Watershed Drought and Ecosystem Services: Spatiotemporal Characteristics and Gray Relational Analysis

This study explored the spatiotemporal characteristics of drought and ecosystem services (using soil conservation services as an example) in the YanHe Watershed, which is a typical water basin in the Loess Plateau of China, experiencing soil erosion. Herein, soil conservation was simulated using the Soil and Water Assessment Tool (SWAT), and the relationship between drought, soil conservation services, and meteorological, vegetation, and other factors since the implementation of the ‘Grain for Green’ Project (GFGP) in 1999, were analyzed using the gray relational analysis (GRA) method. The results showed that: (1) The vegetation cover of the Watershed has increased significantly, and evapotranspiration (ET) increased by 14.35 mm·a−1, thereby increasing water consumption by 8.997 × 108 m3·a−1 (compared to 2000). (2) Drought affected 63.86% of the watershed area, gradually worsening from south to north; it decreased in certain middle areas but increased in the humid areas on the southern edge. (3) The watershed soil conservation services, measured by the soil conservation modulus (SCM), increased steadily from 116.87 t·ha−1·a−1 in 2000 to 412.58 t·ha−1·a−1 in 2015, at a multi-year average of 235.69 t·ha−1·a−1, and indicated great spatial variations, with a large variation in the downstream and small variations in the upstream and midstream areas. (4) Integrating normalized difference vegetation index (NDVI) data into SWAT model improved the model simulation accuracy; during the calibration period, the coefficient of determination (R2) increased from 0.63 to 0.76 and Nash–Sutcliffe efficiency (NSE) from 0.46 to 0.51; and during the validation period, the R2 increased from 0.82 to 0.93 and the NSE from 0.57 to 0.61. (5) The GRA can be applied to gray control systems, such as the ecosystem; herein, vegetation cover and drought primarily affected ET and soil conservation services. The analysis results showed that vegetation restoration enhanced the soil conservation services, but increased ET and aggravated drought to a certain extent. This study analyzed the spatiotemporal variations in vegetation coverage and the response of ET to vegetation restoration in the YanHe Watershed, to verify the significant role of vegetation restoration in restraining soil erosion and evaluate the extent of water resource consumption due to ET in the semi-arid and semi-humid Loess-area basin during the GFGP period. Thus, this approach may effectively provide a scientific basis for evaluating the ecological effects of the GFGP and formulating policies to identify the impact of human ecological restoration on ecosystem services.

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Optimizing micro watershed management for soil erosion control under various slope gradient and vegetation cover conditions using SWAT modeling

10.5194/hess-2017-532 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ghulam Nabi ◽

Fiaz Hussain ◽

Ray-Shyan Wu ◽

Vinay Nangia ◽

Riffat Bibi ◽

...

Keyword(s):

Soil Erosion ◽

Watershed Management ◽

Sediment Yield ◽

Vegetation Cover ◽

Soil Conservation ◽

Swat Model ◽

Yield Reduction ◽

Slope Gradient ◽

Soil And Water ◽

Stone Structures

Abstract. This study evaluated parameters of soil erosion and optimization of micro watersheds by applying a semidistributed basin-scale Soil and Water Assessment Tool (SWAT) model in various small watersheds of the Chakwal and Attock districts of Pothwar, Pakistan. The model was calibrated and validated on a daily basis for a small catchment (Catchment-25) of the Dhrabi watershed without any soil conservation structures. Statistical measures (R2 and EN-S) were used to evaluate model performance; the model performed satisfactorily well for both surface runoff and sediment yield estimations, with the R2 and EN-S values both being greater than 0.75, during calibration (2009–2010) and validation (2011). The model was applied to various small watershed sites in the Chakwal and Attock districts after successful calibration and validation. Soil erosion estimation was performed at these sites having loose stone soil and water conservation structures and being under various slope gradient and vegetation cover conditions. The structures had significant effects, and the average sediment yield reduction engendered by the loose stone structures at the various sites varied from 54 to 98 %. The sediment yield and erosion reductions were also compared under conditions involving vegetation cover change. Agricultural land with winter wheat crops had a higher sediment yield level than did fallow land with crop residue, which facilitated sediment yield reduction along with the soil conservation structures. Analyzing various slope gradients revealed that all selected sites had a maximum slope area of less than 5 %; stone structures were installed at these sites to reduce sediment yield. Based on slope classification analysis, the model was upscaled for the whole districts of Chakwal and Attock. The results indicated that 60 % of Chakwal (4095 km2) and Attock (3918 km2) by area lies in a slope range of 0–4 %; this thus implies that considerable potential exists for implementing soil conservation measures by installing stone structures. Estimates revealed that minimum sediment yield reductions of 122,850 t year−1 in Chakwal District and 117,540 t year−1 in Attock District could be achieved by installing loose stone structures in 60 % of the agricultural areas of both districts having a slope of 0–4 %; these findings can serve as a reference for policymakers and planners. The overarching findings of this study show that the SWAT model provides reliable results for sediment yield and soil erosion estimation, which can be used in rocky mountainous watersheds for erosion control and watershed management.

