Made available in DSpace on 2014-12-17T14:52:52Z (GMT). No. of bitstreams: 1 CarlosCGD.pdf: 1489111 bytes, checksum: 001f763e52671d83a36d43eff64141cc (MD5) Previous issue date: 2006-05-19 / The objective of this study was to investigate the environmental perception of: People with common-sense knowledge on the desertification process in RN. People with scientific knowledge on the desertification process in RN. Focal points in the combat at desertification of the RN and public ministery representant with actions in interinstitutional articulations promoter (and/or relative actions) at the desertification process in the RN. The research was carried in the city of Natal-RN and in two small cities of the Serid? region (RN): Caic? and Currais Novos. The research carried, is classified as exploratory and 22 people were interviewed. The research includes: The propension/intensity of the desertification in the RN and in the Serid? region; Evaluation of the knowledge of those interviewed, concerning the subject desertification ; Problems in order to combat desertification; Causes of desertification; The profile of the interviewed. The results of this present study indicate that the a desertification process is more agressive in the Serid? region than in the state of RN, being the two following: the absence of preocupation of the affected population with the process and the escarcity of governamental recurses, indicates how problems greather in the combat to the phenomen. Decreasing of produtivity in the agriculture and increasing of the migration to the urbans centers have been the main consequences of the process, that have at water scarcity, deforestation and extraction of argil (being this, regional factor), relevant variables in the influence to the surgiment of the desertification process of the RN / O objetivo deste trabalho foi investigar a percep??o ambiental de: Detentores de conhecimento popular acerca do processo de desertifica??o no RN. Detentores de conhecimento cient?fico acerca do processo de desertifica??o no RN. Pontos focais no combate ? desertifica??o do RN e representante do minist?rio p?blico que atuasse na promo??o de articula??o interinstitucional (e/ou a??es relacionadas) ao processo de desertifica??o no RN. A pesquisa foi realizada em Natal-RN e em dois munic?pios da regi?o do Serid? (RN): Caic? e Currais Novos. A pesquisa realizada, que ? enquadrada como explorat?ria, contou com 22 pesquisados e abordou: A propens?o/intensidade da desertifica??o no RN e no Serid?; Avalia??o do conhecimento do pesquisado, acerca do assunto desertifica??o ; Problemas no combate ? desertifica??o; Causas da desertifica??o; Perfil dos pesquisados. Os resultados obtidos apontam que a desertifica??o ? mais grave na regi?o do Serid? que no Estado como um todo, sendo a falta de preocupa??o da popula??o afetada pelo processo e a escassez de recursos governamentais, indicadas como principais problemas no combate ao fen?meno. Perda de produtividade agr?cola e eleva??o da migra??o para os centros urbanos evidenciaram-se como as principais conseq??ncias do processo, que tem na escassez de ?gua, no desmatamento e na retirada de argila (sendo esse ?ltimo, fator regional), vari?veis de destacada import?ncia na influ?ncia ao surgimento do processo de desertifica??o do RN

An evaluation for Lag time, defined as the time from the centroid of rainfall excess to the centroid of direct runoff, was performed for seven small watersheds in the Southwestern United States. The size of these watersheds range in size from 0.33 to 4.37 ha. The evaluation period goes from 2000 to 2010. This evaluation was compared versus 28 lag time equations.The USDA-ARS Southwest Watershed Research Center has developed an electronic data processing system where rainfall and runoff data is collected from sensors in the field and are transmitted to computers in the office.Prior to these data sets there were no measurable rainfall and runoff data. This digital data is generated by means of synchronized clocks in rain gages and flumes. As a result, the data from this electronic processing system offers a unique opportunity for hydrologic research. This infrastructure is a characteristic not often available in many other sites and a condition not enjoyed in previous investigations.There are several definitions of lag time depending on what particular time period is used to describe the occurrence of unit rainfall and runoff. But, time parameters currently lack commonly-accepted standard definitions.The various definitions for time parameters such as Lag Time, Time of Concentration, Time to Peak, Equilibrium Time and others, sometimes, are used interchangeably. Another aspect is that in Lag time determination, centers of mass play a critical role. This study found out that depending of the loss model chosen to estimate rainfall excess, it shall influence the determination of center of mass and hence the lag time.Some negative values were obtained for lag time when measured from peak of runoff to centroid of effective rainfall. However, in the lag time definition from centroid of effective rainfall to centroid of direct runoff, negative values were not obtained.One field in particular, time parameters currently lacks commonly-accepted standard definitions. This has become a source of profound confusion in this branch of science to the point where teams of scientists writing about and discussing hydrological Time Parameters can be compared to the aftermath at the Tower of Babel.

