Hydrographic and nutrient measurements in the vicinity of the Daintree River plume associated with Cyclone Sadie and other high rainfall events in 1994 (north Queensland)

Water was sampled at three stations located between Port Douglas and Undine Reef and at a single station on the leeward side of Agincourt Reef twice before Cyclone Sadie (January 11 and 18, 1994) and twice after Cyclone Sadie (February 1 and 3, 1994). Water samples were collected with a water bottle from the sea surface and near the bottom at each of these four stations. Salinity was immediately determined using a YSI conductivity meter. Duplicate 10 ml subsamples were collected from each bottle, filtered with disposable syringe filters and stored frozen for later analyses of nitrate and phosphate using a multichannel segmented flow autoanalyzer. Observations of the Daintree River plume were made following a further period of heavy rainfall, which occurred from the 18-20 February, 1994. A series of hydrographic measurements were conducted at eleven stations between Cape Tribulation and Port Douglas on February 21 and 22. At 4 stations close to the mouth of the Daintree River, water samples were collected from two to four different depths using Niskin bottles. Duplicate 10 ml subsamples were obtained, processed as described above, and analysed for dissolved inorganic and organic nitrogen. A 100 ml subsample was also obtained from each bottle, filtered onto a Whatman GF/F glass fibre filter, stored frozen and analysed for chlorophyll by fluorometry. This research was undertaken to gain a greater understanding of the dispersion of flood plumes in the local/regional context. As a result of Cyclone Sadie, between 250 and 400mm of rain fell in areas to the north of Cairns over the period January 29-31, 1994. Another period of heavy rainfall occurred from the 18-20 February, 1994. While this rainfall was less widespread and less intense than that associated with Cyclone Sadie, the Daintree area received about 170 mm of rain on February 18, 1994.

本研究于1994年萨迪气旋（Cyclone Sadie）过境前的1月11日、18日，以及过境后的2月1日、3日，分别在道格拉斯港（Port Douglas）与安丁礁（Undine Reef）之间的3个采样站位，以及阿金考特礁（Agincourt Reef）背风侧的1个采样站位采集水样。4个站位的水样均采用采水器从海面及近底层采集。盐度采用YSI电导仪当场测定。从每个采水器中采集两份平行的10毫升子样品，经一次性针式过滤器过滤后冷冻保存，后续采用多通道分段流动式自动分析仪对硝酸盐与磷酸盐进行分析。
1994年2月18日至20日的新一轮强降雨过后，对丹特里河（Daintree River）羽状流开展了观测。1994年2月21日至22日，在苦难角（Cape Tribulation）与道格拉斯港之间的11个站位实施了一系列水文测量。在靠近丹特里河河口的4个站位，采用尼斯金采水器（Niskin bottles）采集了2至4个不同深度的水样。采集两份平行的10毫升子样品，按前述方法处理后，分析其中的溶解态无机氮与有机氮含量。从每个采水器中另取100毫升子样品，经Whatman GF/F玻璃纤维滤膜（Whatman GF/F glass fibre filter）过滤后冷冻保存，采用荧光光度法测定叶绿素含量。
本研究旨在深入理解局地及区域尺度下洪水羽状流的扩散特征。受萨迪气旋影响，1994年1月29日至31日期间，凯恩斯（Cairns）以北区域累计降雨量达250至400毫米。1994年2月18日至20日再次出现强降雨过程，尽管此次降雨的覆盖范围与强度均弱于萨迪气旋带来的降雨，但丹特里区域在1994年2月18日的降雨量仍达到约170毫米。