SAR change detection for monitoring the impact of the rehabilitation of the Arghandab irrigation system in Afghanistan

2012 ◽  
Author(s):  
Jennifer Busler ◽  
Mohsen Ghazel ◽  
Vinay Kotamraju ◽  
Lisa Vandehei ◽  
Guy Aubé ◽  
...  
Keyword(s):  
Change Detection ◽  
Irrigation System ◽  
The Impact

scholarly journals A Systematic Review of Landsat Data for Change Detection Applications: 50 Years of Monitoring the Earth

2021 ◽  
Vol 13 (15) ◽  
pp. 2869
Author(s):  
MohammadAli Hemati ◽  
Mahdi Hasanlou ◽  
Masoud Mahdianpari ◽  
Fariba Mohammadimanesh
Keyword(s):  
Time Series ◽  
Change Detection ◽  
Policy Development ◽  
Atmospheric Correction ◽  
Open Data ◽  
Detection Methods ◽  
Landsat 8 ◽  
Landsat Images ◽  
Detection Analysis ◽  
The Impact

With uninterrupted space-based data collection since 1972, Landsat plays a key role in systematic monitoring of the Earth’s surface, enabled by an extensive and free, radiometrically consistent, global archive of imagery. Governments and international organizations rely on Landsat time series for monitoring and deriving a systematic understanding of the dynamics of the Earth’s surface at a spatial scale relevant to management, scientific inquiry, and policy development. In this study, we identify trends in Landsat-informed change detection studies by surveying 50 years of published applications, processing, and change detection methods. Specifically, a representative database was created resulting in 490 relevant journal articles derived from the Web of Science and Scopus. From these articles, we provide a review of recent developments, opportunities, and trends in Landsat change detection studies. The impact of the Landsat free and open data policy in 2008 is evident in the literature as a turning point in the number and nature of change detection studies. Based upon the search terms used and articles included, average number of Landsat images used in studies increased from 10 images before 2008 to 100,000 images in 2020. The 2008 opening of the Landsat archive resulted in a marked increase in the number of images used per study, typically providing the basis for the other trends in evidence. These key trends include an increase in automated processing, use of analysis-ready data (especially those with atmospheric correction), and use of cloud computing platforms, all over increasing large areas. The nature of change methods has evolved from representative bi-temporal pairs to time series of images capturing dynamics and trends, capable of revealing both gradual and abrupt changes. The result also revealed a greater use of nonparametric classifiers for Landsat change detection analysis. Landsat-9, to be launched in September 2021, in combination with the continued operation of Landsat-8 and integration with Sentinel-2, enhances opportunities for improved monitoring of change over increasingly larger areas with greater intra- and interannual frequency.

scholarly journals A simulation study on the effect of climate change on crop water use and chill unit accumulation

2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Abiodun A. Ogundeji ◽  
Henry Jordaan
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Use ◽  
Irrigation System ◽  
Future Climate ◽  
Crop Water ◽  
Crop Water Use ◽  
Chill Unit ◽  
The Future ◽  
The Impact

Climate change and its impact on already scarce water resources are of global importance, but even more so for water scarce countries. Apart from the effect of climate change on water supply, the chill unit requirement of deciduous fruit crops is also expected to be affected. Although research on crop water use has been undertaken, researchers have not taken the future climate into consideration. They also have focused on increasing temperatures but failed to relate temperature to chill unit accumulation, especially in South Africa. With a view of helping farmers to adapt to climate change, in this study we provide information that will assist farmers in their decision-making process for adaptation and in the selection of appropriate cultivars of deciduous fruits. Crop water use and chill unit requirements are modelled for the present and future climate. Results show that, irrespective of the irrigation system employed, climate change has led to increases in crop water use. Water use with the drip irrigation system was lower than with sprinkler irrigation as a result of efficiency differences in the irrigation technologies. It was also confirmed that the accumulated chill units will decrease in the future as a consequence of climate change. In order to remain in production, farmers need to adapt to climate change stress by putting in place water resources and crop management plans. Thus, producers must be furnished with a variety of adaptation or management strategies to overcome the impact of climate change.

scholarly journals The Impact of Using Small-Scale Irrigation Motor Pumps on Farmers’ Household Incomes in Ethiopia: A Quasi-Experimental Approach