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Analysing the Impact of Climate Change on Hydrological Ecosystem Services in Laguna del Sauce (Uruguay) Using the SWAT Model and Remote Sensing Data

Remote Sensing ◽

10.3390/rs13102014 ◽

2021 ◽

Vol 13 (10) ◽

pp. 2014

Author(s):

Celina Aznarez ◽

Patricia Jimeno-Sáez ◽

Adrián López-Ballesteros ◽

Juan Pablo Pacheco ◽

Javier Senent-Aparicio

Keyword(s):

Climate Change ◽

Remote Sensing ◽

Ecosystem Services ◽

Water Resources ◽

Swat Model ◽

Remote Sensing Data ◽

Erosion Control ◽

Sensing Data ◽

Extreme Precipitation Events ◽

The Impact

Assessing how climate change will affect hydrological ecosystem services (HES) provision is necessary for long-term planning and requires local comprehensive climate information. In this study, we used SWAT to evaluate the impacts on four HES, natural hazard protection, erosion control regulation and water supply and flow regulation for the Laguna del Sauce catchment in Uruguay. We used downscaled CMIP-5 global climate models for Representative Concentration Pathways (RCP) 2.6, 4.5 and 8.5 projections. We calibrated and validated our SWAT model for the periods 2005–2009 and 2010–2013 based on remote sensed ET data. Monthly NSE and R2 values for calibration and validation were 0.74, 0.64 and 0.79, 0.84, respectively. Our results suggest that climate change will likely negatively affect the water resources of the Laguna del Sauce catchment, especially in the RCP 8.5 scenario. In all RCP scenarios, the catchment is likely to experience a wetting trend, higher temperatures, seasonality shifts and an increase in extreme precipitation events, particularly in frequency and magnitude. This will likely affect water quality provision through runoff and sediment yield inputs, reducing the erosion control HES and likely aggravating eutrophication. Although the amount of water will increase, changes to the hydrological cycle might jeopardize the stability of freshwater supplies and HES on which many people in the south-eastern region of Uruguay depend. Despite streamflow monitoring capacities need to be enhanced to reduce the uncertainty of model results, our findings provide valuable insights for water resources planning in the study area. Hence, water management and monitoring capacities need to be enhanced to reduce the potential negative climate change impacts on HES. The methodological approach presented here, based on satellite ET data can be replicated and adapted to any other place in the world since we employed open-access software and remote sensing data for all the phases of hydrological modelling and HES provision assessment.

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How spatial vegetation distribution affects soil erosion and sediment transport

10.5194/egusphere-egu21-7882 ◽

2021 ◽

Author(s):

Malte Kuegler ◽

Thomas Hoffmann ◽

Jana Eichel ◽

Lothar Schrott ◽

Juergen Schmidt

Keyword(s):

