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1.
Sci Total Environ ; 917: 170177, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38280589

RESUMEN

The present study evaluated sustainable development indicators of the Nekarood Watershed in Iran using global Sustainable Development Goals (SDGs) indicators. Identifying values and thresholds, justification of optimum values, ranking, and performance assessment of the associated SDGs' indicators were accordingly addressed. Moreover, due to a lack of complete information and ecological conditions, 77 indicators were selected based on compliance with the indicators of global SDGs. These indicators were used to evaluate the development situation of the study area. The indicators were then normalized, weighed, aggregated, and ranked into four categories from achieving to highly challenging. The results showed that among the SDGs, five goals performed above the mean of the global sustainable development goals. So, goals 3 and 1 had the highest performance of 69.82 and 57.97 %, respectively. Likewise, goals 7 and 16 showed the lowest performance beyond the global average of 51.08 and 54.62 %, respectively. SDG3-1-1, SDG3-1-2, SDG3-2-1, and SDG3-2-2 indicators with 100 % performance positively affected SDG3. SDG1-5-1 indicator with 100 % performance also had the most positive effect on SDG1. The performances of nine goals were also lower than the global mean. In this case, the lowest performance was assigned to goal 2, followed by goals 9, 17, 10, and 6, respectively, with 15.24, 19.71, 22.19, 24.98, and 45.78 %. SDG2-4-2, SDG2-4-1, and SDG2-3-1 indicators had the most negative effect on the performance of SDG2. SDG9-2-2 and SDG10-4-1 indicators also had the most negative effect on goals 9 and 10, respectively. The highest performance of the indicators was associated with the Ministry of Health and Medical Education, and the lowest was related to the Ministries of Agriculture Jihad and the Ministry of Industry, Mine, and Trade. The results of the present study verified an overall performance of 36.42 % for the Nekarood Watershed concerning the global SDGs, representing significantly challenging conditions.

2.
Sci Total Environ ; 905: 167123, 2023 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-37741382

RESUMEN

Today, land degradation and the decrease in the expected services of watersheds have been mainly influenced by human-induced activities. Hence, it requires more attention to adaptively manage and provide feasible solutions to watershed disruptions. However, appropriate management of precious commodities such as water, soil, air, and vegetation cover needs insight planning on a proper scale. Nonetheless, such an integrated approach to comprehensive health assessment of watershed resources is yet to be indoctrinated by scholars, implemental agencies, managers, and policymakers. Accordingly, the present endeavor has tried to evaluate the health status of Iran's 30 second-order large watersheds with the pressure-state-response (PSR) approach. In this regard, 44 problem-oriented, influential, and, at the same time, accessible variables with compatible scales at the national level were primarily determined in climatic, hydrologic, anthropogenic, and natural sectors. The collinearity-free and independent variables were then finalized using the variance inflation factor (VIF) test. Ultimately, P, S, and R indices were calculated using the arithmetic mean of 25 normalized variables based on which PSR-based health and security indices were also mapped countrywide. The results indicated that P, S, and R indices varied from 0.49 to 0.69, 0.42 to 0.82, and 0.40 to 0.94, respectively. Health and security indices ranged from 0.46 to 0.69 and 0.30 to 0.89, respectively. The weighted mean of P, S, and R was 0.59, 0.62, and 0.67, respectively, wholly placing them in the intermediate class. The weighted health and security indices were also 0.58 and 0.59, representing the intermediate class. The results showed that study watersheds had different health and security conditions from interplaying watershed-specific factors. The results revealed the necessity of watershed-unique managerial strategies to cope with the existing unfavorable conditions at the country level. However, further insight with high resolution is recommended for the high-priority watersheds to plan implementation and executive projects.

