Dust emission and wind erosion are widespread phenomena in arid and semi-arid regions,which have far-reaching harmful effects to the environment.This study aimed to use microbial induced carbonate precipitation(MICP)m...Dust emission and wind erosion are widespread phenomena in arid and semi-arid regions,which have far-reaching harmful effects to the environment.This study aimed to use microbial induced carbonate precipitation(MICP)method with Bacillus sphaericus to reduce soil losses that occur in a dust-producing area due to wind erosion in the Ilam Province,Iran.Soil samples at the 0-30 cm depth were used and sterilized in an autoclave for 2 h at 121℃ and 103 kPa.Approximately 3 kg soils were weighed and poured in the 35 cm×35 cm×3 cm trays.Different treatments included two levels of B.sphaericus(0.0 and 0.5 OD),three levels of suspension volume(123,264,and 369 mL),two levels of urea-chloride cementation solution(0.0 and 0.5 M),and two levels of bacterial spray(once and twice spray).After 28 d,soil properties such as soil mass loss,penetration resistance,and aggregate stability were measured.The results showed a low soil mass loss(1 g)in F_(14)formulation(twice bacterial spray+264 mL suspension volume+without cementation solution)and a high soil mass loss(246 g)in F_(5) formulation(without bacteria+264 mL suspension volume+0.5 M cementation solution).The highest(42.55%)and the lowest(19.47%)aggregate stabilities were observed in F_(16)and F_(7)formulations,respectively,and the highest penetration resistance(3.328 kg/cm^(2))was observed in F_(18) formulation.According to the final results,we recommended the formulation with twice bacterial spray,0.5 M cementation solution,and 269 mL suspension volume as the best combination for soil surface stabilization.Furthermore,this method is environmentally friendly because it has no adverse effects on soil,water,and plants,thus,it would be an efficient approach to stabilize soil surface.展开更多
Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of R...Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades.This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and temporally.Hence,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique.Rainfall factor was also studied in groundwater level fluctuation during 2009-2019.To analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from them.In the Jakham River basin,75 wells have been identified for water level trend study using the Mann-Kendall statistical test.The statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon season.The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon.The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.展开更多
Abstract： Estimation of evapotranspiration （ET） for mountain ecosystem is of absolute importance since it serves as an important component in balancing the hydrologic cycle. The present study evaluates the performa...Abstract： Estimation of evapotranspiration （ET） for mountain ecosystem is of absolute importance since it serves as an important component in balancing the hydrologic cycle. The present study evaluates the performance of original and location specific calibrated Hargreaves equation （HARG） with the estimates of Food and Agricultural Organization （FAO） Penman Monteith （PM） method for higher altitudes in East Sikkim, India. The results show that the uncalibrated HARG model underestimates ET0 by 0.35 mm day^-1 whereas the results are significantly improved by regional calibration of the model. In addition, this paper also presents the variability in the trajectory associated with the climatic variables with the changing climate in the study site. Non- parametric Mann-Kendall （MK） test was used to investigate and understand the mean monthly trend of eight climatic parameters including reference evapotranspiration （ET0） for the period of 1985 - 2009. Trend of ET0 was estimated for the calculations done by FAO PM equation. The outcomes of the trend analysis show significant increasing （p ≤ 0.05） trend represented by higher Z-values, through MK test, for net radiation （Rn）, maximum temperature （Tmax） and minimum temperature （Train）, especially in the first months of the year. Whereas, significant （0.01 ≥ p ≤0.05） decreasing trend in vapor pressure deficit （VPD） and precipitation （P） is observed throughout the year. Declining trend in sunshine duration, VPD and ET0 is found in spring （March - May） and monsoon （June - November） season. The result displays significant （0.01≤ p ≤0.05） decreasing ET0 trend between （June - December） except in July, exhibiting the positive relation with VPD followed by sunshine duration at the station. Overall, the study emphasizes the importance of trend analysis of ET0 and other climatic variables for efficient planning and managing the agricultural practices, in identifying the changes in the meteorological parameters and to accurately assess the hydrologic water balance of the hilly regions.展开更多