There is an undisputed need to increase accuracy of snow cover estimation in regions comprised of complex terrain, especially in areas dependent on winter snow accumulation for a substantial portion of their annual water supply, such as the Western United States, Central Asia, and the Andes. Presently, the most pertinent monitoring and research needs related to alpine snow cover area (SCA) are: (1) to improve SCA monitoring by providing detailed fractional snow cover (FSC) products which perform well in temporal/spatial heterogeneous forested and/or alpine terrains; and (2) to provide accurate measurements of FSC at the watershed scale for use in snow water equivalent (SWE) estimation for regional water management. To address the above, the presented research approach is based on Landsat Fractional Snow Cover (Landsat-FSC), as a measure of the temporal/spatial distribution of alpine SCA. A fusion methodology between remotely sensed multispectral input data from Landsat TM/ETM+, terrain information, and IKONOS are utilized at their highest respective spatial resolutions. Artificial Neural Networks (ANNs) are used to capture the multi-scale information content of the input data compositions by means of the ANN training process, followed by the ANN extracting FSC from all available information in the Landsat and terrain input data compositions. The ANN Landsat-FSC algorithm is validated (RMSE ~ 0.09; mean error ~ 0.001-0.01 FSC) in watersheds characterized by diverse environmental factors such as: terrain, slope, exposition, vegetation cover, and wide-ranging snow cover conditions. ANN input data selections are evaluated to determine the nominal data information requirements for FSC estimation. Snow/non-snow multispectral and terrain input data are found to have an important and multi-faced impact on FSC estimation. Constraining the ANN to linear modeling, as opposed to allowing unconstrained function shapes, results in a weak FSC estimation performance and therefore provides evidence of non-linear bio-geophysical and remote sensing interactions and phenomena in complex mountain terrains. The research results are presented for rugged areas located in the San Juan Mountains of Colorado, and the hilly regions of Black Hills of Wyoming, USA.

Assessment of the myriad of historic attempts to manage and/or restore degraded drylands offers a rich opportunity to learn from the past, particularly if conducted with full stakeholder engagement. Participatory environmental assessment of past land management and restoration actions would contribute to the improvement of future management techniques in a way relevant to the concerns of people involved with or impacted by these actions. This can also help to deal with the often scant information available, conflicting values and perceptions among stakeholders, and the uncertainties inherent to complex dryland systems. In this study I applied and evaluated a participatory protocol that incorporated multi-criteria decision analysis (MCDA) tools to assess five actions in the San Simon watershed, one of the most extreme examples of degradation and human intervention in southeastern Arizona (U.S.). The participatory assessment process included a semi-structured interview, elicitation of local-based assessment criteria, prioritization of the assessment criteria, estimation of data, a MCDA-based integration and group evaluation of final results. The process was used to evaluate five combinations of grazing management, vegetation management and hydraulic structures implemented between the 1940s and 1980s. The application of this process allowed me to not only evaluate these actions in a participatory way, but also to identify and compare values and perceptions connected to the historic, cultural and scientific narratives used by three different categories of stakeholders (researchers, practitioners and land users). The revised Simos' procedure used to elicit assessment criteria weights proved useful to expose values and perceptions, source of the individual criteria priorities, while revealing conflictive points of views among the stakeholders. The outranking-facilitated participatory assessment, when compared to the unaided baseline assessment, proved useful in making stakeholder preferences explicit in the form of evaluation criteria and weights, while incorporating data and uncertainty. The specific MCDA outranking integration model used, ELECTRE IS, proved to be simple and systematically synthetic, helping stakeholders structure and re-evaluate their unaided assessments. The results of this study provide insights in how stakeholders' knowledge and views can be elicited, explored and effectively incorporated to assess and learn from past land management and restoration actions implemented in drylands.

No description available.