3.
Data Brief ; 50: 109482, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37636128

RESUMEN

Here, we present and release the Global Rainfall Erosivity Database (GloREDa), a multi-source platform containing rainfall erosivity values for almost 4000 stations globally. The database was compiled through a global collaboration between a network of researchers, meteorological services and environmental organisations from 65 countries. GloREDa is the first open access database of rainfall erosivity (R-factor) based on hourly and sub-hourly rainfall records at a global scale. This database is now stored and accessible for download in the long-term European Soil Data Centre (ESDAC) repository of the European Commission's Joint Research Centre. This will ensure the further development of the database with insertions of new records, maintenance of the data and provision of a helpdesk. In addition to the annual erosivity data, this release also includes the mean monthly erosivity data for 94% of the GloREDa stations. Based on these mean monthly R-factor values, we predict the global monthly erosivity datasets at 1 km resolution using the ensemble machine learning approach (ML) as implemented in the mlr package for R. The produced monthly raster data (GeoTIFF format) may be useful for soil erosion prediction modelling, sediment distribution analysis, climate change predictions, flood, and natural disaster assessments and can be valuable inputs for Land and Earth Systems modelling.

4.
Environ Monit Assess ; 195(7): 860, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37335439

RESUMEN

The soil freeze-thaw process is a transition phase of soil water in cold areas that influences the soil's hydrological behavior. However, dynamic phenomena and corresponding consequences have yet to be studied adequately. Therefore, the present study was planned to comparatively analyze the effects of a freezing-thawing cycle on the hydrologic behaviors of loess soil from northeast Iran. Small-size (0.5 × 0.50 m) erosion plots were subjected to a freezing-thawing cycle under governing conditions of the region of the origin soil. The plots were subjected to a freezing-thawing treatment by inducing cold air until the temperature declined to below - 20 °C and lasted for 3 days using a cooling compartment system and then were kept in the laboratory with an ambient temperature of above 10 °C for 2 days. The treated plots and untreated plots were then exposed to a simulated rainfall with an intensity of 72 mm h-1 and 0.5 h duration while they were placed on a slope of 20%. The results indicated that the hybrid processes of freezing-thawing and splash and inter-rill erosions significantly increased runoff generation and soil loss. The time to runoff, runoff volume, and soil loss were 1.65 times less and 1.38 and 2.90 times more, respectively, compared to those reported for the control treatment with significant differences (p < 0.006). The performance of ice lenses, freezing fronts, and the creation of near-saturation moisture after completing the cycle were identified as the most critical factors affecting the different soil behaviors under the frozen-thawed cycle.


Asunto(s)
Monitoreo del Ambiente , Suelo , Congelación , Monitoreo del Ambiente/métodos , Frío , Temperatura
5.
Sci Total Environ ; 856(Pt 1): 158935, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36167132

RESUMEN

Aside from the many services that soil provides, it also stores water and makes it available to crops, which is critical for food security. However, the necessity of further studies for overcoming the existing gap in relation to the role of soil in the water, energy, and food nexus system has been preoccupying the experts and specialists around the world for some time. In this sense, the balance between many key ecosystem components based on the Soil, water, energy, and food (SWEF) nexus framework is one of the key characteristics of holistic and accommodative watershed management systems. To the best of our knowledge, the watershed scale is used as a planning unit for the first time in the current study to construct a conceptual model for adaptive management of optimum land-use/cover allocation using SWEF. The method was then used for the Shazand Watershed, Iran. Numerous metrics, such as soil erosion, soil organic carbon (SOC), water and energy use, mass efficiency, and economic efficiency, were investigated. Finally, a compound indicator was used to generate the SWEF nexus index (SWEFNI) for various land-uses/crops for the node year 2014. SWFENI ranged from 0.19 (worst) for rangeland to 0.78 (best) for almond plantations, according to the findings. The study's present approach may be tested worldwide.


