• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2433
  • 679
  • 156
  • 128
  • 108
  • 78
  • 50
  • 49
  • 33
  • 32
  • 32
  • 32
  • 32
  • 32
  • 30
  • Tagged with
  • 5490
  • 5490
  • 1104
  • 1090
  • 1088
  • 1002
  • 718
  • 690
  • 635
  • 516
  • 474
  • 466
  • 431
  • 419
  • 401
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Economic growth and land conversion in post-reform China, 1996-2005

Dyck, Thomas Aron. January 2008 (has links)
published_or_final_version / Geography / Master / Master of Arts in China Development Studies
62

A framework for modeling and simulating spatial dynamics

Clark, James Dean, 1964- January 1989 (has links)
This work develops a conceptual framework for modeling and simulating spatial dynamics. The framework links modeling of time variability with spatial variability. With current modeling in environmental analysis taking place at the discrete level (modeling fire, hiker behavior, or watershed run-off), it is the task of this thesis to provide a conceptual framework for integration of these discrete components in a systems like simulation environment for modeling their interactions through time. It explores the utility of the discrete event simulation framework developed by Zeigler (1976, 1984) for linking different environmental models in an interactive environment. It expands Zeigler's framework by linking cellular automata methodology to the discrete event methodology. Finally, this thesis demonstrates event modeling and simulation concepts used in the framework.
63

The application of remote sensing for irrigation and water resources management in the Aral Sea Basin, Kazakhstan

Perdikou, Paraskevi Nicou January 2003 (has links)
No description available.
64

A cluster approach to detecting urban spatial structure

Lin, Han-Liang January 2002 (has links)
No description available.
65

An investigation of the effects of land use upon water quality in the Windrush catchment

Johnes, Penny Jane January 1990 (has links)
No description available.
66

Household response to changes in land use in the Knuckles, Sri Lanka

Emeleus, Corrine Sarah Fisher January 2009 (has links)
The tension between conservation objectives and local people’s need for visible livelihoods is complex and often difficult to resolve.  In 2000, the Knuckles Conservation Area was established to include a protected area and a buffer zone to be used for management and restoration.  Prior to this decree, small tracts of land in the buffer zone were used for vegetable cultivation by villagers to supplement production from their titled agricultural plots.  An ethnographic approach was used in seven villages to explore how households have adapted their livelihoods in response to the change in land, and to examine the factors that may help understand the differences in the livelihood activities chosen.  The fundamental needs of the local people in their use of natural resources were not addressed when cultivation in the buffer zones was banned in 1990, creating shortfalls in production for some households, but stimulating others to diversify and invest in higher value crops in their own plots.  Physical, financial, human, and natural assets other than land were important to households as they responded to and coped with change.  Long-term livelihood strategies are dependent on more than just access to assets; the variability of farm and non-farm livelihood activities observed between households is explained by social and cultural factors.  Power relations within the community, personal characteristics of actors such as motivation and risk taking, and local laws and modes of governance all influence, to varying degrees and in complex and multiple ways, how households transform and utilise their assets.  The ability to transform assets is also dependent on the dynamics of the household: age and gender, status, social standing, and caste.  When conservation initiatives are implemented, programmes need to cater for variability among households in terms of their capacity to adapt to reductions in access to land, and in terms of their aspirations for diversifying their livelihood.
67

Social and environmental change in Colonial Michoacan, west central Mexico

Endfield, Georgina Hope January 1998 (has links)
The fall out from the Quincentennial anniversary of the "discovery" of the Americas has yet to settle. One of the key issues still in need of address concerns the nature of the social and environmental change wrought by colonialism. Until recently, research in this field has been determined by a series of antiquated myths, largely creations of Eurocentric Renaissance and Romantic philosophies. This study aims to provide a more objective insight into the degree of regional Colonial impact by focusing on an archival reconstruction of post-Conquest social and environmental change in the highlands ofMichoacan, west central Mexico. Archival evidence suggests that the Spanish encountered an already degraded landscape in this region, reflective of several centuries of pre-Hispanic settlement and exploitation. Contrary to conventional wisdom, however, little evidence emerges to suggest that there was an immediate and deleterious environmental impact following European contact, despite the introduction of livestock and plough technology to an area where they had hitherto been absent. Indeed, tangible evidence of ecological disturbance in the area does not emerge until the 18th century - a period recognised to have been one of population recovery and resource monopolisation. A detailed survey of litigation documents suggests that this period witnessed an acceleration in the number of indigenous claims for land reinstatement, concomitant with a marked increase in the number of references to infertile and degraded territory and apparent heightened concern over water sources. It is here argued that de-intensification of land use in the wake of indigenous depopulation and the imposition of conservative land use practices accounts for the negligible environmental impact in the early post-Conquest period. By the later 17th and 18th centuries, progressive climatic drying, population expansion, resource monopolisation and social inequality had combined to create a period of acute resource stress and landscape instability and consequent civil unrest. It was this untenable situation that was to play itself out in the Wars of Independence that characterised the first two decades of the 19th century.
68

