Effects Of Land Cover Change Research Articles

Islands of Felicity? – The Effect of Land Cover Changes in and around Protected Areas: A Case Study of Bach Ma National Park, Vietnam

In recent decades, Vietnam’s network of protected areas experienced extensive growth. More than 160 terrestrial and marine protected areas (approximately 2.2 million ha) associated with remarkable reforestation demonstrate major changes within environmental policies. Nevertheless, the degradation of the existing natural forest communities, the associated loss of species and decreasing resilience suggest that Vietnam has still not reached a satisfactory point of conserving these natural habitats. The current study presents an impressive example of land cover change over a period of approximately 40 years at the Bach Ma National Park. Deforestation and degradation processes are a result of illegal activities and land use changes, a consequence of the increasing population. However, land use conflicts often occur outside of protected areas where land cover changes are concentrated and accelerated.

Development and assessment of a 250 m spatial resolution MODIS annual land cover time series (2000–2011) for the forest region of Canada derived from change-based updating

Detailed information on the spatial and temporal distribution of land cover is required to evaluate the effects of land cover change on environmental processes. The development of temporally consistent land cover time series (LCTS) from satellite-based earth observation has proven difficult because multi-year observations are acquired under different conditions resulting in high inter-annual reflectance variability. This leads to spurious differences in land cover when standard approaches for image classification are applied to generate multi-year land cover data. To reduce this effect, a common solution has been to first detect change and update a base map for only these change areas. As long as the change commission error is low, this approach will ensure high consistency between maps in the time series. Here we present an approach for change-based LCTS development following from previous research, but with significant advancements in change detection, training, classification, and evidence-based refinement. The method was applied to generate an annual LCTS covering Canada spanning 2000–2011 that is consistent between years and can be used to identify dominant change transitions. Assessment of the LCTS was challenging because multiple maps needed to be evaluated and can be prohibitive particularly for annual time series covering several years. Three approaches were undertaken involving visual examination, comparison with a reference sample derived from Landsat, and comparison with the MODIS Global LCTS V5.1. Visual assessment revealed high inter-map consistency and logical temporal change trajectories of land cover classes. Comparison with the reference sample showed an accuracy of 70% at the 19 class thematic resolution. Accounting for mixed pixels by considering the first or second reference land cover label as correct increased the accuracy to 80%. Comparison with the MODIS Global LCTS showed that the Canada LCTS achieved higher inter-map consistency and accuracy as expected with national relative to global land cover products.

The impact of ecosystem functional type changes on the La Plata Basin climate

In this paper, the effects of land cover changes on the climate of the La Plata Basin in southern South America are investigated using the Weather and Research Forecasting (WRF) Model configured on a 30/10-km two-way interactive nested grid. To assess the regional climate changes resulting from land surface changes, the standard land cover types are replaced by time-varying Ecosystem Functional Types (EFTs), which is a newly devised land-cover classification that characterizes the spatial and interannual variability of surface vegetation dynamics. These variations indicate that natural and anthropogenic activities have caused changes in the surface physical parameters of the basin, such as albedo and roughness length, that contributed to regional climate changes. EFTs are obtained from functional attributes of vegetation computed from properties of the Normalized Difference Vegetation Index (NDVI) to represent patches of the land surface with homogeneous energy and gas exchanges with the atmosphere. Four simulations are conducted, each experimental period ranging from September to November in two contrasting years, 1988 and 1998. The influence of an identical EFT change on the surface heat fluxes, 2-m temperature and humidity, 10-m winds, convective instabilities and large-scale moisture fluxes and precipitation are explored for 1988 (a dry year) and 1998 (a wet year). Results show that the surface and atmospheric climate has a larger response to the same EFT changes in a dry year for 2-m temperature and 10-m wind; the response is larger in a wet year for 2-m water vapor mixing ratio, convective available potential energy, vertically integrated moisture fluxes and surface precipitation. For EFTs with high productivity and a weak seasonal cycle, the nearsurface temperature during the spring of 1988 and 1998 increased by as much as 1°C in the central and western portions of La Plata Basin. Additionally, for higher productivity EFTs, precipitation differences were generally positive in both dry and wet years, although the patterns are not uniform and exhibit certain patchiness with drier conditions.

