scholarly journals Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land-use/land-cover

2014 ◽  
Vol 11 (5) ◽  
pp. 5037-5075 ◽  
Author(s):  
A. T. Woldemichael ◽  
F. Hossain ◽  
R. Pielke
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Energy Budget ◽  
Convective Available Potential Energy ◽  
Atmospheric Modeling ◽  
Precipitation Event ◽  
Land Use Land Cover ◽  
River Watershed ◽  
Precipitation Patterns ◽  
Lulc Changes

Abstract. This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land–atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget which, in turn, change regional convergence and precipitation patterns? and (2) how extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River Watershed (ARW) located in California and the Owyhee River Watershed (ORW) located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are: (1) the control scenario representing the contemporary land-use, (2) the pre-dam scenario representing the natural landscape before the construction of the dams and (3) the non-irrigation scenario representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land–atmosphere processes due to LULC changes, with the control–non-irrigation scenario creating more change than the control–pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase in dewpoint (up to 0.25 °C) was observed, (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m−2) that increased the amount of water vapor to the atmosphere and resulted in a larger convective available potential energy (CAPE), (3) low level wind flow variation was found to be responsible for pressure gradients that affected localized circulations, moisture advection and convergence. At some locations, an increase in wind speed up to 1.6 m s−1 maximum was observed, (4) there were also areas of well developed vertical motions responsible for moisture transport from the surface to higher altitudes that enhanced precipitation patterns in the study regions.

scholarly journals Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land use/land cover

2014 ◽  
Vol 18 (9) ◽  
pp. 3711-3732 ◽  
Author(s):  
A. T. Woldemichael ◽  
F. Hossain ◽  
R. Pielke Sr.
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Energy Budget ◽  
Atmospheric Modeling ◽  
Dew Point ◽  
Precipitation Event ◽  
Land Use Land Cover ◽  
River Watershed ◽  
Precipitation Patterns ◽  
Lulc Changes

Abstract. This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land–atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget, which, in turn, change regional convergence and precipitation patterns? (2) How extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River watershed (ARW), located in California, and the Owyhee River watershed (ORW), located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are (1) the "control" scenario, representing the contemporary land use, (2) the "pre-dam" scenario, representing the natural landscape before the construction of the dams and (3) the "non-irrigation" scenario, representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land–atmosphere processes due to LULC changes, with the control–non-irrigation scenario creating more change than the control–pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase at dew point (up to 0.25 °C) was observed; (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m−2) that increased the amount of water vapor in the atmosphere and resulted in a larger convective available potential energy (CAPE); (3) low-level wind-flow variation was found to be responsible for pressure gradients that affected localized circulations, moisture advection and convergence. At some locations, an increase in wind speed up to 1.6 m s−1 maximum was observed; (4) there were also areas of well-developed vertical motions responsible for moisture transport from the surface to higher altitudes that enhanced precipitation patterns in the study regions.

scholarly journals Effects of Climate and Land Use/Land Cover Changes on Water Yield Services in the Dongjiang Lake Basin

2021 ◽  
Vol 10 (7) ◽  
pp. 466
Author(s):  
Wenbo Mo ◽  
Yunlin Zhao ◽  
Nan Yang ◽  
Zhenggang Xu ◽  
Weiping Zhao ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Water Resource Management ◽  
Water Source ◽  
Water Yield ◽  
Lake Basin ◽  
Lake Area ◽  
Land Use Land Cover ◽  
Lulc Changes ◽  
Regional Water

Spatial and quantitative assessments of water yield services in watershed ecosystems are necessary for water resource management and improved water ecological protection. In this study, we used the InVEST model to estimate regional water yield in the Dongjiang Lake Basin in China. Moreover, we designed six scenarios to explore the impacts of climate and land use/land cover (LULC) changes on regional water yield and quantitatively determined the dominant mechanisms of water yield services. The results are expected to provide an important theoretical reference for future spatial planning and improvements of ecological service functions at the water source site. We found that (1) under the time series analysis, the water yield changes of the Dongjiang Lake Basin showed an initial decrease followed by an increase. Spatially, water yield also decreased from the lake area to the surrounding region. (2) Climate change exerted a more significant impact on water yield changes, contributing more than 98.26% to the water yield variability in the basin. In contrast, LULC had a much smaller influence, contributing only 1.74 %. (3) The spatial distribution pattern of water yield services in the watershed was more vulnerable to LULC changes. In particular, the expansion of built-up land is expected to increase the depth of regional water yield and alter its distribution, but it also increases the risk of waterlogging. Therefore, future development in the basin must consider the protection of ecological spaces and maintain the stability of the regional water yield function.

