Arid District Research Articles

Exploring the Influences of Water-Saving Practices on the Spatiotemporal Evolution of Groundwater Dynamics in a Large-Scale Arid District in the Yellow River Basin

Water-saving practices (WSPs) have been recognized as an effective measure for reducing agricultural water use and alleviating regional water shortages in arid irrigation districts. However, WSPs have also reduced groundwater recharge, thereby causing the depth to groundwater table (DGT) to increase. Therefore, characterizing the impact of WSPs on the spatiotemporal variability in the DGT is of paramount importance for protecting limited groundwater resources. Based on monthly DGT observation data collected from 1990 to 2015 at 206 observation wells in the Hetao Irrigation District (HID), located in Northwest China with an arid climate, the spatiotemporal variations in DGT before and after the application of WSPs were analyzed using the empirical orthogonal function (EOF) method, and the major driving factors of the spatiotemporal DGT changes were also identified using comprehensive approaches. The EOF method revealed four major spatiotemporal DGT patterns both before and after WSPs were applied; these patterns explained 71.39% and 73.99% of the total variability in the HID before and after WSPs application, respectively. In addition, the main controlling factors affecting the DGT dynamics were different before and after WSPs were applied. In terms of the associations of the DGT with the impacting factors, the meteorological factors had the strongest impact on the DGT changes on the long-term scale of 64 months; however, irrigation played a leading role at the seasonal and semiannual scales, especially after WSPs application. The soil texture significantly impacted the spatial DGT patterns, particularly at depths above 150 cm. This study provides a scientific basis for the rational development of local groundwater resources and the scientific management of water-saving irrigation measures.

Seasonal change in species composition and target-site mutations in Anopheles gambiae s.l. in the severe drought area of Kandi, North-eastern Benin

The persistence of malaria transmission in areas with very arid environmental conditions remains enigmatic. The present study investigated seasonal variation of mosquito species composition and Kdr and Ace-1 mutations in Anopheles gambiae s.l. in the very arid district of Kandi in North-eastern Benin.Adult mosquitoes were sampled over 1 year using both human landing catches (HLC) and pyrethrum spray catches in 4 villages belonging to 2 areas of different levels of aridity. The collections were carried out on a bi-monthly basis in the wet season, and once every month in the dry season to better capture the entomological situation in drought period. Females An. gambiae sl specimens were kept aside and analysed by PCR for species identification. Presence of kdr and Ace-1 mutations was also assessed in the An. gambiae s.l. collection.A total of 2,211 host-seeking mosquitoes belonging to 15 species were collected in the study area. An. gambiae s.l. was the most abundant species and represented 67% of the collection. Other Anopheles species were found at very low frequency among which An. funestus, An. pharoensis, An. broheri and An. coustani. Molecular species identification showed in dry season a significantly higher frequency of An. coluzzii over An. gambiae s. s. in both less dry (70% vs 29% with p < 0.001) and driest (70% vs 30% and p = 0.034) areas of the district of Kandi. In the rainy season, there was similar frequency of An. coluzzii and An. gambiae s. s. in the less arid area (53% vs 45%; p = 0.153), while An. coluzzii remained significantly predominant (62% vs 38%; p = 0.012) in the driest zone. The frequency of kdr mutation was significantly higher in dry season than in rainy season (93% vs 84%; p

Biogeographic units in the Chihuahuan Desert: Implications for regionalization and area nomenclature

There are several biogeographic regionalizations of the Chihuahuan Desert province, which differ in the criteria used, and the names and categories given to the different units recognized. We compared maps of these biogeographic regionalizations, detecting similarities and differences in the units recognized, and searched endemic taxa diagnosing them. Eight biotic units are recognized and named: Chihuahuan Desert province, Chihuahuan subprovince (Trans-Pecos and Mapimian districts), and Mexican Plateau subprovince (Saladan, Mexican Southern Arid district and Tehuacán-Cuicatlán Valley districts). These subprovinces and districts are hypothesized to represent natural biotic units, each harboring a particular assemblage of endemic taxa.

