The biogeophysical climatic impacts of anthropogenic land use change during the Holocene

The first agricultural societies were established around 10 ka BP and had spread across much of Europe and southern Asia by 5.5 ka BP with resultant anthropogenic deforestation for crop and pasture land. Various studies (e.g. Joos et al., 2004; Kaplan et al., 2011; Mitchell et al., 2013) have attempted to assess the biogeochemical implications for Holocene climate in terms of increased carbon dioxide and methane emissions. However, less work has been done to examine the biogeophysical impacts of this early land use change. In this study, global climate model simulations with Hadley Centre Coupled Model version 3 (HadCM3) were used to examine the biogeophysical effects of Holocene land cover change on climate, both globally and regionally, from the early Holocene (8 ka BP) to the early industrial era (1850 CE). Two experiments were performed with alternative descriptions of past vegetation: (i) one in which potential natural vegetation was simulated by Top-down Representation of Interactive Foliage and Flora Including Dynamics (TRIFFID) but without land use changes and (ii) one where the anthropogenic land use model Kaplan and Krumhardt 2010 (KK10; Kaplan et al., 2009, 2011) was used to set the HadCM3 crop regions. Snapshot simulations were run at 1000-year intervals to examine when the first signature of anthropogenic climate change can be detected both regionally, in the areas of land use change, and globally. Results from our model simulations indicate that in regions of early land disturbance such as Europe and south-east Asia detectable temperature changes, outside the normal range of variability, are encountered in the model as early as 7 ka BP in the June–July–August (JJA) season and throughout the entire annual cycle by 2–3 ka BP. Areas outside the regions of land disturbance are also affected, with virtually the whole globe experiencing significant temperature changes (predominantly cooling) by the early industrial period. The global annual mean temperature anomalies found in our single model simulations were −0.22 at 1850 CE, −0.11 at 2 ka BP, and −0.03 °C at 7 ka BP. Regionally, the largest temperature changes were in Europe with anomalies of −0.83 at 1850 CE, −0.58 at 2 ka BP, and −0.24 °C at 7 ka BP. Large-scale precipitation features such as the Indian monsoon, the Intertropical Convergence Zone (ITCZ), and the North Atlantic storm track are also impacted by local land use and remote teleconnections. We investigated how advection by surface winds, mean sea level pressure (MSLP) anomalies, and tropospheric stationary wave train disturbances in the mid- to high latitudes led to remote teleconnections.

Effects of roads, topography, and land use on forest cover dynamics in the Brazilian Atlantic Forest

Roads and topography can determine patterns of land use and distribution of forest cover, particularly in tropical regions. We evaluated how road density, land use, and topography affected forest fragmentation, deforestation and forest regrowth in a Brazilian Atlantic Forest region near the city of Sao Paulo. We mapped roads and land use/land cover for three years (1962, 1981 and 2000) from historical aerial photographs, and summarized the distribution of roads, land use/land cover and topography within a grid of 94 non-overlapping 100 ha squares. We used generalized least squares regression models for data analysis. Our models showed that forest fragmentation and deforestation depended on topography, land use and road density, whereas forest regrowth depended primarily on land use. However, the relationships between these variables and forest dynamics changed in the two studied periods; land use and slope were the strongest predictors from 1962 to 1981, and past (1962) road density and land use were the strongest predictors for the following period (1981-2000). Roads had the strongest relationship with deforestation and forest fragmentation when the expansions of agriculture and buildings were limited to already deforested areas, and when there was a rapid expansion of development, under influence of Sao Paulo city. Furthermore, the past(1962)road network was more important than the recent road network (1981) when explaining forest dynamics between 1981 and 2000, suggesting a long-term effect of roads. Roads are permanent scars on the landscape and facilitate deforestation and forest fragmentation due to increased accessibility and land valorization, which control land-use and land-cover dynamics. Topography directly affected deforestation, agriculture and road expansion, mainly between 1962 and 1981. Forest are thus in peril where there are more roads, and long-term conservation strategies should consider ways to mitigate roads as permanent landscape features and drivers facilitators of deforestation and forest fragmentation. (C) 2009 Elsevier B.V. All rights reserved.

