scholarly journals Temporal and Spatial Changes in Crop Patterns, Use of Inputs and Hydrological Alteration in the Case of Fogera Floodplain, Ethiopia

Ecologies ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 380-396
Author(s):  
Mare Addis Desta ◽  
Gete Zeleke ◽  
William A. Payne ◽  
Wubneh Belete Abebe

More than half of the world’s population consumes rice. Recently, the area sown with modern rice varieties has expanded, and the use of chemical fertilizers and pesticides has increased in various countries. Wetland hydrology is also influenced by chemical and physical characteristics. Hence, this research focused on temporal and spatial changes in crop patterns, input usage, and hydrology in the Ethiopian Fogera floodplain, with the following objectives: (a) What are the spatial and temporal trends in crop production patterns? (b) What input changes have occurred to produce rice and other crops? (c) What hydrological changes have occurred in the area with intensification of production systems? Primary data were gathered through a questionnaire, focus group discussions, interviews, and field observations. Secondary data were obtained from Landsat imageries, the SWAT model, water flow measurements, and normalized difference vegetation index (NDVI). NDVI results indicated that the area cultivated for rice is increasing while the area of other crops is decreasing. Agricultural inputs are used in rice systems but were not used before the introduction of rice. Recession farming activities have also diminished wetland areas. Water flow showed a decrease, whereas Nitrogen and Phosphorus showed an increase with Pearson’s correlation values −0.069 and −0.072, respectively. Flow of water was negatively correlated with N and P water concentration, whereas N and P contents were positively correlated. In conclusion, growth of intensive rice systems has had negative environmental consequences on wetland ecology. Therefore, policies to regulate and manage wetland uses are recommended.

2021 ◽  
Author(s):  
Mare Desta ◽  
Gete Zeleke ◽  
William. A. Payne ◽  
Wubneh Abebe

Abstract BauckgroundMore than half of the world's population consumes rice. The area under modern rice varieties has expanded, the use of chemical fertilizers and pesticides has increased in various countries. The hydrology of wetlands are also influenced by its chemical and physical characteristics. Hence, this research focused on temporal and spatial changes in crop patterns, input usage, and hydrological change in Fogera floodplain, with the objectives: a. what are the spatial and temporal trends in crops production pattern? b. What inputs have been used in the past and present to produce rice and other crops? c. What looks like the hydrological alteration of the area? The primary data was gathered through a questionnaire, focus group discussions, interviews, and field observations. Secondary data from Landsat imageries, SWAT input data, water flow, normalized difference vegetation index, and hydrological alteration of the site were collected. To analyze data, tables, graphs, and charts percentage, mean, and correlation were used. ResultNDVI results indicated that rice crop is growing while other variables are decreasing. artificial inputs are currently used but before the introduction of rice were not. Recession farming activities have also diminished wetland. Annual average water flow and rainfall have been trending upward. Flow of water with Nitrogen and Phosphorous has a negative correlation, with Pearson's values -0.069 and -0.072, respectively whereas the value 0.242 indicates that nitrogen and phosphorus have a positive relationship. ConclusionIn conclusion, these extended and intensification of farming practices have an impact on the biodiversity of fauna and flora of the area.


2014 ◽  
Vol 14 (6) ◽  
pp. 1067-1075 ◽  
Author(s):  
Peili Duan ◽  
Lijie Qin

Quantitation of the green, blue and grey water footprints (WFs) of crop production can distinguish the water types and amount in crop production, as well as the degree of freshwater pollution. This paper calculates the WF of maize production and assesses the temporal variability and spatial distribution of WFs in different types of rainfall years over Jilin Province from 1998 to 2012. The results indicated that: (1) the annual average WF of maize production was 1,067 m3/ton, which was 53% green, 24% blue and 23% grey (maize production in Jilin Province relies primarily on green water); (2) the drier the year, the higher the WF of maize production; (3) the highest WF of maize production values among 49 counties in the province were in Antu and Tumen counties, whereas the lowest values occurred in Gongzhuling and Lishu counties, whether the year was humid, average or dry; and (4) the WF of maize production was highest in the eastern region, moderate in the western region and lowest in the middle region.


