The impacts of environmental and socioeconomic factors on the non-point source pollution in a small watershed in the Three Gorges Reservoir Area, China

2021 ◽  
Author(s):  
Jun Deng ◽  
Zhaoxia Li
Keyword(s):  
Land Use ◽  
Socioeconomic Factors ◽  
Fertilizer Application ◽  
Dry Season ◽  
Wet Season ◽  
Topographic Wetness Index ◽  
Wetness Index ◽  
Factors Affecting ◽  
Nps Pollution ◽  
Per Capita

<p>Determining the impacts of environmental and socioeconomic factors on nitrogen (N) and phosphorus (P) loss in the watershed is critical to reducing non-point source (NPS) pollution. This paper, we set 13 sampling points in the main stream and tributaries of watershed and sampled every two weeks from 2018 to 2020 to monitor the total nitrogen (TN) and total phosphorus (TP) concentration in the waterbodies. Twenty-six potential influencing factors affecting the nitrogen and phosphorus loss in the watershed were selected. The partial least squares regression (PLSR) was used to determine the relationship between TN and TP concentrations in the watershed and the 26 selected potential influencing factors. The results showed that the mean TN concentrations and mean TP concentrations in the dry season (11.42 mg·L<sup>−1</sup> and 0.09 mg·L<sup>−1</sup>, respectively) were both less than those in the wet season (13.20 mg·L−1 and 0.11mg·L−1, respectively). The optimal PLSR model explained 69.6%, 73.1% and 66.1% of the TN concentration variability, and 65.7%, 79.5% and 67.4% of the TP concentration variability during annual, dry season and wet season, respectively. According to the importance of the variables in the predicted value (VIP), topographic wetness index (TWI), planting structure (PS), interspersion and juxtaposition index (IJI), Orchard land use (OP), nitrogen fertilizer application (NF), per capita income (INCOME) and catchment area (AREA) were the key factors affecting TN concentration, whereas topographic wetness index (TWI), interspersion and juxtaposition index (IJI), population density (POP), slope gradient (SLOPE) and hypsometric integral (HI) were the key controlling factors of TP concentration. In addition, TN concentration was affected by cropland land use (CP) during the dry season and proportion of labor (LABOR) and per capita agricultural land area (ALA) during the wet season. TP concentration was affected by mean patch size (AREA_MN), phosphate fertilizer application (PF) and patch density (PD) during the dry season and residential area (RP) and values during the wet season. This study illustrates the impact of environmental and socioeconomic factors on NPS pollution, and can be used as a guide for effective NPS pollution control and water quality management.</p>

scholarly journals Pemetaan Indek Kekeringan dan Sebaran Titik Hotspot Daerah Potensi Kebakaran Hutan dan Lahan di Propinsi Riau

2018 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Yotta Autika ◽  
Aras Mulyadi ◽  
Yusni Ikhwan Siregar
Keyword(s):  
Land Use ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Dry Season ◽  
Wet Season ◽  
Index Method ◽  
Spi Index ◽  
Maximum Duration ◽  
Relationship Of ◽  
The Relationship

Riau is one of the most vulnerable provinces to forest and land fires in Indonesia. The potency for forest and land fires is inseparable from the presence of peatlands and exacerbated by drought. The purpose of this research is to know the characteristics of meteorological drought using SPI (Standardized Precipitation Index) method and its relation with forest and peatland fire as one of disaster management effort in Riau Province. The data used in this research are monthly rainfall data from meteorology station and rainfall posts of BMKG, hotspot data from NOAA satellite, map of Forest Use Agreement (TGHK), peat land map and land use map. Analysis of drought characteristics was done by calculating monthly SPI-1 then determining the maximum duration, intensity, severity and drought exposure. Determination of the severity of the drought by weighting and suspension method was based on duration and intensity while drought exposure was done by overlaying the map of the severity of the drought with the land use map. Meanwhile, to know the potential of forest and land fires began with the selection of hotspots on peatlands and forest areas every month then created a graph of the relationship of meteorological drought with the number of hotspots. Then, to see the relationship of drought distribution to the distribution of hotspots in dry season (MK) and wet season (MH) of 2015 was done by overlaying cover the drought distribution with hotspot distribution. The result shows that drought characteristic in the most of Riau province has maximum duration around 4-6 months, dry category of intensity, high category of severity with exposure area in paddy field, field, habitation, and plantation. Then, negative SPI Index (dry condition) has potential to increase the number of hotspots otherwise positive SPI index (wet condition) leads to low occurrence of hotspot. The drought distribution in the dry season (July, August, September) of 2015 triggers the number of hotspots during drought conditions, while in wet season (April, November, December) of 2015 are dominated by normal conditions, some areas are dry and wet, resulting in lower hotspots distribution compared to the dry season.