Study of the relationship between roads, relief, land use, and natural vegetation in the Ibiuna Plateau - SP, focusing on landscape ecology

Roads facilitate access by deforestation agents, being relevant in studies approaching conservationist matters in rainforests. It is important to understand the relationship between road distribution, relief, land use, and forest coverage in order to evaluate where forests are more vulnerable. This study aimed at: 1) understanding the relationship between relief and density and road connectivity in three moments in time; and 2) evaluating the relationship between distance from roads and forest coverage, farmlands and rural and urban facilities in a fragmented Atlantic Forest landscape in three moments in time. Maps of roads, altitude, and land use and coverage were used. Chi-square tests showed that: 1) density and road connectivity did not present significant relationship with the relief; and 2) forest areas occupy areas distant from the roads, while farmlands and rural and urban facilities occupy areas nearer the roads. Roads and land use, regardless of relief, influence forest coverage distribution. Thus, we suggest that roads are taken into account in conservationist strategies and environmental planning.

Small-Scale Farmers Land Use and Socioeconomic Situation in the Mount Elgon District in Northwestern Kenya : A Minor Field Study - Combined Field Mapping and Interview

This Minor Field Study was carried out during November and December in 2011 in the Mount Elgon District in Western Kenya. The objective was to examine nine small-scale farming household´s land use and socioeconomic situation when they have joined a non-governmental organization (NGO) project, which specifically targets small-scale farming households to improve land use system and socioeconomic situation by the extension of soil and water conservation measures. The survey has worked along three integral examinations methods which are mapping and processing data using GIS, semi structured interviews and literature studies.   This study has adopted a theoretical approach referred to as political ecology, in which landesque capital is a central concept. The result shows that all farmers, except one, have issues with land degradation. However, the extent of the problem and also implemented sustainable soil and water conservation measures were diverse among the farmers. The main causes of this can both be linked to how the farmers themselves utilized their farmland and how impacts from the climate change have modified the terms of the farmers working conditions. These factors have consequently resulted in impacts on the informants’ socioeconomic conditions. Furthermore it was also registered that social and economic elements, in some cases, were the causes of how the farmers manage their farmland. The farmer who had no significant problem with soil erosion had invested in trees and opportunities to irrigate the farmland. In addition, it was also recorded that certain farmers had invested in particular soil and water conservation measures without any significant result. This was probably due to the time span these land measures cover before they start to generate revenue.  The outcome of this study has traced how global, national and local elements exist in a context when it comes to the conditions of the farmers´ land use and their socioeconomic situation. The farmers atMt.Elgon are thereby a component of a wider context when they are both contributory to their socioeconomic situation, mainly due to their land management, and also exposed to core-periphery relationships on which the farmers themselves have no influence.

The Impact of Land Use Patterns and Watershed Characteristics on China Lake, Kennebec County, Maine

China Lake is located in Kennebec County, Maine. Since 1983 the lake has suffered from yearly algal blooms as a result of the addition of excess nutrients. The nutrient load was amplified by erosion within the watershed. Erosion varies widely depending on a number of factors, including the slope of the land, the type of soil, and the way the land is being used. Certain land use types have a high potential to add nutrients to the environment, while others may help absorb excess nutrients and prevent erosion and runoff into the lake. A comprehensive examination of the China Lake watershed was completed using GIS to calculate the erosion potential for the entire area, taking into account past and present land use patterns. This information will help the towns around the lake to make informed decisions about future development and land management.

