scholarly journals Ecological and Environmental Effects of Estuarine Wetland Loss Using Keyhole and Landsat Data in Liao River Delta, China

2021 ◽  
Vol 13 (2) ◽  
pp. 311
Author(s):  
Hongyan Yin ◽  
Yuanman Hu ◽  
Miao Liu ◽  
Chunlin Li ◽  
Jiujun Lv
Keyword(s):  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Ecological Risk ◽  
Potential Ecological Risk ◽  
Wetland Loss ◽  
Ecological Effects ◽  
Paddy Fields ◽  
Suitable Habitat ◽  
Estuarine Wetland

An estuarine wetland is an area of high ecological productivity and biodiversity, and it is also an anthropic activity hotspot area, which is of concern. The wetlands in estuarine areas have suffered declines, which have had remarkable ecological impacts. The land use changes, especially wetland loss, were studied based on Keyhole and Landsat images in the Liao River delta from 1962 to 2016. The dynamics of the ecosystem service values (ESVs), suitable habitat for birds, and soil heavy metal potential ecological risk were chosen to estimate the ecological effects with the benefit transfer method, synthetic overlaying method, and potential ecological risk index (RI) method, respectively. The driving factors of land use change and ecological effects were analyzed with redundancy analysis (RDA). The results showed that the built-up area increased from 95.98 km2 in 1962 to 591.49 km2 in 2016, and this large change was followed by changes in paddy fields (1351.30 to 1522.39 km2) and dry farmland (189.5 to 294.14 km2). The area of wetlands declined from 1823.16 km2 in 1962 to 1153.52 km2 in 2016, and this change was followed by a decrease in the water area (546.2 to 428.96 km2). The land use change was characterized by increasing built-up (516.25%), paddy fields (12.66%) and dry farmland (55.22%) areas and a decline in the wetland (36.73%) and water areas (21.47%) from 1962–2016. Wetlands decreased by 669.64 km2. The ESV values declined from 6.24 billion US$ to 4.46 billion US$ from 1962 to 2016, which means the ESVs were reduced by 19.26% due to wetlands being cultivated and the urbanization process. The area of suitable habitat for birds decreased by 1449.49 km2, or 61.42% of the total area available in 1962. Cd was the primary soil heavy metal pollutant based on its concentration, accumulation, and potential ecological risk contribution. The RDA showed that the driving factors of comprehensive ecological effects include wetland area, Cd and Cr concentration, river and oil well distributions. This study provides a comprehensive approach for estuarine wetland cultivation and scientific support for wetland conservation.

Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy field to various drylands

2021 ◽  
Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Rhizosphere Soil ◽  
Agricultural Land Use ◽  
Metal Bioavailability ◽  
Soil Rhizosphere ◽  
Divergent Response

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...

scholarly journals Assessment of Heavy Metal Pollution Levels in Sediments and of Ecological Risk by Quality Indices, Applying a Case Study: The Lower Danube River, Romania

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Surface Sediments ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Danube River ◽  
Pollution Indices

It is a well–known fact that heavy metal pollution in sediments causes serious problems not only in the Danube basin, but also in the large and small adjacent river streams. A suitable method for assessing the level of heavy metals and their toxicity in sediments is the calculation of pollution indices. The present research aims to assess heavy metal pollution in the Lower Danube surface sediments collected along the Danube course (between 180 and 60 km) up to the point where the Danube River flows into the Danube Delta Biosphere Reserve (a United Nations Educational, Scientific and Cultural Organization – UNESCO, protected area). In addition, this monitored area is one of the largest European hydrographic basins. Five heavy metals (Cd, Ni, Zn, Pb, Cu) were analyzed in two different seasons, i.e., the autumn of 2018 and the spring of 2019, using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Our assessment of heavy metal pollution revealed two correlated aspects: 1. a determination of the potential risks of heavy metals in sediments by calculating the Potential Ecological Risk Index (RI), and 2. an evaluation of the influence of anthropogenic activities on the level of heavy metal contamination in the surface sediments, using three specific pollution indices, namely, the Geo–Accumulation Index (Igeo), the Contamination Factor (CF), and the Pollution Load Index (PLI). The results of this pioneering research activity in the region highlighted the presence of moderate metal (Ni and Cd) pollution and a low potential ecological risk for the aquatic environment.

scholarly journals Assessment on the rates and potentials of soil organic carbon sequestration in agricultural lands in Japan using a process-based model and spatially explicit land-use change inventories – Part 1: Historical trend and validation based on nation-wide soil monitoring

