The Experts below are selected from a list of 3696 Experts worldwide ranked by ideXlab platform
Kerong Zhang - One of the best experts on this subject based on the ideXlab platform.
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forest restoration efforts drive changes in land use land cover and water related ecosystem services in china s han river basin
Ecological Engineering, 2019Co-Authors: Wenhua Qi, Hongran Li, Quanfa Zhang, Kerong ZhangAbstract:Abstract China began implementing the world’s most ambitious afforestation and forest conservation projects in 2000s. However, whether the forest restoration efforts facilitate forest recovery, and whether the changes in land-use/land-cover (LULC) driven by afforestation projects affect ecosystem services remains poorly understood. Here, we investigated the changes in LULC and water-related ecosystem services (i.e., water yield, water purification, and soil conservation) using the InVEST (Integrated Valuation of Environmental Service and Tradeoffs) model in China’s Han River basin, the water source region of the South-to-North Water Transfer Project (Middle Route). Our study indicated that forest restoration projects greatly facilitated conversion of shrublands and croplands into forests, which dominated the LULC change (LULCC) and subsequently improved the water purification and soil conservation services but slightly decreased water yield services during 2000–2010. By excluding the influence of climatic factors, we found that 4.79 × 108 m3 of water yield were reduced by LULCC, which equals to 0.69% of water yield in 2000. In contrast, the LULCC improved soil conservation services markedly and reduced 1.72 × 107 t sediment, i.e., 12.8% of sediment export in 2000. Meanwhile, 761.7 t nitrogen loading was cut down by the LULCC. The Danjiangkou Reservoir subwatershed, the water supply site for the water transfer project, showed a net decrease of 302 t nitrogen loading from 2000 to 2010. Although the nitrogen loading showed a decreasing trend in 40 out of 50 Subwatersheds during 2000–2010, ten Subwatersheds showed increasing trends, including the Ren River, Laoguan River, Bai River, Diao River, Youshui River, Tang River, Han River, Xushui River, Sanjia River, and Dan River. These regions should be taken as the priorities for ecosystem restoration and environmental management in the future.
Bryan C Pijanowski - One of the best experts on this subject based on the ideXlab platform.
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The Impact of Future Land Use Scenarios on Runoff Volumes in the Muskegon River Watershed
Environmental Management, 2010Co-Authors: Deepak K. Ray, Jonah M. Duckles, Bryan C PijanowskiAbstract:In this article we compared the response of surface water runoff to a storm event for different rates of urbanization, reforestation and riparian buffer setbacks across forty Subwatersheds of the Muskegon River Watershed located in Michigan, USA. We also made these comparisons for several forecasted and one historical land use scenarios (over 140 years). Future land use scenarios to 2040 for forest regrowth, urbanization rates and stream setbacks were developed using the Land Transformation Model (LTM). Historical land use information, from 1900 at 5-year time step intervals, was created using a Backcast land use change model configured using artificial neural network and driven by agriculture and housing census information. We show that (1) controlling the rate of development is the most effective policy option to reduce runoff; (2) establishing setbacks along the mainstem are not as effective as controlling urban growth; (3) reforestation can abate some of the runoff effects from urban growth but not all; (4) land use patterns of the 1970s produced the least amount of runoff in most cases in the Muskegon River Watershed when compared to land use maps from 1900 to 2040; and, (5) future land use patterns here not always lead to increased (worse) runoff than the past. We found that while ten of the Subwatersheds contained futures that were worse than any past land use configuration, twenty-five (62.5%) of the Subwatersheds produced the greatest amount of runoff in 1900, shortly after the entire watershed was clear-cut. One third (14/40) of the Subwatersheds contained the minimum amount of runoff in the 1960s and 1970s, a period when forest amounts were greatest and urban amounts relatively small.
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forecasting land use change and its environmental impact at a watershed scale
Journal of Environmental Management, 2005Co-Authors: Zhenxu Tang, Bernard A. Engel, Bryan C PijanowskiAbstract:Urban expansion is a major driving force altering local and regional hydrology and increasing non-point source (NPS) pollution. To explore these environmental consequences of urbanization, land use change was forecast, and long-term runoff and NPS pollution were assessed in the Muskegon River watershed, located on the eastern coast of Lake Michigan. A land use change model, LTM, and a web-based environmental impact model, L-THIA, were used in this study. The outcomes indicated the watershed would likely be subjected to impacts from urbanization on runoff and some types of NPS pollution. Urbanization will slightly or considerably increase runoff volume, depending on the development rate, slightly increase nutrient losses in runoff, but significantly increase losses of oil and grease and certain heavy metals in runoff. The spatial variation of urbanization and its impact were also evaluated at the subwatershed scale and showed Subwatersheds along the coast of the lake and close to cities would have runoff and nitrogen impact. The results of this study have significant implications for urban planning and decision making in an effort to protect and remediate water and habitat quality of Muskegon Lake, which is one of Lake Michigan's Areas of Concern (AOC), and the techniques described here can be used in other areas.
Hang Zhou - One of the best experts on this subject based on the ideXlab platform.