Analysis of land use and occupancy in permanent preservation areas according to the hydrography of Ribeirão Água Fria - Bofete, SP - Brazil

Os conflitos de uso são determinados pelas ocupações inadequadas do solo, como é o caso de ocupação do solo dentro de áreas de preservação permanente. O presente trabalho teve como objetivos determinar as classes de uso do solo e se há conflitos dentro de áreas de preservação permanente ao longo da rede de drenagem da microbacia do Ribeirão Água Fria, município de Bofete (SP). Situa-se geograficamente entre as coordenadas: 48°09'30 a 48°18'30 de longitude WGr., 22°58'30 a 23°04'30 de latitude sul com uma área de 15.242,84 ha. O mapa de uso do solo foi elaborado por meio da interpretação diretamente na tela do computador de imagem digital de satélite. Nos dados orbitais, a área de estudo está inserida no quadrante A, da imagem TM/Landsat-5, órbita 220, ponto 76, passagem de 8/09/2007. O Sistema de Informação Geográfica empregado foi o Cartalinx. As áreas de conflito da microbacia foram obtidas a partir do cruzamento entre os mapas de uso do solo e de APPs. Os resultados permitiram concluir que mais da metade da área (51,09%) está ocupada por pastagens, reflexo de solos arenosos e de baixa fertilidade. Constatou-se, ainda, que apesar de quase metade da microbacia estar coberta com algum tipo de vegetação (48,78% de mata natural/reflorestamento), possui aproximadamente um terço das áreas de preservação permanente utilizadas inadequadamente por pastagens (88,15%), reflorestamento (10,42%) e solo exposto (1,43%), totalizando 343,07 ha de áreas conflitantes em um total de 993,26 ha de APPs.

The definition of potential infiltration areas in Guaratingueta watershed, Paraiba do Sul Basin, Southeastern Brazil: an integrated approach using physical and land-use elements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effect of the land use on phytoplankton assemblages of a Cerrado stream (Brazil)

OBJETIVO: Nosso objetivo foi investigar se o uso do solo do ambiente terrestre adjacente influencia a estrutura das assembleias fitoplanctônicas (composição, riqueza, diversidade e abundância) e biomassa (clorofila-a) em um riacho de Cerrado durante diferentes períodos do ano. MÉTODOS: Os trabalhos de campo foram realizados trimestralmente durante dois anos. RESULTADOS: As variáveis físico-químicas que melhor indicaram as diferenças nas condições da água foram condutividade, oxigênio dissolvido e transparência. Também houve um notável aumento na concentração de nitrogênio, fósforo e material em suspensão na água durante o verão devido aos efeitos da pluviosidade. As assembleias fitoplanctônicas foram compostas por 64 espécies. Cryptophyceae foi o grupo mais abundante, seguido por Bacillariophyceae. Para ambos os anos, a riqueza e a diversidade foram maiores durante a primavera e no outono, enquanto que a abundância do fitoplâncton e a concentração de clorofila-a foram mais elevados durante o outono e verão. A análise de agrupamento e a analise de correspondência canônica mostraram que a sazonalidade e o uso do solo são fatores importantes na estruturação das assembleias ao longo do ano. As alterações nas assembleias fitoplanctônicas ocorreram provavelmente em função da variação na intensidade e freqüência da mistura da água e da entrada de nutrientes oriundo do sistema terrestre adjacente para o aquático. CONCLUSÃO: A estrutura das assembleias fitoplanctônicas mostrou ser altamente influenciada pelo uso do solo, corroborando com a hipótese inicial do trabalho.

Impacts of Climate Change and the End of Deforestation on Land Use in the Brazilian Legal Amazon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evolutionary heuristic to determine future land use

In the spatial electric load forecasting, the future land use determination is one of the most important tasks, and one of the most difficult, because of the stochastic nature of the city growth. This paper proposes a fast and efficient algorithm to find out the future land use for the vacant land in the utility service area, using ideas from knowledge extraction and evolutionary algorithms. The methodology was implemented into a full simulation software for spatial electric load forecasting, showing a high rate of success when the results are compared to information gathered from specialists. The importance of this methodology lies in the reduced set of data needed to perform the task and the simplicity for implementation, which is a great plus for most of the electric utilities without specialized tools for this planning activity. © 2008 IEEE.