scholarly journals Spatial-Temporal Changes in Soil Organic Carbon and pH in the Liaoning Province of China: A Modeling Analysis Based on Observational Data

2019 ◽  
Vol 11 (13) ◽  
pp. 3569 ◽  
Author(s):  
Li Qi ◽  
Shuai Wang ◽  
Qianlai Zhuang ◽  
Zijiao Yang ◽  
Shubin Bai ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Environmental Variables ◽  
Spatial Variations ◽  
Liaoning Province ◽  
Mean Annual Precipitation ◽  
Topographic Wetness Index ◽  
Infrared Band ◽  
Wetness Index

Quantification of soil organic carbon (SOC) and pH, and their spatial variations at regional scales, is a foundation to adequately assess agriculture, pollution control, or environmental health and ecosystem functioning, so as to establish better practices for land use and land management. In this study, we used the random forest (RF) model to map the distribution of SOC and pH in the topsoil (0–20 cm) and estimate SOC and pH changes from 1982 to 2012 in Liaoning Province, Northeast China. A total of 10 covariates (elevation, slope gradient, topographic wetness index (TWI), mean annual temperature (MAT), mean annual precipitation (MAP), visible-red band 3 (B3), near-infrared band 4 (B4), short-wave infrared band 5 (B5), normalized difference vegetation index (NDVI), and land-use data) and a set of 806 (in 1982) and 973 (in 2012) soil samples were selected. Cross-validation technology was used to test the performance and uncertainty of the RF model. We found that the prediction R2 of SOC and pH was 0.69 and 0.54 for 1982, and 0.63 and 0.48 for 2012, respectively. Elevation, NDVI, and land use are the main environmental variables affecting the spatial variability of SOC in both periods. Correspondingly, the topographic wetness index and mean annual precipitation were the two most critical environmental variables affecting the spatial variation of pH. The mean SOC and pH decreased from 18.6 to 16.9 kg−1 and 6.9 to 6.6, respectively, over a 30-year period. SOC distribution generated using the RF model showed a decreasing SOC trend from east to west across the city in the two periods. In contrast, the spatial distribution of pH showed an opposite trend in both periods. This study provided important information of spatial variations in SOC and pH to agencies and communities in this region, to evaluate soil quality and make decisions on remediation and prevention of soil acidification and salinization.

scholarly journals Analysis of the Rice Yield under an Agrivoltaic System: A Case Study in Japan

Environments ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 65
Author(s):  
Ruth Anne Gonocruz ◽  
Ren Nakamura ◽  
Kota Yoshino ◽  
Masaru Homma ◽  
Tetsuya Doi ◽  
...  
Keyword(s):  
Land Use ◽  
Solar Radiation ◽  
Rice Yield ◽  
Fertilizer Application ◽  
Agricultural Crops ◽  
Factors Affecting ◽  
Photovoltaic Panels ◽  
System A ◽  
Upper Limit

Agrivoltaic systems, comprising photovoltaic panels placed over agricultural crops, have recently gained increasing attention. Emerging interest in these systems led us to investigate their influence on rice crops. Various factors affecting rice crop yield, including fertilizer application, temperature, and solar radiation, were directly observed, and measured to evaluate changes associated with the shading rates of photovoltaic systems installed above rice crops. The results suggest that the allowable upper limit of the shading rate for agrivoltaic installations ranges from 27 to 39%, which sustains at least 80% of the rice yield, a condition set by the Japanese Ministry of Agriculture, Forestry and Fisheries for these systems. If such systems are applied to rice paddies in Japan at 28% density, they could generate 284 million MWh/yr. This is equivalent to approximately 29% of the total Japanese electricity demand, based on 2018 calculations. This projection indicates the potential of agrivoltaic systems for efficient land use and sustainable energy generation.

scholarly journals FACTORS AFFECTING LIVEWEIGHT OF GOAT AND SHEEP IN TWO LOCATION WITHIN OGUN STATE.