Asunto(s)
Ecosistema , Suelo , Conservación de los Recursos Naturales/métodos , Agua , Carbono , Productos Agrícolas
6.
Environ Monit Assess ; 194(3): 152, 2022 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-35132506

RESUMEN

The relationship between soil organic carbon (SOC) and environmental parameters was investigated in the Galazchai Watershed, Iran. Therefore, correlating the SOC amounts with remote sensing (RS) indices, topographic variables, and soil texture was analyzed. Some 125 soil samples gather from the upper 30 cm, and the weight of each sample was about 0.5 kg. The RS indices, consisting of difference vegetation index (DVI), enhanced vegetation index (EVI), optimized soil adjusted vegetation index (OSAVI), normalized difference vegetation index (NDVI), and soil adjusted vegetation index (SAVI), were used. Topographic variables included slope, elevation, aspect, and topographical wetness index (TWI), as well as clay and silt contents. The ordinary least square (OLS) and the geographically weighted regression (GWR) were employed to develop the SOC relationship considering different combinations of the variables. Results showed that none of the combinations of variables accurately estimated SOC (R2 < 0.32 and p value > 0.001). However, EVI with GWR (R2 = 0.291) and OSAVI, clay, slope, and aspect with GWR (R2= 0.32) better estimated SOC. Therefore, results showed that the study remotely sensed indices and environmental field inventory variables could not favorably predict the SOC content. These results can be attributed to the low SOC values varying from 0.917 to 3.355%, with a mean of 2.194 ± 0.522 in the study watershed. However, studies using more uniformly distributed and denser sampling in the study area and other methods to investigate the relationship between variables are recommended.


Asunto(s)
Carbono , Suelo , Carbono/análisis , Monitoreo del Ambiente , Análisis de los Mínimos Cuadrados , Regresión Espacial
7.
Sci Total Environ ; 791: 148389, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34412389

RESUMEN

The present study was conducted to comprehensively evaluate watershed sustainability with the help of an initiative barometer developed based on different dimensions of social, economic, environmental, and policy. The newly developed barometer was then applied to assess the temporal variation of sustainability for the Shazand Watershed, Iran, for four-node years of 1986, 1998, 2008, and 2016. The appropriate criteria were then adapted to calculate the study dimensions. The effect sizes of selected criteria on each dimension were also determined. Consequently, the status of each dimension and integrated watershed sustainability status were mapped for four-node years. The results indicated that study dimensions were unevenly distributed over the Shazand Watershed. So that, the social dimension had high effectiveness across different sub-watersheds, and the policy dimension had a poor situation in all study years. In addition, the respective sustainability index of 0.32, 0.32, 0.35, and 0.35 for node years of 1986, 1998, 2008, and 2016 verified a slight improvement. Overall, the proposed barometer of sustainability facilitated understanding the dimensional sustainability and comprehensive watershed sustainability and provided references for policy formulations and watershed management. Besides, the developed barometer has a high potential for evaluating sustainability for other watersheds worldwide.


Asunto(s)
Conservación de los Recursos Hídricos , Agua Potable , Irán
8.
Sci Total Environ ; 728: 138866, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32570320

RESUMEN

Controlling soil erosion, especially in its initial stages, is greatly important in natural resources management. Consequently, the present research aimed to control splash and interrill erosion in two soil types (marl at Marzan-Abad and loess at Maraveh-Tapeh sites in northern Iran) using biochar (BC) and polyacrylamide (PAM). We established 0.5 × 0.5-m plots and applied BC (800 g·m-2), PAM (2 g·m-2), and BC + PAM (800 g·m-2 + 2 g·m-2) with control plots and three replications on a slope of ~25%. We used a rainfall simulator to achieve rainfall intensity of 50 mm·h-1 with 30-min duration in the experiments. Analysis of the results obtained from the variables of splash and interrill erosion during the rainfall-runoff process showed that the PAM significantly (p ≤ 0.05) increased all study variables of splash erosion. For interrill erosion, it reduced the variables of soil loss and sediment concentration. However, the difference was not significant (p > 0.05) compared to the control plot and runoff from the two treatment sites increased relative to that from the control plots. The plot treated with BC showed decreased runoff volume, runoff coefficient, and soil loss compared to the control plot at the Marzan-Abad site, but the differences were not statistically significant (p > 0.05). However, the plot in which loess soil was treated with BC at the Maraveh-Tapeh site exhibited considerably (p ≤ 0.05) increased runoff and soil loss compared to the control plot. The entire results verified a wide range for benefit reduction of study treatments from +25.09 to -37.49% for runoff and from +38.59 to -231% for soil loss with more effectiveness for Maraveh-Tapeh Loess soil as well as combined application of BC and PAM. These findings contribute to improved understanding of proper application of soil amendments to control runoff and soil loss in loam and loess soils.

