Purple Crow Lidar (PCL) measurements of the vibrational Raman-shifted backscatter from water vapour and nitrogen molecules allows height profiles of the water-vapour mixing ratio to be measured from 500 m up into the lower stratosphere. In addition, the Raman nitrogen measurements allow the determination of temperature profiles from about 10 to 40 km altitude. However, external calibration of these measurements is necessary to compensate for instrumental effects, uncertainties in our knowledge of the relevant molecular cross sections, and atmospheric transmission. A comparison of the PCL-derived water-vapour concentration and temperature profiles with routine radiosonde measurements from Detroit and Buffalo on 37 and 141 nights, respectively, was undertaken to provide this calibration. The calibration is then applied to the measurements and monthly mean-temperature and water-vapour profiles are determined.PACS Nos.: 42.68.Wt, 42.79.Qx

Sugarcane cultivation is an agricultural activity of worldwide importance. This crop has been cultivated in Mexico for centuries, impacting important productive areas like the study region called Huasteca Potosina which is located at the Central-East part of Mexico. The relationship between soil conditions, weather and production per hectare allows identifying the edaphological and climatic conditions (aptitude levels) for cultivating sugarcane in the study area. The objective of this research work is to analyze the relation between the cultivated hectares and production of sugarcane. Likewise, to explain its behavior and interpret the contribution of N and C released to the atmosphere for burning sugar cane in association with events and meteorological parameters involved in the flux of water between soil and atmosphere such as drought, evapotranspiration and rainfall. The methods and indicators for burning waste provided by the Intergovernmental Panel on Climate Change (IPCC), the value of potential evapotranspiration as Thornthwaite and drought severity index were applied in order to understand the correlations between the drought severity index and potential evapotranspiration, and between C and N release and potential rainfall availability. The results show the increment of harvested hectares and the loss of water from the soil by the increase of periods of drought events and evapotranspiration. The volatilized nutrients in soil varied from 1.32 × 10 5 to 2.17 × 10 5 t for C and from 1.32 × 10 3 t to 2.17 × 10 3 t for N during the burning of sugarcane, affecting production levels with values fluctuating between 38 t/ha to 77 t/ha for the term of 1990-2010. Palabras clave: calidad del suelo, eventos meteorológicos, quema de residuos, flujo de agua Rev. Int. Contam. Ambie. 32 (2) 177-189, 2016 DOI: 10.20937/RICA.2016 D.E. Flores-Jiménez et al. 178 RESUMENEl cultivo de caña de azúcar es una actividad agrícola de importancia mundial llevada a cabo en México durante siglos, impactando importantes áreas productivas como la región de estudio llamada Huasteca Potosina, localizada al este central de México. La relación entre las condiciones del suelo, clima y producción por hectárea permite identificar las condiciones edafológicas y climáticas (niveles de aptitud) para cultivar la caña de azúcar en el área de estudio. Bajo este contexto, el objetivo fue analizar la relación entre las hectáreas cultivadas y la producción de caña de azúcar y explicar su comportamiento al interpretar las contribuciones del N y C liberados a la atmósfera por la quema de caña asociados a eventos y parámetros meteorológicos involucrados en el flujo de agua entre el suelo y la atmósfera como sequía, evapotranspiración y lluvia. Los métodos e indicadores para la quema de residuos provistos por el Panel Intergubernamental del Cambio Climático (IPCC, por sus siglas en inglés), el valor de la evapotranspiración potencial por Thornthwaite y el índice de severidad de la sequía fueron aplicados para comprender las correlaciones entre...

La pérdida de recursos forestales en la región Huasteca es un problema complejo que requiere un enfoque multidisciplinario y un proceso participativo de actores locales para detectar problemas y elaborar estrategias para mitigarlos. El objetivo del trabajo fue analizar la percepción local de la población respecto a la valoración ambiental y pérdida de los recursos forestales en el “Ejido Laguna del Mante” y la “Comunidad Tocoy” de la Huasteca de San Luis Potosí. Se desarrolló una metodología de análisis para avaluar la percepción local de la población y se aplicaron entrevistas semiestructuradas a actores claves. Asimismo, se realizó un mapeo participativo de percepción del pasado, presente y futuro de los recursos forestales y otros usos de suelo. Finalmente, se clasificó y calculó el cambio de cobertura y uso de suelo para ambas comunidades. Los resultados indican que la población percibe la pérdida y degradación de sus recursos forestales de acuerdo con su conocimiento local, basado fundamentalmente en las experiencias de sus actividades productivas, expresadas en entrevistas y mapas participativos de percepción. Ambas comunidades sufrieron procesos considerables de deforestación en el periodo 1973-2014. La metodología sobre percepción local apoyadas en mapeo participativo y análisis de cambios de cobertura y uso de suelo, permitió entender escenarios del estado de los recursos forestales y la dinámica productiva desarrollada en el área de estudio, y debe servir como herramienta para el desarrollo de estrategias y generación de políticas locales en post de la conservación y manejo de coberturas forestales en la Huasteca.

This study aims to analyze temporal changes in land use and land cover change (LUCC) as well as identify areas for natural regeneration and potential areas for forest restoration in the Huasteca region for the period from 1976 to 2007. Changes were quantified in numbers and, additionally, cartography was used to identify and map the main affected areas. Different models based on Geographic Information Systems (GIS) demonstrated that LUCC have occurred on an area of 11718.82 km 2 , representing 17.84% of the region's surface. Agriculture and the growth of pasture could be identified as the main human-induced activities that have led to landscape modification. In addition, forest cover is affected by a deforestation rate which is higher than the national average. Further important changes include a change from natural land cover to non-original land cover, affecting an area of 4911.88 km 2 in the period from 1976-1993, and an area of 1892.5 km 2 in the period from 1993-2002. Smaller changes could be observed for the period from 1993-2002 with an affected area of 1029.78 km 2. At the same time, a natural regeneration from nonoriginal to original land cover took place from 1976-1993 on an area of 1318.68 km 2 , and also on an area of 974.18 km 2 between 1993 an 2002. The surface that underwent a natural regeneration of forest cover made up 1932.07 km 2. At the same time, an area of 5739.29 km 2 for potential forest restoration was identified. Drawing on GIS methods and techniques, the development of thematic maps for land use, land use and land cover changes for the years of analysis (1976-1993-2002-2007) proved to be very adequate for the evaluation and analysis of the land cover and land use change, in particular with regard to the decrease of natural vegetation cover.

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