2021 ◽  
Vol 23 (1) ◽  
pp. 12-15
Author(s):  
C. O. N. IKEOBI ◽  
O. A. FALETI
Keyword(s):  
Dry Season ◽  
West African ◽  
Wet Season ◽  
The West ◽  
Southwestern Nigeria ◽  
Factors Affecting ◽  
West African Dwarf ◽  
Ogun State ◽  
West African Dwarf Goat ◽  
The Mean

A study was conducted over two years  With the to determine the changes in the liveweight of Yankasa sheep and Maradi goat in goats and sheep in two locations in Ogun State, South-Western Nigeria Factors found to be important included breed of goat, season, location, and sex of the animal. The Maradi goat had a greater variation in its liveweight than the West African' dwarf goat. The mean weekly gain in the liveweight of goats was 0.18±02 dry season and 0.26±0.05 kg in the wet season. Liveweight changes were greater in yearling Yankasa sheep reared in this part of the Southwestern Nigeria than in older ones; these differences were significantly greater in the dry than in the wet season.

scholarly journals Land use and landscape pattern impacts on water quality at multiple spatial scales in a subtropical large river

2021 ◽  
Author(s):  
Xiao Shu ◽  
Weibo Wang ◽  
Mingyong Zhu ◽  
Jilei Xu ◽  
Xiang Tan ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
River Water ◽  
Total Nitrogen ◽  
Landscape Pattern ◽  
Spatial Scales ◽  
Dry Season ◽  
Wet Season ◽  
Spatial And Temporal Scales ◽  
Multiple Spatial Scales

Abstract The coupling between land use/landscape pattern and water quality in river system varies across different spatial and temporal scales. It is important to understand the association between water quality and land use/landscape pattern across different spatial and temporal scales for the protection of water resources. Here, we measured seasonal water quality at 12 sub-basins in the upper reaches of the Han River (UHR) between 2010 and 2018. We conducted factor analysis and redundancy analysis to determine the links between land use and water quality at multiple spatial scales and to identify the main factors influencing water quality. We found that the concentration of nutrients, including total nitrogen, total phosphorus, nitrate-N, and ammonium-N were higher during the wet season than the dry season. Total nitrogen was identified as the main driver of nutrient pollution of UHR, whereas total phosphorus was identified as another potential nutrient pollutant. We also found that water quality parameters had a stronger related to land use types over the wet season than the dry season. Croplands and urban lands increased phosphorus concentrations of river water, whereas forest and grass lands decreased the nitrogen concentrations of river water at the sub-basins scale. Land use at riparian zone scales better explained variations in water quality than land use at sub-basin scales. The explained variations in landscape metrics were generally higher over the dry season compared to that over the wet season. The largest patch index and Shannon's diversity index were the main predictors of river water quality in UHR.

Some Factors affecting Breeding and Oviposition of the Red Locust, Nomadacris septemfasciata (Serv.)

1959 ◽  
Vol 50 (2) ◽  
pp. 333-353 ◽  
Author(s):  
P. Symmons ◽  
A. J. M. Carnegie
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Dry Season ◽  
Oviposition Site ◽  
Nomadacris Septemfasciata ◽  
Wet Season ◽  
Red Locust ◽  
Factors Affecting ◽  
Outbreak Area ◽  
Primary Object

