tailieunhanh - GIS for Water Resources and Watershed Management - Chapter 13

Mức nước các Great Lakes Laurentian kênh kết nối và Rise và mùa thu của họ trong mô hình Dự đoán hàng năm liên quan đến các mô hình theo mùa của lượng mưa, dòng chảy và bay hơi. Biến thể của mùa đông để độ mùa hè trung bình thấp mức độ cao từ 0,37 mét trên hồ Superior với hồ Ontario là 0,6 mét (US Army Corps of Engineers, 1985). Ngoài ra Hồ Mức tăng và sự suy giảm trong mô hình không thể đoán trước SAU nhiều năm dài hạn biến động của điều kiện khí hậu. | CHAPTER 13 Historical Aerial Photographs and a Geographic Information System GIS to Determine Effects of Long-Term Water Level Fluctuations on Wetlands along the St. Marys River Michigan USA Donald C. Williams and John G. Lyon INTRODUCTION Water levels of the Laurentian Great Lakes and their connecting channels rise and fall in predictable annual patterns related to the seasonal patterns of precipitation runoff and evaporation. Variations of winter low levels to summer high levels average from meters on Lake Superior to meters on Lake Ontario . Army Corps of Engineers 1985 . Lake levels also rise and decline in unpredictable multiyear patterns following long-term fluctuations of climatic conditions in and around the Great Lakes basin. Historically the ranges of Great Lake annual water level averages have been from to meters from their respective historic means . Army Corps of Engineers 1985 . The Great Lakes long-term water level fluctuations have recurred about every two to three decades. These fluctuations have broad influences on the areas of the wetlands situated along the lake and connecting channel shores Jaworski et al. 1979 Harris et al. 1981 Enslin and McIntosh 1982 Lyon and Drobney 1984 Busch and Lewis 1984 Quinlan 1985 Greene 1987 Bukata et al. 1988 Williams 1995 . The subject of this chapter is the use of a Geographic Information System GIS to study the influences of long-term water level fluctuations on the wetland areas of the St. Marys River. The St. Marys River is a connecting channel between Lakes Superior and Huron that borders on the . and Canada. The river water levels are largely controlled by the levels of Lake Huron Williams 1995 such that wetland areas along the St. Marys undergo fluctuations corresponding to those of Great Lakes wetlands. A GIS was used to measure area changes in five different St. Marys River coastal wetland classes. These area change data were used to characterize wetland class responses to water