2014 ◽  
Vol 11 (16) ◽  
pp. 4429-4442 ◽  
Author(s):  
Y. Yagasaki ◽  
Y. Shirato
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Land Use Change ◽  
Paddy Fields ◽  
Spatially Explicit ◽  
Crop Fields ◽  
Upland Crop ◽  
Soc Stock ◽  
Stock Change ◽  
Soc Stocks

Abstract. In order to estimate a country-scale soil organic carbon (SOC) stock change in agricultural lands in Japan, while taking into account the effect of land-use changes, climate, different agricultural activities and the nature of soils, a spatially explicit model simulation system was developed using Rothamsted Carbon Model (RothC) with an integration of spatial and temporal inventories. Simulation was run from 1970 to 2008 with historical inventories. Simulated SOC stock was compared with observations in a nation-wide stationary monitoring program conducted during 1979–1998. Historical land-use change, characterized by a large decline in the area of paddy fields as well as a small but continuous decline in the area of orchards, occurred along with a relatively large increase in upland crop fields, unmanaged grasslands, and settlements (i.e. conversion of agricultural fields due to urbanization or abandoning). Results of the simulation on SOC stock change under varying land-use change indicated that land-use conversion from agricultural fields to settlements or other lands, as well as that from paddy fields to croplands have likely been an increasing source of CO2 emission, due to the reduction of organic carbon input to soils and the enhancement of SOC decomposition through transition of soil environment from anaerobic to aerobic conditions. The area-weighted mean concentrations of the simulated SOC stocks calculated for major soil groups under paddy fields and upland crop fields were comparable to those observed in the monitoring. Whereas in orchards, the simulated SOC stocks were underestimated. As the results of simulation indicated that SOC stock change under managed grasslands and settlements has been likely a major sink and source of CO2 emission at country-scale, respectively, validation of SOC stock change under these land-use types, which could not have been accomplished due to limited availability or a lack of measurement, remains a forthcoming challenge.

scholarly journals Dampak Alih Fungsi Lahan Sawah Terhadap Kondisi Sosial Ekonomi Masyarakat Kecamatan Baitussalam Kabupaten Aceh Besar

2018 ◽  
Vol 3 (4) ◽  
pp. 219-226
Author(s):  
Yasfir Ma'arif ◽  
Teuku Fauzi ◽  
Safrida Safrida
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Paddy Fields ◽  
Selling Price ◽  
Land Conversion ◽  
Family Needs ◽  
A Value ◽  
The Social ◽  
Positive Results

Abstrak  Pertumbuhan  penduduk dan dinamika pembangunan telah menggeser pemanfaatan lahan yang akhirnya menimbulkan kompleksitas permasalahan lahan yang semula berfungsi sebagai media bercocok tanam (pertanian), berangsur-angsur berubah menjadi multifungsi pemanfaatan. Berubahnya pemanfaatan lahan pertanian ke non pertanian dapat disebut juga sebagai alih fungsi lahan. Kabupaten Aceh Besar adalah salah satu kabupaten yang terus menghadapi permasalahan alih fungsi lahan, khususnya lahan sawah. Alih fungsi lahan ini mengakibatkan luas lahan sawah di Aceh Besar terus menurun. Lahan yang paling banyak mengalami alih fungsi lahan adalah jenis lahan sawah yang menjadi lahan non pertanian. Penelitian ini bertujuan untuk mengidentifikasi faktor-faktor yang menyebabkan terjadinya alih fungsi lahan sawah dan mengidentifikasi dampak sosial dan ekonomi yang dialami petani mantan pemilik lahan akibat alih fungsi lahan sawah menjadi lahan non pertanian. Berdasarkan hasil regresi secara parsial dari analisis regresi faktor harga jual, kebutuhan hidup dan kondisi lahan berpengaruh nyata terhadap konversi lahan sawah di  Kecamatan Baitussalam Kabupaten Aceh Besar. Bedasarkan hasil regresi secara serempak dari hasil regresi didapatkan bahwa harga jual, kebutuhan hidup dan kondisi lahan secara serempak mempengaruhi konversi lahan sawah di Kecamatan Baitussalam Kabupaten Aceh Besar. Berdasarkan isu dampak sosial sebagai akibat alih fungsi lahan di lihat dari keinginan kondisi lama, meningkatkan rasa kerjasama dan kekeluargaan, serta kemampuan memenuhi kebutuhan keluarga mendapatkan hasil yang positif dengan nilai ≥ 50%. Berdasarkan isu dampak ekonomi sebagai akibat alih fungsi lahan di lihat dari peningkatan pendapatan mendapatkan hasil yang positif dengan nilai ≥ 50%.Impact Of Paddy Fields Function  On Community Socio-Economic Conditions Of Baitussalam District, Aceh Besar RegencyAbstract  Population growth and the dynamics of development have shifted land use which eventually led to the complexity of the problem of land that used to function as a farming medium (agriculture), gradually becoming a multifunctional use. Changing the use of agricultural land to non-agriculture can also be referred to as land conversion. Aceh Besar District is one of the districts that continues to face the problem of land conversion, especially rice fields. The conversion of this land function has caused the area of paddy fields in Aceh Besar to continue to decline. The land that has experienced the most land use change is the type of rice field that becomes non-agricultural land. This study aims to identify the factors that cause the conversion of paddy fields and identify the social and economic impacts experienced by farmers former landowners due to the conversion of paddy fields to non-agricultural land. Based on the partial regression results from the regression analysis, the factors of selling price, life necessity and land conditions have a significant effect on the conversion of paddy fields in Baitussalam District, Aceh Besar District. Based on the simultaneous regression results from the regression results, it was found that the selling price, life needs and land conditions simultaneously affected the conversion of paddy fields in Baitussalam District, Aceh Besar District. Based on the issue of social impacts as a result of land use change seen from the desires of the old conditions, increasing the sense of cooperation and kinship, as well as the ability to meet family needs get positive results with a value of ≥ 50%. Based on the issue of economic impact as a result of the transfer of land functions, it can be seen from the increase in income that has a positive result with a value of ≥ 50%.

