GIS cho đánh giá đất dựa trên hoạt động gây ô nhiễm môi trường ven biển Theo Heathcote (1998), sự phát triển của các phương án quản lý khả thi (cấu trúc và phi cấu trúc hành động) trong một lưu vực đòi hỏi việc xác định tất cả các nguồn điểm và điểm ô nhiễm. Xả nước thải từ công nghiệp, đô thị và nhà máy xử lý nước thải, nơi một ống hoặc outfalls khuếch tán vào một cơ quan nước được gọi là "điểm nguồn" ô nhiễm. Một loại nguồn, được gọi là một "điểm nguồn" (NPS), được. | CHAPTER SEVENTEEN GIS for Assessing Land-Based Activities that Pollute Coastal Environments . Euán-Avila . Liceaga-Correa and H. Rodríguez-Sánchez INTRODUCTION According to Heathcote 1998 the development of workable management options structural and non-structural actions in a watershed requires the identification of all point and non-point sources of pollution. Discharge of effluents from industrial urban and sewage treatment plants where a pipe or diffuser outfalls into a water body are called point sources of contamination. Another type of source called a non-point source NPS is described as the diffuse drainage of rainwater from urban industrial and agricultural lands that can introduce nutrients pesticides and metals to water bodies. Non-point sources are some of the more serious forms of pollution and the effects are often less obvious than those of point sources Abel 1998 . Clapman et al. 1998 indicated that agricultural impacts on ground and surface water quality are more significant than other land use impacts because of their large aerial extent compared to other human land uses. Lack of information related to agricultural practices may lead to overuse of fertilizers and herbicides and deforestation with serious impacts on soil erosion and water quality. The Yucatan Peninsula is blessed with large freshwater reserves bays and coastal lagoons and an exclusive economic zone of 200 000 km2. However the maintenance of the water quality seems to be an enormous challenge for the State and other interested groups considering the unfulfilled basic needs of a large part of the population rates of population growth immigration and lack of an integrated approach to the management of the resources and coastal areas. In June 1996 a massive kill of 20 000 fish of the species Ariusfelis was reported in the Bay of Chetumal State of Quintana Roo SEMARNAP 1996 . Studies reported harm to their organs and accumulation of PCBs organochlorine insecticides and .