9.
Sci Total Environ ; 698: 134265, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31505356

RESUMEN

Collaborative management is increasingly applied to indicate environmental and socio-economic negotiations in every corner of the world. The engagement of multiple stakeholders accompanying experience, science, and economy probing skills is expected to unravel such issues. However, the collaborative approaches to manage existing issues at watershed scale have not been adequately applied. Therefore, the present study has exemplified the establishment of a comanagement framework for the soil management for two case studies i.e., Schleswig-Holstein State of Germany and Galazchai Watershed of Iran using a stakeholder oriented approach applying game theory based methods. Due to management perspectives, different stakeholder groups were involved to investigate effective soil conservation practices. Farmers, consultants, and service providing companies in Germany and residents, policy making institutions and executive organizations in Iran were detected as key stakeholders. The Condorcet and Fallback bargaining methods were used to diagnosis agreement point. Based upon the results, the developed case study in Germany demonstrated close relation among farmers and consultants (53%) in contrast with service providing companies. The same situation was observed among residents and policy makers in Iran. Besides, the tendency to implement mechanical practices among farmers in Iran was about 60% (149 of 243), however, in Germany 86% of farmers prefer to use managerial practices.

10.
Sci Total Environ ; 698: 134319, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31518782

RESUMEN

Neutralizing land degradation due to overexploitation of natural resources is an acceptable strategy under developing conditions. However, this important approach has not been adequately introduced and adopted in the world. The present study therefore aimed to calculate Land Degradation Neutrality (LDN) for the Shazand Watershed with an area about 1740 km2 located in central arid and semi-arid region of Iran. The LDN status was basically assessed using three indicators, viz. land use and land cover, soil organic carbon and land productivity using Land Cover/Use Changes (LUC), Soil Organic Carbon (SOC) and Net Primary Productivity (NPP) metrics for two sub-periods during 2000 to 2016. Towards this, 140 soil samples were then taken from the top 30-cm of the soil from homogeneous units representing an area ≥ 1-km2 for four different main land uses including irrigated farms, rain fed farms, range lands, and orchards. Consequently, SOC and various soil properties such as sand, silt, clay, gravel, bulk density (BD), pH, electrical connectivity (EC), calcium carbonate (CaCO3) and nitrogen (N) were analyzed. NPP metric was also obtained using MODIS satellite images for three periods of 2000-2008, 2008-2016, and 2000-2016. The results of combination of study metrics indicated that net loss occurred in irrigated lands, rain fed lands, and range lands in the first eight-year period (2000-2008) and in contrary a balanced and stable situation in the second eight-year period (2008-2016). Overall, the LDN status in the Shazand Watershed was in a net loss situation during the period from 2000 to 2016 in irrigated lands, rain fed lands, and range lands covered areas of 12,290, 44,170 and 66,630 ha, respectively.

