博斯腾湖农田排水及其污染物空间分布特征分析The Characteristics of Spatial Distribution of the Agricultural Drainage and Pollutions into Bosten Lake
庄晴, 盈丽莎, 张建平
农田排水, 污染物, 空间分布特征, 博斯腾湖Agricultural Drainage, Pollutants, Characteristics of Spatial Distribution, Bosten Lake
《Advances in Environmental Protection》, Vol.5 No.5, 2015-09-04
博斯腾湖曾经是我国内陆最大的淡水湖泊，也是焉耆盆地、孔雀河沿岸及塔里木河下游的重要水源地。自上世纪五十年代以来，随着工农业的发展，经农田排水进入湖泊的污染物增多，水质开始劣化。农田排水是造成湖水污染最主要的原因。为定量辨析农田排水污染特征的空间分布及其近年来的年际变化，本文首先基于遥感影像，结合实地调查，绘制了26条主要排渠的空间分布图；其次根据2002年6月至2003年5月的农田排水监测数据对农田排水量及各种污染物含量进行估算；最后，选取8条主干渠将其与2007年前人的估算结果进行了对比。研究结果表明：1) 26条排渠的污水排放总量、TN和TP含量分别为4.3亿m3、1287 t和10 t；2) 进入大湖区的17条排渠中，黄水总干排的污水排放量和TP含量最大，分别为1.35亿m3和4.3 t；而TN含量最大的为22团南干排，为296 t；3) 依据26条排渠的水质数据，选取单因子指数法对其污染浓度进行水质评价，并对污染因子的浓度进行排序；4) 选取8条主干渠，其污水量、TN和TP含量之和分别为3.6亿m3、1193 t和9.6 t。2007年与2002年6月至2003年5月相比，其污水总量、TN和TP含量分别占后者的81.4%、46.0%和527.7%。
Bosten Lake was once China’s largest inland freshwater lake. Also, it is the important water source for the Yanqi Basin, the banks of Qongquehe, and the Tarim River. Since the 1950’s, the develop-ment of industry and agriculture has caused not only increased pollution into the lake, but also the water quality has deteriorated. Farmland drainage is the main cause for the water pollution. To quantitatively analyze the farmland drainage pollution, data were gathered for the characteristics of spatial distribution and for the annual changes in recent years. The following items below were used for obtaining these data: First, there is the basis of the remote sensing images and the field survey, where we represent the GIS’s plotting for the 26 main drainage canals. Secondly, by using the monitoring data of the drainage water into the lake during the period of June 2002 to May 2003, we can approximately estimate the increased amounts of wastewater and pollutants. Then lastly, we will use the results of the eight most important canals to be compared with the data for the year 2007. The criteria set above helped produce the following information: 1) The total drainage volume of wastewater, TN, and TP content of 26 main drainage canals was 4.3 × 108 m3, 1287 t and 10 t respectively; 2) For the 17 drainage canals into the Lake, the Yellow Main Dry Line had the largest total drainage volume of wastewater and TP content, 1.35 × 108 m3 and 4.3 t respectively; while the largest TN content was at the 22nd South Dry Line, 296t; 3) The grades of water quality for all of the drainage canals have now been classified and then arranged by the single factor index method and by the concentration of the pollutants; 4) Among all the drainages, we have selected eight most important canals whose total drainage volume of wastewater, TN, and TP content were respectively 3.6 × 108 m3, 1193 t and 9.6 t. Therefore, by comparing the data obtained from the year 2007 with those obtained from the period of June 2002 to May 2003, we have found that the percentage increase of wastewater, TN, and TP content was respectively 81.4%, 46.0% and 527.7%.