Effects of climate and land use changes on water quantity and quality of coastal watersheds of Narragansett Bay

2021 ◽  
pp. 151082
Author(s):  
Evan R. Ross ◽  
Timothy O. Randhir
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Narragansett Bay ◽  
Water Quantity ◽  
Coastal Watersheds ◽  
Water Quantity And Quality

Influences of land use changes on the dynamics of water quantity and quality in the German lowland catchment of the Stör

2021 ◽  
Author(s):  
Chaogui Lei ◽  
Paul Wagner ◽  
Nicola Fohrer
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Arable Land ◽  
Hydrologic Model ◽  
Water Quantity ◽  
Water Yield ◽  
Near Surface ◽  
Daily Streamflow ◽  
Land Use Types ◽  
Water Quantity And Quality

<p>Understanding the impacts of land use changes (LUCC) on the dynamics of water quantity and quality is necessary to identify suitable mitigation measures that are needed for sustainable watershed management. Lowland catchments are characterized by a strong interaction of streamflow and near-surface groundwater that intensifies the risk of nutrient pollution. In this study, a hydrologic model (Soil and Water Assessment Tool, SWAT) and partial least squares regression (PLSR) were used to quantify the impacts of different land use types on the variations in actual evapotranspiration (ET), surface runoff (SQ), base flow (BF), and water yield (WYLD) as well as on sediment (SED), total phosphorus (TP), and total nitrogen (TN). To this end, the model was calibrated and validated with daily streamflow data (30 years) and daily sediment and nutrient data from measurement campaigns (3 years in total). Three model runs over thirty years were performed using the different land use maps of 1987, 2010, and 2019, respectively. Land use changes between those years were used to explain the modelled changes in water quantity and quality on the subbasin scale applying PLSR. SWAT achieved a good performance for streamflow (calibration: NSE=0.8, PBIAS=5.5%; validation: NSE=0.78, PBIAS=5.1%) and for TN (calibration: NSE=0.65, PBIAS= -11.3%; validation: NSE=0.87, PBIAS=2.7%) and an acceptable performance for sediment and TP (calibration: NSE=0.49-0.53, PBIAS=25.8% -29.7%; validation: 0.51-0.7, PBIAS= -23.9% - -8.7%) in Stör catchment. The variations in ET, SQ, BF, WYLD, SED, TP, and TN could be explained to an extent of 67%-88% by changes in the area, shape, dominance, and aggregation of individual land use types. They were largely correlated with the major LUCC in the study area i.e. a decrease of arable land, and a respective increase of pasture and settlement. The change in the percentage of arable land affected the dynamics of SED, TP, TN and BF, indicated by a Variable Influence on Projection (VIP) > 1.2 and largest absolute regression coefficients (RCs: 0.45-0.72 for SED, TP, TN; -0.84 for BF). The change in pasture area affected ET, SED, TP, and TN, as indicated by VIPs >1.  The change in settlement percentage had VIP up to 1.62 for SQ and was positively and significantly influenced it (RC: 1.28). PLSR helped to identify the key contributions from individual land use changes on water quantity and quality dynamics. These provide a quantitative basis for targeting most influential land use changes to mitigate impacts on water quality in the future.</p>

scholarly journals Influences of land use changes on the dynamics of water quantity and quality in the German lowland catchment of the Stör

2021 ◽  
Author(s):  
Chaogui Lei ◽  
Paul D. Wagner ◽  
Nicola Fohrer
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Changes ◽  
Arable Land ◽  
Hydrologic Model ◽  
Water Quantity ◽  
Near Surface ◽  
Daily Streamflow ◽  
Land Use Types ◽  
Water Quantity And Quality