scholarly journals Geospatial analysis of wetlands based on land use/land cover dynamics using remote sensing and GIS in Sindh, Pakistan

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Hamza Islam ◽  
Habibuulah Abbasi ◽  
Ahmed Karam ◽  
Ali Hassan Chughtai ◽  
Mansoor Ahmed Jiskani
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Vegetation Cover ◽  
Vegetation Index ◽  
Kappa Statistics ◽  
Natural Ecosystem ◽  
Land Use Land Cover ◽  
Dry Land ◽  
Lulc Changes ◽  
Manchar Lake

In this study, the Land Use/Land Cover (LULC) change has been observed in wetlands comprises of Manchar Lake, Keenjhar Lake, and Chotiari Reservoir in Pakistan over the last four decades from 1972 to 2020. Each wetland has been categorized into four LULC classes; water, natural vegetation, agriculture land, and dry land. Multitemporal Landsat satellite data including; Multi-Spectral Scanner (MSS), Thematic Mapper (TM), and Operational Land Imager (OLI) images were used for LULC changes evaluation. The Supervised Maximum-likelihood classifier method is used to acquire satellite imagery for detecting the LULC changes during the whole study period. Soil adjusted vegetation index technique (SAVI) was also used to reduce the effects of soil brightness values for estimating the actual vegetation cover of each study site. Results have shown the significant impact of human activities on freshwater resources by changing the natural ecosystem of wetlands. Change detection analysis showed that the impacts on the land cover affect the landscape of the study area by about 40% from 1972 to 2020. The vegetation cover of Manchar Lake and Keenjhar Lake has been decreased by 6,337.17 and 558.18 ha, respectively. SAVI analysis showed that soil profile is continuously degrading which vigorously affects vegetation cover within the study area. The overall classification accuracy and Kappa statistics showed an accuracy of >90% for all LULC mapping studies. This work demonstrates the LULC changes as a critical monitoring basis for ongoing analyses of changes in land management to enable decision-makers to establish strategies for effectively using land resources.

scholarly journals Impacts of Aerosol Particle Size Distribution and Land Cover Land Use on Precipitation in a Coastal Urban Environment Using a Cloud-Resolving Mesoscale Model

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Nathan Hosannah ◽  
Jorge E. Gonzalez
Keyword(s):  
Land Use ◽  
Particle Size ◽  
Land Cover ◽  
Aerosol Particle ◽  
Mesoscale Model ◽  
Cloud Condensation Nuclei ◽  
Atmospheric Modeling ◽  
Urban Environments ◽  
Precipitation Event ◽  
Aerosol Particle Size

Urban environments influence precipitation formation via response to dynamic effects, while aerosols are intrinsically necessary for rainfall formation; however, the partial contributions of each on urban coastal precipitation are not yet known. Here, the authors use aerosol particle size distributions derived from the NASA aerosol robotic network (AERONET) to estimate submicron cloud condensation nuclei (CCN) and supermicron CCN (GCCN) for ingestion in the regional atmospheric modeling system (RAMS). High resolution land data from the National Land Cover Database (NLCD) were assimilated into RAMS to provide modern land cover and land use (LCLU). The first two of eight total simulations were month long runs for July 2007, one with constant PSD values and the second with AERONET PSDs updated at times consistent with observations. The third and fourth runs mirrored the first two simulations for “No City” LCLU. Four more runs addressed a one-day precipitation event under City and No City LCLU, and two different PSD conditions. Results suggest that LCLU provides the dominant forcing for urban precipitation, affecting precipitation rates, rainfall amounts, and spatial precipitation patterns. PSD then acts to modify cloud physics. Also, precipitation forecasting was significantly improved under observed PSD and current LCLU conditions.

scholarly journals Relationship between design floods and land use land cover (LULC) changes in a tropical complex catchment

