Original article
Land degradation assessment based on environmental geoindicators in the Fortaleza metropolitan region, state of Ceara´, Brazil L.V. Zuquette Æ O.J. Pejon Æ J.Q. dos Santos Collares of crisis in the environments of developing countries (Stocking 1993). According to Blaike and Brookfield (1987) degraded land is that which has lost quality or suffered a decline in its capabilities. Changes are identified in geological, biological, and socio-economic processes, assessed by different magnitude, severity, effects, and extension. These conditions can occur due to global changes, intense exploitation, inadequate land use, and accelerated natural processes such as erosion, flooding, gravitational mass movements, among others. The concept of land degradation varies from author to author depending on his area of specialty. Johnson and Lewis (1995) define land degradation as a significant decrease in either an areas biological productivity or its usefulness due to human interference. For Lindskog and Tengberg (1994) land degradation is a reduction of the physical, chemical, or biological status of the land, which may restrict its productive capacity. Johnson and others (1997) define land degradation as any change or disturbance of the land perceived as deleterious or undesirable. This definition includes the idea of perKeywords Land degradation Æ Geoindicators Æ ception because degradation is a term whose meaning Erosion Æ Coastal Æ Water Æ Pollution Æ Brazil Æ reflects perceptions, viewpoints, time frames, and value Fortaleza attachments. Barrow (1991) also wrote that to establish the significance of land degradation, an assessment is necessary of extension, degree of damage and whether the land degradation is controlled or reversible. Degraded land can be characterized by studies developed at different scales. The scale Introduction depends on the extension reached, the kind of affected Land degradation is portrayed as one of the Worlds major biological conditions and geological materials, intensities environmental problems. It is perceived as a key indicator and land use activities. Conacher and Sala (1999) identified the main problems related to land degradation in 11 zones in the Mediterranean as: accelerated erosion; flooding; sedimentation and Received: 5 April 2003 / Accepted: 13 August 2003 river channel changes; vegetation loss; fire; water shortPublished online: 10 October 2003 ages; and declining water quality. ª Springer-Verlag 2003 In Brazil, human interference and natural processes have resulted in different types of land degradation (Table 1), L.V. Zuquette (&) Æ O.J. Pejon each having specific magnitude, severity, and effects Departamento de Geotecnia, Escola de Engenharia de Sa˜o Carlos, 400 Av Trabalhador Sa˜o-Carlense, 13566–13590 Sa˜o Carlos, Brasil resulting from agricultural, as well as urban, industrial, and mining activities, and natural processes. Several E-mail:
[email protected] Fax: +55-16-2739509 methods of land degradation assessment are available but the use of geoindicators is recommended because they J.Q. dos Santos Collares CPRM, 60190–070 Fortaleza, Brasil identify a minimum set of parameters that describe shortAbstract This paper summarizes the results obtained by land degradation assessment in the Fortaleza Metropolitan Region, in the state of Ceara´, Brazil. Area assessment was done in a two-phase study: the characterization of the environmental components by field and laboratory work, and a more detailed study in the degraded sites. Environmental geoindicators were used to classify the degradation level for each drainage basin as low, intermediate, or high. Coastal erosion, gravitational mass movements, dune movements, water erosion, sedimentation, water pollution, sanitary landfills in inappropriate sites, caves and abandoned mines of aggregates exploitation and occupation in swamp areas are the main land degradation sources registered in the region. Among the drainage basins for degradation level, 5 were classified as high, 3 as intermediate, and 4 as low. These problems have affected the people living in the region and demanded heavy investments to rehabilitate degraded areas.
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DOI 10.1007/s00254-003-0892-0
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Table 1 Main types of land degradation found in Brazil Human interference
Natural processes
Agriculture
Urban
Industrial
Mining
Soil/rock
Geomorphology
Water
Vegetation
Water and soil pollution
Air, soil, and water pollution
Morphometric changes
Morphometric changes
Decline of biodiversity
Soil compaction Erosion rate
Air, soil, and water pollution Erosion rate
Decline of biodiversity
Soil compaction Erosion rate
Air, soil, and water pollution Acid rain
Cementation
Runoff changes
Desertification
Crusting
Runoff changes
Deforestation
–
Salinization Water balance
Deforestation Sediment load
Runoff changes Flooding –
– –
– –
Leaching
Channel density changes
–
–
–
–
–
Decrease in biomass, carbon and biodiversity Desertification Silting Deforestation
Morphometric changes
–
Sediment load Channel density changes Geomorphological changes Mass movement
Channel changes Channel density changes Morphometric changes – –
Infestation
Deforestation
Channel changes Channel density changes –
–
–
–
–
Mass movement Flooding Relief changes Silting
– – – –
– – – –
– – – –
– – – –
– – – –
Relief changes – – –
term environmental dynamics, and are proxies representing all the parameters on which processes depend (Berger 1997). Geoindicators are defined as measures of surface or near-surface geological processes and phenomena that vary significantly over periods of less than 100 years and that provide meaningful information for environmental assessment (IUGS 1992 apud Berger 1996). Environmental indicators have been used for integrating environmental monitoring; they allow identification of environmental changes, impacts, and hazard damage. According to Berger and Iams (1996) geoindicators can be used to assess environmental changes and measure the integrity, stability, and sustainability of the biological and physical environment. For Dumanski and Pieri (2000) these same indicators also serve as instruments for monitoring land degradation. Indicators should both quantify and simplify information about complex phenomena that is not immediately detectable (Hammond and others 1995). Fortaleza metropolitan region is located in the northeastern region of Brazil, in the state of Ceara´, between longitudes 3815 and 39 W and latitudes 330 E 415 S. Fortaleza metropolitan region has an area of about 3,500 km2, over which some of the land degradation types shown in Table 1 occur. This region is similar to many other cities around the World; the city has expanded rapidly and the environment has been strongly affected. Today 3.5 million inhabitants live in the region, mainly in the coastal area (within15 km of the beach). The increasing necessity for population space for people arriving from rural zones combined with high birthrates (approximately 2%/year), have produced several economic, social, and environmental problems.
Biomass changes – – –
In urban areas, several forms of human activity combined with natural conditions are responsible for land degradation. Sources of environmental damage are very frequent in all parts of the region and present varied intensity according to geology (unconsolidated materials, rocks), relief and the dynamics of water. A study was carried out to assess causes of environmental degradation in the region through the use of environmental geoindicators.
