Estimating nonpoint source pollution load using four modified export coefficient models in a large easily eroded watershed of the loess hilly–gully region, China

Wu, Lei; Li, Pengcheng

doi:10.1007/s12665-016-5857-1

Cited by 33 publications

(4 citation statements)

References 21 publications

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“…The ECM has certain applicability to simulate the pollution load for areas with insufficient data. The improved ECM can increase the accuracy and applicability of estimating the pollution output in river basins [6,7,33,34]. The study area is located in a mountainous area with 90% of the slope above 85 • .…”

Section: Model Structurementioning

confidence: 99%

Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Duan

Peng

et al. 2019

Water

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The limitations of water quality management and assessment methods in China can be ascertained by comparison with other countries. However, it is unreasonable to use a uniform standard to evaluate water quality throughout China because one standard cannot fully account for the regional differences in background water quality. This study aimed to provide a basis for environmental water management decision-making. Areas seriously affected by background pollutants were identified by comparing several factors across 31 provinces in China. By coupling an improved export coefficient model (ECM) with a mechanistic model, a suitable pollutant yield coefficient was determined and its rationality was analysed. The export coefficient model was applied to estimate the pollutant (chemical oxygen demand and ammonia nitrogen) output of the basin in 2015. The spatial distribution characteristics of the pollutants were determined by simulating the pollutant outputs of 22 sub-basins and nine water function zones. For the year 2020, the simulation results of pollutant outputs far exceed the sewage discharge limit in water function zones and the pollutant concentration was much higher than the standard. Considering background pollutant outputs, more reasonable sewage discharge limit and water quality evaluation method are proposed.

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Section: Model Structurementioning

confidence: 99%

Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Duan

Peng

et al. 2019

Water

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“…Majiagou River watershed is one of the most typical soil erosion regions of the Loess Plateau. The implementation of a returning farmland project in 1997 was an important strategy to improve the ecological environment of the Loess Plateau (Teng et al, 2015;Wu et al, 2016e). According to existing research results (Zheng et al, 2005;Ma et al, 2016), the main pollution control measures and their reduction rates are summarized in Table 1.…”

Section: Soil Conservation Measures and Nps Pollution Control Measuresmentioning

confidence: 99%

Optimal allocation of nonpoint source pollution control measures using two modern comprehensive evaluation methods

Tang

2018

Water Policy

Self Cite

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Nonpoint source (NPS) pollution has been studied for many years but it exhibits random, widespread, complex uncertainties which make it difficult to manage and control. We employ group decision-making utilizing the fuzzy comprehensive evaluation method (FCE) and the analytic hierarchy process method (AHP) and comparatively evaluate the optimal allocation of NPS pollution control measures. Here, we present the top-three evaluation results ranked as follows: combination of contour tillage and vegetative filter strips (CT & VFS), vegetative filter strips (VFS), and combination of contour tillage and fertilizer reduction and vegetative filter strips (CT & FR & VFS). The fourth, fifth and sixth results by FCE method are chemical fertilizer reduction (FR), returning farmland to forest or pasture (RF), and combination of contour tillage and fertilizer reduction (CT & FR), while the corresponding results by AHP method are returning farmland to forest or pasture (RF), combination of contour tillage and fertilizer reduction (CT & FR), and fertilizer reduction (FR). The seventh results for each of the two methods are contour tillage (CT), which has a positive but limited effect on nutrient loss reduction. Our results provide new underlying insights needed to guide the resonable allocation of NPS pollution control measures.

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“…Yan'an city, a hill and gully region of Loess Plateau, was established as a representative experimental area with an area of 707 km 2 for ecological rehabilitation [43]. Nevertheless, it still has prominent environmental problems and a fragile ecosystem influenced by human activities and economic growth, being recognized as the significant characterization indexes for ecological security [44,45]. Primary interactions and explanatory threshold of substantial environment variables for LES evaluation are still fuzzy.…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Evaluation and Driving Mechanism of Land Ecological Security in Yan’an, a Typical Hill-Gully Region of China’s Loess Plateau, from 2000 to 2018

Zhang

Xue

Zhang

2021

Forests

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Forest landscape restoration and ecosystem of Loess Plateau have enhanced prominently, since the policy implementation (1999) of the Grain for Green Project in China. Land ecological security (LES) performs an extremely critical function for protecting vulnerable land resources and sustaining forest ecosystem stability. Predecessors’ studies substantially concentrate on biophysical and meteorologic variables using numerous grounded methodologies, little research has been launched on systematic natural-socio-economic-ecological relationships and how these contributions and regulations for LES evaluation. Here, pressure-state-response (PSR) model was used to establish the evaluation system of LES in regional-scale, and LES was classified into five levels measured by ecological security index (S), including high (S ≥ 0.75), medium−high (0.65 ≤ S < 0.75), medium (0.55 ≤ S < 0.65), medium−low (0.45 ≤ S < 0.55), and low (S < 0.45) level, for systematically analyzing its spatiotemporal distribution characteristic and response mechanism to explanatory variables in Yan’an, northwest China, from 2000 to 2018. The results demonstrated that: (1) LES status was mainly characterized by medium−high level and medium level, and maintained profound stability. (2) zone with medium−high LES level was mainly concentrated in western and southern regions, continuously expanding to northeast regions, and possessed the largest territorial area, accounting for 37.22–46.27% of the total area in Yan’an. (3) LES was primarily susceptible to normalized differential vegetation index, vegetation coverage, and land surface temperature with their optimal impacting thresholds of 0.20–0.64, 0.20–0.55, and 11.20–13.00 °C, respectively. (4) Normalized differential vegetation index and vegetation coverage had a significant synergistic effect upon LES based on their interactive explanation rate of 31% and had significant variation consistency (positive and negative) with LES, which were powerfully suggested to signal the intensification of the regional eco-security level in the persistent eco-greening process.

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Estimating nonpoint source pollution load using four modified export coefficient models in a large easily eroded watershed of the loess hilly–gully region, China

Cited by 33 publications

References 21 publications

Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Optimal allocation of nonpoint source pollution control measures using two modern comprehensive evaluation methods

Spatiotemporal Evaluation and Driving Mechanism of Land Ecological Security in Yan’an, a Typical Hill-Gully Region of China’s Loess Plateau, from 2000 to 2018

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