Soil Erosion ◽

Vegetation Cover ◽

Vegetation Pattern ◽

Vegetation Coverage ◽

Future Research ◽

Initial Increase ◽

Vegetation Patterns ◽

Erosion Rates ◽

Catchment Areas ◽

The Impact

There are a multitude of factors that affect soil erosion and the process of sediment movement. One particular factor known to have a considerable impact is vegetation coverage within catchment areas.&#160; Previous studies have examined the impact of vegetation cover on erosion.&#160;However, there is a lack of research on how the spatial distribution of vegetation influences erosion rates.A greater understanding of hillslope erosion is fundamental in modelling previous and future topographic changes under various climate conditions. Here, the physical based erosion model EROSION 3D &#169; is used to evaluate the impact of a variety of vegetation patterns and degrees of vegetation cover on sediment erosion and transport. The model was applied on a natural catchment in La Campana (Central Chile). For this purpose, three different vegetation patterns were created: (i) random distribution, (ii) water-dependent distribution (TWIR) and (iii) banded vegetation pattern distribution. Additional to this, the areas covered by vegetation generated in the first step were expanded by steps of 10% [0...100%]. The Erosion3D &#169; model then was applied on all vegetation patterns and degrees of cover.Our results show an initial increase of soil erosion with increasing plant coverage within the catchment up to a certain cover threshold ranging between 10 and 40%. At larger vegetation cover soil erosion rates decline. The strength of increase and decline, as well as the cover-threshold is strongly conditioned by the spatial vegetation pattern. In the light of this, future research should pay particular attention to the properties of the plants and their distribution, not solely on the amount of biomass within catchment areas.

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The Impact Factors Analysis of the Continuous Safety of the Yangtze River Shipping

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.655-657.2279 ◽

2013 ◽

Vol 655-657 ◽

pp. 2279-2283

Author(s):

Lu Wang ◽

Qing Liu ◽

Kai Jin Xu ◽

Xiao Li Xu

Keyword(s):

Continuous Improvement ◽

Yangtze River ◽

Safety Management ◽

Gray Relational Analysis ◽

Impact Factors ◽

The Yangtze River ◽

Safety Standards ◽

Relational Analysis ◽

Factors Analysis ◽

The Impact

This paper aims to analyze factors affect the continuous safety of the Yangtze River shipping, it studied the connotation and feature of continuous safety, and based on which selecting safety input, human behavior, safety management, safety state, safety culture as the main impact aspects, using the gray relational analysis to extract the key impact factors belong to the abovementioned five aspects. The result shows that safety management, safety input and safety state have bigger impact on sustainable safety state and continuous improvement of system safety standards.

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Effects of vegetation restoration on soil organic carbon redistribution along the Loess slope

10.5194/egusphere-egu2020-2481 ◽

2020 ◽

Author(s):

Xiaoxia Zhang ◽

Xiang Li ◽

Yipeng Liang ◽

Tonggang Zha

Keyword(s):

Spatial Distribution ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Effective Means ◽

Vegetation Restoration ◽

Managed Forests ◽

Carbon Cycles ◽

Loess Slope ◽

The Impact

Soil organic carbon (SOC) redistribution along the Loess slope under the effect of soil erosion plays an important role in understanding mechanism of SOC spatial distribution and turnover, hence to its effects on global carbon cycle. Vegetation restoration has been taken as an effective method to alleviate soil erosion on the Loess Plateau, while little research focused on the impact of vegetation restoration on the redistribution processes, especially the spatial distribution and stability of SOC. Here, we quantified the SOC stock and pool distribution on the loess slopes along geomorphic gradients under naturally regenerating forests (NF) and artificial black locust plantation (BP), using corn field as a control (CK).The results were as follows: &#160;(1) vegetation restoration, especially NF, effectively slowed down the migration of SOC resulting from soil erosion and reduced the heterogeneity of SOC distribution. The ratios of topsoil SOC in the sedimentary area to the stable area were 109%, 143%, and 210% under the NF, BP, and CK, respectively. And (2) Vegetation restoration reduced the loss of labile organic carbon by alleviating the loss of dissolved organic carbon (DOC) and easily oxidized organic carbon (EOC) during migration. Both DOC/SOC and EOC/SOC ratios under NF and BP presented far less differences between the sedimentary and erosion zones than CK.A schematic diagram of SOC cycle patterns and redistribution along the loess slope under vegetation restoration based on our findings and discussions. The results suggested that vegetation restoration in the Loess slope, NF in particular, was an effective means for alleviating the redistribution and spatial heterogeneity of SOC and reducing soil erosion. Information from this study is useful for understanding the carbon cycles in restored ecosystems and evaluating the ecosystem services of natural and managed forests in soil erosion control and carbon sequestration.

