The nitrate export in subtropical mountainous catchment: implication for land use change impact

Abstract. Agricultural activity is the dominant factor affecting water quality and nitrate export, which causes eutrophication and episodic acidification in downstream water bodies (e.g., reservoirs, lakes, and coastal zones). However, in subtropical mountainous areas such environmental impact due to the land use change was rarely documented. In this study, we investigated 16 sub-catchments during 2007 and 2008 in the Chi-Chia-Wan catchment where is the sole habitat for the endemic species, Formosan landlocked salmon (Oncorhynchus masou formosanus). The results revealed that the NO3-N concentration in pristine catchments varied from 0.144 to 0.151 mg/L without significant seasonal variation. This concentration was comparable with other forestry catchments around the world. However, the annual nitrate export was around 375.3–677.1 kg/km2/yr, much higher than other catchments due to the greater amount of rainfall. This is an important baseline for comparisons with other climate areas. As for the impact of agricultural activities, the catchments with some human disturbance, ~5.2% of the catchment area, might yield 5947.2 kg N/km2/yr – over 10-times higher than that of pristine catchment. Such high export caused by such a low level of disturbance might indicate that subtropical mountainous area is highly sensitive to agricultural activities. As for the land-use effect on nitrate yield, the forestry land might yield 488.5 ± 325.1 kg/km2/yr and the vegetable farm could yield 298 465.4 ± 3347.2 kg/km2/yr – 1000-times greater than the forestry. The estimated nitrate yields for land use classes were a crucial basis and useful for the land manager to assess the possible impacts (e.g., non-point source pollution evaluation and the recovery of land expropriation).

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Assessing the Effect of Land Use Change on Surface Runoff in a Rapidly Urbanized City: A Case Study of the Central Area of Beijing

Land ◽

10.3390/land9010017 ◽

2020 ◽

Vol 9 (1) ◽

pp. 17 ◽

Cited By ~ 7

Author(s):

Shanshan Hu ◽

Yunyun Fan ◽

Tao Zhang

Keyword(s):

Land Use ◽

Land Use Change ◽

Correlation Analysis ◽

Surface Runoff ◽

Flood Control ◽

Central Area ◽

Dominant Factor ◽

Landsat Images ◽

Rapid Urbanization ◽

The Impact

The change in land use during the process of urbanization affects surface runoff and increases flood risk in big cities. This study investigated the impact of land use change on surface runoff in Beijing’s central area during the period of rapid urbanization from 1984 to 2019. Land use maps of 1984, 1999, 2009, and 2019 were generated by image classification of Landsat images. Surface runoffs were calculated with the Soil Conservation Service curve number (SCS-CN) model. Correlation analysis was used to identify the dominant factor of land use change affecting surface runoff. The result showed that the variation trend of surface runoff was consistent with the trend of impervious land in Beijing’s central area, which increased during 1984~2009 and decreased during 2009~2019. Correlation analysis showed that changes in surface runoff were most strongly correlated with changes in impervious surfaces when compared with the correlation of runoff with other types of land use. The results of this study may provide a reference for city flood control and urban planning in fast growing cities worldwide, especially in developing countries.

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The impact of historical land use change from 1850 to 2000 on secondary particulate matter and ozone

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-14997-2016 ◽

2016 ◽

Vol 16 (23) ◽

pp. 14997-15010 ◽

Cited By ~ 15

Author(s):

Colette L. Heald ◽

Jeffrey A. Geddes

Keyword(s):

Land Use ◽

Particulate Matter ◽

Air Quality ◽

Land Use Change ◽

Tropospheric Ozone ◽

Surface Ozone ◽

Deposition Velocity ◽

Agricultural Activity ◽

The Impact ◽

Global Mean

Abstract. Anthropogenic land use change (LUC) since preindustrial (1850) has altered the vegetation distribution and density around the world. We use a global model (GEOS-Chem) to assess the attendant changes in surface air quality and the direct radiative forcing (DRF). We focus our analysis on secondary particulate matter and tropospheric ozone formation. The general trend of expansion of managed ecosystems (croplands and pasturelands) at the expense of natural ecosystems has led to an 11 % decline in global mean biogenic volatile organic compound emissions. Concomitant growth in agricultural activity has more than doubled ammonia emissions and increased emissions of nitrogen oxides from soils by more than 50 %. Conversion to croplands has also led to a widespread increase in ozone dry deposition velocity. Together these changes in biosphere–atmosphere exchange have led to a 14 % global mean increase in biogenic secondary organic aerosol (BSOA) surface concentrations, a doubling of surface aerosol nitrate concentrations, and local changes in surface ozone of up to 8.5 ppb. We assess a global mean LUC-DRF of +0.017, −0.071, and −0.01 W m−2 for BSOA, nitrate, and tropospheric ozone, respectively. We conclude that the DRF and the perturbations in surface air quality associated with LUC (and the associated changes in agricultural emissions) are substantial and should be considered alongside changes in anthropogenic emissions and climate feedbacks in chemistry–climate studies.