Abstract. Understanding the impacts of land use changes (LUCC) on the dynamics of water quantity and quality is necessary to identify suitable mitigation measures that are needed for sustainable watershed management. Lowland catchments are characterized by a strong interaction of streamflow and near-surface groundwater that intensifies the risk of nutrient pollution. This study aims to reveal the relationship between long-term land use change and the water and nutrient balance in a typical lowland catchment in northern Germany. A hydrologic model (Soil and Water Assessment Tool, SWAT) and partial least squares regression (PLSR) were used to quantify the impacts of different land use types on the variations in actual evapotranspiration (ET), surface runoff (SQ), base flow (BF), and water yield (WYLD) as well as on sediment yield (SED), total phosphorus (TP) and total nitrogen (TN) loads. To this end, the model was calibrated and validated with daily streamflow data (30 years) as well as sediment and nutrient data from two water quality measurement campaigns (3 years in total). Three model runs over thirty years were performed using land use maps of 1987, 2010, and 2019, respectively. Land use changes between those years were used to explain the modelled changes in water quantity and quality on the subbasin scale applying PLSR. SWAT achieved a very good performance for daily streamflow values (calibration: NSE = 0.79, KGE = 0.88, PBIAS = 0.3 %; validation: NSE = 0.79, KGE = 0.87, PBIAS = 7.2 %), a satisfactory to very good performance for daily TN (calibration: NSE = 0.64, KGE = 0.71, PBIAS = −11.5 %; validation: NSE = 0.86, KGE = 0.91, PBIAS = 5 %), a satisfactory performance for daily sediment load (NSE = 0.54–0.65, KGE = 0.58–0.59, PBIAS = −22.2 %–12 %), and an acceptable performance for daily TP (calibration: NSE = 0.56, KGE = 0.65, PBIAS = −4.7 %; validation: NSE = 0.29, KGE = 0.22, PBIAS = −46.2 %) in the Stör Catchment. The variations in ET, SQ, BF, WYLD, SED, TP, and TN could be explained to an extent of 61 %–88 % by changes in the area, shape, dominance, and aggregation of individual land use types. They were largely correlated with the major LUCC in the study area i.e. a decrease of arable land, and a respective increase of pasture and settlement. The change in the areal percentage of arable land positively affected the dynamics of SED, TP, TN and negatively affected BF, indicated by a Variable Influence on Projection (VIP) > 1.16 and large absolute regression coefficients (RCs: 0.6–0.88 for SED, TP, TN; −1.65 for BF). The change in pasture area was negatively affecting SED, TP, and TN (RCs: −0.69–−0.12, VIPs > 1) while positively affecting ET (RC: 0.09, VIP: 0.92). The change in settlement percentage had a VIP of up to 1.17 for SQ and positively and significantly influenced it (RC: 1.16, p-value < 0.001). PLSR helped to identify the key contributions from individual land use changes on water quantity and quality dynamics. These provide a quantitative basis for targeting most influential land use changes to mitigate impacts on water quality in the future.

scholarly journals Suitable Land-Use and Land-Cover Allocation Scenarios to Minimize Sediment and Nutrient Loads into Kwan Phayao, Upper Ing Watershed, Thailand

2021 ◽  
Vol 11 (21) ◽  
pp. 10430
Author(s):  
Jiraporn Kulsoontornrat ◽  
Suwit Ongsomwang
Keyword(s):  
Land Use ◽  
Ecosystem Service ◽  
Land Use Changes ◽  
Nutrient Export ◽  
Nutrient Loads ◽  
Landsat Images ◽  
Svm Algorithm ◽  
Crucial Information ◽  
S Model

Human activity and land-use changes have affected the water quality of Kwan Phayao, Upper Ing watershed, due to the associated high sediment load and eutrophication. This study aims to identify suitable LULC allocation scenarios for minimizing sediment and nutrient export into the lake. For this purpose, the LULC status and change were first assessed, based on classified LULC data in 2009 and 2019 from Landsat images, using the SVM algorithm. Later, the land requirements of three scenarios between 2020 and 2029 were estimated, based on their characteristics, and applied to predict LULC change using the CLUE-S model. Then, actual LULC data in 2019 and predicted LULC data under three scenarios between 2020 and 2029 were used to estimate sediment and nutrient export using the SDR and NDR models. Finally, the ecosystem service change index identified a suitable LULC allocation for minimizing sediment or/and nutrient export. According to the results, LULC status and change indicated perennial trees and orchards, para rubber, and rangeland increased, while forest land and paddy fields decreased. The land requirements of the three scenarios provided reasonable results, as expected, particularly Scenario II, which adopts linear programming to calculate the land requirements for maximizing ecosystem service values. For sediment and nutrient export estimation under the predicted LULC for the three scenarios, Scenario II led to the lowest yield of sediment and nutrient exports, and provided the lowest average ESCI value among the three scenarios. Thus, the LULC allocation under Scenario II was chosen as suitable for minimizing sediment or/and nutrient export into Kwan Phayao. These results can serve as crucial information to minimize sediment and nutrient loads for land-use planners, land managers, and decision makers.

scholarly journals What the past suggests about future development of ecosystem service values applicable to USDA agricultural program evaluations