Comparison of PMP-Driven Probable Maximum Floods with Flood Magnitudes due to Increasingly Urbanized Catchment: The Case of American River Watershed

Abstract Since historical (predam) data are traditionally the sole criterion for dam design, future (postdam) meteorological and hydrological variability due to land-use and land-cover change cannot be considered for assessing design robustness. For example, postdam urbanization within a basin leads to definite and immediate increase in direct runoff and reservoir peak inflow. On the other hand, urbanization can strategically (i.e., gradually) alter the mesoscale circulation patterns leading to more extreme rainfall rates. Thus, there are two key pathways (immediate or strategic) by which the design flood magnitude can be compromised. The main objective of the study is to compare the relative contribution to increase in flood magnitudes through direct effects of land-cover change (urbanization and less infiltration) with gradual climate-based effects of land-cover change (modification in mesoscale storm systems). The comparison is cast in the form of a sensitivity study that looks into the response to the design probable maximum flood (PMF) from probable maximum precipitation (PMP). Using the American River watershed (ARW) and Folsom Dam as a case study, simulated peak floods for the 1997 (New Year's) flood event show that a 100% impervious watershed has the potential of generating a flood that is close to design PMF. On the other hand, the design PMP produces an additional 1500 m3 s−1 peak flood compared to the actual PMF when the watershed is considered 100% impervious. This study points to the radical need for consideration future land-cover changes up front during the dam design and operation formulation phase by considering not only the immediate effects but also the gradual climatic effects on PMF. A dynamic dam design procedure should be implemented that takes into account the change of land–atmospheric and hydrological processes as a result of land-cover modification rather than relying on historical records alone.

Assessment of land cover changes & water quality changes in the Zayandehroud River Basin between 1997–2008

Water quality of rivers is strongly influenced by landscape characteristics of their watershed, including land use /cover types, and their spatial configuration. This research evaluates the effects of land cover changes on the water quality of the Zayandehroud River, which is the most important river in the center of Iran. The main goal of this study was to quantify the change in rangelands, forests, and bare lands in the Zayandehroud river basin, which suffered intense human interference, in a period of 11 years (1997-2008), and to evaluate how landscape patterns (including the number of patches, edge density, percentage of rangelands, forests, and bare lands) influence on the 14 water quality indices (including BOD5, EC, NO3, P, and TDS) measured in 10 stations along the river. Results showed that from 1997 to 2008, bare lands increased from 5.8 to 20%, while rangelands decreased from 70 to 55% in the whole basin. The results indicated that water quality was significantly correlated with both the proportions and configuration of rangeland and bare land areas. The total edge (TE) of rangeland area had positive effects on water quality, especially on BOD5 and EC. Percentage of landscape (PLAND) and largest patch index (LPI) metrics of rangeland had positive effect on decreasing nutrient (NO3, PO4). The results showed that water quality was more likely degraded when there was high edge density (ED) of bare lands. Results of this study also revealed that degradation of rangeland lead to the degradation of water quality. Finding of this study highlights the importance of rangeland conservation in water quality management at landscape scale.

The effect of land-cover change on vegetation greenness-based satellite agricultural drought indicators: a case study in the southwest climate division of Indiana, USA

During the last decade, the use of the normalized difference vegetation index (NDVI) for drought monitoring applications has drawn many criticisms, mainly because a number of drivers such as land-cover/land-use change, pest infestation, and flooding may depress the NDVI, further causing false drought identification. In this study, the impacts of land-cover change on the NDVI-derived satellite drought indicator, the vegetation condition index (VCI), are presented. It was found that the VCI is sensitive to changes in land cover, especially deforestation, the land cover changes from evergreen and deciduous forests to other land-cover classes. However, because the scale of land-cover changes was very small across the study area, only trivial drought alerts were observed in the VCI-based drought maps during non-drought years. Because drought is a large-scale climate event, it is reasonable to neglect these alerts. Besides, when the VCI was averaged to climate division scale, the results obtained through the VCI method were in good agreement with those acquired by the meteorological data-based drought indices such as the Palmer drought severity index and standardized precipitation index.