Methodology Land degradation is studied at different scales (local, regional, national and global) depending on magnitude, severity, causes, and extension affected by observed changes, and size of the total region (Gray 1999; Dahlberg 2000; Riksen and DeGraaff 2001). Such studies are currently being developed using satellite image or aerial photos for temporal analysis and large-scale work, field investigation to observe environmental changes, and laboratory tests to determine physical-chemical features. The focus of this methodology is related to geoindicators because they provide fundamental information for assessing land degradation levels. These geoindicators were derived from basic mapping at regional and local scales. Several researchers have proposed geoindicators for various objectives. Berger (1997) indicated a general geoindicator list (with 27 items) and the environmental changes reflected by them, as well as human and natural influences on these geoindicators. According to Morton (2002), transitory surface water levels; shoreline position; wetland distribution; coral reef;
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landforms; sediment sequence and composition; lateral zonation; and temporal successions of vegetation are good geoindicators for monitoring environmental changes in the humid tropics and also riverine and shoreline changes. For river and river valleys Osterkamp and Schumm (1996) and Osterkamp (2002) suggested as adequate geoindicators the following rainfall-runoff relations: soil movements and slope features; drainage density; changes in sediment storage; stream-channel morphology; sediments discharge; flooding frequency; flow duration; and dissolved loads, among others. Adding to the Morton (2002) and Osterkamp (2002) suggestions, Gupta (2002) proposed a group of geoindicators for tropical urbanization: flooding, groundwater, slope, river channels, climate, land use, air quality, waste-water disposal, low lying areas, seismic disturbances, volcanic activity; sand accumulation and dunes. The Fortaleza metropolitan region is located in a tropical zone (4 southern latitude). It presents a large coastal zone and part of the region is constituted of a high residual massif up to 800 m in altitude, annual rainfall is about 1,500 mm and there is dense natural vegetation. Combining the natural characteristics and geoindicators proposed by the above authors, among others, we selected 19 environmental geoindicators (Table 2) to assess land degradation levels. In the case of this study, an environmental geoindicator checklist (Table 2) was proposed to assess the basins considering the follow criteria, according to Neimanis & Kerr (1996): 1. Geoindicators should be credible scientifically and understandable by the nonspecialist 2. Scientific validity is necessary 3. Geoindicators must be measured during more than one time period 4. Environmental changes due to natural processes and human activities should be reflected by the geoindicators 5. They must be clear and simple Table 2 Environmental geoindicators used to assess land degradation levels
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Number
Environmental geoindicators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Shoreline position Soil and sediment erosion Relief changes Channel changes Surface water quality Stream sediment storage Dune changes Slope failures Stream channel changes Vegetation changes Ground water quality Pollution sources frequency Flooding frequency and intensities Urban and construction damages Depression of groundwater level Alteration of groundwater flow direction Alteration of surface water flow direction Organic material destruction Salt water intrusion into shallow groundwater aquifer
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6. 7. 8. 9.
Geoindicators should be relevant They must be representative of the phenomenon Threshold is very important in selecting geoindicators Geographic scope
Based on these considerations, environmental geoindicators (Table 2) were used to assess land degradation levels of the drainage basins in the Fortaleza metropolitan region. This study defined 12 drainage basins in the region, and 19 environmental geoindicators as attributes by which to classify each basin relative to land degradation level. The geoindicators proposed in this study were selected for the following reasons; (1) the low cost of associated laboratory tests and (2) low cost data can be collected by field work and also obtained via aerial photos taken on different dates and at different scales. All of this data is related to hydrological, geomorphological, climatic and geological components, as well as to vegetation, water quality, and land-use patterns. These environmental geoindicators were considered in qualitative and quantitative ways and they were derived using remote sensing products and/or field measurements and observations. Each geoindicator was analyzed by class in terms of presence, frequency, and intensity. In terms of presence, class limits were established according to the number of environmental geoindicators compared to the total number of environmental geoindicators represented as a percentage: Low Level
Intermediate Level High Level
when less than eight environmental geoindicators (36% of total environmental geoindicators) were detected at different sites in the basin if between 8 and 13 (between 36 and 68% of total environmental geoindicators) environmental geoindicators were registered when more than 13 environmental geoindicators (more than 68% of total environmental geoindicators) were observed
Frequency is considered as the number of sites in each basin where the environmental geoindicator was detected; the classes are: Low frequency Intermediate frequency High frequency
less than three sites from three to five sites more than five sites
Intensity is the combination of volume and extension of each site where the environmental geoindicator was detected: Low intensity Intermediate intensity High intensity
when less than 1000 m2 and 2000 m3 between 1000 and 5000 m2 and 2000– 5000 m3 more than 5000 m2 and 5000 m3
Finally, drainage basins were classified as low, intermediate, or high degradation level considering presence, frequency, and intensity classes.
Original article
Fig. 2 Shows the transition zone between the interior plain and the high residual massif. 1 Large colluvial deposits covering residual soils from gneisses and granites constitute this zone. 2 Residual unconsolidated materials Fig. 1 Location map of the Fortaleza metropolitan region
Geomorphological zones In this region, altitudes vary from 0 to 800 m, though are mostly lower than 100 m, with three units delimited: the coastal zone, interior plains, and high residual massif:
The preceding data were obtained following and using a combination of techniques including:
Coastal Zone
composed of dunes, beaches, fluviomarine plains, with slopes less than 5% and some localized active, stable, and dead cliffs, 1. employment of aerial photos from different dates to get with slopes steeper than 100%. This zone information about landforms, geology, drainage chanis mainly occupied by residences, tourist nels, land-uses, drainage basin boundaries and to assess centers and services. changes in relief and land surface. Interior Plain characterized by altitudes varying between 2. Field and laboratory work were also developed to Zone 0 and 100 m; valleys are u-shaped and obtain measurements and to directly observe natural rectilinear, presenting low inclinations conditions and changes, according to environmental (predominantly between 2 and 20%). geoindicators permitting detection of such environThere are fluvial plains comprised of mental degradation. During fieldwork, data based on sandy alluvium. This zone is predomimore than 200 drillings were collected related to nantly deforested and now characterized lithology, soil, and water conditions. For geological by agriculture, urbanized areas, grazing material and water, samples were taken to perform lands and scattered mines. laboratory tests. A group of maps (lithological, High Residual formed by granitic and migmatitic rocks unconsolidated materials, pollution sources and Massif with altitudes of up to 800 meters. The drainage basins) and charts (slope, environmental slopes can exceed 500% in specific places, problems, and water resources) were drawn based on although they are predominantly higher the collected information from works previously than 20% with average values of around described. 100%. The valleys are v-shaped and have a These maps and charts permitted assessment of environhigh inclination. Fig. 2 shows the interior mental problems and degraded land. This paper shows plain zone and high residual massif. Dense only the lithological map, environmental problems, and vegetation constituted of various native water resources chart. tree species covers more than 90% of the area. Widely scattered plantations, quarries, and residences occur.
Description of study area
Climatic characteristics Climatic characteristics vary according to geomorphological division (Table 3). Location and urban centers The annual potential evapotranspiration varies from The Fortaleza metropolitan region is located in Ceara´, 1,500 mm in the coastal zone to 2,800 mm in the interior Brazil (Fig. 1). Several urban centers, with populations varying between 1,000 and 180,000 inhabitants, and Fort- plain, but can reach values higher than 3,300 mm when a long dry period occurs. During eight months per year, a aleza, with 2 million inhabitants, are included in the total water deficit of around 800 mm is frequent due to region.