Land use image classification through optimum-path forest clustering

Land use classification has been paramount in the last years, since we can identify illegal land use and also to monitor deforesting areas. Although one can find several research works in the literature that address this problem, we propose here the land use recognition by means of Optimum-Path Forest Clustering (OPF), which has never been applied to this context up to date. Experiments among Optimum-Path Forest, Mean Shift and K-Means demonstrated the robustness of OPF for automatic land use classification of images obtained by CBERS-2B and Ikonos-2 satellites. © 2011 IEEE.

Application of landsat images for quantifying the energy balance under conditions of land use changes in the semi-arid region of Brazil

In the Nilo Coelho irrigation scheme, Brazil, the natural vegetation has been replaced by irrigated agriculture, bringing importance for the quantification of the effects on the energy exchanges between the mixed vegetated surfaces and the lower atmosphere. Landsat satellite images and agro-meteorological stations from 1992 to 2011 were used together, for modelling these exchanges. Surface albedo (α0), NDVI and surface temperature (T0) were the basic remote sensing retrieving parameters necessary to calculate the latent heat flux (λE) and the surface resistance to evapotranspiration (rs) on a large scale. The daily net radiation (Rn) was obtained from α0, air temperature (Ta) and short-wave transmissivity (τsw) throughout the slob equation, allowing the quantification of the daily sensible heat flux (H) by residual in the energy balance equation. With a threshold value for rs, it was possible to separate the energy fluxes from crops and natural vegetation. The averaged fractions of Rn partitioned as H and λE, were in average 39 and 67%, respectively. It was observed an increase of the energy used for the evapotranspiration process inside irrigated areas from 51% in 1992 to 80% in 2011, with the ratio λE/Rn presenting an increase of 3 % per year. The tools and models applied in the current research, can subsidize the monitoring of the coupled climate and land use changes effects in irrigation perimeters, being valuable when aiming the sustainability of the irrigated agriculture in the future, avoiding conflicts among different water users. © 2012 SPIE.

Geotechnology applied to land use and sealing in urban areas

Through the geotechnology's use, the aim of this study was to characterize the urban occupation interference and occurrence of floods in the upstream area of watershed from the stream Wenzel (Rio Claro-SP/Brazil). Urbanized watersheds are composed of a variety of features and the development of cartographic material allowed the analysis of the evolution of land used for 1958 and 2006 scenarios. The thematic maps were generated using software Spring 4.3.3, wherein it got the separation of matters from vegetation cover and other intra urban features. Procedures of digital processes and classification of surface cover allowed quantifying the occupied area by each coverage type: woody vegetation, grass, grass with bare soil, bare soil, building, asphaltic sheets and exposed soil. Quantification of the different covers' occupied areas allowed relating the parameter Curve Number (Soil Conservation Service) as efficient methodology for runoff values estimative. The results indicate vegetation cover's reduction, intensive surface's sealing and suppression of water bodies. These factors imply changes of hydrological dynamics of the source, increasing flow and transfer of larger volumes of water and flood peaks to downstream sectors. The use of geotechnology allowed analyzing the evolution of urbanization and it permits also to infer about trends for future or inadequate occupancy to hydrological and environmental point of view. © 2013 IEEE.

Cellular automata-based spatial dynamic modeling for analyzing urban land use change

This paper analyzes land use change in Rio Claro City and its surroundings, located in the southeastern state of Sao Paulo, in the period from 1988 to 1995, using air-borne digital imagery and a cellular automata model. The simulation experiment was carried out in the Dinamica EGO platform and the results revealed a constrained urban sprawl, resulting from both the densification of residential areas implemented in previous years and the economic recession that led to an internal financial crisis in Brazil during the early 1990s. The simulation outputs were validated using a multi-resolution procedure based on a fuzzy similarity index and showed a satisfactory fitness in relation to the historical reference data. © 2013 IEEE.