Argentina - Flood Protection Project : environmental assessment (Vol. 1 of 4) : Final report

I MINISTERIO DEL INTERIOR SUE UNDAD CENTRAL DE COORDINACION PARA LA EMERGENCIA ESTUDIOS AMBIENTALES REGIONALES PARA EL PROYECTO DE CONTROL DE INLNDACIONES 3 INFORME FINAL Febrero - Agosto de 1995. II L21 I - I L Autores: Juan Schnack (Consultor Principal) - C _ Fernando De Francesco 6 Carlos Gallian __- _- __ I Juan J. Neiff K Norberto Oldani I Enriqlie Schnack Gustavo Spinelli - . ^ - , .i*f *~~~~~~~~~~~~~~~~~~~~~~ ~ ~~~~~~~~~~~~~~~~~~~~ ,4 __ _ _ _ _ _ __ __  I I MtIINISTERIO DEL INTERIOR SUB UNIDAD CENTRAL DE COORDINACION PARA LA EMERGENCIA l I REGIONAL E NVIRONMENTAL STUDIES FOR THE FLOOD CONTROL PROJECT I EXECUTIVE SUMARY U February - August 1995. Juan Schnack Fernando De Francesco Carlos Galliari Juan J. Neiti Norberto Oldani Eunrique Schnack | ~~~~~~~~~~~~~~~~~~~Gustavo Spinetli I I  IE CONTENTS L iTRODUCTION 2 1. CONTENTS AND STUDY AREA 2 I 2. ENVIRONMENTAL ANALYSIS 2 | 3. OBJECTIVES 2 4. SOURCES OF INFORMATION 2 I ~5. ZONIFICATION 2 ILIL THE PHYSICAL ENVIRONMENT 2 1. INTRODUCTION 3 2. REGIONAL CLIMATEAND HYDROLOGY 3 I 3. GEOLOGICAL FRAiMEWORK 4 I 4. GEOMORPHOLOGY AND HYDROLOGY 4 [U FLOOD ANALYSIS 4 I 1. PHYSICAL ASPECTS 5 | 2. HISTORIC ANALYSIS 5 I 3. DAMAGE EVALUATION 5 IV. THE BIOTIC ENVIRONNENT 5 Ii1. THE PULSATILE REGIME OF THE GREAT RIVERS AND THEIR INFLUENCE ON THIE BIOTA 5 I 2. WETLANDS 5 j 3. VEGETATION 6 4 FISH 6 I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I  I 5. VERTEBRATES (EXCLUDING FISHES) 6 6. DIPTERA VECTORS OF DISEASES 6 V. FLOODING: AN ECOLOGICAL APPROACH 6 Ii1. INTRODUCTION 6 I 2. RIVERS AS MACROSYSTEMS 6 3. THE FITRS FUNCTION (FF) 6 4. THE FF OF THE PARAGUAY, PARANA AND URUGUAY SYSTEMS 7 5. THE FF AND lTS IMPLICANCY IN THE ALLUVIAL PLAIN 7 VL THE NATURAL PROTECTED AREAS 7 .VI THE ANTHROPIC ENVIRONMENT 7 1. REGIONAL CONTEXT 7 1 2. CULTURAL IERITANCE 7 I 3. COLONIZATION AND MGRATION FLUXES 7 I 4. REGIONAL SOCIAL AND ECONOMIC CONTEXTS 7 VIII. REGIONAL ENVIRONMENTAL PROBLEMS AND FLOODS. IDENTIFICATION AND PROPOSALS 8 1. URBAN AND PERrURBAN ECOSYSTEMS 8 1 2. NATURAL ECOSYSTEMS 8 I 3. EDUCATION 8 j 4. INSTITUTIONAL ORGANIZATION 9 5. THE ENVIRONMENT AND ITS IMPACTS ON DEFENSES 9 IX. FLOOD CONTROL PROJECTS AND ENVIRONMENTAL IMPLICATIONS 9 I  1. REGIONAL EFFECTOS 9 2. ENVRONMENTAL ANALYSIS 9 3. METHODOLOGY 9. I X. ADDIONAL STUDEES. PROJECTS 9 II1. FLOOD CONTROL PROJECTS AND ENVIRONMENTAL MANAGEMENT 9 2. ENVIRONMENTAL MANAGEMENT PROCEDURES 9 3. ENVIRONiMENTAL SUPERVISION FOR FLOOD CONTROL PROJECTS 10 I 4. PROGRAMS 10 I I I I I I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I  I ElI. INTRODUCTION i1. CONTENTS AND STUDY AREA The study area included the Paraguay, Paana. and Uruguay rivers' floodplains. This is a macrosystem I containing diverse subsystems differing in their structure and function. Its ecological stability depends on the conservation of such heterogeneity. Men activities lead to environrental simplification, and a deterioriation of its abiotic and biotic components. In most of the area man has extended its range to the floodplain. We suggest thatwithtin the anthropic envirornent the potential negative impacts from the structures