Land-Use Changes in Southwestern Guatemala: Assessment of their Effects and Sustainability

Land-use changes in the Pacific coastal plain of southwest Guatemala have accelerated in the past twenty years as native arable and pasture lands have been converted at an increasing rate to oil palm and banana plantations. This study of the changes during this period has been made by remote-sensing analyses calibrated to field observations and water analyses. It has been determined that the changes, which include soil erosion, measureable contamination of streams by sediment and chemicals, and deterioration of lands adjoining plantations, have a long-range detrimental (non-sustainable) effect in terms of the ecosystem. As an example of the effects on adjoining lands, there is excess of water on them during the wet season, when the plantations use drainage procedures, and water shortages during the dry season, when the plantations use much of the available water for irrigation.;These empirical observations of land degradation and productivity deterioration outside the plantations accompanying the introduction and expansion of the plantations are confirmed and substantiated by statistical treatment of remotely sensed data. In particular, vegetative cover, as measured by the Normalized Difference Vegetation Index (NDVI), indicates statistically significant differences during the period of plantation activity. This finding is supported by the results of permutation tests and variability trend analysis, which are well suited for testing non-parametric data, a characteristic of the data of this study area. Water quality, especially values of chloride, arsenic, nitrites, and nitrates, is also of concern, when compared with international standards.;The results of this study should aid in decision-making of the Guatemala governing bodies as they decide what practices are in the best interests of the people---practices that are sustainable. Also, this study shows that surface-calibrated remote-sensing methods allow assessment of land-use changes in areas that otherwise would be without assessments because of budgetary restrictions.;This study also includes compilation/synthesis of background information in terms of meaningful parameters of sustainability and the physical setting, as they pertain to Guatemala. Correspondingly, the first parts of the dissertation focus on generalizations of sustainability and land-use changes and the geology, soils, and hydrology of the region.