Environmental Assessment in Neotropical Watersheds: A Multi-Factorial Approach

Elaine F Celestino,Elaine A L Kashiwaqui,Jhony F M Da Silva,Leandro F Celestino,Maristela C Makrakis,Sergio Makrakis

doi:10.3390/su11020490

Abstract

This study evaluated the environmental conditions of two watersheds selected on the basis of similarities in land use. The environmental conditions of the watersheds were analyzed using two geoprocessing methods and in situ evaluations by applying the rapid assessment protocol (RAP). Geospatial image processing was used to analyze land use, slope, soil classification, and rainfall, while RAP was used to evaluate the connectivity and size of riparian corridors. The results revealed varied uses of land with the landscape matrix in both watersheds, composed of agriculture, pasture, and urban centers. Urban centers were defined as spots and riparian zones as corridors. The analysis of environmental fragility considering all the geospatial variables, classified both watersheds as having medium fragility. The most fragile sites were the urban centers, which had a high slope and degraded riparian zone. Onsite assessments have shown that corridors do not have the size required by legislation; they are fragmented and unstructured, and they contain exotic species. We also propose that a multi-factorial approach be used to evaluate watersheds, associating geospatial assessments and onsite analyses that consider the limitations pointed out in each protocol. This reduces sampling errors and shows the actual state of conservation in riparian zones.

Highlights

Watersheds are recognized as the smallest environmental units for planning management actions [1]
This study tries to answer the following questions: i) Are the processed images used to classify areas as preserved reliable? and ii) Which parameters are needed to classify a geographic area as preserved? To answer these questions, we evaluated the conservation status of two neotropical watersheds through the analysis of environmental fragility and connectivity of riparian zones (RZs)
We propose the use of factors associated with image processing and onsite environmental analysis with rapid assessment protocol (RAP)

Summary

Introduction

Watersheds are recognized as the smallest environmental units for planning management actions [1] This point of view considers the drainage area, along with biological, hydrological, geomorphological, and ecological factors that are exclusive to each watershed [2]. These factors have natural characteristics in the dynamic equilibrium of energy and matter [1]. This equilibrium has been altered by many anthropogenic actions such as deforestation, expansion of urban centers, and agricultural activities [3]. Geoprocessing contains sets of techniques for collecting, storing, processing, manipulating and integrating geospatial images [8] and it is used in several areas of knowledge such as geography, statistics, health, and the environment

Methods

Results

Conclusion