Cost and returns of milk production in selected arid district of Rajasthan

The significance of the sector further increase in arid western Rajasthan where frequent droughts are the primary concern. Milch animals are kept as farming household from very long time in India. The Bikaner district of Rajasthan is selected for the study purposively as it is having largest cattle population and another reason for selecting the district is that if has higher indigenous cattle population in the area is second largest enterprise after crop production. Predetermined samples of 180 farmers, selected farmers were categorized into small, medium and large herd-size categories using cumulative square root frequency method. It was evaluated region wise cost of concentrate of indigenous cows; green fodder and total feed cost per day per indigenous cow were highest for canal irrigated region causing highest variable cost also. Due to good feed, the returns were highest in the area. It was found by the perusal of result that per litre cost of milk production was highest for unirrigated region followed by canal irrigated region and least by tube well irrigated region but average per day milk production and net return per day per buffalo was highest on tube well irrigated region followed by canal irrigated region and least unirrigated region, respectively.

Long-Term Homogeneity, Trend, and Change-Point Analysis of Rainfall in the Arid District of Ananthapuramu, Andhra Pradesh State, India

The objective of this study is to evaluate the homogeneity, trend, and trend change points in the rainfall data. Daily rainfall data was collected for the arid district of Ananthapuramu, Andhra Pradesh state, India from 1981 to 2016 at the subdistrict level and aggregated to monthly, annual, seasonal rainfall totals, and the number of rainy days. After quality checks and homogeneity analysis, a total of 27 rain gauge locations were considered for trend analysis. A serial correlation test was applied to all the time series to identify serially independent series. NonParametric Mann–Kendall test and Spearman’s rank correlation tests were applied to serially independent series. The magnitude of the trend was calculated using Sen’s slope method. For the data influenced by serial correlation, various modified versions of Mann–Kendall tests (pre-whitening, trend-free pre-whitening, bias-corrected pre-whitening, and two variants of variance correction approaches) were applied. A significant increasing summer rainfall trend is observed in six out of 27 stations. Significant decreasing trends are observed at two stations during the southwest monsoon season and at two stations during the northeast monsoon season. To identify the trend change points in the time series, distribution−free cumulative sum test, and sequential Mann–Kendall tests were applied. Two open−source library packages were developed in R language namely, ”modifiedmk” and ”trendchange” to implement the statistical tests mentioned in this paper. The study results benefit water resource management, drought mitigation, socio−economic development, and sustainable agricultural planning in the region.

Farmers' perception towards shelterbelts in hot arid regions of Rajasthan: An analysis by garrett's ranking technique

Shelterbelt plantations are one of the biggest ecofriendly technologies to address wind erosion, control sand movement and related problems in the arid areas, which cover 12 per cent of India and more than half of Rajasthan. However, the role of shelterbelts in arid agriculture is changing. A survey was undertaken to investigate the farmers' perception toward field shelterbelts/windbreaks and its impact in farmers' fields in the arid district of Bikaner, Rajasthan. Questionnaire, group discussion and observations were used for data collection. The respondents of the study were the farmers having already established shelterbelts in their farms. The study revealed that farmers were using windbreaks on agricultural lands mainly to protect crops from strong winds, provide shade to livestock, reduce crop damage from frost and cold winds, reduce soil erosion etc.; while the biggest challenge was the competition by trees to the crops growing below them. The farmers' preference for tree species was also noted to have changed over the years. Though old shelterbelts were mainly of Acacia tortilis, farmers now prefer Dalbergia sissoo (45 per cent prevalence), since it does not affect crop growth and for its economic timber value. Other species like Zizyphus sp., Eucalyptus sp., Cordia myxa etc. when used as shelterbelts provide fruits and fuelwood which provide additional income to farmers.

Deficit irrigation enhances contribution of shallow groundwater to crop water consumption in arid area