2020 ◽  
Vol 12 (19) ◽  
pp. 8142
Author(s):  
Wubamlak Ayichew Workneh ◽  
Jun Takada ◽  
Shusuke Matsushita
Keyword(s):  
Rural Areas ◽  
Large Scale ◽  
Irrigation System ◽  
Poverty Rate ◽  
Average Treatment Effect ◽  
Small Scale ◽  
Growth Data ◽  
Canal Irrigation ◽  
The Impact ◽  
Small Scale Irrigation

Sectoral economic growth data in Ethiopia show that the agriculture sector has the lowest growth, which is caused by frequent drought and inefficient technologies, among other factors. As a result, the productivities of land and labor, as well as the income of small-scale farm households, are very low, and rural areas have a relatively high poverty rate. A quasi-experiment was applied to understand the impact of using small-scale irrigation motor pumps on farmers’ livelihood improvement. Specifically, a survey was conducted in 2019 on a sample of 92 small-scale irrigation motor pump and canal irrigation users as the treatment and control groups. The weighted propensity score matching method was applied to eliminate initial differences and adjust sampling proportions across the groups. Based on the average treatment effect on the treated estimation results, we cannot state that the mean income difference in small-scale irrigation motor pump users and canal irrigation system users is different from zero. This indicates that countries with little capital to invest in large-scale irrigation projects can introduce household-level small-scale irrigation motor pumps to improve farmers’ incomes.

scholarly journals Effectiveness of Irrigation Access on Sticky Rice Productivity: Evidence from Lao PDR

2019 ◽  
Vol 11 (20) ◽  
pp. 5839 ◽  
Author(s):  
Bouasone Sengsourivong ◽  
Masaru Ichihashi
Keyword(s):  
Irrigation System ◽  
Lao Pdr ◽  
Policy Implications ◽  
Total Production ◽  
Rice Productivity ◽  
Monitoring Procedure ◽  
Local Farmer ◽  
The Difference ◽  
The Impact

This study estimates the impact of irrigation on household sticky rice productivity in Lao People’s Democratic Republic (Lao PDR) by applying propensity score matching (PSM) and the difference-in-differences (DID) method. This paper utilizes panel data from the Lao Expenditure and Consumption Survey (LECS) from 2003 to 2013. The results show that the average sales value and total production of sticky rice for irrigated households is greater than those for non-irrigated households by around 36 to 38% per season. Moreover, irrigated households experience improved sticky rice productivity of approximately 2.44 tons per hectare, per season, compared to non-irrigated households. In particular, compared to households with access to irrigation in one period of the surveys, households with access to irrigation in two periods of the surveys have nearly double the sticky rice productivity. Therefore, long-term access to irrigation is more effective for sticky rice productivity. However, we cannot find any evidence to support the impact of irrigation on household consumption. Some policy implications that can be derived from this research are that farmers should be intensively promoted to make the most use of irrigation, development of irrigation system is highly needed, and to ensure effectiveness of irrigation utilization local farmer involvement in monitoring procedure of irrigation is necessary.

scholarly journals Use of Automated Change Detection and VGI Sources for Identifying and Validating Urban Land Use Change

2020 ◽  
Vol 12 (7) ◽  
pp. 1186 ◽  
Author(s):  
A.-M. Olteanu-Raimond ◽  
L. See ◽  
M. Schultz ◽  
G. Foody ◽  
M. Riffler ◽  
...  
Keyword(s):  
Land Use ◽  
Change Detection ◽  
Urban Areas ◽  
Detection Algorithm ◽  
Geographic Information ◽  
Urban Land Use ◽  
Basic Knowledge ◽  
User Profiles ◽  
Local Authorities ◽  
The Impact

