scholarly journals Combining Global Remote Sensing Products with Hydrological Modeling to Measure the Impact of Tropical Forest Loss on Water-Based Ecosystem Services

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 413 ◽  
Author(s):  
Michael S. Netzer ◽  
Gabriel Sidman ◽  
Timothy R.H. Pearson ◽  
Sarah M. Walker ◽  
Raghavan Srinivasan
Keyword(s):  
Remote Sensing ◽  
Ecosystem Services ◽  
Point Source ◽  
Hydrological Modeling ◽  
Forest Loss ◽  
Point Source Pollution ◽  
Water Based ◽  
Spatial Datasets ◽  
The Impact ◽  
Non Point Source Pollution

In the Lower Mekong River Basin (LMB), deforestation rates are some of the highest in the world as land is converted primarily into intensive agriculture and plantations. While this has been a key for the region’s economic development, rural populations dependent on the freshwater water resources that support their fishing and agriculture industries are increasingly vulnerable to the impacts of flood, drought and non-point source pollution. Impacts of deforestation on ecosystem services (ES) including hydrological ES that control the availability and quality of fresh water across the landscape, regulating floods and droughts, soil erosion and non-point source pollution are known. Despite this understanding at the hillslope level, few studies have been able to quantify the impact of wide-scale deforestation on larger tropical watersheds. This study introduces a new methodology to quantify the impact of deforestation on water-based ES in the LMB with a focus on Cambodia by combining spatial datasets on forest loss from remote sensing and spatially-explicit hydrological modeling. Numerous global and regional remote sensing products are synthesized to develop detailed land use change maps for 2001 to 2013 for the LMB, which are then used as inputs into a hydrological model to develop unique spatial datasets that map ES changes due to deforestation across the LMB. The results point to a clear correlation between forest loss and surface runoff, with a weaker but upward trending relationship between forest loss and sediment yield. This resulted in increased river discharge for 17 of the 22 watersheds, and increased sediment for all 22 watersheds. While there is considerable variability between watersheds, these results could be helpful for prioritizing interventions to decrease deforestation by highlighting which areas have experienced the greatest change in water-based ES provision. These results are also presented in a web-based platform called the Watershed Ecosystem Service Tool.

INTEGRATING WATERSHED AND ECOSYSTEM SERVICE MODELS TO ASSESS BEST MANAGEMENT PRACTICE EFFICIENCY: GUIDELINES FOR LAKE ERIE MANAGERS AND WATERSHED MODELLERS

2020 ◽  
Author(s):  
Carlos Arnillas ◽  
Cindy Yang ◽  
Sophia A Zamaria ◽  
Alexey Neumann ◽  
Aisha Javed ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Point Source ◽  
Lake Erie ◽  
Environmental Data ◽  
Nutrient Cycles ◽  
Point Source Pollution ◽  
Best Management ◽  
Local Soil ◽  
The Impact ◽  
Non Point Source Pollution

Lake Erie is the shallowest and most biologically productive system of the Great Lakes, surrounded by large urban, industrial and agricultural areas. This combination prompted extensive efforts to promote Best Management Practices (BMPs) to mitigate non-point source pollution in Lake Erie’s watershed. Recent technical and conceptual advancements caution that significant variability exists in the BMP efficiency to reduce the severity of runoff and nutrient concentrations due to differences in implementation, the dependence of operational performance on local soil and climatic conditions, storm events and seasonality, and declining performance over time owing to imperfect maintenance. Given the uncertainty surrounding the design and efficiency of BMPs in abating non-point source pollution, our primary objective is to review the critical strengths and potential weaknesses of nine agricultural BMPs promoted for use in the Lake Erie watershed. We examine the capacity of the current generation of watershed process-based models to recreate possible BMP-mediated changes in the water and nutrient cycles. After reviewing modelling strategies (dynamic, external forcing, and empirical) to recreate non-linear watershed responses and feedback loops to BMP efficiency, our study recommends adopting dynamic representations of the interplay among key mechanisms, like soil moisture, water table, nutrient availability, plant uptake and subsequent growth. Notwithstanding the increased sophistication of complex mathematical models, their learning capacity is usually compromised by the coarse resolution of environmental data and limited empirical knowledge to accurately parameterize environmental properties and partially understood biogeochemical processes. In this context, we highlight the expression of the value of ecosystem services in monetary terms as a critical information piece when considering trade-offs among costly and diverse policy decisions. Consistent with the Integrated Watershed Management framework, we advocate the adoption of a rigorous mass-balance approach to assess the impact of BMPs on nutrient cycles, as well as the integration of the projected environmental improvements with terrestrial ecosystem services, beneficial use impairments, and aquatic ecosystem services. The proposed strategy has the potential to improve the decision-making process by identifying cost-effective management actions and balancing different goods and services provided by the agroecosystems at different time scales.