Observations were made on the red locust, Nomadacris septemfasciata (Serv.), between October 1957 and February 1958 in an area of grassland, six miles long by one mile wide, marked out by beacons and divided lengthwise by a line of beacons down the centre, in the Rukwa Valley of south-west Tanganyika.One half of the plot had been burnt off completely in the latter part of the dry season; the other half was unburnt and carried in part a four-year accumulation of growth and in part an area of standing grass that had regenerated after a damaging fire during the previous wet season and then, for the most part, flooded. Vegetation profiles were made along the whole length of the plot, and rain gauges, soil thermometers and soil tensiometers were installed at regular intervals along the three lines of beacons. Assessments of the population and distribution of adult locusts within the plot were made from Land-Rover or on foot in mid-October, mid-December (ten days after the onset of the rains) and early in January. A systematic search was made for egg-pods, starting at the end of December, along furrows ploughed down the middle of each of a number of narrow strips mown in the grass in sets near each beacon and sampling equally the burnt and unburnt halves of the plot. The first hoppers were seen on 3rd January, and assessments of hopper populations were carried out four times during January.The primary object of the work was to study the effect on choice of oviposition site and on incubation success of the type and condition of the grassland (whether burnt during the previous dry season, at an earlier date, or left unburnt) and its possible bearing on control of the species in an outbreak area. Data were also obtained on the conditions of air temperature, soil moisture, soil temperature and rainfall in which eggs are laid and incubated; and the effect of variations in these factors on oviposition and on incubation success was examined.It was observed that, in the hot, dry conditions of mid-October, adult locusts were completely absent, from the recently burnt-over ground, and were found almost exclusively in that part of the standing grass that had suffered a wet-season burn. By mid-December, the locusts had spread out from the unburnt into the burnt-over zone, where the grass had put out fresh growth, but many were still to be found hi the former, with a concentration along the line of contact with the latter. By early January, the size of the population had been greatly reduced and it was evenly distributed over the whole plot.The distribution of egg-pods snowed that the locusts had laid almost exclusively in the burnt-over zone, about 50 per cent. being found within 0·1 mile of the line of contact with the unburnt zone.The hoppers were likewise almost exclusively confined to the burnt-over zone, and with numbers significantly higher in the ¼-mile band next to the contact line than in the band at ¼–½ mile from it. The numbers of hoppers in the unburnt grass was significantly lower than might have been expected from the results of the egg-pod survey, suggesting that survival was lower there than under fresh grass following a dry-season fire. A subsidiary experiment, in which adult locusts were confined in cages placed on the lately burnt-over zone, the early-burnt and unburnt areas, respectively, suggested that, where there was no choice of oviposition site, the greatest number of surviving egg-pods occurred in the first zone, almost as many in the second and about half as many in the third.During the incubation period, the soil under the unburnt grass was significantly colder, and tended to be moister, to moisten more slowly and to dry out less rapidly than that which had been burnt over. No significant correlation was found between incubation success in the burnt-over zone and total rainfall, mean recorded soil temperature or soil moisture.It is concluded that, since these observations show that, for oviposition, adults of N. fasciata exhibit a very significant preference for ground that has been burnt over in the previous dry season, the burning of selected strips should lead to the concentration of oviposition and, consequently, of hoppers, thus making chemical control of the latter easier and cheaper.There was some evidence, also, that when locusts could not move to bare ground, either oviposition or egg-pod survival (or both) were least successful where the grass cover was thickest.

Analyzing Land Use Impacts on Streamflow Response in a Tropical Watershed: A Hydrometric and Geochemical Approach

2020 ◽  
Author(s):  
Nicola Mathura ◽  
Kegan Farrick
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Critical Zone ◽  
Dry Season ◽  
Future Climate Change ◽  
Wet Season ◽  
Forested Catchment ◽  
Streamflow Response ◽  
The Caribbean ◽  
Geochemical Approach