The Pueblo of Laguna in New Mexico maintains a tribal scholarship program to assist students in their pursuit of higher education. This research was initiated to assess from the graduates' perspective how effectively the tribe utilized its subsidized academic capital. The purpose of the study was to identify obstacles, incentives, distractions, or alternative opportunities that Laguna college graduates encountered on their academic paths that influenced their perceptions about working for the tribe. Several challenges were identified that if addressed could profoundly benefit the tribe by increasing the retention of tribal graduates for the professional roles for which they were academically trained. A mixed methods research design was employed to examine why graduates educated with considerable assistance from their tribe were not working for their tribe in the capacity for which they earned degrees. Within this study, both quantitative and qualitative approaches were used to gather, report, and interpret the data. The combined use of a survey as the quantitative method and interviews as the qualitative method provided a balanced view of the perceptions of the Laguna graduates. An analysis of both sets of data indicated that several significant rifts existed between the arenas of tribal professional employment opportunities, college level academic attainment, and the existing secondary school system. Conversely, notions of tribal student loyalty and an intense desire to contribute to community were confirmed. Based on the findings, it was recommended that several critical decisions regarding the future of the Pueblo's higher education priorities be made. Further, it was recommended that the tribe increase their efforts to capitalize on the intrinsic community connectedness demonstrated by the Laguna graduates.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The exploitation of southwestern rivers is discussed in the context of American intrusion, acquisition and development of Arizona. The first Americans in the region were beaver trappers who quickly decimated the Sonoran beaver but otherwise wrought little environmental impact. Immediately following the acquisition of the region by the U.S. after the Mexican war, gold miners descended upon it from California. They quickly scarred hills and streams, diverting water for placers, building piles of ugly rubble and logging off entire forests. The large numbers of people and towns that followed created a need for more home grown food products and large storage dams were soon built. When these washed out the stored floodwaters did more sharp, tragic damage downstream than even the seasonal floods of the past. The common municipal practice of dumping raw sewage into waterways soon brought water pollution. Following the national reclamation act of 1902, large dams were soon built on major waterways and the multiple use projects came into existence. Today, even the Indians, in their quest for economic betterment are destroying natural waters. They have learned a major lesson from the whites---the rivers they used only for basic needs a century ago, may be more profitable if overused without regard for tomorrow.

From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / Evaporation is a major hydrologic process in arid and semiarid lands. A brief review of evaporation literature indicates that a unique parameter, color, is desirable. Artificially colored water was used in a west Texas experiment to monitor evaporation rate and to note the effect of color on evaporation. Artificially green water had a higher evaporation rate than sewage and runoff. Five different colored waters were studied from 1966 to 1970. Color seems to affect the amount of adsorbed radiation as well as the extent of black radiation. The trend for a higher daily rate of evaporation existed for colored waters except during periods of low air temperature. Seven graphs are presented to support these conclusions.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Much future computer modeling of the responses of groundwater to water development stresses may be poorly done if the errors and limitations of digital models are not fully appreciated by groundwater hydrologists. Two digital models were constructed of the Tucson basin, one with 1,890 nodes of 1/4 square mile area each and one with 509 nodes of 1 square mile each. The starting point for the digital model was the 2-dimensional, linear, parabolic, time-and space-invariant differential equation of incompressible flow through porous media. An explicit finite-difference equivalent was determined, and a set of 1,890 equations were put in implicit form and solved on a computer in less than 20 seconds at a cost of 2.00 dollars. The errors associated with the model are discussed. In deciding what new data collected in the Tucson basin would give the most improvement in the digital model, a statistical decision theory approach was utilized in which expected opportunity loss and expected worth of sample were calculated for 5 variables. The data was computed using about 110 seconds of computer time, costing about 13.00 dollars. This technique has the advantage of including basin dynamics in estimating worth of additional data by means of using the digital model to compute all values of predicted and 'true' water levels included in the loss function.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / A study was made to determine how the evaporation rate from a bare Adelanto loam soil in Phoenix changes with season and with time since the last irrigation. The evaporation rates were determined by precision lysimeters in a bare field, with measurements being taken in every month of the year for at least a week after irrigation. The data exhibited a cosine-shaped curve, with a maximum evaporation rate of about 5 mm/day in summer and a minimum rate of about 2 mm/day in winter. By the seventh day, seasonal effects virtually disappear, and the evaporation rate is the same in both summer and winter, being about 2 mm/day after the 7th day and about 0.75 mm/day after the 21st day. It is generally accepted that soil dries in 3 stages, and the transition between the 1st and 2nd stages occurs when atmospheric conditions are no longer critical. In previous laboratory studies of soil drying, with constant atmospheric conditions, stage 1 was easily distinguished from stage II, and these results correlated closely with the equations of Gardner and Hillel. The individual drying curves of this field study were qualitatively different from the laboratory studies and did not confirm the predictions of the equations, suggesting that diurnal variations in temperature and other meteorological parameters have caused the difference.