Using Arc GIS to explore the impact of environmental and ecological factors on water body

2021 ◽  
Vol 7 (6) ◽  
pp. 6247-6261
Author(s):  
Xiaoqing Liu ◽  
Juanfen Wang
Keyword(s):  
Water Quality ◽  
Numerical Model ◽  
Point Source ◽  
River Water ◽  
Ecological Factors ◽  
River Water Quality ◽  
Pollution Sources ◽  
Point Source Pollution ◽  
The Impact ◽  
Non Point Source Pollution

As water pollution is more and more serious, ArcGIS is proposed to explore the impact of environmental and ecological factors on water. Taking the river water quality as the research object, this paper simulates and analyzes the endogenous and non-point source pollution and water quality through indoor physical model experiment, hydrological and water quality numerical model and water quality numerical model, and analyzes the impact of different environmental changes on river water quality and pollution sources from micro and macro perspectives. The main contents include: experimental study on the influence mechanism of overlying water velocity, disturbance and water temperature on sediment endogenous release, construction and simulation of watershed non-point source pollution model, construction and simulation of watershed river water quality model, as well as the impact of environmental change on river water quality and quantitative analysis of river pollution sources.

scholarly journals Impacts of drought on the quality of surface water of the basin

2013 ◽  
Vol 10 (11) ◽  
pp. 14463-14493
Author(s):  
B. B. Huang ◽  
D. H. Yan ◽  
H. Wang ◽  
B. F. Cheng ◽  
X. H. Cui
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Point Source ◽  
Surface Water Quality ◽  
Point Sources ◽  
Point Source Pollution ◽  
Drought And Flood ◽  
The Impact ◽  
Non Point Source Pollution

Abstract. Under the background of climate change and human's activities, there has been presenting an increase both in the frequency of droughts and the range of their impacts. Droughts may give rise to a series of resources, environmental and ecological effects, i.e. water shortage, water quality deterioration as well as the decrease in the diversity of aquatic organisms. This paper, above all, identifies the impact mechanism of drought on the surface water quality of the basin, and then systematically studies the laws of generation, transfer, transformation and degradation of pollutants during the drought, finding out that the alternating droughts and floods stage is the critical period during which the surface water quality is affected. Secondly, through employing indoor orthogonality experiments, serving drought degree, rainfall intensity and rainfall duration as the main elements and designing various scenario models, the study inspects the effects of various factors on the nitrogen loss in soil as well as the loss of non-point sources pollution and the leaching rate of nitrogen under the different alternating scenarios of drought and flood. It comes to the conclusion that the various factors and the loss of non-point source pollution are positively correlated, and under the alternating scenarios of drought and flood, there is an exacerbation in the loss of ammonium nitrogen and nitrate nitrogen in soil, which generates the transfer and transformation mechanisms of non-point source pollution from a micro level. Finally, by employing the data of Nenjiang river basin, the paper assesses the impacts of drought on the surface water quality from a macro level.

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