Effect of Land Cover Changes on the Sediment and Water Quality Characteristics of Brays Bayou Watershed
Effect of Land Cover Changes on the Sediment and Water Quality Characteristics of Brays Bayou Watershed
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DOI：
10.1007/s11270-017-3538-7
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发表时间：
2017-09-01
影响因子：
2.9
通讯作者：
Wilson, Bobby L.
中科院分区：
文献类型：
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作者：
Bhandari, Sharmila;Sridhar, B. B. Maruthi;Wilson, Bobby L.
由于城市化导致的不透水地表的迅速增加往往加剧了洪水的频率，这反过来又增加了环境污染物的径流。Brays Bayouwatershed （BBW）是一个高度城市化和人口密集的流域，主要位于德克萨斯州的哈里斯县。我们的研究目的是：(1)分析和解释Brays bayou流域土地利用和土地覆盖的时空变化；(2)确定Brays Bayou的营养物质、重金属和细菌污染。在布雷河沿岸选定的采样地点收集了水和沉积物样本，并分析了各种营养物质和金属浓度。对水样中的粪便大肠菌群进行了细菌分析。利用Landsat Thematic Mapper （TM）卫星图像对BBW研究区近30年（1980 - 2010）的土地利用和土地覆盖变化进行了处理和分析。我们的遥感分析显示，1984年至2010年期间，BBW的植被损失约为28.4%（9463英亩）。植被面积的减少导致不透水地表面积的增加。沉积物样品中Al、Cu、Fe、Pb和Zn呈向Brays bau下游方向增加的趋势。在某些Brays Bayou采样地点发现铅浓度最高（70毫克/公斤）。Brays Bayou的大肠杆菌浓度向下游方向下降，低于200个最大可能数/100 ml。遥感与化学和生物分析相结合，有助于了解土地覆盖变化对河口水质的影响。
Rapid increase in impervious surfaces due to urbanization often intensifies the frequency of flooding which in turn increases runoff of environmental pollutants. The Brays Bayouwatershed (BBW) is a heavily urbanized and densely populated watershed located mostly in Harris County, TX. The objectives of our study are (1) to analyze and interpret the spatial and temporal land use and land cover changes in BBW and (2) to determine nutrient, heavy metal, and bacterial contamination in the Brays Bayou. Water and sediment samples were collected from selected sampling locations along the Brays Bayou and analyzed for various nutrient and metal concentrations. Bacterial analysis was conducted to enumerate the fecal coliform bacteria in water samples. Landsat Thematic Mapper (TM) satellite images sampled from over three decades (19802010) for the BBW study area were processed and analyzed for land use and land cover changes. Our remote sensing analysis revealed that the BBW lost about 28.4% (9463 acres) vegetation during the period of 1984 to 2010. The loss in vegetative areas resulted in increased impervious surface areas. In sediment samples, increasing trends for Al, Cu, Fe, Pb, and Zn were observed towards the downstream of Brays Bayou. Lead concentrations were found at the highest concentration (70 mg/kg) in certain Brays Bayou sampling locations. Escherichia coli concentrations decreased towards the downstream of Brays Bayou and were found below 200 maximum probable numbers/100 ml. Integration of remote sensing along with the chemical and biological analysis helped to understand the impact of land cover changes on the bayou water quality.