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Table 3 Basic climatic data for Fortaleza metropolitan region
Geomorphological zones
Coastal zone High residual massive Interior plain
Annual average temperature (oC)
Insolation
Rainfall
Maximum
Minimum
Daily amplitude
(h/year)
(mm/year)
39 25 33
19 15 23
5 5 5
2,650 2,650 2,650
1,200)1,400 1,400–1,600 900–1,400
Fig. 3 Lithological map
types of rainfall and very low field capacity of the unconsolidated materials.
Results Lithological map Lithologically, the region is constituted of two main groups (Fig. 3).
Thickness varies between 7 and 10 meters. The weathered profiles are very heterogeneous due to spatial distribution of lithotypes and position in relief. These unconsolidated materials occur predominantly in areas with declivities of less than 10%. 2. Residual unconsolidated materials from igneous and metamorphic lithologies
These materials, developed from gneiss, granites, and migmatites, present a thickness of less than 2 m and the 1. Composed of sandstones, siltstones, conglomerates and weathered profiles are little developed, thus retaining some claystones of the Barreiras Formation of Tertiary age. intrinsic characteristics of the rocks. These profiles present two well defined layers: a lower layer that keeps the 2. Constituted of a large diversity of igneous and geological characteristics of the rock, and an upper layer metamorphic lithologies including granites, gneisses, classifiable as residual unconsolidated material, with a migmatites, pyroxenites, phonolites and trachytes. sandy texture and generally less than 1 m in thickness. These materials are found in areas where declivities are less Unconsolidated materials than 2%. Due to relief evolution, small colluvial deposits Unconsolidated materials were classified and delimited overlying the residual materials are very common. according to genetic grades, texture, mineralogy, thickness, and the presence of rock blocks and hydromorphic 3. Residual unconsolidated materials from granites/ migmatites evidence. The following units were defined: In the highland areas consisting of granitic-migmatite rocks, the weathered profiles can show varied materials and depth, normally controlled by fractured zones. The 1. Residual from Barreiras Formation valleys are associated with fracture and fault lines, and This unit consists mainly of unconsolidated material from there is talus on the valley slopes (mainly in the lower portion). siltstones, claystones, and to a lesser extent sandstones. A-Residual units
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heterogeneous spatial distribution, mineralogy, and Rocks outcrop in the higher portions of the hill slopes or grain-size distribution. in zones where declivities are higher than 100%. The weathered profiles present a thickness varying from 0.5 m 3. Dunes and palaeodunes are located in the coastal zone and present a sandy texture (>95% fine and medium to several meters within small distances (<50 m), sand), without cohesion, thickness varies between 2 conferring high variability to the area. and 50 m, and hydraulic conductivity is higher than 10)5 m/s. Dunes present depths varying according to B-Transported unconsolidated materials In this region, several kinds of transported unconsolidated wind direction and intensity. materials were found and delimited overlying lithologies of 4. Low-depth palaeodunes present as its main characterthe Barreiras Formation, igneous and metamorphic rocks, istic a depth of less than 5 m overlying other geological such as dunes and palaeodunes, alluvial and colluvial material. However the palaeodunes are characterized by deposits. an outcropping layer rich in organic materials due to vegetation presenting more stability. 1. Alluvial deposits occur in the flood zones of the main rivers in the region. They present varied textures and thickness, bad drainability, and a high percentage of Water resources chart organic materials. In the fluviomarine plains, they are This chart is presented in Fig. 4, where 4 aquifers and 12 classified as swamp and present high saline concendrainage basins are delimited. It was derived from an tration. These materials overly igneous and metamor- association of lithological, unconsolidated material and phic rock in the interior plain zone, but in the coastal drainage basin maps with an aquifer chart. The Coco´, zone cover rocks of the Barreiras Formation or dunes Maranguapinho, Ceara´, Jua, Cauı´pe Rivers and coastal and palaeodunes. basins are entirely within in this region. Parts of Sa˜o 2. Colluvial deposits consisting of rock blocks and sandy Gonc¸alo,Gererau and Curu Basins are also included and particles are found at the foot of the highlands. These only the upstream Caponga Funda, Catu, and Pacoti are materials present a thickness of between 1 and 25 m outside the region. All drainage basins have been seriously and varied geotechnical characteristics, due to their affected by chemical and biological contaminants from Fig. 4 Water resources chart
agriculture, urban, and industrial activities. Among the basins, two are more important than the others for water supply. The Ceara´ and Pacoti Basins are
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responsible for about 50% of the total regional stream discharge. There are 23 reservoirs in the third part of the Ceara´ Basin and 25 in the upstream half of the Pacoti Basin. Considering the stream discharge/km2 rates, the Jua´, Pacoti, Caponga Funda, and Gererau´ Basins stand out because of their contribution to the total regional stream discharge. Jua´ and Caponga Funda Basins present special characteristics due to consisting predominantly of lithologies of the Barreiras Formation, dunes and palaeodunes. The urban occupation of these basins has intensively affected the infiltration rate and annual discharges. The groundwater sources are:
Urbanization The region has been undergoing an intense urbanization process for the past 80 years. According to Instituto Brasileiro de Geografia e Estatı´stica (2002) the population of 1.6 million inhabitants in 1980 increased to 2.3 million in 1991, 2.5 million in 1994 and 3 million in 2000. The urbanized areas are concentrated in three sections: (1) coastal zone, mainly in the downstream parts of the Coco´, Ceara´, Maranguapinho, and Pacoti Basins; (2) in the Maranguapinho Basin an intensely urbanized corridor, links the urban areas of Fortaleza, Maranguape, Maracanau, and other small cities along the Maranguapinho River; and (3) two urban corridors have – Dunes and palaeodunes: consisting of sand, they are developed parallel to the Coco´ River. Associated with distributed along the coastal zone. Average thickness is urbanization several environmental changes have ocabout 10 m, but absolute values range from 1 to curred such as: canalization, man-made slopes, earth fills, 30 meters. sanitary landfills, aggregate exploitation, and relief – Alluvial deposits: found predominantly overlying all changes. regional lithologies, however they are intensely exploited when they cover igneous and metamorphic rocks in Deforestation the interior plain zone. These deposits present varied During the last 50 years intense deforestation caused by volumes which controls the discharge of the wells. The agriculture, cattle raising, urbanization, and other land average thickness is about 5 m, but can range between 1 uses has occurred in the region. These activities have and 10 meters. altered