2021 ◽  
Author(s):  
Yaru Zhang ◽  
Yi He ◽  
Yanlin Li ◽  
Liping Jia

Abstract The spatiotemporal variation and driving force of Normalized Difference Vegetation Index (NDVI) is helpful to regional ecological environment protection and natural resource management. Using the Sen and Mann–Kendall methods, Hurt index, Space transfer matrix and Geodetector, this study investigated the temporal and spatial changes and driving forces of NDVI during 1982 - 2015. The results showed that:(1)For the period 1982 to 2015, the high vegetation coverage was mainly distributed in Qinling Mountains and Daba mountain, while the value of NDVI was low in high altitude area in the west, low altitude in the East and Hanjiang River valley.(2)The change trend of NDVI in Qinba Mountains is mainly to maintain stable and slow growth. And the slow growth changes significantly. NDVI increased slowly mainly in the East and northwest.(3)The future change trend of NDVI in Qinba Mountain is mainly slow growth and stability, which indicates that the ecological construction in Qinba Mountains is good. (4) Through the geographical detector, the main factors affecting NDVI in Qinba Mountains are natural factors mainly including rainfall, soil type and digital elevation model (DEM), while human activities mainly including population density have little influence on NDVI in Qinba Mountains. Natural environment factors and human activities make a great difference on the spatial distribution of NDVI. This study provides a help for the sustainable development of the naturel environment in Qinba Mountains.


Author(s):  
Anatoly Kusher

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1917
Author(s):  
Benedykt Pepliński ◽  
Wawrzyniec Czubak

In many circles, brown coal continues to be viewed as a cheap source of energy, resulting in numerous investments in new opencast brown coal mines. Such a perception of brown coal energy is only possible if the external costs associated with mining and burning coal are not considered. In past studies, external cost analysis has focused on the external costs of coal burning and associated emissions. This paper focuses on the extraction phase and assesses the external costs to agriculture associated with the resulting depression cone. This paper discusses the difficulties researchers face in estimating agricultural losses resulting from the development of a depression cone due to opencast mineral extraction. In the case of brown coal, the impacts are of a geological, natural-climatic, agricultural-productive, temporal, and spatial nature and result from a multiplicity of interacting factors. Then, a methodology for counting external costs in crop production was proposed. The next section estimates the external costs of crop production arising from the operation of opencast mines in the Konin-Turek brown coal field, which is located in central Poland. The analyses conducted showed a large decrease in grain and potato yields and no effect of the depression cone on sugar beet levels. Including the estimated external costs in the cost of producing electricity from mined brown coal would significantly worsen the profitability of that production.


Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Wakjira Takala Dibaba ◽  
Tamene Adugna Demissie ◽  
Konrad Miegel

Excessive soil loss and sediment yield in the highlands of Ethiopia are the primary factors that accelerate the decline of land productivity, water resources, operation and function of existing water infrastructure, as well as soil and water management practices. This study was conducted at Finchaa catchment in the Upper Blue Nile basin of Ethiopia to estimate the rate of soil erosion and sediment loss and prioritize the most sensitive sub-watersheds using the Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated and validated using the observed streamflow and sediment data. The average annual sediment yield (SY) in Finchaa catchment for the period 1990–2015 was 36.47 ton ha−1 yr−1 with the annual yield varying from negligible to about 107.2 ton ha−1 yr−1. Five sub-basins which account for about 24.83% of the area were predicted to suffer severely from soil erosion risks, with SY in excess of 50 ton ha−1 yr−1. Only 15.05% of the area within the tolerable rate of loss (below 11 ton ha−1yr−1) was considered as the least prioritized areas for maintenance of crop production. Despite the reasonable reduction of sediment yields by the management scenarios, the reduction by contour farming, slope terracing, zero free grazing and reforestation were still above the tolerable soil loss. Vegetative contour strips and soil bund were significant in reducing SY below the tolerable soil loss, which is equivalent to 63.9% and 64.8% reduction, respectively. In general, effective and sustainable soil erosion management requires not only prioritizations of the erosion hotspots but also prioritizations of the most effective management practices. We believe that the results provided new and updated insights that enable a proactive approach to preserve the soil and reduce land degradation risks that could allow resource regeneration.


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