Simulation of the influence of historical land cover changes on the global climate

Abstract. In order to estimate biogeophysical effects of historical land cover change on climate during last three centuries, a set of experiments with a climate system model of intermediate complexity (MPM-2) is performed. In response to historical deforestation, the model simulates a decrease in annual mean global temperature in the range of 0.07–0.14 °C based on different grassland albedos. The effect of land cover changes is most pronounced in the middle northern latitudes with maximum cooling reaching approximately 0.6 °C during northern summer. The cooling reaches 0.57 °C during northern spring owing to the large effects of land surface albedo. These results suggest that land cover forcing is important for study on historical climate change and that more research is necessary in the assessment of land management options for climate change mitigation.

A Simulation Study on Climatic Effects of Land Cover Change in China

The regional climate model RegCM4 was used to investigate the regional climate effects of land cover change over China. Two 24-year simulations (1978–2001), one with the land cover derived from the MODIS data and the other with the CLCV (Chinese land cover derived from vegetation map) data, were conducted for a region encompassing China. The differences between the MODIS and CLCV data reflect characteristics of desertification and degradation of vegetation in China. Results indicate that the land cover change has important impacts on local climate through mechanisms related to changes in surface energy, water budgets and macro-scale circulation. In summer, the land cover change leads to a decrease in surface air temperature over southern China, a reduction in precipitation and an increase in surface air temperature in the transitional climate zone and the northern Tibetan Plateau, and an increase in inter-annual variability of surface air temperature in the marginal monsoon zone and northwestern China. Strengthened southwesterly winds increase precipitation to some extent in central and eastern Inner Mongolia by enhancing water vapor transport. In winter, enhanced northerly winds, bringing more dry and cold air, lead to a reduction in precipitation and temperature over areas south of the Yellow River. CitationYu, Y., and Z.-H. Xie, 2013: A simulation study on climatic effects of land cover change in China. Adv. Clim. Change Res.,4(2), doi: 10.3724/SP.J.1248.2013.117.

Effect of land-cover change on the vegetation types and ecosystem services of the Tlokwe Municipal Area, North West Province

Effect of land-cover change on the vegetation types and ecosystem services of the Tlokwe Municipal Area, North West Province

Dry season precipitation over the Mesoamerican Biological Corridor is more sensitive to deforestation than to greenhouse gas driven climate change

To prevent the loss of biodiversity in northern Central America, which is one of 34 global biodiversity hotspots, the Mesoamerican Biological Corridor, a network of protected parks and reserves has been proposed. While on-going deforestation to croplands and pastures outside the protected regions is likely to effect the dry season precipitation over the regenerated and extant forests in the proposed protected regions, global climate change driven precipitation changes may also be a significant factor, at least at some locations. This study compares the effects of land cover change to the effects of elevated greenhouse gas concentrations on precipitation in the proposed areas of the Mesoamerican Biological Corridor network. Using 5 consecutive dry season simulations of the effects of land cover change that included dry, wet and normal years, and using statistically downscaled global climate model (GCM) precipitation from the fourth assessment report (AR4), a larger expanse of the proposed protected regions was found more sensitive to precipitation decreases due to land cover changes. Two specific protected regions however stand out: the Maya Highlands and some areas of the Maya lowlands that were more sensitive to global climate change driven precipitation decreases. In these protected regions it is likely that irrespective of local policies the climate change signal would dominate.