this area strongly affecting the Pacoti, Coco´, – Barreiras Formation: This presents intense heterogene- Maranguapinho, Ceara´, Cauipe, Sa˜o Gonc¸alo, Geruau´, ity with permeable and nonpermeable layers. When a and Curu´ Basins. In 80% of the high residual massive permeable layer occurs, hydrogeological parameters are zone, and approximately 50% in the Caponga Funda and very favorable for urban water supply needs. The total Jua´ Basins, respectively, the natural vegetation is thickness is around 40 m, and permeable layers can preserved. In the Coco´, Maranguapinho, Ceara´, Cauipe, reach a thickness of 20 m in some sites and Sa˜o Gonc¸alo Basins, more than 75% of the area has – Fractured aquifer: This presents high heterogeneity and been deforested, including the riparian vegetation. depends on specific hydraulic characteristics of the Deforestation combined with geological materials has fractures. As the rivers are associated with fractures, the caused intense water erosion and, consequently, channel success of water wells depends on recharge by rivers and stream changes, sedimentation, and organic material and alluvial deposits in open fractures. The waters destruction. from fractured aquifers present a high saline concentration, when associated with saline unconsolidated Mining materials. In the study region are many sites where sand, clay, and The waters from dunes/palaeodunes and alluvial deposits aggregates used for civil construction are exploited. present varied concentrations of Cl) and Na+. The Cl) There are sites where aggregates have been taken from concentration can reach 2000 ppm when the waters are granites, gneisses, migmatites and phonolites, and others very close to the salt water lens. where limestones are exploited as agricultural fertilizer. In these quarries, several procedures are used, e.g. removal of sterile materials (soil and rock blocks), deforestation, and Land degradation causes blasting with explosives. Sand from dunes, palaeodunes and sandy soils have been exploited during the last Agriculture Agricultural practices have been developed in the majority 20 years, mainly in coastal zones. of the basins, at different intensities and with various types of plantations and soil cultivation. In Caponga Funda, Catu and Pacoti Basins, and the intermediate portion from the Coco´, upstream of the Maranguapinho and downstream from the Jua Basins, agricultural practices have been more intensive than in the other basins where agriculture is carried out close to the drainage channels, lakes, and reservoirs. Most of the region consists of soil inadequate for agriculture practices, because of water retention, low fertility, saline concentration, depth and stones.
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Analysis After the first part of the study was carried out, a more detailed study was undertaken to delimit sites more affected by human interference and natural processes causing land degradation. The distribution of human interferences and natural processes responsible for land degradation is shown in Fig. 5.
Original article
Such civil constructions have brought about serious changes in erosion behavior and sediment transport by rivers, winds and longshore current. This disequilibrium has caused intense coastal erosion Related to human activities that has produced great economic and environmental losses since many beaches, piers, roads, and residences Accelerated erosion of the coastal zone have been destroyed. According to Pilkey (1991), coastal erosion is a shoreline At Iparana Beach, the coastal line has eroded approxiproblem globally. It is related to dynamic equilibrium that mately 350 m over the last 25 years. can be affected by: sea level; wave and tidal energy; sedi- Civil constructions are responsible for changes in the ment supply; and spatial position. Forbes and Liverman morpho-dynamic aspects of coastal zone erosion/sedi(1996) pointed out that coastal position is a basic and mentation (Fig. 6b). The dynamic of the processes is measurable parameter for assessing shoreline zone affected predominantly by: environmental degradation due to natural or accelerated – Rates of erosion by wind from dunes to beaches erosion processes. Morton (1996) showed that natural processes and human – Sediment retention in the small dam reservoirs activities are responsible for shoreline changes. Among – Changes in marine wave orientation due to port moles human uses, coastal constructions are emphasized. The Ceara´, Coastal, Maranguapinho, Coco´, and Pacoti The coastal zones of the countries in America (U.S.A., Basins are more affected by coastal erosion than the other Brazil, Puerto Rico), Europe (Portugal, Spain, Netherlands, basins. The association of urbanization, deforestation, the France), Asia, Africa (Nigeria), and Australia have been natural characteristics of the geological materials, and affected in the last 50 years by erosion. ocean currents are responsible for this. The coastal line in the Fortaleza metropolitan region is Coastal problems similar to those in Fortaleza were found 35-km long and intense urban occupation is its principal on the West Dorset coast of England (Brunsden and Moore characteristic. Since 1940 several civil constructions have 1999). been built in this area, including: piers in the port of According to geoindicators proposed by Bush and others Mucuripe (Fig. 6); residences near the beaches; roads and (1999), most of the coastal zone presents erosion classified streets on the dunes; small dams in the main rivers, and ; as severe. deforestation of the dunes and sandy areas.
Fig. 5 Distribution of problems responsible for land degradation in the Fortaleza metropolitan region
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Fig. 7 Salt exploitation and roads in fluvio-marine plains responsible for vegetation and stream channel changes
Fig. 6a,b a Aerial photo of the Mucuripe port area taken in 1972. b Low-altitude aerial photo of the Mucuripe port area taken in 1995. It shows several environmental changes and intense urban occupation
Swamp area and sedimentation of lakes These areas can be considered as wetlands which Maltby (1986) defines as a collective term for zones, whose formation has been dominated by water, including: marshes, fens, bogs, peat lands, swamps, mangrove forest, coastal salt marshes and irrigated fields. Regional swamps and lakes, mainly located in the alluvial plains, cover an area larger than 700 ha. The lakes are characterized as sources of potable water for supplying the population, and the swamps are a good economic resource due to the exploitation of saline, fishing, and agricultural activities (Fig. 7). The main human activities that accelerate area degradation are:
– The earth required for implementing civil works in
Fig. 8 Swamp area reduced by agriculture, roads, streets, and sand exploitation, all of which have deeply affected the swamp and wet areas. Vegetation damage and increasing sediment in the rivers affect surface water quality and flood frequency
water bodies has occurred to allow residential construction (Fig. 8). b-Salines have been exploited in the fluvio-marine plains since the founding of the city and have occupied increasing areas. To prepare them, small earth dikes are built to prevent water flow and destruction of vegetation. c-Changes in the drainage channels canalization of rivers in urban zones have affected surface water flow direction and total discharge.