Land use and land cover (LULC) mapping is often undertaken by national mapping agencies, where these LULC products are used for different types of monitoring and reporting applications. Updating of LULC databases is often done on a multi-year cycle due to the high costs involved, so changes are only detected when mapping exercises are repeated. Consequently, the information on LULC can quickly become outdated and hence may be incorrect in some areas. In the current era of big data and Earth observation, change detection algorithms can be used to identify changes in urban areas, which can then be used to automatically update LULC databases on a more continuous basis. However, the change detection algorithm must be validated before the changes can be committed to authoritative databases such as those produced by national mapping agencies. This paper outlines a change detection algorithm for identifying construction sites, which represent ongoing changes in LU, developed in the framework of the LandSense project. We then use volunteered geographic information (VGI) captured through the use of mapathons from a range of different groups of contributors to validate these changes. In total, 105 contributors were involved in the mapathons, producing a total of 2778 observations. The 105 contributors were grouped according to six different user-profiles and were analyzed to understand the impact of the experience of the users on the accuracy assessment. Overall, the results show that the change detection algorithm is able to identify changes in residential land use to an adequate level of accuracy (85%) but changes in infrastructure and industrial sites had lower accuracies (57% and 75 %, respectively), requiring further improvements. In terms of user profiles, the experts in LULC from local authorities, researchers in LULC at the French national mapping agency (IGN), and first-year students with a basic knowledge of geographic information systems had the highest overall accuracies (86.2%, 93.2%, and 85.2%, respectively). Differences in how the users approach the task also emerged, e.g., local authorities used knowledge and context to try to identify types of change while those with no knowledge of LULC (i.e., normal citizens) were quicker to choose ‘Unknown’ when the visual interpretation of a class was more difficult.

Spatially correlated rainfall in a protective irrigation system

2006 ◽  
Vol 11 (2) ◽  
pp. 179-199 ◽  
Author(s):  
JOHANNUS A. JANMAAT
Keyword(s):  
Irrigation System ◽  
Supply And Demand ◽  
Spot Market ◽  
Expected Returns ◽  
Return Volatility ◽  
Rainfall Events ◽  
Spatially Correlated ◽  
Complete Market ◽  
Water Surplus ◽  
The Impact

Allowing water to be traded in an irrigation system with de facto riparian rights can increase the efficiency of water use. With irrigation supplementing uncertain rainfall, both supply and demand for water are uncertain. When rainfall events are positively correlated, water supply and demand movements are negatively correlated, causing large price fluctuations. Using a stylized two crop, two region irrigation system, numerical integration over a bivariate rainfall distribution is used to demonstrate the impact of varying rainfall correlation on water price, expected returns, and return variability. A spot market for water captures the majority of the returns to water rights transfers, relative to a complete market. This spot market results in higher returns and reduced return volatility for farmers in the water deficit region, while farmers in the water surplus region see greater returns but also greater return volatility.

scholarly journals CRITICAL VARIABLES OF MORPHO-PHYSIOLOGICAL RICE PLANT UNDER STAGNANT FLOODING CONDITIONS

2021 ◽  
Vol 22 (1) ◽  
pp. 1
Author(s):  
Nurwulan Agustiani ◽  
Sujinah Sujinah ◽  
Indrastuti Apri Rumanti
Keyword(s):  
Grain Yield ◽  
Water Depth ◽  
Rice Yield ◽  
Irrigation System ◽  
Block Design ◽  
Grain Filling ◽  
System Control ◽  
New Variety ◽  
Panicle Number ◽  
The Impact

<p class="abstrakinggris"><span lang="EN-US">Stagnant flooding (SF) stress has contributed decreasing rice production in Indonesia. The study aimed to explore critical variables of rice growth that contribute to the decreasing grain yield under SF conditions and a common irrigation system (control). The experiment was arranged in a complete randomized block design with four replications to test 10 rice genotypes (Inpari 30 Ciherang Sub-1, Inpara 3, Inpara 4, Inpara 8, IRRI119, IRRI154, IR42, IR14D121, IR14D157, and Tapus). The water depth was managed according to the farmer’s practices for control, while for SF plots the standing water depth was gradually increased from 35 days after transplanting and was maintained at 50 cm until harvest. Results showed that plant height, tillering ability, leaf greenness, panicle number per hill and grain filling percentage were critical growth variables that affect grain yield at optimal conditions. The yield of the 10 genotypes decreased by 25–50% under SF conditions. Inpara 3 had the stable yield in those two watering conditions. Therefore, it could be used as a check variety for SF condition. Inpara 9 and IRRI119 experienced decreased yield of more than 50% under SF conditions. The key factors determining the decreased yield were tillering ability and green leaf level. Optimization of the two variables at SF conditions will largely determine rice yield associated with panicle number per hill and grain number per panicle. Results of the study are useful as preliminary recommendations for designing new variety and cultivation techniques to reduce the impact of SF stress on rice yield.</span></p>

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