2020 ◽  
Vol 49 (1) ◽  
pp. 7-22
Author(s):  
LeRoy T. Hansen
Keyword(s):  
Land Use ◽  
Spatial Resolution ◽  
Future Development ◽  
Ecosystem Service ◽  
Land Use Changes ◽  
Program Evaluations ◽  
The Past ◽  
Limited Applicability ◽  
Program Benefit

Much of the research on ecosystem service values (ESVs) has limited applicability to USDA program benefit analyses, largely because the models/data/results (1) lack spatial breadth and hence cannot be applied in national analyses of USDA programs, and (2) do not link land use changes to the changes in ESs. This article provides an overview of a set of 15 ESVs related to agriculture's impacts on erosion in order to identify (1) weaknesses in methods, data, and assumptions that limit the quality of the ESVs and means of avoiding such weaknesses in future ESV development, and (2) approaches that might improve the reliability and spatial resolution of future ESV estimates.

scholarly journals Assessment of impacts of agricultural and climate change scenarios on watershed water quantity and quality, and crop production

2016 ◽  
Author(s):  
Awoke D. Teshager ◽  
Philip W. Gassman ◽  
Justin T. Schoof ◽  
Silvia Secchi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Agricultural Land ◽  
Agricultural Landscapes ◽  
Water Quantity ◽  
Agricultural Land Use ◽  
Water Quantity And Quality

Abstract. Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental, and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists that describes the combined impacts of agricultural land use change and climate change on future bioenergy crop yields and watershed hydrology. In this study, the Soil and Water Assessment Tool (SWAT) eco-hydrological model was used to model the combined impacts of five agricultural land use change scenarios and three downscaled climate pathways (representative concentration pathways, RCPs) that were created from an ensemble of eight atmosphere-ocean general circulation models (AOGCMs). These scenarios were implemented in a well calibrated SWAT model for the Raccoon River watershed (RRW) located in western Iowa. The scenarios were executed for the historical baseline, early-century, mid-century, and late-century periods. The results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid and late 21st century.

scholarly journals Water Quantity and Quality of Six Lakes in the Arid Xinjiang Region, NW China

2014 ◽  
Vol 1 (2) ◽  
pp. 115-125 ◽  
Author(s):  
Jinglu Wu ◽  
Wen Liu ◽  
Haiao Zeng ◽  
Long Ma ◽  
Ruidong Bai
Keyword(s):  
Water Quantity ◽  
Nw China ◽  
Water Quantity And Quality

scholarly journals Assessment of Land-Use/Cover Changes and Its Ecological Effect in Rapidly Urbanized Areas—Taking Pearl River Delta Urban Agglomeration as a Case

2021 ◽  
Vol 13 (9) ◽  
pp. 5075
Author(s):  
Panpan Hu ◽  
Feng Li ◽  
Xiao Sun ◽  
Yali Liu ◽  
Xinchuang Chen ◽  
...  
Keyword(s):  
Land Use ◽  
Pearl River Delta ◽  
Land Use Changes ◽  
River Delta ◽  
Ecological Environment ◽  
Pearl River ◽  
Environment Quality ◽  
The Pearl River Delta ◽  
The Pearl River

Based on the land-use data of 2000 and 2015, this study makes a quantitative analysis of the ecological environment effect in Pearl River Delta using the ecological environment quality index and the ecological contribution rate of land-use change types. The results showed the following: (1) During 2000–2015, the land-use changes in Pearl River Delta mainly manifested in the reduction of cultivated land, forest land, water area, and unused land, while the area of construction land and grassland showed an increasing trend. The quality of ecological environment in the Pearl River Delta was largely stable but slightly declined overall; (2) Over the past 15 years, the comprehensive ecological environment index of the Pearl River Delta urban agglomeration has decreased by 0.02. With an average annual decrease of 0.11%. The spatial expansion caused by urbanization had the most profound impact on the decline of the ecological environment quality in the Pearl River Delta; (3) The eco-environmental quality indices of various cities in the Pearl River Delta declined to varying degrees. The city with the largest decline was Dongguan, followed by Shenzhen and Zhongshan. The spatial differentiation characteristics of the eco-environmental quality index indicate that the ecological quality preferences of cities distributed around the study area and close to the inland areas, while the ecological quality of the central coastal cities are biased. The quality of the ecological environment is related to the basis of the regional ecological environment. The research results have important practical significance for maintaining regional ecological balance and promoting the sustainable use of land resources, and they provide a reference for the study of the ecological and environmental effects of land-use changes in key cities in economically developed areas.

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