Detail New approaches for determining sustainable yield from the regional karst aquifer of the southeastern coastal plain Bibliografi Author: Bacchus, Sydney T. ; Brook, George A. (Advisor) Topik: HYDROLOGY|ENGINEERING; ENVIRONMENTAL|BIOLOGY; ECOLOGY Bahasa: (EN )    ISBN: 0-599-80671-0     Penerbit: UNIVERSITY OF GEORGIA     Tahun Terbit: 1999     Jenis: Theses - Dissertation Fulltext: 9975120.pdf (0.0B; 0 download) Abstract The semiconfined, regional Floridan aquifer is a primary source of water in the southeastern (SE) Coastal Plain of the United States. This source has been considered inexpensive and inexhaustible. However, sustainable yield of the Floridan has been exceeded in Florida and Georgia, resulting in damage to: private wells and property; depressional wetlands and other natural resources; groundwater quality; and, structural integrity of the aquifer matrix. Groundwater prices do not include restitution for this damage. Water resource agencies use hydrologic models to address saltwater intrusion and contamination of the upper Floridan due to upconing, but have not acknowledged environmental damage due to preferential flow. Hydrologic models cannot determine the sustainable yield of the Floridan, because data are insufficient to establish hydrologic requirements of associated natural systems. Ecological models also are inadequate because current techniques cannot detect initial stages of damage, such as premature decline of trees, which may continue for years before their death. The irreversible damage referenced above occurs because early stages of unsustainable yield cannot be determined or detected. Forested depressional wetlands of the SE Coastal Plain are associated with discontinuities in the semiconfining layer between the regional aquifer and overlying surficial aquifers. Pond-cypress is a dominant canopy species in these wetlands, and appears to be the first canopy species to exhibit symptoms of premature decline due to groundwater mining. In this study, mature pond-cypress trees from south Georgia and throughout Florida were assigned to one of three classes based on symptoms of premature decline. Cluster analysis of NIR reflectance data from dried, milled branch tips collected from the assigned trees suggested that NIR reflectance is correlated with assigned classes, rather than site location. Samples from Class 1 (few/no symptoms) were discriminated from Class 2 (moderate symptoms) plus Class 3 (severe symptoms) for 1996 and 1997, using NIR reflectance. Models developed from each set of winter samples accurately predicted samples from the remaining set. These results suggest that pond-cypress trees are hydroecological indicators of anthropogenic groundwater perturbations. Since NIR reflectance was correlated with symptoms of premature decline of pond-cypress trees, these symptoms could be used as a rapid, inexpensive means of evaluating areas where anthropogenic groundwater perturbations are occurring or are proposed. Analysis of NIR reflectance from branch tips provides more detailed information about the condition of the trees. These approaches may provide the first scientifically-based means of determining sustainable yield of the Floridan. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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