Agricultural water conservation is important in arid and semi-arid areas where water resources are deficient and agriculture irrigation accounts for a high proportion of water use. Thus, efficient deficit irrigation methods, which the supplied water is less than potential evapotranspiration have been developed. In semi-arid areas, groundwater can contribute to crop’s water consumption but less is known about impact of deficit irrigation on the contribution. We conducted, therefore, a two-year field experiments with deficit flood irrigation for maize in an arid district with shallow groundwater in China. Four irrigation practices were tested with water applied at approximately 82.5%, 75%, 67.5% and 60% of the 540mm potential evapotranspiration (PET) in 2014 and the 500mm in 2013 over the crop growing season. We found that the upward flux between soil water and groundwater varied from 5mm with input water of 488mm to 60mm with input water of 353mm. The yield of maize decreased by only 15% from 10.0 to 8.5t/ha for the WS treatment (irrigated at 60% of PET) compared with the WH treatment (irrigated at 82.5% of PET) due to more groundwater contribution to the crop growing with less irrigation. As a consequence, the water use efficiency (WUE), defined as quotient of the yield and plant evapotranspiration was not significantly different among different irrigation treatments. However, the irrigation water use efficiency (IWUE), which is the yield per unit of water applied, increased significantly with the decreasing amount of water applied due to the contribution of upward fluxes. The implication is that deficit irrigation enhances the contribution of groundwater to crop water use and will not produce an obvious reduction of yield within a stable shallow groundwater level.

Theoretical Study on Establishing Hydro-Eco Dynamic Monitoring System in Large-Scale and Arid Irrigation District

As for some large-scale and arid irrigation district in China, such as Jinghuiqu irrigation district and Shihezi reclamation district, hydro-ecosystem was gradually degenerated and imbalanced due to water shortage and unreasonable exploitation. In order to study hydrological elements, water cycle process and ecological response caused by human activities and other factors, and improve the quality of hydro-ecosystem, scientific connotation of establishing hydro-eco dynamic monitoring system in large-scale and arid irrigation district was defined. Hydro-ecosystem dynamic monitoring indexes including meteorological elements, hydrological elements, ecological elements closely related to hydrological elements and cycle, and socio-economic elements were proposed. Comprehensive monitoring methods based on automatic monitoring net, remote sensing satellite monitoring, field test and investigation were determined, and overall framework of hydro-eco dynamic monitoring was designed, which provided a theoretical basis for establishing hydro-eco dynamic monitoring system in large-scale and arid irrigation district.

黑河中游湿地景观破碎化过程及其驱动力分析

在遥感和GIS技术支持下,基于1975-2010年长时间序列遥感影像,选取斑块密度指数(<em>PD</em>)、景观内部生境面积指数(<em>IA</em>)、斑块平均面积指数(<em>MPS</em>)、斑块形状破碎化指数(<em>FS₁、FS₂</em>)等具有典型生态意义的景观指数模型,系统分析了黑河中游湿地景观的破碎化过程,并结合灰色关联分析、主成分分析等方法,探讨了影响研究区湿地景观破碎化过程的各驱动因子。结果表明:近35年来,研究区湿地景观破碎化主要表现为斑块平均面积的萎缩,斑块密度的上升以及斑块形状破碎化指数的增大。整个研究时段内,研究区湿地斑块平均面积减少了48.95hm²,斑块密度的上升0.006个/hm²;导致黑河中游湿地景观破碎化发生和发展的驱动力包含自然和人文两个方面。自然因子对湿地景观破碎化进程的影响则主要体现在气温和降水上,而且气温对湿地景观破碎化进程的影响程度明显大于降水。但在1975-2010年间的这一较小时间尺度上,人类活动对湿地景观破碎化的贡献率明显高于自然因子,人类活动能力的增强以及影响范围的不断扩大是引发黑河中游湿地景观破碎化的主因。;Heihe River is one of the most important inland rivers in the northwest arid district of our country. Wetlands that distributed along the middle Heihe River Basin has a great significance to the eco-environment safety of northwestern regions in our country. It plays a key role in preventing the Tengger Desert and Badain Jaran Desert to be a whole. However, it had been destructed by human activities and climate change deeply in recent years. So the research of the wetlands in Heihe River is urgently needed. Based on satellite images of 1975, 1987, 1992, 2001 and 2010, the paper chose some typical landscape index models, such as patch density, landscape internal habitat area index, mean patch size, <em>FS</em> and so on, to analyze the wetland landscape fragmentation process and its drivers of the middle Heihe River Basin between 1975 and 2010, combining with grey relational analysis, principal component analysis and other analytical methods. The results indicated that fragmentation process of wetland landscape in the middle reaches of the Heihe River mainly expressed as the shrinkage of internal habitat area and mean patch size, the increase of fragmentation index and the enlargement of <em>FS</em> in the past 35 years. In the entire period of study, the mean patch size of the wetlands in middle Heihe River Basin decreased 48.95 hm² corresponding to the patch density raised 0.006 Ind/hm². In terms of patch shape fragmentation index, it mainly expressed as the increasing of mean patch shape fragmentation index and area-weighted mean shape fragmentation index. Especially the values of the mean patch shape fragmentation index and area-weighted mean shape fragmentation index increased from 0.524, 0.269 to 0.556 and 0.276 between 1992 and 2010. So it can draw a conclusion that wetland landscape fragmentation has been the main manifestations of wetland degradation in the study area throughout the study period. The dominant driving force which led to the middle reach of the Heihe River wetland landscape fragmentation and development is human factors. Natural factors on the process of wetland landscape fragmentation have a certain influence. Yet the contribution of human activities on the wetland landscape fragmentation was significantly higher than the natural factors in a smaller time scale. The increased capacities as well as the expanding influence sphere of human activities act as the main cause of the middle reach of the Heihe River wetland landscape fragmentation. In addition, natural factors also have some influence on the process of wetland landscape fragmentation. Furthermore, the impact of natural factors on the process of wetland landscape fragmentation is mainly reflected in the temperature and precipitation. Comparing with precipitation, in the natural context of arid environments just like the study area, the temperature plays a significantly greater actor in the process of wetland landscape fragmentation.