parts of the swamps. Most of the earth fill is constituted of waste produced by civil constructions and composed Water pollution of cement, iron, wood and CaO. Percolated liquids The Department of the Environment, UK (1990) defines present pH higher than ten, which has seriously affected contaminated land as that which represents an actual or animals and vegetation and polluted the waters. potential hazard to health or the environment as a result of – Deforestation of sites near lakes and swamps: current or previous use. Water pollution may affect both developed and developing countries, in urban and rural a-urban activities have greatly increased over the last zones. 50 years, demanding space. Intense deforestation near 416
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waters which can easily be contaminated by human activities. Waste deposits The use of landfill for solid waste has been the most common practice for disposal of both domestic and industrial waste in many countries. The main problems associated with sanitary landfills are possible water, soil, and air pollution which depend on the characteristics of leachate; design and treatment of the landfill base and walls; climatic conditions; groundwater level depths; permeability and physico-chemical characteristics of rock types and soils. Solid and liquid waste and other garbage from urban residences, industries and hospitals are disposed of at a Fig. 9 site called Jangurussu, located on the Coco River flood This photo shows an area being prepared for occupation by houses plain on alluvial material and sandstones of the Barreiras and other kinds of buildings. Such occupations have affected sand Formation. These materials have a high permeability and movement and lake quality are considered good shallow aquifers. The uncontrolled sanitary landfill is 30 m high and covers an area of 1.0 km2. It receives 1,500 ton/day, which represents 75% of regional solid waste. This waste deposit is 20 km from Futuro beach (coastal line). There are neither protective installations nor technological equipment to safeguard the environmental components. The leachate produced by waste and garbage disposed of in the Jangurussu landfill flow into the Coco River and are transported to Futuro beach, which is one of the main regional tourist attractions. The leachate also flows into the geological materials constituting the regional aquifers. The other 25% of waste and garbage is disposed of in the sanitary landfill of Caucaia, located on metamorphic rocks (Fig. 5) in the municipality of Caucaia. Two new sanitary landfills are planned (Fig. 5); one of them is located on metamorphic rocks in the city of Maracanau, and the second is on Barreiras Formation rocks on the left side of the Pacoti River, in Aquiraz. Fig. 5 Fig. 10 A river seriously affected by liquid wastes disposed of directly into the shows the four sites where urban garbage and industrial water bodies waste will be disposed of within the next few years. The Jangurussu and Aquiraz landfills present a high potential for polluting the Barreiras Formation and also Biological and chemical products from cesspools, ceme- the groundwater of the dunes/palaeodunes. The waste and teries, septic tanks, sanitary landfills, lagoons, and other garbage disposed of in both can reach the Coco and Pacoti waste and garbage disposal sites have polluted the major Rivers and be carried into the ocean. Waste can spread to beaches such as Futuro and Goiabeiras, due to ocean rivers, lakes, and groundwater. currents flowing toward the northwest (see Fig. 5). The aquifer consisting of sandstones of the Barreiras Formation and lakes are the principal sources of water for Mining population and industry. These water sources have been the environmental component most affected by pollutants Associated with surface mining are such degrading pro(Figs. 9 and 10). There are cemeteries and sanitary landfills cesses as silting, erosion, gravitational mass movements and severe geomorphologic changes, as pointed out by located in aquifer recharge areas. The surface water has presented contamination by coliformes, nitrates, chlorines Marchetti and Panizza (2001). and ions from urban, agricultural, and industrial activities. Martin Duque and others (1998) showed that areas affected by quarries present morphographic, morphodyMost of these are transported by surface runoff. Liquid namic, and morphoevolutionary changes. wastes from houses and industries are disposed of in Baraldi and others (2001) observed that the main cesspools or thrown directly into a water body. The Barreiras Aquifer presents contamination by nitrates and environmental modifications caused by quarries are : inorganic ions from cesspools and agricultural practices. creation of regular-shaped depressions, minor isolated artificial relief, and creation of artificial ponds; partial or Almost all water sources used to supply human and industrial necessities are from shallow aquifers or surface total destruction of fluvial terraces; erosion and instability
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of quarry scarps; depression of piezometric surface; alteration of groundwater flow direction; formation of periodically flooded areas; permanent removal of areas from farming use; alteration of farming practices; and changes to the pedological characteristics of soil. In the studied region, many sites exist where sand, clay, and aggregates are used for civil construction (Figs. 5 and 11). The principal problem results from exploitation of sand from dunes and sandy soils (Fig. 12). Such exploitation has produced deep excavation; intense erosion processes; silting of rivers and lakes; and forest destruction. These activities have been responsible for negative environmental impacts such as: erosion; deforestation; damage of houses and other buildings by explosions; scars on the land; inadequate disposal of sterile materials; powder; landslides; and rock fall and rolling. As pointed out by Lubke and Avis (1999) and Allen and others (1990), dune mining has had enormous impact in some coastal portions of the regions, similar to that which occurred in countries such as Australia, India, South Africa, and the USA. Natural processes Dune movement Wind erosion has affected sandy areas at different intensities depending on vegetation cover, soil roughness, soil moisture, and grain size (Riksen and DeGraaff 2001). Fig. 13 shows dune and palaeodune distribution in part of the region. Fig. 14 shows the same area 23 years later, now affected by sedimentation, rectification of natural canalization of the channel and urban occupation of dunes and palaeodunes. Such modifications have deeply affected groundwater recharge, erosion rates, organic material content, and vegetation. Deforestation and intense urban occupation by residences and tourism undertakings have modified dune and palaeodune zones. This occupation has been responsible for particle desegregation and erosion rate increase caused by wind and surface water flow (Fig. 15).
The data obtained from field work and interpretation of aerial photographs that represent several time periods show that dunes displace up to 25 m/year in the dry period and 0.1 m/year in the rainy period. However, Pacoti, Catu, Jua, and Caiuipe Basins present dune movements as natural process due to incipient urbanization on the dunes and palaeodunes. In the Fortaleza metropolitan region, as has also been shown in studies developed by Riksen and DeGraaff (2001) on four sites, one each in England, Sweden, Germany, and the Netherlands, the main damage from wind erosion are: sedimentation on roads and houses; lake and river impairment (physical effects); costs of repairing roads, houses, public equipment; and production losses (economic effects). Gravitational mass movements Among natural hazards, landslides occur in every country in the world, affecting man both directly and indirectly and causing loss of life and property, reservoir silting and river pollution (Radbruch-hall and Varnes 1976). In high residual massifs, many gravitational mass movements, such as landslides, rock fall, and earth flow have occurred, associated with the following environmental factors:
– Rock blocks controlled by geological structure charac-
– – – –
teristic in the higher altitudes of this specific geomorphological zone. Normally, during high intensity rainfalls these blocks fall towards drainage channels. Dislocated materials can travel up to 2 km, damaging houses, farms, and plantations. High rainfall intensities (>2,850 mm/year), mainly between February and May. Accelerated deforestation of highest part of the highlands to allow agricultural development and construction of residences. Residential occupation of inadequate areas located near drainage channels, steep slopes and scarps. Declivities greater than 100%.
Fig. 11a,b Aggregate exploitation quarry. See relief and vegetation changes. a Aerial photo took in 1972, b Photo taken in 1995
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Fig. 12 Sand exploitation exemplifying land degradation in dunes and palaeodunes. The height of the face is around 20 m. Vegetation and organic material have been destroyed
Fig. 13 Aerial photograph (1972) of the coastal zone; sandy dunes and palaeodunes; and fluvio-marine plains
The most important gravitational mass movement occurred on 30 April 1974 in the City of Maranguape, when rainfall intensity was 128 mm/24 hrs. It destroyed many residences and other civil constructions. In 1912, 1917, 1920, and 1949, rainfall was even greater than in1974, but gravitational mass movements did not occur because no damage owing to human interference in the area had occurred. The Maranguapinho Basin is the most affected among basins, because the upstream portion is supported by high residual massif. Coco´, Jua, Caiuipe, and Sa˜o Gonc¸alo Basins have portions supported by high residual massif but the gravitational mass movements have not damaged residences and infrastructure systems.