Climate responses to historical land cover changes

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 56:147-155 (2013) - DOI: https://doi.org/10.3354/cr01150 Climate responses to historical land cover changes Ye Wang1,2,*, Xiaodong Yan2,3 1College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China 2Key Laboratory of Regional Climate-Environment for East Asia, Chinese Academy of Sciences, Beijing 10029, PR China 3State Key Laboratory of Earth Surface Processes and Resource Ecology (ESPRE), College of Global Change and Earth System Science, Beijing Normal University, 19 Xinjiekouwai Street, Haidian District, Beijing 100875, PR China *Email: wytea@126.com ABSTRACT: This study assessed the biogeophysical effects of land cover change on climate using MPM-2 during the past millennium. Simulations based on the Climate and Environmental Retrieval and Archive (CERA) land cover dataset were carried out to equilibrium from AD 800 to 2000 after a spin-up time of 5300 yr. We concluded that there was a cooling biogeophysical effect of about 0.13°C in global mean annual temperature in response to historical deforestation, with a maximum cooling of 0.5°C over Eurasia and a minimum cooling of 0.02°C at low latitudes over the Southern Hemisphere. Much larger contrasts were found on a seasonal scale, while these changes were largely offset on an annual scale. Seasonally, cooling occurred in the middle northern latitudes and warming occurred in the low southern latitudes due to historical deforestation. The effect of land cover change was most pronounced over Eurasia, with a maximum cooling of approximately 0.8°C at middle latitudes during summer and a maximum warming of 0.1°C at low latitudes over the Southern Hemisphere during the Northern Hemisphere summer, owing to the changes in albedo and precipitation. These results suggest that changes in land cover triggered a chain of feedbacks in the climate system, and they highlight the need for further research in this area. KEY WORDS: Biogeophysical effects · Climate change · Land cover change · Earth system model at intermediate complexity · EMIC · Modeling Full text in pdf format PreviousNextCite this article as: Wang Y, Yan X (2013) Climate responses to historical land cover changes. Clim Res 56:147-155. https://doi.org/10.3354/cr01150 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 56, No. 2. Online publication date: March 26, 2013 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2013 Inter-Research.

Study of canopy transpiration based on a distributed hydrology model in a small karst watershed of southwest China

Understanding temporal and spatial distribution of canopy transpiration is indispensable in hydrology and hydroecology. Canopy transpiration in a karst basin is controlled by meteorological conditions, plant species, and water in soil and rock fractures. Estimation of canopy transpiration at catchment scale in such heterogeneously hydrogeological conditions is challenging. Hydrological modeling is a useful method to estimate canopy transpiration at catchment scale, and it can be used to evaluate the effect of land-cover change. In this study, a distributed hydrological model was used to estimate canopy transpiration within a small karst watershed for the period July 28, 2007, to October 19, 2007. The results show that transpiration was about 19.2 percent of total rainfall, and daily transpiration rate in this basin ranged from 0.01 to 3.4 mm/day with an average of 0.8 mm/day during the study period. Epikarst water is an important water source for canopy transpiration in addition to soil water in the karst basin. And land-cover change has important effects on canopy transpiration in this area.

Effects of Land Cover Changes on Soil Arthropod Community in Horqin Sand Land, China

The composition and diversity of soil macroarthropod communities in six types of land cover were studied during 2008 and 2009 in Horqin Sand Land, Inner Mongolia, to understand effects of land cover changes on soil macro-arthropod. The results showed that species richness, diversity and population density of the soil arthropods were the highest in the natural grasslands, followed by the fixed sand-lands and the plantations. Although the richness, diversity and population density were lower in the dry and irrigated farmlands, they were significantly higher than those in the moving sand dunes. Anthicidae were numerically dominant in natural grasslands, fixed sand dunes, plantations and irrigated farmlands, while Tenebrionidae were most common in the dry farmlands. There were no significantly dominant species in the moving sand dunes. The proportion of herbivore and omnivores was higher in fixed sand dunes compared with moving sand dunes, and likewise, the proportions of predators and omnivores were higher in irrigated farmlands compared with dry farmlands. In addition, the proportion of predators and omnivores were lower in plantations compared with fixed sand dunes or natural grasslands. The abundance and diversity of soil arthropods was most closely correlated with soil temperature, soil organic matter and total P content. 

Land-cover change effects on trophic interactions: Current knowledge and future challenges in research and conservation

Understanding the effects of land-cover alterations on ecosystem functioning has become a major challenge in ecological research during the last decade. This has stimulated a rapid growth in research investigating the links between land-cover change and biotic interactions, but to date no study has evaluated the progress towards achieving this scientific goal. With the aim of identifying gaps in current knowledge and challenging research areas for the future, we reviewed the scientific literature published during the last decade (1998–2010) investigating land-cover change effects on trophically-mediated biotic interactions. Our results reveal a disproportionate focus on particular trophic interactions and ecosystem types. Furthermore, in most cases, the measurement of trophic interactions is carried out neglecting the identity of the interacting species and the interrelation between the type of land-cover change effects. Finally, inappropriate temporal scales are applied to cope with spatiotemporal resource fluctuations for the interacting species. We suggest that the ongoing patterns and trends of research hamper efforts to achieve a truly comprehensive understanding of the effects of land-cover alterations on trophic interactions, and hence on ecosystem functioning in human-impacted landscapes. We therefore recommend alternative research trends and indicate gaps in current knowledge that need to be filled. Furthermore, we highlight that these biases could also limit the effectiveness of management actions aimed at ensuring the resilience and long-term conservation of natural habitats worldwide.