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Predicting pasture production under poplars using canopy closure images

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2006.68.2625 ◽

2006 ◽

pp. 325-330

Author(s):

A.J. Wall ◽

P.D. Kemp ◽

A.D. Mackay

Keyword(s):

Soil Erosion ◽

Soil Conservation ◽

Dry Matter ◽

High Growth ◽

High Growth Rate ◽

Tree Canopy ◽

Canopy Closure ◽

Pasture Production ◽

Poplar Trees ◽

The Impact

Poplar trees serve a wide variety of purposes on New Zealand farms. Their high growth rate and ability to establish from poles make them a very suitable tree species for soil conservation plantings on erosion-prone hill pastures. The impact that such plantings have on understorey pasture production as the tree canopy develops in size was determined by measuring pasture dry matter (DM) production on three North Island sheep and beef hill farms. Poplars markedly reduced annual pasture production by up to 50% at high canopy closure. To maintain pasture production at 65-75% of uneroded open pasture, poplar canopy closure should not exceed 50%. However, it must be emphasised that the loss in production through soil erosion (e.g. slips or earthflows) without poplars can be even greater, more permanent, and much more unpredictable. Keywords: Populus, soil erosion, agroforestry, digital images, canopy closure, understorey pasture

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Understanding Intra-Annual Dynamics of Ecosystem Services Using Satellite Image Time Series

Remote Sensing ◽

10.3390/rs12040710 ◽

2020 ◽

Vol 12 (4) ◽

pp. 710 ◽

Cited By ~ 3

Author(s):

Trinidad del Río-Mena ◽

Louise Willemen ◽

Anton Vrieling ◽

Andy Nelson

Keyword(s):

Ecosystem Services ◽

Spatial Variability ◽

Ecosystem Service ◽

Vegetation Cover ◽

Agricultural Land ◽

Supply And Demand ◽

Satellite Image ◽

Field Measurements ◽

Temporal Variations ◽

The Impact

Landscape processes fluctuate over time, influencing the intra-annual dynamics of ecosystem services. However, current ecosystem service assessments generally do not account for such changes. This study argues that information on the dynamics of ecosystem services is essential for understanding and monitoring the impact of land management. We studied two regulating ecosystem services (i. erosion prevention, ii. regulation of water flows) and two provisioning services (iii. provision of forage, iv. biomass for essential oil production) in thicket vegetation and agricultural fields in the Baviaanskloof, South Africa. Using models based on Sentinel-2 data, calibrated with field measurements, we estimated the monthly supply of ecosystem services and assessed their intra-annual variability within vegetation cover types. We illustrated how the dynamic supply of ecosystem services related to temporal variations in their demand. We also found large spatial variability of the ecosystem service supply within a single vegetation cover type. In contrast to thicket vegetation, agricultural land showed larger temporal and spatial variability in the ecosystem service supply due to the effect of more intensive management. Knowledge of intra-annual dynamics is essential to jointly assess the temporal variation of supply and demand throughout the year to evaluate if the provision of ecosystem services occurs when most needed.

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Enhancing rating prediction for recommendation by metric learning with gray relational analysis

Grey Systems Theory and Application ◽

10.1108/gs-05-2021-0073 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Jiangmei Chen ◽

Wende Zhang ◽

Qishan Zhang

Keyword(s):