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Variable Streamflow Contributions in Nested Subwatersheds of a US Midwestern Urban Watershed
Water Resources Management, 2017Co-Authors: Liang Wei, Jason A. Hubbart, Hang ZhouAbstract:Quantification of runoff is critical to estimate and control water pollution in urban regions, but variation in impervious area and land-use type can complicate the quantification of runoff. We quantified the streamflow contributions of Subwatersheds and the historical changes in streamflow in a flood prone urbanizing watershed in US Midwest to guide the establishment of a future pollution-control plan. Streamflow data from five nested hydrological stations enabled accurate estimations of streamflow contribution from five Subwatersheds with variable impervious areas (from 0.5% to 26.6%). We corrected the impact of Missouri river backwatering at the most downstream station by comparing its streamflow with an upstream station using double-mass analysis combined with Bernaola-Galvan Heuristic Segmentation approach. We also compared the streamflow of the urbanizing watershed with seven surrounding rural watersheds to estimate the cumulative impact of urbanization on the streamflow regime. The two most urbanized Subwatersheds contributed >365 mm streamflow in 2012 with 657 mm precipitation, which was more than fourfold greater than the two least urbanized Subwatersheds. Runoff occurred almost exclusively over the most urbanized Subwatersheds during the dry period. The frequent floods occurred and the same amount of precipitation produced ~100 mm more streamflow in 2008–2014 than 1967–1980 in the urbanizing watershed; such phenomena did not occur in surrounding rural watersheds. Our approaches provide comprehensive information for planning on runoff control and pollutant reduction in urban watersheds.
Wenhua Qi - One of the best experts on this subject based on the ideXlab platform.
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forest restoration efforts drive changes in land use land cover and water related ecosystem services in china s han river basin
Ecological Engineering, 2019Co-Authors: Wenhua Qi, Hongran Li, Quanfa Zhang, Kerong ZhangAbstract:Abstract China began implementing the world’s most ambitious afforestation and forest conservation projects in 2000s. However, whether the forest restoration efforts facilitate forest recovery, and whether the changes in land-use/land-cover (LULC) driven by afforestation projects affect ecosystem services remains poorly understood. Here, we investigated the changes in LULC and water-related ecosystem services (i.e., water yield, water purification, and soil conservation) using the InVEST (Integrated Valuation of Environmental Service and Tradeoffs) model in China’s Han River basin, the water source region of the South-to-North Water Transfer Project (Middle Route). Our study indicated that forest restoration projects greatly facilitated conversion of shrublands and croplands into forests, which dominated the LULC change (LULCC) and subsequently improved the water purification and soil conservation services but slightly decreased water yield services during 2000–2010. By excluding the influence of climatic factors, we found that 4.79 × 108 m3 of water yield were reduced by LULCC, which equals to 0.69% of water yield in 2000. In contrast, the LULCC improved soil conservation services markedly and reduced 1.72 × 107 t sediment, i.e., 12.8% of sediment export in 2000. Meanwhile, 761.7 t nitrogen loading was cut down by the LULCC. The Danjiangkou Reservoir subwatershed, the water supply site for the water transfer project, showed a net decrease of 302 t nitrogen loading from 2000 to 2010. Although the nitrogen loading showed a decreasing trend in 40 out of 50 Subwatersheds during 2000–2010, ten Subwatersheds showed increasing trends, including the Ren River, Laoguan River, Bai River, Diao River, Youshui River, Tang River, Han River, Xushui River, Sanjia River, and Dan River. These regions should be taken as the priorities for ecosystem restoration and environmental management in the future.
Monica G Turner - One of the best experts on this subject based on the ideXlab platform.
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importance of landscape heterogeneity in sustaining hydrologic ecosystem services in an agricultural watershed
Ecosphere, 2015Co-Authors: Jiangxiao Qiu, Monica G TurnerAbstract:The sustainability of hydrologic ecosystem services (freshwater benefits to people generated by terrestrial ecosystems) is challenged by human modification of landscapes. However, the role of landscape heterogeneity in sustaining hydrologic services at scales relevant to landscape management decisions is poorly understood. In particular, the relative importance of landscape composition (type and proportion of land cover) and configuration (spatial arrangement of cover types) is unclear. We analyzed indicators of production of three hydrologic services (freshwater supply, surface and ground water quality) in 100 Subwatersheds in an urbanizing agricultural landscape (Yahara Watershed, Wisconsin, USA) and asked: (1) How do landscape composition and configuration affect supply of hydrologic services (i.e., does spatial pattern matter)? (2) Are there opportunities for small changes in landscape pattern to produce large gains in hydrologic services? Landscape composition and configuration both affected supply of hydrologic services, but composition was consistently more important than configuration for all three services. Together landscape composition and configuration explained more variation in indicators of surface-water quality than in freshwater supply or groundwater quality (Nagelkerke/adjusted R2: 86%, 64%, and 39%, respectively). Surface-water quality was negatively correlated with percent cropland and positively correlated with percent forest, grassland and wetland. In addition, surface-water quality was greater in Subwatersheds with higher wetland patch density, disaggregated forest patches and lower contagion. Surface-water quality responded nonlinearly to percent cropland and wetland, with greater water quality where cropland covered below 60% and/or wetland above 6% of the subwatershed. Freshwater supply was negatively correlated with percent wetland and urban cover, and positively correlated with urban edge density. Groundwater quality was negatively correlated with percent cropland and grassland, and configuration variables were unimportant. Collectively, our study suggests that altering spatial arrangement of land cover will not be sufficient to enhance hydrologic services in an agricultural landscape. Rather, the relative abundance of land cover may need to change to improve hydrologic services. Targeting Subwatersheds near the cropland or wetland thresholds may offer local opportunities to enhance surface-water quality with minimal land-cover change.