Study on Potential Ecological Risk Assessment of Sediment from the Yangtze River (Chongqing Downtown Section) in China

2011 ◽  
Vol 414 ◽  
pp. 262-267 ◽  
Author(s):  
Wen Bing Ma ◽  
Fei Wang ◽  
Qin Zhai ◽  
Xing Yang ◽  
Yu Zhou ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Ecological Risk ◽  
Yangtze River ◽  
Heavy Metal Contamination ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Monitoring Site ◽  
The Yangtze River ◽  
Site Factor ◽  
National Monitoring

The potential ecological risk index,proposed by Hakanson, was employed for evaluating the heavy metal contamination of the Yangtze River sediment in Chongqing downtown section. Basing on the analysis of last fifteen years monitored data from two national monitoring sections, the results indicated that: The potential ecological risk of the Yangtze River Chongqing downtown section was classified as moderate. The sequence of potential ecological risk was Zn< Pb (As) < As (Pb) < Cu < Cd< Hg, while the concentration of heavy metal in the sediment was Zn> Cu >Pb> As > Cd > Hg. The concentrations of Cd and Cu had significant correlation, Hg should be taken into prior consideration for pollution control and reduction due to its highest potential ecological risk. The RI in 2005 was highest, Hg contributed the most. All the heavy metal except for Pb had distinctive variance, but the variance of RI was not significant annually, It might carried the connotation of little difference on Pb emission amount. According to the location of monitoring site factor variance analysis, it implied that only the potential ecological risk of As and Cd varied significantly.

scholarly journals Potential ecological risk assessment and prediction of soil heavy-metal pollution around coal gangue dump

2014 ◽  
Vol 14 (6) ◽  
pp. 1599-1610 ◽  
Author(s):  
X. Jiang ◽  
W. X. Lu ◽  
H. Q. Zhao ◽  
Q. C. Yang ◽  
Z. P. Yang
Keyword(s):  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Pearson Correlation ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Coal Gangue ◽  
Index Method ◽  
Soil Heavy Metal

Abstract. The aim of the present study is to evaluate the potential ecological risk and trend of soil heavy-metal pollution around a coal gangue dump in Jilin Province (Northeast China). The concentrations of Cd, Pb, Cu, Cr and Zn were monitored by inductively coupled plasma mass spectrometry (ICP-MS). The potential ecological risk index method developed by Hakanson (1980) was employed to assess the potential risk of heavy-metal pollution. The potential ecological risk in the order of ER(Cd) > ER(Pb) > ER(Cu) > ER(Cr) > ER(Zn) have been obtained, which showed that Cd was the most important factor leading to risk. Based on the Cd pollution history, the cumulative acceleration and cumulative rate of Cd were estimated, then the fixed number of years exceeding the standard prediction model was established, which was used to predict the pollution trend of Cd under the accelerated accumulation mode and the uniform mode. Pearson correlation analysis and correspondence analysis are employed to identify the sources of heavy metals and the relationship between sampling points and variables. These findings provided some useful insights for making appropriate management strategies to prevent or decrease heavy-metal pollution around a coal gangue dump in the Yangcaogou coal mine and other similar areas elsewhere.

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