scholarly journals Of irrigation canals and multifunctional agroforestry: traditional agriculture facilitates Woolly-necked Stork breeding in a north Indian agricultural landscape

2021 ◽  
pp. e01793
Author(s):  
Swati Kittur ◽  
K.S. Gopi Sundar
2002 ◽  
Vol 67 (4) ◽  
pp. 665-676 ◽  
Author(s):  
Jonathan E. Damp ◽  
Stephen A. Hall ◽  
Susan J. Smith

The introduction of maize agriculture into the Southwest and onto the Colorado Plateau was accompanied by irrigation techniques. Twenty-six radiocarbon dates at two sites, K'yana Chabina and K'yawa:na'a Deyatchinanne, in the Zuni area of New Mexico, establish the use of irrigation canals to between 3,000 and 1,000 years ago. Associated features and the presence of nearby habitation sites independently corroborate the chronology of canal building. The geomorphology of the Zuni landscape and the morphology of the irrigation canals are consistent with the artificial construction of the canals. Pollen evidence points to an agricultural landscape and the cultivation of maize.


2017 ◽  
Vol 93 (02) ◽  
pp. 180-189 ◽  
Author(s):  
Mark Baah-Acheamfour ◽  
Scott X. Chang ◽  
Edward W. Bork ◽  
Cameron N. Carlyle

Canadian agriculture is a source of greenhouse gases (GHG) and agroforestry has the potential to sequester carbon (C), and mitigate agricultural GHG emissions. Agroforestry systems are common features in Canada’s agricultural landscape; however, there are limited empirical data to support implementation of agroforestry practices for GHG mitigation. This shortfall of data may be a contributing factor to the lack of policy that supports the use of agroforestry for GHG mitigation in the Canadian agricultural landscape. We reviewed published studies that compared C stocks in vegetation and soils, and/or GHG emissions in agroforestry systems to traditional agriculture across Canada, with the aims of assessing the benefit of adopting agroforestry for GHG reduction. We then identified data gaps and obstacles that could direct future research. We found that most studies reported increases in vegetation and soil organic C storage in areas with woody species compared to herbaceous crops. Agroforestry systems also reduced the emission of CH4 and N2O, and increased CO2 respiration from soil, but few studies have examined these gases. The small set of studies we reviewed demonstrated the potential of agroforestry to store terrestrial C and mitigate GHG emissions. However, additional research is required to verify this pattern across geographic regions, determine the regional potential for development of agroforestry systems, and assess the potential atmospheric GHG reduction at regional and national scales.


Author(s):  
Lei Luo ◽  
Xinyuan Wang ◽  
Rosa Lasaponara ◽  
Bo Xiang ◽  
Jing Zhen ◽  
...  

This paper describes the use of the Chinese Gaofen-1 (GF-1) satellite imagery to automatically extract tertiary Linear Archaeological Traces of Tuntian Irrigation Canals (LATTICs) located in the Miran site. The site is adjacent to the ancient Loulan Kingdom at the eastern margin of the Taklimakan Desert in western China. GF-1 data was processed following atmospheric and geometric correction, and spectral analyses were carried out for multispectral data. The low values produced by SSI indicate that it is difficult to distinguish buried tertiary LATTICs from similar backgrounds using spectral signatures. Thus, based on the textual characteristics of high-resolutionGF-1 panchromatic data, this paper proposes an automatic approach that combines joint morphological bottom and hat transformation with a Canny edge operator. The operator was improved by adding stages of geometric filtering and gradient vector direction analysis. Finally, the detected edges of tertiary LATTICs were extracted using the GIS-based draw tool and converted into shapefiles for archaeological mapping within a GIS environment. The proposed automatic approach was verified with an average accuracy of 95.76% for 754 tertiary LATTICs in the entire Miran site and compared with previous manual interpretation results. The results indicate that GF-1 VHR PAN imagery can successfully uncover the ancient tuntian agricultural landscape. Moreover, the proposed method can be generalized and applied to extract linear archaeological traces such as soil and crop marks in other geographic locations.


Author(s):  
Elena Makarycheva

The aim of the article is to develop a method for calculating water losses from irrigation channels in determining the permeability of rock in the zone of filtration flow on the basis of the law of infiltration A.N. Kostyakov using the results of studies of free filtration from pits and foundation pits in loess loams. Pressure movement of water in irrigation canals is subject to the laws of two-phase flow, in which – in contrast to the Darcy law for the zone of saturation plays an important role, the volume and its change in time. The filtration rate (VF) increases with increasing rock moisture (θ) along the S-curve, while the pressure gradient (I = dh/dz) decreases. The dependences of these parameters on the pressure are represented by power functions, and their product CDP = VFI does not change in time and can serve as a characteristic of the filtration flow under the channel. When installing paired piezometers near the water chore line in the channel and determining the graph I(t) by the value of the twophase flow constant CDP, it is possible to calculate the filtration rate at a number of times and the water losses during unsteady filtration. Water losses from the channels at equilibrium humidity increases with increasing head according to the formula A.N. Kostyakova, in which the water permeability of rocks is characterized by a steady filtration rate at a head of 1.0 m, and the gradient is the function of pressure. The application of the proposed method of calculating losses in the design of irrigation systems will increase the reliability of the justification of the volume of anti-filtration measures and the forecast of the groundwater level.


2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Nirmala Dorasamy ◽  
Olayemi Bakre

The majority of the South African rural populace is directly or indirectly engaged in agricultural practices to earn a livelihood. However, impediments such as climate change, water shortages, and inadequacy of institutional support have undermined these once thriving subsistence farming communities. Furthermore, poor leadership in hydrology, coupled with a lack of depth in skills at all government levels to facilitate the understanding of the importance of groundwater, has made it near impossible for subsistence farmers to benefit optimally from groundwater. The 2012 drought experienced in South Africa paralysed several subsistence farming communities in KwaZulu-Natal. To revamp subsistence farming and assist these farmers across South Africa, the Department of Water and Sanitation launched interventions, but despite the enormous resources expended, indicators (e.g. unsustainable farming practices, poor crop yield, pitiable living conditions, and poor standards of living) provide evidence that these interventions have not yielded the desired results. This paper seeks to suggest practicable interventions aimed at reducing the vulnerability of subsistence farmers in KwaZulu-Natal. The study pursued a qualitative approach in that it solicited the views of experts on groundwater and in related fields to gain an in-depth perspective. Some of the core challenges undermining the sustainability and growth of subsistence farming in the study area were found to be the inadequacy of experts on groundwater, water shortages, institutional deficiencies, lack of political will, and lack of coordination among stakeholders. Pragmatic recommendations are made to address these challenges, among other things to encourage a South African-Chinese partnership in the hydrology sector.


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