Fig. 14 Low-altitude aerial photo (1995) of the same place shown in Fig. 13. Note environmental changes: 1 sedimentation; 2 rectification of river canalization
Fig. 15 Dune movement towards residential areas and covering houses and streets in Fortaleza. 1 Palaeodunes protected by vegetation. 2 Portion of dune movement towards streets and houses
These problems occur every year in the rainy period due to high rainfall intensities associated with rapid sedimentation in the river channel. This happens from February to May when rainfall can reach 80% of the annual total. All drainage channels can be affected by flooding in varying intensities due to low gradients. In some periods, rainfalls are very high: in April 1995 the rainfall was about 612 mm; February, March, April and May 1985 the rainfall was about 2,200 mm; in March 1986 about 765 mm (highest rainfall index since 1975). Deforestation in the drainage basins and sedimentation of water channels are the main causes of flooding. In each rainy period 30,000 inhabitants Flooding areas can be affected by flooding and illnesses, waterway related Intense rainfall and lack of environmental regulation of illnesses such as cholera, hepatitis, dengue, meningitis and human activities in basins leads to increased soil erosion leptospirosis. In April 2001, the Maranguapinho Plain was rates. heavily flooded and about 10,000 inhabitants were afAffected areas are mainly located in the flood plains of the fected, hundreds of houses were damaged, and 20 people Coco´, Maranguapinho and Ceara´ Rivers (Fig. 5). died.
Environmental Geology (2004) 45:408–425
419
420
Environmental Geology (2004) 45:408–425 Vegetation changes Ground water quality Depression of groundwater level Salt water intrusion into shallow groundwater aquifer Shoreline position
Urbanization
Pacoti 747.06
Catu 247.3
Stream channel changes
Agriculture
Surface water Unconsolidated material Groundwater Relief Urbanization Deforestation
Mining Agriculture <50
1
<2
Urbanization
Relief
50
Agriculture
Unconsolidated material Groundwater
<1
Mining
Surface water
<51
Swamp area Gravitational mass movement Flooding Water pollution Waste disposal Water erosion
Dune movement Sedimentation
Water pollution
Swamp area
Water pollution
Relief changes Channel changes Surface water quality Stream sediment storage Dune changes Slope failures Stream channel changes Vegetation changes Ground water quality Pollution sources frequency Flooding frequency and intensities Organic material destruction Salt water intrusion into shallow groundwater aquifer
20 80 1 40
Channel changes Stream sediment storage Dune changes Vegetation changes Ground water quality Depression of groundwater level Alteration of surface water flow direction Salt water intrusion into shallow groundwater aquifer Shoreline position Soil and sediment erosion
Relief changes
Soil and sediment erosion
20 1
2 10
50
3
5
2
Dune changes
Unconsolidated Material Groundwater Relief
<1
Swamp area
Mining
Surface water
Degradation geoindicators from table 2
Caponga Funda 75.47
Percentage of the basin degraded
Types
Types
Percentage of the basin
Environmental problems
Land degradation causes
Affected environmental component
Drainage basins/ area (km2)
Table 4 Land degradation level of the drainage basins
H I H L I H I I H H L
I H
H I H L I H I I H H L
I H
H H
L
L H H
I L I I I I I
L
L
L
I L L L
L
L
Intensity*
I L I I I L I
L
L
L
I L L L
L
L*
Frequency*
High
Intermediate
Low
Degradation level
Original article
Surface water Unconsolidated material - Groundwater - Relief
Surface water Unconsolidated material Groundwater Relief
Surface water Unconsolidated material Groundwater Relief
Coco´ 483.96
Maran Guapinho 265.05
Coastal basins 31.04
100
20 80
Agriculture Deforestation
Urbanization
1 to 2 60
20 >75
Agriculture Deforestation
Mining Urbanization
<1 50
Mining Urbanization
Stream sediment storage Dune changes Slope failures Stream channel changes Vegetation changes Ground water quality Pollution sources frequency Flooding frequency and intensities Urban and construction damages Depression of groundwater level Alteration of surface water flow direction Organic material destruction Shoreline position Soil and sediment erosion
8 80 1 45
100
Water pollution
Relief changes Channel changes Surface water quality
60 2 40
Water pollution Waste disposal Water erosion
10 10
Stream sediment storage Dune changes Slope failures Stream channel changes Vegetation changes Ground water quality Pollution sources frequency Flooding frequency and intensities Urban and construction damages Alteration of surface water flow direction Organic material destruction Shoreline position Soil and sediment erosion
5
Coastal erosion Dune movement
Relief changes Channel changes Surface water quality
10 <1 5
2 2
Relief changes Channel changes Surface water quality
Shoreline position Soil and sediment erosion
5 5 2
1 1
Sedimentation Swamp area Gravitational mass movement Flooding
Coastal erosion Dune movement
Sedimentation Swamp area Gravitational mass movement Flooding Water pollution Waste disposal Water erosion
Coastal erosion Dune movement
I H H
I H I I H I I H L I H H I
H H H
I H I I I H I H L L I H H H
H H H
H H
I H H
I H I I H I I H L I H H I
H H H
I H I I H H I H L L I H H H
H H H
H H
High
High
High
Original article
Environmental Geology (2004) 45:408–425
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422
Environmental Geology (2004) 45:408–425
Jua´ 132.67
Surface water Unconsolidated material Groundwater
Ceara´ 598.73
Relief
Surface water Unconsolidated material Groundwater
Relief
Affected environmental component
Drainage basins/ area (km2)
Table 4 (Contd.)
