scholarly journals Channel Adjustments in Iranian Rivers: A Review

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 672 ◽  
Author(s):  
Somaiyeh Khaleghi ◽  
Nicola Surian
Keyword(s):  
Climate Change ◽  
Controlling Factors ◽  
Sand Mining ◽  
Negative Effects ◽  
National Scale ◽  
Channel Changes ◽  
Channel Adjustments ◽  
Main Controlling Factors ◽  
Semi Arid ◽  
Different Climates

Channel adjustments in Iranian rivers have been intense over the last decades due to natural and human factors. Iran has six major basins, all with different climates, from very humid to very arid. This work is a review of the available studies and data about channel adjustments in Iranian rivers, and aims to reconstruct a first outline, at a national scale, of types, magnitude, and causes of adjustments. The results show that most of the rivers have undergone incision (1 to 2 m and, in some cases, up to 6 to 7 m) and narrowing (from 19% to 73%), although widening (from 22% to 349%) has occurred in some rivers. Narrowing is due to dams and sediment mining; widening is due to climate change and sediment mining. Incision is due to gravel and sand mining, dams, channelization, with in-channel mining being the main cause of incision. Channel adjustments have occurred in basins with different climates, but it seems that widening has been more intense in arid and semi-arid climates. Such adjustments have several negative effects (e.g., damage to bridges, degradation of river ecosystems, and instability of banks). The comparison between Iran and other countries shows that narrowing and incision have been the dominant processes in most of the rivers, while damming and in-channel mining have been used as the main controlling factors. Data about adjustments in Iranian rivers are neither homogeneous nor complete for all the rivers. This lack of completeness implies that our understanding of channel changes, and their causes, should be improved by further investigation.

DISSEMINATION AND USE OF INFORMATION ON CLIMATE CHANGE AND VARIABILITY: A CASE STUDY OF FARMERS IN MALUGA AND CHIBELA VILLAGES IN SEMI-ARID CENTRAL TANZANIA

Mousaion ◽  
2016 ◽  
Vol 33 (3) ◽  
pp. 1-24
Author(s):  
Emmanuel Elia ◽  
Stephen Mutula ◽  
Christine Stilwell
Keyword(s):  
Climate Change ◽  
Data Collection ◽  
Diffusion Of Innovations ◽  
Agricultural Development ◽  
Agricultural Sector ◽  
Policy Framework ◽  
Accurate Information ◽  
Adaptation To Climate Change ◽  
Climate Change And Variability ◽  
Semi Arid

This study was part of broader PhD research which investigated how access to, and use of, information enhances adaptation to climate change and variability in the agricultural sector in semi-arid Central Tanzania. The research was carried out in two villages using Rogers’ Diffusion of Innovations theory and model to assess the dissemination of this information and its use by farmers in their adaptation of their farming practices to climate change and variability. This predominantly qualitative study employed a post-positivist paradigm. Some elements of a quantitative approach were also deployed in the data collection and analysis. The principal data collection methods were interviews and focus group discussions. The study population comprised farmers, agricultural extension officers and the Climate Change Adaptation in Africa project manager. Qualitative data were subjected to content analysis whereas quantitative data were analysed to generate mostly descriptive statistics using SPSS.  Key findings of the study show that farmers perceive a problem in the dissemination and use of climate information for agricultural development. They found access to agricultural inputs to be expensive, unreliable and untimely. To mitigate the adverse effects of climate change and variability on farming effectively, the study recommends the repackaging of current and accurate information on climate change and variability, farmer education and training, and collaboration between researchers, meteorology experts, and extension officers and farmers. Moreover, a clear policy framework for disseminating information related to climate change and variability is required.

scholarly journals The Effects of US State-Level Energy and Environmental Policies on Clean Tech Innovation and Employment

2016 ◽  
Vol 6 (2) ◽  
pp. 1 ◽  
Author(s):  
Ross Gittell ◽  
Josh Stillwagon
Keyword(s):  
Climate Change ◽  
Climate Change Policy ◽  
State Level ◽  
Environmental Policies ◽  
Environmental Benefits ◽  
Level Energy ◽  
Negative Effects ◽  
Employment Benefits ◽  
Technology Industry ◽  
Change Policy