Effects of land cover change on temperature and rainfall extremes in multi-model ensemble simulations

Abstract. The impact of historical land use induced land cover change (LULCC) on regional-scale climate extremes is examined using four climate models within the Land Use and Climate, IDentification of robust impacts project. To assess those impacts, multiple indices based on daily maximum and minimum temperatures and daily precipitation were used. We contrast the impact of LULCC on extremes with the impact of an increase in atmospheric CO2 from 280 ppmv to 375 ppmv. In general, consistent changes in both high and low temperature extremes are similar to the simulated change in mean temperature caused by LULCC and are restricted to regions of intense modification. The impact of LULCC on both means and on most temperature extremes is statistically significant. While the magnitude of the LULCC-induced change in the extremes can be of similar magnitude to the response to the change in CO2, the impacts of LULCC are much more geographically isolated. For most models, the impacts of LULCC oppose the impact of the increase in CO2 except for one model where the CO2-caused changes in the extremes are amplified. While we find some evidence that individual models respond consistently to LULCC in the simulation of changes in rainfall and rainfall extremes, LULCC's role in affecting rainfall is much less clear and less commonly statistically significant, with the exception of a consistent impact over South East Asia. Since the simulated response of mean and extreme temperatures to LULCC is relatively large, we conclude that unless this forcing is included, we risk erroneous conclusions regarding the drivers of temperature changes over regions of intense LULCC.

Effects of urbanization on Song Sparrow (Melospiza melodia) population connectivity

Urbanization may affect genetic differentiation among animal populations because it converts native vegetation to novel land cover types that can affect population connectivity. The effect of land cover change on genetic differentiation may vary among taxa; mobile birds may be least affected. Regardless, genetic differentiation between populations should be best predicted by measures of distance that incorporate the effect of land cover on movement. We studied the relationship between land cover and genetic differentiation in Song Sparrows (Melospiza melodia) at eighteen sites in the Seattle metropolitan region. We generated a series of hypothetical “resistance surfaces” based on land cover and development age, calculated “resistance distances” between pairs of sampling sites, and related them to pairwise genetic differentiation. Genetic differentiation was best described by a multiple regression model where resistance to gene flow (1) linearly increased with age of development and (2) was greater in high- and medium-density urbanization than in native forest land cover types (R 2 = 0.15; p = 0.003). The single variable with the highest correlation with genetic differentiation was derived from a linear relationship between development age and resistance (R 2 = 0.08; p = 0.007). Our results thus suggested that urban development reduced population connectivity for Song Sparrows. However, the relation of development age to genetic differentiation suggested that equilibrium was not yet reached. Hence, the effects of lost connectivity will increase. Our understanding of the landscape genetics of this recently anthropogenically modified landscape benefited from considering population history.

Effect of land-cover change on Africa's burnt area

As Africa contributes some 64% of the global extent of area burnt annually, uncertainty concerning fire activity in the continent is an important issue. In this study, we quantify the effect of land-cover conversion from natural vegetation to agriculture on burnt area extent. This is based on the comparison of contemporary fire distribution in 189 protected areas where agricultural activity is largely absent with that occurring in the surrounding regions, where agriculture is practised. Results indicate a decrease in the total area burnt annually in Africa linked to the loss of natural vegetation communities due to expanding agricultural lands. Land-use change within the savanna vegetation units of Africa has led to a decrease in burnt area in the order of ~8×105hayear–1, which corresponds to 0.4% of the area currently burnt in Africa. The resulting decrease in the quantity of biomass burnt in any year would be between 3.4 and 9Tg, depending on the estimates of aboveground fuel biomass. Deforestation in the humid tropical forest domains may act as a small counterbalance to the trend of decreasing burnt area linked to land-use change in the short term.