for protection against fluds should be less significant than those caused by floods when these structures are lacking. We evaluated the adequacy of these -ttructures I considering those currently existent and those programmed for the near future, a special point to be dealt with in order to recommend future trends of urban expansion. I 2. ENVIRONMENTAL ANALYSIS The main environmental components for the Flood Control Project are summarized as shown in Fig. I.2. (see main report. page 4). 3. OBJECTIVES The main objectives are directed to describe the most relevant environmental features of the Paraguay. Parana, and Uruguay rivers flood plains, regarding their abiotic, biotic and anthropic components, and their conformity with the pulsatile regime. The obtained basic information has been used to assess those potential environmental impacts that I would be produced by the flood control projects.: I 4. SOURCES OF IFORMATION Different Governmental Entities were relevated. Edited infornations required revisions of Scientific Libraries, I i.e., the School of Natural Sciences. National University of La Plata, the National Institute of Limnology (INALI), the Northeastern Center of Applied Ecology (CECOAL). The INALI also facilitated us satellite images from the studied area. The Institute of Technology (ZITEC) from Santa Fe was particularly helpful to solve methodological problems, specially concerning cartography. 5. ZONIFICATION 0Zonification was based on images. maps, and tables including the most relevant aspects concerning floods. Composite MSS color scanning images MSS (4,5 and 7 bands) were processed from the Parani river at the highest recent flood (1983). MSS digital products (Landsat 5) from the same areas during a dry period (July, 1987) were also utlitized. Images were adapted to the IDRISI formnat (480 x 500; Easunan, 1990). Scanned images were converted from PCX to JPEG formnt by means of the Aldus Photolister Program. Thus, color became redder as contrast and saturation increased. This made it possible to contrast the vegetation which emerged above the river water during flood. To recognise water covered areas only band 7 was used. A special pallette was designed to constrast water (rose) and vegetation (green). Furthernore, the normalized for vegetation difference (ND7) and the chromaticity indexes were processed, the latter contrasting suspended material. IH. THE PHYSICAL ENVIRONMENT 2  I. 1. INTRODUCTION 3 Regional climate, geology, geoniorphology, and hydrology are described and related to floods. I 2 REGIONAL CLIMATE AND HYDROLOGY. 2. I.Climate I The Koppen System of Climate Classification was adopted. Based upon the simultaneous analysis of temperature and rainfall, together with the distribution of vegetation units, climate groups and subgroups could be E defined. Different regions in the studied area were defined as follows: Aw: tropicaL mean annual temperature higher than I 8C, annual rainfall abundant, except in winter (dry season). Cwa: temperate and wrnm, mean temperure higher than 22C in summner and dry winter. Cra: temperate and warnm without dry season. I BSh: serniarid. annual rainfall not exceding 750 mrn and annual mean temperpture higher than 1