11.
Environ Monit Assess ; 191(9): 595, 2019 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-31463613

RESUMEN

Runoff coefficient (RC) is one of the important parameters, which is often considered in surface runoff and peak flood discharge estimation methods in various projects of watershed management and flood control. However, the effect of variability of RC due to human-induced activities on hydrologic behavior of the watershed has not been adequately considered globally. Therefore, the present research was carried out using 18 hyetographs and their corresponding hydrographs during 1984 to 2012 after considering the existence of suitable Landsat 7 (ETM+ and TM) satellite images with corresponding storm events for the Amameh Watershed located in Tehran Province, Iran. The object-oriented classification method was used to derive land use maps from satellite images. Afterward, four time periods were determined based on mean and standard deviation of residential area variations. The temporal distribution pattern of RC was then derived using a ranking method. The one- and two-way analyses of variance were also used to investigate the effect of residential area and rainfall variables on RC. Relationships among residential area as well as rainfall variables as independent variables and mean RC storm-wise as dependent variable were then modeled using two and multiple linear regressions. The results showed that RCs reduced in order of third, second, fourth, and first quartiles with respective values of 42.4, 38.2, 15.8, and 3.6%. The results also showed that RCs in the second and first quartiles and in the third and fourth quartiles were non-significantly decreased and increased by increasing of residential area, respectively. So that the highest variations occurred in first quartile with slope of - 144%. The results further proved that rainfall amount, φ index, and residential area with respective standardized regression coefficients (ß) of 0.629, - 0.465, and - 0.108 had the highest controlling effects on RCs. The finding of the current research proved the temporal variability of RCs at storm scale with more determinant effectiveness of rainfall properties than urbanized interferences. It helps hydrologists and watershed mangers designate appropriate strategies leading to proper implementations of developmental projects.


Asunto(s)
Monitoreo del Ambiente , Inundaciones/prevención & control , Urbanización , Movimientos del Agua , Hidrología , Irán , Lluvia , Imágenes Satelitales
12.
Sci Total Environ ; 648: 880-893, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30144756

RESUMEN

The current study aimed to comprehensively assess the potential watershed health (WH) using an adapted reliability, resilience and vulnerability (RelResVul) framework for the 24 sub-watersheds of Shazand, Markazi Province, Iran. Towards this goal, the appropriate criteria and acceptable corresponding thresholds were adapted to calculate the main WH indictors of reliability (Rel), resilience (Res) and vulnerability (Vul). Accordingly, the RelResVul framework was conceptualized and customized for five criteria of standardized precipitation index (SPI), normalized difference vegetation index (NDVI), soil erosion, and low and high flow discharges. The effect sizes of used criteria and indicators on the Shazand WH status were also determined. Consequently, the status of Rel, Res and Vul indicators and integrated WH status were mapped for four years of 1986, 1998, 2008 and 2014 and for the whole watershed by developing an integrated watershed health index (IWHI). Finally, the change detection approach was applied to determine the trend of changes in IWHI during last three decades. The results approved the high variability in effectability of Rel, Res and Vul indicators and integrated health status of the Shazand Watershed from the selected criteria in study four years. The results revealed that in the all study years, the Rel indicator almost had the higher contribution rate (≥34%) in the Shazand WH. None of sub-watersheds in the study years were assessed in a healthy status in terms of IWHI based on the RelResVul framework. In terms of WH change detection over the study periods, WH was found to declining by some 4% in the periods of 1986-1998 and 1986-2008 due to impact of industrialization and urban development. Whilst, the health status was non-significantly improved in other study periods. The present procedure can be supposed as a screening tool for a directive and efficient management of the watersheds.

13.
J Environ Manage ; 232: 22-36, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30466009

RESUMEN

Assessment of watershed health and prioritization of sub-watersheds are needed to allocate natural resources and efficiently manage watersheds. Characterization of health and spatial prioritization of sub-watersheds in data scarce regions helps better comprehend real watershed conditions and design and implement management strategies. Previous studies on the assessment of health and prioritization of sub-watersheds in ungauged regions have not considered environmental factors and their inter-relationship. In this regard, fuzzy logic theory can be employed to improve the assessment of watershed health. The present study considered a combination of climate vulnerability (Climate Water Balance), relative erosion rate of surficial rocks, slope weighted K-factor, topographic indices, thirteen morphometric characteristics (linear, areal, and relief aspects), and potential non-point source pollution to assess watershed health, using a new framework which considers the complex linkage between human activities and natural resources. The new framework, focusing on watershed health score (WHS), was employed for the spatial prioritization of 31 sub-watersheds in the Khoy watershed, West Azerbaijan Province, Iran. In this framework, an analytical network process (ANP) and fuzzy theory were used to investigate the inter-relationships between the above mentioned geo-environmental factors and to classify and rank the health of each sub-watershed in four classes. Results demonstrated that only one sub-watershed (C15) fell into the class that was defined as 'a potentially critical zone'. This article provides a new framework and practical recommendations for watershed management agencies with a high level of assurance when there is a lack of reliable hydrometric gauge data.