Changing Land Use, Climate, and Hydrology in the Winooski

Hackett, William 02 October 2009 (has links)
This study analyzes temporal trends and periodicity in seventy years of publicly available stream discharge and climate data for the Winooski River Basin of northern Vermont as well as lake level data for adjacent Lake Champlain. We also use random sampling and manual, point-based classification of recent and historical aerial imagery to quantify land use change over the past seventy years in the 2,704 km2 Winooski River Basin of northern Vermont. We find a general increase in annual precipitation, discharge, and mean lake level with time in the basin; discharge increases 18% over the period of record while precipitation increases by 14%. Over the last 70 years, mean annual temperature has increased at the Burlington Vermont station by 0.78 degrees Celsius (1.4 degrees Fahrenheit). Four sets of aerial photographs, taken at intervals of 12 to 29 years between 1937 and 2003 at thirty randomly selected sites, demonstrate that actively cleared land area has decreased by 14%, while forested land and impervious surfaces increased by 10% and 5%, respectively. Spectral analysis of precipitation, discharge and lake level data show a ~7.6 year periodicity, which is in phase with the North Atlantic Oscillation (NAO); higher than average precipitation and discharge are most likely when the NAO is in a positive mode. The NAO relationship demonstrates that discharge is largely controlled by precipitation; anthropogenic changing climate and changing land use over the past 70 years appear to have subtly changed the seasonality of discharge and caused an increase in base flow.
69

Trading constraints and the investment value of real estate investment trusts : an empirical examination

Mühlhofer, Tobias January 2005 (has links)
This study focuses on the property-derived cash flows that a REIT investor earns. We observe that, in the short run, REIT investors are only exposed to the income cash flows of a REIT's underlying portfolio and not to its property price fluctuations. Specifically, investors miss out on the component of appreciation returns not contained in income. Chapter 3 observes this phenomenon and argues, without proof, that this is due to the trading restrictions that REITs face in order to operate tax free, which impose minimum holding periods on properties in REITs' portfolios. Chapters 4 and 5 show that the trading-restrictions explanation is indeed the reason for this phenomenon. Specifically, chapter 4 tests how REITs with different firm characteristics are differently affected by the trading constraints. Firstly, we test for size effects and find that medium-sized and large firms offer investors better exposure to short-term fluctuations in property appreciation than small firms. This supports the trading restrictions hypothesis, as large firms are less affected by these. Secondly, we test for the effects of the degree of diversification in a REIT's portfolio and find that, while investing in a REIT which is diversified by property type gives an investor better exposure to appreciation cash flows, investing in one whose portfolio is merely geographically diversified does not. Finally, we test whether UPREITs give an investor better exposure to property appreciation cash flows and find strongly that this is so. Since the partnership that holds the property in an UPREIT is not subject to selling constraints, we find our hypothesis strongly supported. Chapter 5 analyzes holding periods and selling decisions. We firstly simulate a possible filter-based market timing strategy which significantly outperforms a simple buy-and-hold strategy, and demonstrate to what extent holding periods shorter than what is allowed are required. We then analyze actual holding periods of properties in REITs' portfolios and model the decision to hold a property beyond four years, finding strong evidence that there is an incentive to do so in a rising market. This gives strong support to the trading-restrictions explanation.
70

Carrying capacity as a constraint affecting land use

Chang, Wilson Wu-Chun January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries

Page generated in 0.058 seconds