tailieunhanh - AQUATIC EFFECTS OF ACIDIC DEPOSITION - CHAPTER 4

Mức độ và Tầm quan trọng của axit hóa nước bề mặt Đối với các khu vực của Hoa Kỳ xác định là có nguồn tài nguyên thủy sản nhạy cảm, một số thông tin có liên quan đã được biên soạn và đánh giá tiếp theo để tích hợp NAPAP Đánh giá (IA) về mối quan hệ giữa tải lắng đọng (N và S) và mức độ (dự kiến) ước tính, độ lớn, và thời gian tác dụng thủy sản (cf, Sullivan và Eilers, năm 1994; van Sickle và Giáo Hội, năm 1995, EPA, 1995a; NAPAP năm 1998). Những nghiên. | 4 Extent and Magnitude of Surface Water Acidification For the regions of the . identified as having sensitive aquatic resources some relevant information has been compiled and evaluated subsequent to the NAPAP Integrated Assessment IA regarding the relationship between deposition loading N and S and the estimated or expected extent magnitude and timing of aquatic effects . Sullivan and Eilers 1994 van Sickle and Church 1995 EPA 1995a NAPAP 1998 . These studies have generally employed for this task a weight of evidence evaluation of the relationships between deposition and effects as followed by NAPAP in the IA NAPAP 1991 . There were six types of evidence used in the IA to assess the extent and magnitude of acidification in sensitive regions and the sensitivity of aquatic resources to changes in deposition magnitude and timing 1. Watershed models that project or hindcast chemical changes in response to changes in sulfur deposition particularly the MAGIC model . 2. Biological response models linked to the outputs from watershed chemistry models. 3. Inferences from current surface water chemistry in relation to current levels of deposition. 4. Trend analyses based on comparing recent and past measurements of chemistry and fishery status during the past one or two decades in regions that have experienced large recent changes in acidic deposition. 5. Paleolimnological reconstructions of past water chemistry using fossil remains of algae deposited in lake sediments. 6. Results from watershed or lake acidification deacidification experiments. Evidence of each type contributes to our understanding of the quantitative importance of the various acidification and neutralization processes for surface waters in the areas of interest. 69 2000 by CRC Press LLC 70 Aquatic Effects of Acidic Deposition The total concentration of the mineral acid anions in surface waters that are derived from atmospheric deposition of air pollutants .