<p>This paper explores the influence of US state-level policies meant to address climate change on clean technology industry development. The largest influence of climate change policies is identified as being on energy research employment. Only some policies seem to contribute positively to clean tech employment while other policies appear to discourage employment growth. The magnitudes of the short term effects, even when statistically significant, are modest. Negative impacts on employment are identified for several mandate-oriented, so called command and control, policies including vehicle greenhouse gas standards, energy efficiency resource standards, and renewable portfolio standards with the former two having increasing negative effects over time. The findings suggest that climate change policy advocates should be careful to not assume that there will be positive clean tech employment benefits from state-level energy and environmental policies. Instead, the benefits from these policies may derive primarily from other considerations beyond the scope of this paper, including health and environmental benefits and reduction of dependence on foreign energy sources.</p>

scholarly journals Effect of Temperature on Sowing Dates of Wheat under Arid and Semi-Arid Climatic Regions and Impact Quantification of Climate Change through Mechanistic Modeling with Evidence from Field

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 927
Author(s):  
Jamshad Hussain ◽  
Tasneem Khaliq ◽  
Muhammad Habib ur Rahman ◽  
Asmat Ullah ◽  
Ishfaq Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Grain Yield ◽  
Arid Region ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Seasonal Temperature ◽  
Sowing Dates ◽  
Rcp 8.5 ◽  
Semi Arid Region ◽  
Semi Arid

Rising temperature from climate change is the most threatening factor worldwide for crop production. Sustainable wheat production is a challenge due to climate change and variability, which is ultimately a serious threat to food security in Pakistan. A series of field experiments were conducted during seasons 2013–2014 and 2014–2015 in the semi-arid (Faisalabad) and arid (Layyah) regions of Punjab-Pakistan. Three spring wheat genotypes were evaluated under eleven sowing dates from 16 October to 16 March, with an interval of 14–16 days in the two regions. Data for the model calibration and evaluation were collected from field experiments following the standard procedures and protocols. The grain yield under future climate scenarios was simulated by using a well-calibrated CERES-wheat model included in DSSAT v4.7. Future (2051–2100) and baseline (1980–2015) climatic data were simulated using 29 global circulation models (GCMs) under representative concentration pathway (RCP) 8.5. These GCMs were distributed among five quadrants of climatic conditions (Hot/Wet, Hot/Dry, Cool/Dry, Cool/Wet, and Middle) by a stretched distribution approach based on temperature and rainfall change. A maximum of ten GCMs predicted the chances of Middle climatic conditions during the second half of the century (2051–2100). The average temperature during the wheat season in a semi-arid region and arid region would increase by 3.52 °C and 3.84 °C, respectively, under Middle climatic conditions using the RCP 8.5 scenario during the second half-century. The simulated grain yield was reduced by 23.5% in the semi-arid region and 35.45% in the arid region under Middle climatic conditions (scenario). Mean seasonal temperature (MST) of sowing dates ranged from 16 to 27.3 °C, while the mean temperature from the heading to maturity (MTHM) stage was varying between 12.9 to 30.4 °C. Coefficients of determination (R2) between wheat morphology parameters and temperature were highly significant, with a range of 0.84–0.96. Impacts of temperature on wheat sown on 15 March were found to be as severe as to exterminate the crop before heading. The spikes and spikelets were not formed under a mean seasonal temperature higher than 25.5 °C. In a nutshell, elevated temperature (3–4 °C) till the end-century can reduce grain yield by about 30% in semi-arid and arid regions of Pakistan. These findings are crucial for growers and especially for policymakers to decide on sustainable wheat production for food security in the region.

Reforestation can compensate negative effects of climate change on amphibians

2021 ◽  
Vol 260 ◽  
pp. 109187
Author(s):  
Quezia Ramalho ◽  
Luara Tourinho ◽  
Mauricio Almeida-Gomes ◽  
Mariana M. Vale ◽  
Jayme A. Prevedello
Keyword(s):  
Climate Change ◽  
Negative Effects

Large shrubs partly compensate negative effects of grazing on hydrological function in a semi-arid savanna

2019 ◽  
Vol 38 ◽  
pp. 58-68 ◽  
Author(s):  
Arnim Marquart ◽  
David J. Eldridge ◽  
Samantha K. Travers ◽  
James Val ◽  
Niels Blaum
Keyword(s):  
Negative Effects ◽  
Semi Arid
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