Metric Learning ◽

Prediction Algorithm ◽

Gray Relational Analysis ◽

Rating Data ◽

Data Sparsity ◽

Content Type ◽

Relational Analysis ◽

Rating Prediction ◽

Real World Datasets ◽

The Impact

PurposeThe purpose of the paper is to improve the rating prediction accuracy in recommender systems (RSs) by metric learning (ML) method. The similarity metric of user and item is calculated with gray relational analysis.Design/methodology/approachFirst, the potential features of users and items are captured by exploiting ML, such that the rating prediction can be performed. In metric space, the user and item positions can be learned by training their embedding vectors. Second, instead of the traditional distance measurements, the gray relational analysis is employed in the evaluation of the position similarity between user and item, because the latter can reduce the impact of data sparsity and further explore the rating data correlation. On the basis of the above improvements, a new rating prediction algorithm is proposed. Experiments are implemented to validate the effectiveness of the algorithm.FindingsThe novel algorithm is evaluated by the extensive experiments on two real-world datasets. Experimental results demonstrate that the proposed model achieves remarkable performance on the rating prediction task.Practical implicationsThe rating prediction algorithm is adopted to predict the users' preference, and then, it provides personalized recommendations for users. In fact, this method can expand to the field of classification and provide potentials for this domain.Originality/valueThe algorithm can uncover the finer grained preference by ML. Furthermore, the similarity can be measured using gray relational analysis, which can mitigate the limitation of data sparsity.

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The 'Landcare' approach to soil conservation in the Philippines: an assessment of farm-level impacts

Australian Journal of Experimental Agriculture ◽

10.1071/ea06049 ◽

2007 ◽

Vol 47 (6) ◽

pp. 721 ◽

Cited By ~ 7

Author(s):

R. A. Cramb ◽

D. Catacutan ◽

Z. Culasero-Arellano ◽

K. Mariano

Keyword(s):

Soil Erosion ◽

Crop Yield ◽

Soil Conservation ◽

The Philippines ◽

Conservation Practices ◽

Short Term ◽

Farm Level ◽

Conservation Farming ◽

The Impact

‘Landcare’ is a group-based approach to the promotion of conservation farming. A case study of the Landcare program in Lantapan in the southern Philippines is presented to assess the farm-level impacts of this approach. The program was successful in promoting the formation of Landcare groups and a municipal Landcare association, resulting in rapid and widespread adoption of conservation practices, particularly among maize farmers. This in turn significantly reduced soil erosion, though the impact on crop yield and income was somewhat delayed. Adoption was thus not motivated primarily by short-term returns but by a concern to reduce soil erosion and provide a basis for diversification into agroforestry.

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The Effect of Soil Conservation Measures on Runoff, Soil Erosion, TN, and TP Losses Based on Experimental Runoff Plots in Northern China

Water ◽

10.3390/w13172334 ◽

2021 ◽

Vol 13 (17) ◽

pp. 2334

Author(s):

Haiyan Fang

Keyword(s):

Soil Erosion ◽

Soil Conservation ◽

Soil Loss ◽

Northern China ◽

Nutrient Losses ◽

Study Region ◽

Conservation Measures ◽

The Impact ◽

Soil Conservation Measures ◽

Runoff Plots

Total nitrogen (TN) and total phosphorous (TP) are the main pollutants affecting the water quality of the Miyun Reservoir, Beijing. However, few studies have been conducted on their responses to implemented soil conservation measures at a slope scale in northern China. To explore the impact of soil conservation measures on TN and TP losses, field monitored data from 18 runoff plots under natural rainfalls were used to analyze the changing characteristics of runoff, soil loss, and nutrient losses during 2014–2019. The results indicated that runoff, soil erosion, as well a TN and TP losses from the plots varied significantly, depending on land use and soil conservation measures. Bare plots suffered the highest soil, TN, and TP losses, followed by cultivated plots without soil conservation measures, cultivated plots with contour tillage, and other plots. Event-averaged runoff and soil loss rates ranged from 0 to 7.9 mm and from 0 to 444.4 t km−2 yr−1, and event-averaged TN and TP losses from cultivated plots were the highest, with values of 39.8 and 3.0 kg km−2, respectively. Bare and cultivated plots were the main sediment and nutrient sources. Among the cultivated plots, the terraced plot had the lowest soil and nutrient losses. The vegetated plots had insignificantly lower soil and nutrient losses. Most TN and TP were lost in particulate status from the plots, especially from the plots with soil conservation measures. Soil conservation measures can effectively prevent TN and TP losses. To guarantee water resource use, contour tillage is preferred for the bare and cultivated lands in the study region.

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