The study revealed the development of cost effective technology utilized as a practical tool for treatment of seasonal torrent and addressing erosion problems and land use planning.Technology was implemented in a smal...The study revealed the development of cost effective technology utilized as a practical tool for treatment of seasonal torrent and addressing erosion problems and land use planning.Technology was implemented in a small agricultural watershed located in foot hill of Shivalik,India,to assess its prediction capacity of runoff,peak runoff flow and sediment yield.Cost effective technology was evaluated at the event scale by using a database of hydrological,geomorphologic and land use data collected during a two-year period.In the catchment,the gullies which are small to medium in size were treated with gully plugging by erecting loose boulder check dams and erected with different species of plants.Different types of spur were constructed with vegetative reinforcement for channelization of stream flow.The sediments deposited in the first year at downstream was recorded 0.09-81.0 tons,while in the second year it was reduced up to 0.07-16.7 tons.Similarly,up stream sediment deposition was recorded 1.0-72.0 tons and 0.37-13.1 tons in two consecutive years.The D-50 analysis of sediment deposited was carried in three different places of torrent and it was found that deposited particle size material decreased after treatment undertaken in the torrent bed.Therefore,the mechanical as well as vegetative measures helped in the channelization of water course towards the central line with the tune of 10-100 m,stabilization of torrent bed and reclamation of degraded land.展开更多
The study planed to identify a suitable alternative to the FAO 56 Penman-Monteith(FAO56PM)equation for calculating reference evapotranspiration(ET_(0))from chosen te mperature and radiation based models utilizing mont...The study planed to identify a suitable alternative to the FAO 56 Penman-Monteith(FAO56PM)equation for calculating reference evapotranspiration(ET_(0))from chosen te mperature and radiation based models utilizing monthly meteorological data from 30 destinations in diverse agro-ecologial regions of the Northeast(NE)India ie,Assam Bengal Plain(ABP),eastern Himalaya(EH),and the northeastern hilly(NEH)region.Radiation-based IRMAK3 most appropriate in the ABP(weighted root mean square deviation,WRMSD=0.17 mm d^(-1),r^(2)=0.98,for Nagrakata),and TURC model being in the first three rank of most of the sites,with the lowest error and highest correlation in NEH(WRMSD=0.10 mm d^(-1),r^(2)=0.92,for Shillong),and EH(WRMSD=0.23 mm d^(-1),r^(2)=-0.95,for Gangtok).Findings reveal that IRMAK3 and TURC models performed equally well and were observed to be the best among selected modets for the majority of stations followed by FAO24 Blaney-Criddle(FAO24BC),and 1957MAKK Pair-wise regession equations were developed for preferred FAO56PM ET_(0) estimates to ET_(0) estimates by alternative methods.Cross-correlation of eighteen chose methods demonstrated that the five equations(i.e.four radiation-and one temperature-based)performed eceptionally well when contrasted with the FAO56PM model,thus being advised for assessing ET_(0)。under limiting data conditions as have yielded a better estimate of ET_(0) with a small error.展开更多
基金funded by an approved research project of the Shahed University,Iran(9710/97)the Vice President of Science and Technology–Iran National Science Foundation(INSF,97003753)。
文摘Dust emission and wind erosion are widespread phenomena in arid and semi-arid regions,which have far-reaching harmful effects to the environment.This study aimed to use microbial induced carbonate precipitation(MICP)method with Bacillus sphaericus to reduce soil losses that occur in a dust-producing area due to wind erosion in the Ilam Province,Iran.Soil samples at the 0-30 cm depth were used and sterilized in an autoclave for 2 h at 121℃ and 103 kPa.Approximately 3 kg soils were weighed and poured in the 35 cm×35 cm×3 cm trays.Different treatments included two levels of B.sphaericus(0.0 and 0.5 OD),three levels of suspension volume(123,264,and 369 mL),two levels of urea-chloride cementation solution(0.0 and 0.5 M),and two levels of bacterial spray(once and twice spray).After 28 d,soil properties such as soil mass loss,penetration resistance,and aggregate stability were measured.The results showed a low soil mass loss(1 g)in F_(14)formulation(twice bacterial spray+264 mL suspension volume+without cementation solution)and a high soil mass loss(246 g)in F_(5) formulation(without bacteria+264 mL suspension volume+0.5 M cementation solution).The highest(42.55%)and the lowest(19.47%)aggregate stabilities were observed in F_(16)and F_(7)formulations,respectively,and the highest penetration resistance(3.328 kg/cm^(2))was observed in F_(18) formulation.According to the final results,we recommended the formulation with twice bacterial spray,0.5 M cementation solution,and 269 mL suspension volume as the best combination for soil surface stabilization.Furthermore,this method is environmentally friendly because it has no adverse effects on soil,water,and plants,thus,it would be an efficient approach to stabilize soil surface.
文摘Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades.This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and temporally.Hence,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique.Rainfall factor was also studied in groundwater level fluctuation during 2009-2019.To analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from them.In the Jakham River basin,75 wells have been identified for water level trend study using the Mann-Kendall statistical test.The statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon season.The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon.The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.