<p>Climate change and unsustainable land use practices such as quarrying have the potential to negatively impact the hydrology and water resource availability in catchments. Throughout the Caribbean, hillside quarrying has become a common practice. While these activities remove large sections of the critical zone, very little work has been done on how hillside quarrying impacts storm response and catchment water storage.  The study is particularly important given the expected changes to rainfall patterns in the Caribbean under future climate change. We hypothesised that the removal of the critical zone during quarrying will increase the magnitude of streamflow response to storm events due to its close proximity to the river, while also reducing the overall storage of the watershed. This study utilized a hydrometric and geochemical approach with direct measurements of rainfall and streamflow, and bi-weekly water sample collections for geochemistry and <sup>18</sup>O and <sup>2</sup>H stable isotopes between the 3.6 km<sup>2</sup> Acono (forested) and the adjacent 3.6 km<sup>2</sup> Don Juan (quarried) watersheds, located in Trinidad and Tobago. A total of 1207 mm of rainfall occurred, with 87.3% falling from August to November (wet season) and 12.7% from December to March (dry season). The δ<sup> 18</sup>O in rainfall ranged from -7.7 to 0.3 ‰ across both seasons with an average δ<sup>18</sup>O of -3.5±1.8‰ during the wet season and 0.1±0.5‰ in the dry season. During the dry season the mean δ<sup> 18</sup>O of stream water showed a difference between the forested (-2.8±0.3‰) and quarried (-3.1±0.3‰) catchments whereas there was little differences in δ<sup>18</sup>O in the forested catchment (-3.3±0.3 ‰) and quarried catchment–(-3.2±0.27‰) in the wet season. Our stream δ<sup>18</sup>O dry season results suggests that different sources of water or anthropogenic influences such as water from settling ponds in the quarry could have impacted the δ<sup>18</sup>O of the quarried stream as we expected the forested catchment to be more stable. Sample collection at these sites is ongoing and additional parameters such as soil water isotopes and rainfall, soil and stream ion chemistry are expected to improve our understanding of the translation from rainfall to streamflow. This research will allow us to gain a better insight of the current hydrological processes within this catchment and aid in the long term adaptive planning for factors such as climate change and further land use change.</p><p> </p>

scholarly journals Human-Induced Alterations to Land Use and Climate and Their Responses for Hydrology and Water Management in the Mekong River Basin

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1307 ◽  
Author(s):  
Venkataramana Sridhar ◽  
Hyunwoo Kang ◽  
Syed A. Ali
Keyword(s):  
Climate Change ◽  
Land Use ◽  
River Basin ◽  
Dry Season ◽  
Mekong River ◽  
Anthropogenic Factors ◽  
Wet Season ◽  
Industrial Growth ◽  
Mekong River Basin ◽  
Parameter Estimations

The Mekong River Basin (MRB) is one of the significant river basins in the world. For political and economic reasons, it has remained mostly in its natural condition. However, with population increases and rapid industrial growth in the Mekong region, the river has recently become a hotbed of hydropower development projects. This study evaluated these changing hydrological conditions, primarily driven by climate as well as land use and land cover change between 1992 and 2015 and into the future. A 3% increase in croplands and a 1–2% decrease in grasslands, shrublands, and forests was evident in the basin. Similarly, an increase in temperature of 1–6 °C and in precipitation of 15% was projected for 2015–2099. These natural and climate-induced changes were incorporated into two hydrological models to evaluate impacts on water budget components, particularly streamflow. Wet season flows increased by up to 10%; no significant change in dry season flows under natural conditions was evident. Anomaly in streamflows due to climate change was present in the Chiang Saen and Luang Prabang, and the remaining flow stations showed up to a 5% increase. A coefficient of variation <1 suggested no major difference in flows between the pre- and post-development of hydropower projects. The results suggested an increasing trend in streamflow without the effect of dams, while the inclusion of a few major dams resulted in decreased river streamflow of 6% to 15% possibly due to irrigation diversions and climate change. However, these estimates fall within the range of uncertainties in natural climate variability and hydrological parameter estimations. This study offers insights into the relationship between biophysical and anthropogenic factors and highlights that management of the Mekong River is critical to optimally manage increased wet season flows and decreased dry season flows and handle irrigation diversions to meet the demand for food and energy production.

Effects of providing supplements during the wet season on beef production in the Darwin district of the Northern Territory.