25
Urbanization Deforestation
<30
Deforestation Urbanization <10
1 10
Mining Agriculture
>75
1 15
Mining Agriculture
Water pollution
20
1 2
I I L L
Vegetation changes Pollution sources frequency Alteration of surface water flow direction
L
L L
I H I I H I L H L I H L
H
H
H
I L L
I
L
L L
I H I I H I L H L I H L
H
H
H
H H
L
L H H
H H H H L L I L H
Intensity*
H H H H L L I L H
Frequency*
Dune changes
Surface water quality
Stream sediment storage Dune changes Slope failures Stream channel changes Vegetation changes Ground water quality Pollution sources frequency Flooding frequency and intensities Urban and construction damages Alteration of surface water flow direction Organic material destruction Salt water intrusion into shallow groundwater aquifer Shoreline position Soil and sediment erosion
5 50 <1 50
Coastal erosion Dune movement
Surface water quality
1
Gravitational mass movement Flooding Water pollution Waste disposal Water erosion
Channel changes
Relief changes
2
10
1 1
Stream sediment storage Dune changes Stream channel changes Ground water quality Pollution sources frequency Urban and construction damages Depression of groundwater level Alteration of groundwater flow direction Alteration of surface water flow direction Salt water intrusion into shallow groundwater aquifer Shoreline position Soil and sediment erosion
Degradation geoindicators from table 2
Swamp area
Sedimentation
Coastal erosion Dune movement
Percentage of the basin degraded
Types
Types
Percentage of the basin
Environmental problems
Land degradation causes
Intermediate/ low
High
Degradation level
Original article
Surface water Relief
Surface water Relief
Gererau´ 52.67
Curu´ 38.45
L Low, I Intermediate, H High
Surface water Relief
Sa˜o Gonc¸alo 494.59
Surface water Relief
Cauipe 326.99
Mining Deforestation Agriculture
Mining Deforestation Agriculture
Mining Deforestation Agriculture Urbanization
Mining Deforestation Urbanization Agriculture
<2
1 >85
<2
1 >75
<10 <10
<2 >75
Water pollution Water erosion
Water pollution Water erosion
Water pollution Water erosion
Water erosion
5 5
Water pollution Dune movement
1 85
25 50
20 40
20 60
50
2
45
Surface water quality Stream channel changes Alteration of surface water flow direction
L L L
I L L L L L
I L H L I H L L
Stream sediment storage Stream channel changes Vegetation changes Pollution sources frequency Alteration of surface water flow direction Organic material destruction Relief changes Channel changes Surface water quality Stream sediment storage Stream channel changes Alteration of surface water flow direction Relief changes Channel changes
I I
I I L L L I I H H I
L
I I
Channel changes Surface water quality
Channel changes Surface water quality Stream sediment storage Dune changes Stream channel changes Vegetation changes Alteration of surface water flow direction Organic material destruction Soil and sediment erosion Relief changes
Relief changes
Shoreline position Soil and sediment erosion
L L L
I L L L L L
I L H L I H L L
I I
I I L L L I I H H I
L
I I
Low
Low
Low
Intermediate
Original article
Environmental Geology (2004) 45:408–425
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The flood plain of the Pacoti River is very large and flooding has affected agriculture and pasture but not urbanized areas. In accordance with environmental problem sources, each basin was analyzed using environmental geoindicators to assess the land degradation level (Table 4). The Coastal, Pocoti, Ceara´, Coco and Maranguapinho Basins were discovered to have been seriously affected and presented the highest degradation level. Jua and Catu Basins presented an intermediate degradation level. The other basins were classified at low degradation level. The Maranguapinho, Ceara´, Coco´ and Coastal basins are intensely degraded due to anthropogenic causes and, secondarily, due to natural processes. Urbanization is the main problem affecting 100, 60, 50, and 25% of the Coastal, Maranguapinho, Coco´, and Ceara´ Basins, respectively. Deforestation has occurred in more than 75% of these basins as a result of urban and agricultural activities. Water erosion predominates in the upstream portion of the Maranguapinho, Ceara´, and Coco´ Basins while water pollution is found mainly in the Coastal Basin. Problems related to urbanization occur in the downstream portion of the Maranguapinho, Ceara´, and Coco´ Basins and throughout the entire extension of the Coastal Basin. The Ceara´, Maranguapinho and Coco´ Basins present 5, 10 and 15% natural vegetation cover, respectively. Soils developed from igneous and metamorphic rocks in the upstream half are not favorable for agriculture which is mainly developed on alluvial deposits close to drainage channels. The Caponga Funda, Gererau, and Curu Basins are affected by anthropogenic and natural processes. Water pollution and water erosion are common, mainly due to deforestation (>75%) and, secondarily, due to agriculture. In Gererau and Curu Basins, there are some urbanized sites. Agriculture and urbanization are frequent in the Caponga Funda Basins, polluting ground and surface water. The Jua Basin is less affected by anthropogenic and natural processes. More than 50% is covered by natural vegetation in the upstream portion and most of the environmental geoindicators, mainly related to urbanization and agriculture, were detected in 30% of the downstream portion. Good aquifers occur in the downstream portion but water quality will probably be affected in the next few years. Policy measures should be introduced to avoid such water pollution. The Cauipe and Sa˜o Gonc¸alo Basins are more than 75% deforested. Agriculture and urbanization have occupied less than 10%. Agriculture predominates close to the drainage channels, lakes, and reservoirs while urbanization characterized the Coastal portion in dunes and palaeodunes, and the Barreiras Formation. The Catu Basin is very special because it is composed of geological materials characterized by good groundwater conditions. The soils, developed from geological materials, are very good for agriculture. Deforestation is mainly being carried out for agricultural uses while urbanization occurs close to lakes and the sea. Management of agricultural practices is necessary to protect the environment, mainly the ground and surface water. Groundwater and 424
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surface water pollution is being produced by a combination of agriculture uses and groundwater characteristics. The Pacoti Basin, the largest in the region, is very important because dozens of lakes and reservoirs are distributed within its limits. Geological materials with good groundwater characteristics underlie the downstream half, but agriculture and urbanization uses have affected the groundwater quality. Among the regional basins, this basin presents the largest swamp area heavily affected by deforestation and agriculture uses. Water erosion occurs in the upstream half, leading to sedimentation and river, lake, and reservoir pollution. The environmental changes observed in the region are similar to ones that have affected several cities in Asia. According to Yeung (2001), many coastal cities such as Shanghai, Manila, Bombay, Tokyo and hundreds of smaller cities have been affected by: inundation, flooding, silting, beach erosion, and coastal damage to transport infrastructure, drainage systems, buildings, hydrological changes, and surface and groundwater pollution. The Fortaleza metropolitan region, though it has a smaller population than the Mumbai metropolitan region, presents the same environmental problems cited by Murthy and others (2001): coastal erosion; flooding; silting; landfills of solid wastes; destruction of vegetation and wet lands; water pollution; and intense urban occupation.
Conclusions The main problems detected in the region are: coastal zone erosion, dune movements, floods, gravitational mass movements, silting, water pollution, degradation related to aggregate exploitation, and landfill in inappropriate areas such as wetlands and swamps. Rehabilitative and mitigation practices have been used to deal with coastal erosion and dune movements but have not led to adequate results. For other environmental problems a variety of environmental management and protective practices have been introduced or proposed by governmental agencies. The environmental geoindicators chosen permitted a satisfactory assessment of the region for establishing land degradation levels for drainage basins. Environmental problems have been responsible for regional economic losses and municipal public administrations have spent large sums for rehabilitation of sites affected at different intensities. Erosion and sedimentation have influenced the entire coast line; several buildings and roads have been destroyed since 1980. Reforestation of the riparian zones of the Sa˜o Gonc¸alo, Pacoti, Maranguapinho, Caiupe, Gererau´ and Coco´ Basins should be introduced so as to improve the water quality, avoid stream-bank erosion, and protect swamp areas. The Jua, Coco and Catu Basins should be protected because they have better groundwater reserves than the other basins, and since they present intermediate and high degradation level.