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Effects of climate change and human activities on runoff in the Nenjiang River Basin, Northeast China

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-9-11521-2012 ◽

2012 ◽

Vol 9 (10) ◽

pp. 11521-11549 ◽

Cited By ~ 15

Author(s):

L. Q. Dong ◽

G. X. Zhang ◽

Y. J. Xu

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

River Basin ◽

Human Activities ◽

Northeast China ◽

Dominant Factor ◽

Runoff Reduction ◽

Nenjiang River Basin ◽

The Impact

Abstract. The Nenjiang River Basin (NRB) is an important grain-production region with abundant wetlands in Northeast China. Climate change and anthropogenic activities have dramatically altered the spatial and temporal distribution of regional stream discharge and water resources, which poses a serious threat to wetland ecosystems and sustainable agriculture. In this study, we analyzed 55-yr (1956–2010) rainfall and runoff patterns in the river basin to quantitatively evaluate the impact of human activities on regional hydrology. The long-term hydrologic series were divided into two periods: period I (1956–1974), during which minimum land use change occurred, and period II (1975–2010), during which land use change intensified. Kendall's rank correlation test, non-parametric Pettitt test and precipitation-runoff double cumulative curve (DCC) methods were utilized to identify the trends and thresholds of the annual runoff in the upstream, midstream, and downstream basin areas. Our results showed that the runoff in the NRB has continuously declined in the past 55 yr, and that the effects of climate change and human activities on the runoff reduction varied in the upstream, midstream and downstream area over different time scales. For the entire study period, climate change has been the dominant factor, accounting for 69.6–80.3% of the reduction in the total basin runoff. However, the impact of human activities has been increasing from 19.7% during the 1950s–1970s to 30.4% in the present time. Spatially, the runoff reduction became higher from the upstream to the downstream areas, revealing an increasing threat of water availability to the large wetland ecosystem in the lower river basin. Furthermore, the sustainable development of irrigated agriculture in the NRB will be a threat to the survival of the wetlands.

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The Impact of Historical Land Use Change From 1850 to 2000 on Particulate Matter and Ozone

10.5194/acp-2016-793 ◽

2016 ◽

Author(s):

Colette L. Heald ◽

Jeffrey A. Geddes

Keyword(s):

Land Use ◽

Particulate Matter ◽

Air Quality ◽

Land Use Change ◽

Tropospheric Ozone ◽

Surface Ozone ◽

Deposition Velocity ◽

Agricultural Activity ◽

The Impact ◽

Global Mean

Abstract. Anthropogenic land use change (LUC) since pre-industrial (1850) has altered the vegetation distribution and density around the world. We use a global model (GEOS-Chem) to assess the attendant changes in surface air quality and the direct radiative forcing (DRF). We focus our analysis on secondary particulate matter and tropospheric ozone formation. The general trend of expansion of managed ecosystems (croplands and pasturelands) at the expense of natural ecosystems has led to an 11 % decline in global mean biogenic volatile organic compound emissions. Concomitant growth in agricultural activity has more than doubled ammonia emissions and increased emissions of nitrogen oxides from soils by more than 50 %. Conversion to croplands has also led to a widespread increase in ozone dry deposition velocity. Together these changes in biosphere-atmosphere exchange have led to a 14 % global mean increase in biogenic secondary organic aerosol (BSOA) surface concentrations, a doubling of surface aerosol nitrate concentrations, and local changes in surface ozone of up to 8.5 ppb. We assess a global mean LUC-DRF of +0.017 Wm−2, −0.071 Wm−2, and −0.01 Wm−2 for BSOA, nitrate, and tropospheric ozone, respectively. We conclude that the DRF and the perturbations in surface air quality associated with LUC are substantial and should be considered alongside changes in anthropogenic emissions and climate feedbacks in chemistry-climate studies.

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Assessment of land-use change in coastal areas through geographical information systems

RECUBRIMIENTO COMESTIBLE CON BASE DE PIÑON MEXICANO (Jatropha curcas) SOBRE LA CALIDAD DE CHAYOTE MINIMAMENTE PROCESADO ◽

10.32854/agrop.v13i10.1872 ◽

2020 ◽

Vol 13 (10) ◽

Author(s):

Verónica Lango-Reynoso ◽

Karla Teresa González-Figueroa ◽

Fabiola Lango-Reynoso ◽

María del Refugio Castañeda-Chávez ◽

Jesús Montoya-Mendoza

Keyword(s):

Land Use ◽

Land Use Change ◽

Geographical Information Systems ◽

Design Methodology ◽

Scientific Information ◽

Coastal Ecosystems ◽

Coastal Areas ◽

Geographical Information ◽

Coastal Zones ◽

Computer Based

Objective: This article describes and analyzes the main concepts of coastal ecosystems, these as a result of research concerning land-use change assessments in coastal areas. Design/Methodology/Approach: Scientific articles were searched using keywords in English and Spanish. Articles regarding land-use change assessment in coastal areas were selected, discarding those that although being on coastal zones and geographic and soil identification did not use Geographic Information System (GIS). Results: A GIS is a computer-based tool for evaluating the land-use change in coastal areas by quantifying variations. It is analyzed through GIS and its contributions; highlighting its importance and constant monitoring. Limitations of the study/Implications: This research analyzes national and international scientific information, published from 2007 to 2019, regarding the land-use change in coastal areas quantified with the digital GIS tool. Findings/Conclusions: GIS are useful tools in the identification and quantitative evaluation of changes in land-use in coastal ecosystems; which require constant evaluation due to their high dynamism.

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Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

Regional Environmental Change ◽

10.1007/s10113-021-01799-7 ◽

2021 ◽

Vol 21 (3) ◽

Author(s):

Susanne Rolinski ◽

Alexander V. Prishchepov ◽

Georg Guggenberger ◽

Norbert Bischoff ◽

Irina Kurganova ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Organic Carbon ◽

Land Use Change ◽

Soil Organic Carbon ◽

Arable Land ◽

Future Climate ◽

Future Climate Change ◽

Climate Scenarios ◽

The Impact

AbstractChanges in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

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