1991 ◽  
Vol 13 (1) ◽  
pp. 3 ◽  
Author(s):  
TH McCosker ◽  
PK O'Rourke ◽  
AR Eggington
Keyword(s):  
Dry Season ◽  
Pregnancy Rates ◽  
The Other ◽  
Similar Response ◽  
Wet Season ◽  
Protein Nitrogen ◽  
Protein Supplements ◽  
Factors Affecting ◽  
Lactating Cows ◽  
Mineral Supplementation

The effects of four wet season supplementation regimes on the pregnancy rates, mortality and liveweight of 870 Brahman x Shorthorn cross cattle (cows, bulls, heifers and steers) were investigated on Mt Bundey Station from 1980 to 1984. Treatments imposed were (i) Control (no wet season supplement), (ii) Mineral (supplementation with 13 minerals during the wet season), (iii) +Protein (the same minerals plus non-protein nitrogen and protein over the wet season), and (iv) Strategic (consecutive use of salt, mineral and non-protein nitrogen/protein supplements over the early wet, mid wet and late wet season periods respectively). Each treatment was replicated twice and all received a dry season supplement of non-protein nitrogen plus minerals while stocked at one breeder to 14 ha on native pasture. The pregnancy rate of lactating cows in the +Protein regime in 1982 was 77% compared with 60% for the other three regimes (P<0.05). The pregnancy rates in 1983 for both the +Protein (57%) and Strategic (54%) regimes were higher (P<0.05) than the Control (40%) and Mineral (31%) regimes. Mortality rates of breeders and heifers ranged from 2 to 5% in the Mineral, +Protein and Strategic regimes, compared with 8% (1982) and 12% (1983) (P<0.05) in the Control groups. Post pregnancy diagnosis losses were 8% in the +Protein regime compared with 16% in the other regimes (P<0.05). Breeders were 25 to 30 kg heavier in the +Protein than in Control regimes (P<0.05). Liveweight gain of steers in the +Protein regime was 11 to 31% higher than the other three regimes in two of the three steer drafts. Calf weight per breeder in the +Protein treatment was 55% higher in 1983 and 44% higher in 1984 than the other three regimes. It is concluded that wet season supplementation with non-protein nitrogen/protein and minerals has the potential to substantially increase herd productivity in the monsoonal tallgrass region. The response to the wet season +Protein regime, and the absence of a similar response to the Mineral regime, despite a phosphorus, sodium and sulphur deficiency in the pasture, was attributed to an overriding nitrogen requirement. Other factors affecting herd productivity were, paddock variability which was attributed to variation in the proportion of upland compared with floodplain/riparian land units in each paddock and seasonal differences related to the length of the preceding dry season.

Researches on Temporal and Spatial Changes of Suspended Sediment Nutrients and Source Contributions in Xitiaoxi River, China

2014 ◽  
Vol 955-959 ◽  
pp. 3259-3265
Author(s):  
Zhao Peng Lu ◽  
Xu Yin Yuan ◽  
Hai Long Chen ◽  
Huan Wang ◽  
Xue Qiang Zhao
Keyword(s):  
Land Use ◽  
Suspended Sediment ◽  
Arable Land ◽  
Urban Land ◽  
Dry Season ◽  
Wet Season ◽  
Material Source ◽  
Sediment Nutrients ◽  
Geochemical Parameters ◽  
Temporal And Spatial

Xitiaoxi River is the main discharge river of Taihu Lake. It is important to research changes of suspended sediment nutrients and their provenances for the water environment management. This paper analyzes temporal and spatial variations of nutrients in suspended sediments (SS) and establishes the geochemical model to quantify the proportions of SS sources with geochemical parameters in different reaches. The results show that the contents of SS and its nutrients of the downstream are significantly higher than the upstream and midstream. The contents of nutrients in SS in dry season are higher than in wet season. The C/N and IP/OP ratios of SS can effectively reflect the material source types in the different reaches, which are associated with land use types. Woodland is relatively higher contribution to SS in the upstream, arable lands become a major contributor to SS in the midstream, while urban land is the highest contribution to SS in the downstream. Seasonal changes also affect the contributions of land use to SS. Woodland and urban land show more contributions to SS in wet season than in dry season, whereas arable land and bank sediment show the higher proportions for SS source.

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