Regional effects of vegetation restoration on water yield across the Loess Plateau, China

Abstract. The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability and hydrologic processes at the large scale. The objective of this study was to explore ways to examine the spatial and temporal effects of a large ecological restoration project on water yield across the Loess Plateau region in northern China. We estimated annual water yield as the difference between precipitation input and modelled actual evapotranspiration (ET) output. We constructed a monthly ET model using published ET data derived from eddy flux measurements and watershed streamflow data. We validated the ET models at a watershed and regional levels. The model was then applied to examine regional water yield under land cover change and climatic variability during the implementation of the Grain-for-Green (GFG) project during 1999–2007. We found that water yield in 38% of the Loess Plateau area might have decreased (1–48 mm per year) as a result of land cover change alone. However, combined with climatic variability, 37% of the study area might have seen a decrease in water yield with a range of 1–54 mm per year, and 35% of the study area might have seen an increase with a range of 1–10 mm per year. Across the study region, climate variability masked or strengthened the water yield response to vegetation restoration. The absolute annual water yield change due to vegetation restoration varied with precipitation regimes with the highest in wet years, but the relative water yield changes were most pronounced in dry years. We concluded that the effects of land cover change associated with ecological restoration varied greatly over time and space and were strongly influenced by climatic variability in the arid region. The current regional vegetation restoration projects have variable effects on local water resources across the region. Land management planning must consider the influences of spatial climate variability and long-term climate change on water yield to be more effective for achieving environmental sustainability.

Physically Based, Hydrologic Model Results Based on Three Precipitation Products1

Abstract: The main objective of the study is to examine the accuracy of and differences among simulated streamflows driven by rainfall estimates from a network of 22 rain gauges spread over a 2,170 km2 watershed, NEXRAD Stage III radar data, and Tropical Rainfall Measuring Mission (TRMM) 3B42 satellite data. The Gridded Surface Subsurface Hydrologic Analysis (GSSHA), a physically based, distributed parameter, grid‐structured, hydrologic model, was used to simulate the June‐2002 flooding event in the Upper Guadalupe River watershed in south central Texas. There were significant differences between the rainfall fields estimated by the three types of measurement technologies. These differences resulted in even larger differences in the simulated hydrologic response of the watershed. In general, simulations driven by radar rainfall yielded better results than those driven by satellite or rain‐gauge estimates. This study also presents an overview of effects of land cover changes on runoff and stream discharge. The results demonstrate that, for major rainfall events similar to the 2002 event, the effect of urbanization on the watershed in the past two decades would not have made any significant effect on the hydrologic response. The effect of urbanization on the hydrologic response increases as the size of the rainfall event decreases.

Differences in throughfall and net precipitation between soybean and transitional tropical forest in the southern Amazon, Brazil

The expansion of soybean cultivation into the Amazon in Brazil has potential hydrological effects at local to regional scales. To determine the impacts of soybean agriculture on hydrology, a comparison of net precipitation (throughfall, stemflow) in undisturbed tropical forest and soybean fields on the southern edge of the Amazon Basin in the state of Mato Grosso is needed. This study measured throughfall with troughs and stemflow with collar collectors during two rainy seasons. The results showed that in forest 91.6% of rainfall was collected as throughfall and 0.3% as stemflow, while in soybean fields with two-month old plants, 46.2% of rainfall was collected as throughfall and 9.0% as stemflow. Hence, interception of precipitation in soybean fields was far greater than in intact forests. Differences in throughfall, stemflow and net precipitation were found to be mainly associated with differences in plant structure and stem density in transitional forest and soybean cropland. Because rainfall interception in soybean fields is higher than previously believed and because both the area of cropland and the frequency of crop cycles (double cropping) are increasing rapidly, interception needs to be reconsidered in regional water balance models when consequences of land cover changes are analyzed in the Amazon soybean frontier region. Based on the continued expansion of soybean fields across the landscape and the finding that net precipitation is lower in soy agriculture, a reduction in water availability in the long term can be assumed.