Asunto(s)
Monitoreo del Ambiente , Contaminación Difusa , Conservación de los Recursos Naturales , Hidrología , Irán
14.
Environ Monit Assess ; 191(1): 45, 2018 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-30593598

RESUMEN

Designation of representative watersheds (RWs) as a reference area representing key behavior of the whole region is an essential tool to provide a time and cost-effective basis for monitoring watershed performance against different driving forces. It is more important in developing countries facing lack of necessary investments in one hand and ever-increasing human interventions and need to assess the outcome behavior of the system in another hand. However, this serious affair has been less considered worldwide, in general, and in developing countries, in particular. Therefore, in the present study, a quantitative-based method of Representative Watershed Index (RWI) with potential range from 0 to 100 has been formulated using four important criteria and available national-wide raster data of elevation (meter), slope (%), rainfall erosivity factor (t m ha-1 cm h-1), and land use. The approach was then applied to the data prepared for the unique and invaluable global water ecosystem of the Urmia Lake Basin (ULB), north-western Iran, as a case study. The input raster was overlaid via matrices programming in the MATrix LABoratory (MATLAB) 2016 and Geographic Information System (GIS) 9.3 software environments. The RWIs were accordingly computed for 61 sub-watersheds of the ULB. The RWIs resulted from quadri-partite dimensional matrices that varied from 5.54 to 53.46 with respective maximum dissimilarity and resemblance with the entire 61 study sub-watersheds in the region. However, the sub-watershed with RWI of 40.65 (No. 57) was proposed as the final RW for the whole ULB due to hydrological independency, appropriate locality, and existence of functioning meteorological and hydrometric stations. The identified RW would be suggested to be considered as the basis for future insight monitoring and assessing environmental issues for the region eventually leading to an appropriate adaptive watershed management. Graphical abstract ᅟ.


Asunto(s)
Ecosistema , Monitoreo del Ambiente/métodos , Lagos , Sistemas de Información Geográfica , Hidrología , Irán
15.
Sci Rep ; 7(1): 4175, 2017 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-28646132

RESUMEN

The exposure of the Earth's surface to the energetic input of rainfall is one of the key factors controlling water erosion. While water erosion is identified as the most serious cause of soil degradation globally, global patterns of rainfall erosivity remain poorly quantified and estimates have large uncertainties. This hampers the implementation of effective soil degradation mitigation and restoration strategies. Quantifying rainfall erosivity is challenging as it requires high temporal resolution(<30 min) and high fidelity rainfall recordings. We present the results of an extensive global data collection effort whereby we estimated rainfall erosivity for 3,625 stations covering 63 countries. This first ever Global Rainfall Erosivity Database was used to develop a global erosivity map at 30 arc-seconds(~1 km) based on a Gaussian Process Regression(GPR). Globally, the mean rainfall erosivity was estimated to be 2,190 MJ mm ha-1 h-1 yr-1, with the highest values in South America and the Caribbean countries, Central east Africa and South east Asia. The lowest values are mainly found in Canada, the Russian Federation, Northern Europe, Northern Africa and the Middle East. The tropical climate zone has the highest mean rainfall erosivity followed by the temperate whereas the lowest mean was estimated in the cold climate zone.

16.
Environ Monit Assess ; 189(5): 238, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28451960

RESUMEN

The temporal variability of phosphorus (P) transport and the relationships between discharge, suspended sediment concentration and particulate (PP), and soluble (SP) phosphorus were examined. The study was conducted at the event scale in seven tributaries of the Zarivar Lake watershed in Kurdistan Province (Iran) from March 2011 to April 2012. Based on eight runoff events, 82% of the total P was the PP carried out by suspended sediment. Results showed a high variability of P transport during different runoff events. It was found that soil erosion was the source of the high P load. For all tributaries, PP was linearly related to both discharge and suspended sediment concentration. However, the relationships of SP and PP with discharge and suspended sediment concentration showed different hysteresis patterns. The relationship between PP and discharge was generally characterized by a clockwise pattern (i.e., lower part contribution of the sub-watersheds) but the patterns between SP and discharge were mainly anticlockwise (i.e., upper part contribution of the sub-watersheds or perhaps due to a subsurface flow contribution).


