Land Loss Rates: Louisiana Coastal Plain
Land Loss Rates: Louisiana Coastal Plain
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DOI：
10.5724/gcs.91.12.0034
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发表时间：
1993-04
影响因子：
--
通讯作者：
L. D. Britsch;J. Dunbar
中科院分区：
文献类型：
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作者：
L. D. Britsch;J. Dunbar
土地流失测绘和速率曲线的发展，62个四边形在密西西比河三角洲和贝壳滩平原显示，土地流失率和趋势在整个路易斯安那州沿海地区变化显着。土地损失率被定义为每个四边形的4个时间段（1930年至1956-1958年，1956-1958年至1974年，1974年至1983年，1983年至1990年）。各个四合院之间土地流失率的差异是地质和水文环境的函数，也是导致土地流失的因素，如沉降、风暴引起的侵蚀、溪流和河流的渠化以及运河疏浚。在1983年至1990年期间，在绘制的62个四合院中，有8个四合院每年损失超过1%的土地面积，而21个四合院每年损失超过0.5%。在区域范围内，整个路易斯安那沿海平原的土地损失率从1956-1958年至1974年期间的41.83平方英里的平均年损失率下降到1983年至1990年期间的25.34平方英里。丧失土地的百分比也从1956-1958年至1974年期间的每年0.51%下降到1983 - 1990年期间的每年0.35%。区域土地损失率可能会继续缓慢下降，直到达到背景率。
Land loss mapping and rate curve development for 62 Quadrangles in the Mississippi River deltaic and chenier plains shows that land loss rates and trends vary significantly throughout coastal Louisiana. Land loss rates were defined for each Quadrangle for 4 time periods (1930's to 1956-1958, 1956-1958 to 1974, 1974 to 1983, and 1983 to 1990). Differences in land loss rates among the individual quadrangles are a function of the geologic and hydrologic setting and the factors which contribute to land loss such as subsidence, storm induced erosion, channelization of streams and rivers, and canal dredging. Of the 62 quadrangles mapped, 8 quadrangles are losing more than 1 percent of their land area each year, while 21 quadrangles are losing more than 0.5 percent per year during the 1983 to 1990 period. On a regional scale, the land loss rate for the entire Louisiana Coastal Plain has decreased from an average yearly rate of 41.83 square miles in the 1956-1958 to 1974 period to 25.34 square miles during the 1983 to 1990 period. The percentage of land being lost is also decreasing from 0.51 percent per year in the 1956-1958 to 1974 period to 0.35 percent per year during the 1983 to 1990 period. The regional land loss rate will probably continue to decrease slowly until a background rate is reached.