water access for UA during a drought requires examining the social and institutional context of water management and use. In metropolitan California, the highly decentralised water supply system combined with the diverse institutional arrangements that support UA create an uneven landscape of water access. Consequently, the pressure to change water-consuming practices – that is, the stress that institutional drought responses place on different water users – is geographically and socially differentiated. Among UA water users, responses to drought have also varied, in part because the possibilities for change are constrained by the sociotechnical arrangements of UA sites and the different purposes of UA.  相似文献   

15.
Brown, Casey, William Werick, Wendy Leger, and David Fay, 2011. A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes. Journal of the American Water Resources Association (JAWRA) 47(3):524‐534. DOI: 10.1111/j.1752‐1688.2011.00552.x Abstract: In this paper, we present a risk analysis and management process designed for use in water resources planning and management under climate change. The process incorporates climate information through a method called decision‐scaling, whereby information related to climate projections is tailored for use in a decision‐analytic framework. The climate risk management process begins with the identification of vulnerabilities by asking stakeholders and resource experts what water conditions they could cope with and which would require substantial policy or investment shifts. The identified vulnerabilities and thresholds are formalized with a water resources systems model that relates changes in the physical climate conditions to the performance metrics corresponding to vulnerabilities. The irreducible uncertainty of climate change projections is addressed through a dynamic management plan embedded within an adaptive management process. Implementation of the process is described as applied in the ongoing International Upper Great Lakes Study.  相似文献   

16.
The beliefs of Americans about the proper relationship between humans and their environment were profoundly affected by waves of immigration from Europe. Immigrants valued ownership of land, individuality, freedom, domination of nature, and technological development. These themes remain strong today as centerpieces of the American dominant social paradigm (DSP).That DSP has been reexamined and found wanting by an increasing proportion of Americans. This departure from the old DSP has progressed further among the public than among the elite who have a greater stake in preserving the status quo. Environmentalists constitute a vanguard trying to lead the people to a new, more environmentally oriented social paradigm. The beliefs of the old DSP and the new environmental paradigm (NEP) are contrasted in Table 2. Briefly, the NEP advocates stress love of nature rather than domination of it; compassion for other peoples, future generations, and other species; planning to avoid risk; limits to growth; fundamental social change; and a new structuring of politics.These two worldviews are likely to be in vigorous conflict for several decades in the USA. Social learning, spurred by deterioration of the old ways, is likely to lead Americans to a new perspective on their relationship to nature.With the advice and assistance of Barbara V. Fisher.  相似文献   

17.
There is increasing concern about the use of lethal methods to control wild mammal populations, especially those methods that may have significant impacts on animal welfare. The continued use of dogs to hunt wild mammals in England and Wales, principally foxes (Vulpes vulpes), red deer (Cervus elaphus), brown hares (Lepus europaeus) and mink (Mustela vison), has become a focus for political debate and has been the subject of a recent UK government inquiry. This paper reports the results of a questionnaire study to quantify the use, effectiveness and acceptability of the different methods currently used to manage these four species, and future changes in management following a possible ban on hunting with dogs. There was no straightforward relationship between culling pressure and perceived pest status of the different species from the questionnaire data. For foxes and brown hares, the proportion of land managers (practitioners) carrying out lethal control was higher than that considering these species to be pests. However, the reverse was the case for mink. The most frequently used and effective control methods, which were most acceptable to practitioners and public alike, were various forms of shooting. The general public perceived hunting with dogs as one of the least acceptable means of control for all four species. Practitioners thought that hunting with dogs for red deer and the use of terriers against foxes were among the least acceptable forms of control, but considered hunting with dogs in other situations and for other species to be relatively acceptable. Most practitioners said a ban on hunting with dogs would make no difference to their management of the four species. A ban on hunting with dogs would have minimal impact on populations of foxes, red deer and mink, but it may be of conservation benefit to hares.  相似文献   

18.
According to the National Wild Turkey Federation, there has been a 450% increase in the number of licensed wild turkey hunters since 1973. Unfortunately, there is a paucity of research articles focusing specifically on turkey hunting. Most human dimensions of wildlife research have focused on either deer or waterfowl hunting. In this study, dimensions of hunting quality, days afield, and harvest were examined among a sample of 739 Virginia fall turkey hunters. Quality of a hunting season, rather than a specific hunt, was examined. Principal components analysis (PCA) revealed five domains of attributes of a high-quality turkey-hunting season: wildlife interaction, education, being away, social interaction, and hunting skills. The domains of hunting quality revealed by the PCA are similar to domains found previously for spring turkey hunters as well as other types of hunters. Also examined were hunter perceptions of overall hunting quality, the number of days spent hunting turkeys during the fall season, and harvest success. For comparative purposes and agency needs, hunters were segmented into three categories based on days spent hunting: low frequency (1 to 2 days), medium frequency (3 to 4 days), and high frequency (≥5 days). The influence of these variables to respondents’ perceptions of overall quality was examined using a series of regression models. Variables found to be significant predictors of quality were wildlife interaction and harvest success. Hunters who killed a turkey reported a significantly higher quality season than those who did not kill a turkey.  相似文献   

19.
Leidner, Andrew J., M. Edward Rister, Ronald D. Lacewell, and Allen W. Sturdivant, 2011. The Water Market for the Middle and Lower Portions of the Texas Rio Grande Basin. Journal of the American Water Resources Association (JAWRA) 47(3):597‐610. DOI: 10.1111/j.1752‐1688.2011.00527.x Abstract: Regional water management on the United States’ side of the middle and lower portions of the Rio Grande basin of Texas has been aided by a functioning water market since the early 1970s. The water market operates over a region that stretches from the Amistad Reservoir to the Rio Grande’s terminus into the Gulf of Mexico. This article provides an overview of the organizations, institutions, policies, and geographic particulars of the region’s water‐management system and its water market. In recent years, this region has experienced high population growth, periodic droughts, and a reallocation of water resources from the area’s agricultural sector to the municipal sector. Demand growth for potable water and a relatively fixed supply of raw water are reflected in increasing prices for domestic, municipal, and industrial water rights. Rising prices in the presence of scarcity and the transfer of water from lower‐value to higher‐value uses indicate that the market is operating as suggested by economic theory. Reasons for the market’s functionality are presented and discussed. Finally, suggestions are presented which might mitigate potential complications to market operations from aquifer depletion and aid the management of instream river flows.  相似文献   

20.
Huang, Biao, Christian Langpap, and Richard M. Adams, 2011. Using Instream Water Temperature Forecasts for Fisheries Management: An Application in the Pacific Northwest. Journal of the American Water Resources Association (JAWRA) 47(4):861‐876. DOI: 10.1111/j.1752‐1688.2011.00562.x Abstract: Water temperature is an important factor affecting aquatic life within the stream environment. Cold water species, such as salmonids, are particularly susceptible to elevated water temperatures. This paper examines the potential usefulness of short‐term (7 to 10 days) water temperature forecasts for salmonid management. Forecasts may be valuable if they allow the water resource manager to make better water allocation decisions. This study considers two applications: water releases from Lewiston Dam for management of adult Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River and leasing water from agriculture for management of steelhead trout (Oncorhynchus mykiss) in the John Day River. We incorporate biophysical models and water temperature distribution data into a Bayesian framework to simulate changes in fish populations and the corresponding opportunity cost of water under different levels of temperature forecast reliability. Simulation results indicate that use of the forecasts results in increased fish production and that marginal costs decline as forecast reliability increases, suggesting that provision and use of such stream temperature forecasts would have potential value to society.  相似文献   

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