Original article
Portions of the Ceara´, Maranguapinho, Jua, and Coco´ Basins supported by high residual massif covered by dense vegetation should be protected to avoid gravitational mass movements and other environmental problems. Rehabilitation and mitigation measures, agronomic management, reforestation, urban planning, and sanitation measures are strongly recommended for the whole region. Most aquifers present intermediate contamination level stemming from biological and chemical pollutants. In all drainage basins large degraded areas were observed and streams presented intermediate to high pollution levels caused by chemical and biological products and high sediment percentages. The region urgently needs an environmental program designed to regulate and rehabilitate the affected areas.
References Allen NT, Brooks DR, Jesson JG (1990) Multiple land-use and mineral sands mining on Australias east coast. In: Proc Aust Min Ind Co Environ Workshop, vol 2, Wollongong, October 1990, pp 159–194 Baraldi F, Castaldini D, Marchetti M (2001) Geomorphological impact assessment in the River Mincio plain (Province of Mantova, Northern Italy). In: Marchetti M, Pinas V (eds) Geomorphology and environmental impact assessments. Balkema, Rotterdam, pp 7–30 Barrow CJ (1991) Land degradation. Cambridge University Press, New York, 295 pp Berger AR (1996) The geoindicator concept and its application: an introduction. In: Berger AR, Iams WJ (eds) Geoindicators: assessing rapid environmental changes in Earth systems. Balkema, Rotterdam, pp 1–14 Berger AR, Iams WJ (eds) (1996) Geoindicators: assessing rapid environmental changes in Earth systems. Balkema, Rotterdam, 466 pp Berger AR (1997) Assessing rapid environmental change using geoindicators. Environ Geol 32(1):36–44 Blaike P, Brookfield H (1987) Land degradation and society. Methuen, London Brunsden D, Moore R (1999) Engineering geomorphology on the coast: lessons from West Dorset. Geomorphology 31:391–409 Bush DM, Neal WJ, Young RS, Pilkey OH (1999) Utilization of geoindicators for rapid assessment of coastal-hazard risk and mitigation. Ocean Coast Manage 42:647–670 Conacher AJ, Sola M (eds) (1999) Land degradation in Mediterranean environments of the World: nature and extent, causes and solutions. Wiley, New York, 491 pp Dahlberg AC (2000) Interpretations of environmental change and diversity: a critical approach to indications of degradation – The case of Kalakamate, northeast Botswana. Land Degrad Dev 11:549–562 Department of the Environment (1990) The governments response to the First Report from the House of Commons Select Committee on the environment on contaminated land. HMSO, London Dumansk J, Pieri C (2000) Land quality indicators: research plan. Agr Ecosyst Environ 81:93–102 FAO (1979) A provisional methodology for soil degradation assessment. FAO, Rome Forbes DL, Liverman DGE (1996) Geological indicators in the coastal zone. In: Berger AR, Iams WJ (eds) Geoindicators:
assessing rapid environmental changes in Earth systems. Balkema, Rotterdam, pp 175–195 Gray LC (1999) Is land being degraded? A multi-scale investigation of landscape change in southwestern Burkina Faso. Land Degrad Dev 10:329–343 Gupta A (2002) Geoindicators for tropical urbanization. Environ Geol 42:736–742 Hammond A, Adriaanse A, Rodenburg E, Bryant D, Woodward R (1995) Environmetal indicators: a systematic approach to measuring and reporting on environmental policy performance in the context of sustainable development. World Resources Institute, Washington, DC Instituto Brasileiro de Geografia e Estatı´stica (2002) Dados sobre os censos desenvolvidos no Brasil desde 1980 ate´ 2002. Instituto Brasileiro de Geografia e Estatı´stica, Rio de Janeiro, Brasil Johnson D, Lewis L (1995) Land degradation: creation and destruction. Blackwell, Oxford, 490 pp Johnson DN, Lamb P, Saul M, Winter-Nelson AE (1997) Meaning of environmental terms. J Environ Qual 26:581–589 Lindskog P, Tengberg A (1994) Land degradation, natural resources and local knowledge in the Sahel zone of Burkina Faso. Geojournal 33:365–375 Lubke RA, Avis AM (1998) A review of the concepts and application of rehabilitation following heavy mineral dune mining. Mar Poll Bull 37(8–12):546–557 Maltby E (1986) Water logged wealth : why waste the Worlds wet places? Earthscan, London, 530 pp Marchetti M, Panizza M (2001) Geomorphology and environmental impact assesssment: - a case study in Moema (Dolomites – Italy). In: Marchetti M, Pinas V (eds) Geomorphology and environmental impact assessments. Balkema, Rotterdam, pp 71–82 Martin Duque JF, Pedroza J, Dı´ez A, Sanz MA, Carrasco RM (1998) A geomorphological design for the rehabilitation of an abandoned sand quarry in central Spain. Landscape Urban Plan 42:1–14 Morton RA (1996) Geoindicators of coastal wet land and shorelines. In: Berger AR, Iams WJ (eds) Geoindicators: assessing rapid environmental changes in Earth systems. Balkemia, Rotterdam, pp:207–232 Morton RA (2002) Coastal geoindicators of environmental change in the humic tropics. Environ Geol 42:711–724 Murthy RC, Rao YR, Inamdar AB (2001) Integrated coastal management of Mumbai metropolitan region. Ocean Coast Manage 44:355–369 Neimanis U, Kerr A (1996) Developing national environmental geoindicators. In: Berger AR, Iams WJ (eds) Geoindicators: assessing rapid environmental changes in Earth systems. Balkemia, Rotterdam, pp 369–376 Osterkamp WR, Schumm SA (1996) Geoindicators for river and river-valley monitoring. In: Berger AR, Iams WJ (eds) Geoindicators: assessing rapid environmental changes in Earth systems. Balkemia, Rotterdam, pp 97–114 Osterkamp WR (2002) Geoindicators for river and river-valley monitoring in the humid tropics. Environ Geol 42:725–735 Pilkey OH (1991) Coastal erosion. Episodes 14(1):46–51 Radbruch-hall DA, Varnes DJ (1976) Landslide-cause and effects. Bull Int Assoc Eng Geol 14:205–216 Riksen MJPM, DeGraaf J (2001) On-site and off-site affects of wind erosion on European light soils. Land Degrad Dev 12:1–11 Stocking MA (1993) Soil erosion in developing countries: where geomorphology fears to tread. School of Development Studies Discussion. Paper no 241 Yeung YM (2001) Coastal mega cities in Asia: transformation, sustainability and management. Ocean Coast Manage 44:319–333
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