文摘Abstract： Estimation of evapotranspiration （ET） for mountain ecosystem is of absolute importance since it serves as an important component in balancing the hydrologic cycle. The present study evaluates the performance of original and location specific calibrated Hargreaves equation （HARG） with the estimates of Food and Agricultural Organization （FAO） Penman Monteith （PM） method for higher altitudes in East Sikkim, India. The results show that the uncalibrated HARG model underestimates ET0 by 0.35 mm day^-1 whereas the results are significantly improved by regional calibration of the model. In addition, this paper also presents the variability in the trajectory associated with the climatic variables with the changing climate in the study site. Non- parametric Mann-Kendall （MK） test was used to investigate and understand the mean monthly trend of eight climatic parameters including reference evapotranspiration （ET0） for the period of 1985 - 2009. Trend of ET0 was estimated for the calculations done by FAO PM equation. The outcomes of the trend analysis show significant increasing （p ≤ 0.05） trend represented by higher Z-values, through MK test, for net radiation （Rn）, maximum temperature （Tmax） and minimum temperature （Train）, especially in the first months of the year. Whereas, significant （0.01 ≥ p ≤0.05） decreasing trend in vapor pressure deficit （VPD） and precipitation （P） is observed throughout the year. Declining trend in sunshine duration, VPD and ET0 is found in spring （March - May） and monsoon （June - November） season. The result displays significant （0.01≤ p ≤0.05） decreasing ET0 trend between （June - December） except in July, exhibiting the positive relation with VPD followed by sunshine duration at the station. Overall, the study emphasizes the importance of trend analysis of ET0 and other climatic variables for efficient planning and managing the agricultural practices, in identifying the changes in the meteorological parameters and to accurately assess the hydrologic water balance of the hilly regions.
基金The project was funded by National Agricultural Technology Project(NATP)in village Johranpur-Kulahriwala during 2001-2005,Govt.of India.
文摘The study revealed the development of cost effective technology utilized as a practical tool for treatment of seasonal torrent and addressing erosion problems and land use planning.Technology was implemented in a small agricultural watershed located in foot hill of Shivalik,India,to assess its prediction capacity of runoff,peak runoff flow and sediment yield.Cost effective technology was evaluated at the event scale by using a database of hydrological,geomorphologic and land use data collected during a two-year period.In the catchment,the gullies which are small to medium in size were treated with gully plugging by erecting loose boulder check dams and erected with different species of plants.Different types of spur were constructed with vegetative reinforcement for channelization of stream flow.The sediments deposited in the first year at downstream was recorded 0.09-81.0 tons,while in the second year it was reduced up to 0.07-16.7 tons.Similarly,up stream sediment deposition was recorded 1.0-72.0 tons and 0.37-13.1 tons in two consecutive years.The D-50 analysis of sediment deposited was carried in three different places of torrent and it was found that deposited particle size material decreased after treatment undertaken in the torrent bed.Therefore,the mechanical as well as vegetative measures helped in the channelization of water course towards the central line with the tune of 10-100 m,stabilization of torrent bed and reclamation of degraded land.
文摘The study planed to identify a suitable alternative to the FAO 56 Penman-Monteith(FAO56PM)equation for calculating reference evapotranspiration(ET_(0))from chosen te mperature and radiation based models utilizing monthly meteorological data from 30 destinations in diverse agro-ecologial regions of the Northeast(NE)India ie,Assam Bengal Plain(ABP),eastern Himalaya(EH),and the northeastern hilly(NEH)region.Radiation-based IRMAK3 most appropriate in the ABP(weighted root mean square deviation,WRMSD=0.17 mm d^(-1),r^(2)=0.98,for Nagrakata),and TURC model being in the first three rank of most of the sites,with the lowest error and highest correlation in NEH(WRMSD=0.10 mm d^(-1),r^(2)=0.92,for Shillong),and EH(WRMSD=0.23 mm d^(-1),r^(2)=-0.95,for Gangtok).Findings reveal that IRMAK3 and TURC models performed equally well and were observed to be the best among selected modets for the majority of stations followed by FAO24 Blaney-Criddle(FAO24BC),and 1957MAKK Pair-wise regession equations were developed for preferred FAO56PM ET_(0) estimates to ET_(0) estimates by alternative methods.Cross-correlation of eighteen chose methods demonstrated that the five equations(i.e.four radiation-and one temperature-based)performed eceptionally well when contrasted with the FAO56PM model,thus being advised for assessing ET_(0)。under limiting data conditions as have yielded a better estimate of ET_(0) with a small error.