Asunto(s)
Monitoreo del Ambiente , Fósforo/análisis , Contaminantes Químicos del Agua/análisis , Irán , Lagos/química , Suelo , Movimientos del Agua
17.
Sci Total Environ ; 587-588: 168-176, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-28249754

RESUMEN

Quantitative response of the watershed health to climate variability is of critical importance for watershed managers. However, existing studies seldom considered the impact of climate variability on watershed health. The present study therefore aimed to analyze the temporal and spatial variability of reliability (Rel), resilience (Res) and vulnerability (Vul) indicators in node years of 1986, 1998, 2008 and 2014 in connection with Standardized Precipitation Index (SPI) for 24 sub-watersheds in the Shazand Watershed of Markazi Province in Iran. The analysis was based on rainfall variability as one of the main climatic drivers. To achieve the study purposes, the monthly rainfall time series of eight rain gauge stations distributed across the watershed or neighboring areas were analyzed and corresponding SPIs and Rel ResVul indicators were calculated. Ultimately, the spatial variation of SPI oriented Rel ResVul was mapped for the study watershed using Geographic Information System (GIS). The average and standard deviation of SPI-Rel ResVul index for the study years of 1986, 1998, 2008 and 2014 was obtained 0.240±0.025, 0.290±0.036, 0.077±0.0280 and 0.241±0.081, respectively. In overall, the results of the study proved the spatiotemporal variations of SPI-Rel ResVul watershed health index in the study area. Accordingly, all the sub-watersheds of the Shazand Watershed were grouped in unhealthy and very unhealthy conditions in all the study years. For 1986 and 1998 all the sub-watersheds were assessed in unhealthy status. Whilst, it declined to very unhealthy condition in 2008 and then some 75% of the watershed ultimately referred again to unhealthy and the rest still remained under very unhealthy conditions in 2014.


Asunto(s)
Sequías , Ecosistema , Monitoreo del Ambiente , Ríos , Conservación de los Recursos Naturales , Sistemas de Información Geográfica , Irán , Lluvia , Suelo , Movimientos del Agua
18.
Sci Total Environ ; 541: 483-490, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26410722

RESUMEN

Many different amendments, stabilizers, and conditioners are usually applied for soil and water conservation. Biochar is a carbon-enriched substance produced by thermal decomposition of organic material in the absence of oxygen with the goal to be used as a soil amendment. Biochar can be produced from a wide range of biomass sources including straw, wood, manure, and other organic wastes. Biochar has been demonstrated to restore soil fertility and crop production under many conditions, but less is known about the effects of its application on soil erosion and runoff control. Therefore, a rainfall simulation study, as a pioneer research, was conducted to evaluate the performance of the application of vinasse-produced biochar on the soil erosion control of a sandy clay loam soil packed in small-sized runoff 0.25-m(2) plots with 3 replicates. The treatments were (i) no biochar (control), (ii) biochar (8 tha(-1)) application at 24h before the rainfall simulation and (iii) biochar (8 tha(-1)) application at 48 h before the rainfall simulation. Rainfall was applied at 50 mm h(-1) for 15 min. The mean change of effectiveness in time to runoff could be found in biochar application at 24 and 48 h before simulation treatment with rate of +55.10% and +71.73%, respectively. In addition, the mean runoff volume 24 and 48 h before simulation treatments decreased by 98.46% and 46.39%, respectively. The least soil loss (1.12 ± 0.57 g) and sediment concentration (1.44 ± 0.48 gl(-1)) occurred in the biochar-amended soil treated 48 h before the rainfall simulation. In conclusion, the application of vinasse-produced biochar could effectively control runoff and soil loss. This study provided a new insight into the effects of biochar on runoff, soil loss, and sediment control due to water erosion in sandy clay loam soils.

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