2018 ◽  
Vol 11 (14) ◽  
Author(s):  
Jabir Haruna Abdulkareem ◽  
Wan Nor Azmin Sulaiman ◽  
Biswajeet Pradhan ◽  
Nor Rohaizah Jamil
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Use Land Cover ◽  
Lulc Changes ◽  
Design Floods

scholarly journals An Analysis of Urban Land Use/Land Cover Changes in Blantyre City, Southern Malawi (1994–2018)

2020 ◽  
Vol 12 (6) ◽  
pp. 2377 ◽  
Author(s):  
John Mawenda ◽  
Teiji Watanabe ◽  
Ram Avtar
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Urban Land ◽  
Urban Land Use ◽  
Sustainable Growth ◽  
Sub Saharan Africa ◽  
Support Vector ◽  
Land Use Land Cover ◽  
Lulc Changes ◽  
Bare Land

Rapid and unplanned urban growth has adverse environmental and social consequences. This is prominent in sub-Saharan Africa where the urbanisation rate is high and characterised by the proliferation of informal settlements. It is, therefore, crucial that urban land use/land cover (LULC) changes be investigated in order to enhance effective planning and sustainable growth. In this paper, the spatial and temporal LULC changes in Blantyre city were studied using the integration of remotely sensed Landsat imageries of 1994, 2007 and 2018, and a geographic information system (GIS). The supervised classification method using the support vector machine algorithm was applied to generate the LULC maps. The study also analysed the transition matrices derived from the classified map to identify prominent processes of changes for planning prioritisation. The results showed that the built-up class, which included urban structures such as residential, industrial, commercial and public installations, increased in the 24-year study period. On the contrary, bare land, which included vacant lands, open spaces with little or no vegetation, hilly clear-cut areas and other fallow land, declined over the study period. This was also the case with the vegetation class (i.e., forests, parks, permanent tree-covered areas and shrubs). The post-classification results revealed that the LULC changes during the second period (2007–2018) were faster compared to the first period (1994–2007). Furthermore, the results revealed that the increase in built-up areas systematically targeted the bare land and avoided the vegetated areas, and that the vegetated areas were systematically cleared to bare land during the study period (1994–2018). The findings of this study have revealed the pressure of human activities on the land and natural environment in Blantyre and provided the basis for sustainable urban planning and development in Blantyre city.

Impacts of Postdam Land Use/Land Cover Changes on Modification of Extreme Precipitation in Contrasting Hydroclimate and Terrain Features

2014 ◽  
Vol 15 (2) ◽  
pp. 777-800 ◽  
Author(s):  
Abel T. Woldemichael ◽  
Faisal Hossain ◽  
Roger Pielke
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Extreme Precipitation ◽  
Windward Side ◽  
Leeward Side ◽  
Land Use Land Cover ◽  
Climate Feedbacks ◽  
River Watershed ◽  
Flat Terrain ◽  
Terrain Features

Abstract Understanding the impact of postdam climate feedbacks, resulting from land use/land cover (LULC) variability, on modification of extreme precipitation (EP) remains a challenge for a twenty-first-century approach to dam design and operation. In this study, the Regional Atmospheric Modeling System (RAMS, version 6.0) was used, involving a number of predefined LULC scenarios to address the important question regarding dams and their impoundments: How sensitive are the hydroclimatology and terrain features of a region in modulating the postdam response of climate feedbacks to EP? The study region covered the Owyhee Dam/Reservoir on the Owyhee River watershed (ORW), located in eastern Oregon. A systematic perturbation of the relative humidity in the initial and boundary condition of the model was carried out to simulate EP. Among the different LULC scenarios used in the simulation over the ORW, irrigation expansion in the postdam era resulted in an increase in EP up to 6% in the 72-h precipitation total. The contribution of the reservoir on EP added 8% to the 72-h total when compared to the predam LULC conditions. To address the science question, a previously completed investigation on the Folsom Dam [American River watershed (ARW)] in California was compared with the ORW findings on the basis of contrasting differences in hydroclimatology and terrain features. The results indicate that the postdam LULC change scenarios impact EP of ORW (Owyhee Dam) much greater than the EP of the ARW (Folsom Dam) because of its semiarid climate and flat terrain. EP was less sensitive to LULC changes on the windward side of the mountainous terrain of ARW as compared to the leeward side of the flat terrain of ORW.

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