Acid mine drainage and heavy metal contamination in groundwater of metal sulfide mine at arid territory (BS mine, Western Australia)

The issues of acid mine drainage (AMD) and heavy metals contamination in the metal sulfide mine in the arid district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan (BS) nickel sulfide mine (Western Australia). The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility (TSF) and in the background of the mine (away from TSF), respectively, and the pH and electric conductivity ( E c) were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified (pH mean≈5, pH min=3), and the average contents of heavy metals (Co, Cu, Zn, Cd) and Al, Mn are of 1–2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from mill process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.

Research on runoff forecast approaches to the Aksu River basin

The Aksu River (the international river between China and Kirghiz) has become the main water source for the Tarim River. It significantly influences the Tarim River’s formation, development and evolution. Along with the western region development strategy and the Tarim River basin comprehensive development and implementation, the research is now focused on the Aksu River basin hydrologic characteristic and hydrologic forecast. Moreover, the Aksu River is representative of rivers supplied with glacier and snow melt in middle-high altitude arid district. As a result, the research on predicting the river flow of the Aksu River basin has theoretical and practical significance. In this paper, considering the limited hydrometeorological data for the Aksu River basin, we have constructed four hydrologic forecast approaches using the daily scale to simulate and forecast daily runoff of two big branches of the Aksu River basin. The four approaches are the upper air temperature and the daily runoff correlation method, AR(p) runoff forecast model, temperature and precipitation revised AR(p) model and the NAM rainfall-runoff model. After comparatively analyzing the simulation results of the four approaches, we discovered that the temperature and precipitation revised AR(p) model, which needs less hydrological and meteorological data and is more predictive, is suitable for the short-term runoff forecast of the Aksu River basin. This research not only offers a foundation for the Aksu River and Tarim Rivers’ hydrologic forecast, flood prevention, control and the entire basin water collocation, but also provides the hydrologic forecast reference approach for other arid ungauged basins.

Reaction of Some Peach (Prunus persica) Varieties to the Leaf Curl Disease Caused by Taphrina deformans in Arid District of Turkey

Reaction of Some Peach (Prunus persica) Varieties to the Leaf Curl Disease Caused by Taphrina deformans in Arid District of Turkey

Pyrenophora graminea in Fields Sown-spring Barley Angora in Arid District of Turkey

Pyrenophora graminea in Fields Sown-spring Barley Angora in Arid District of Turkey

Estimation of Evapotranspiration at Alfalfa Field on Irrigated Land in Arid District

For the purpose of estimating the evapotranspiration on an irrigated land in arid district, the budget of radiation, the budget of energy and meteorological parameters were measured at an alfalfa field in an irrigated farm. In the daytime, the latent heat flux increased to 450 W/m2 which was about 4.5 times greater than the sensible heat flux. The bulk transfer coefficient of sensible heat flux was estimated to be 0.0088. The canopy resistance (rc) on the alfalfa field was equal to zero before 10 o'clock because of the evaporation of dew. The rc values were about in the range of 40∼60 sec/m from 12 till 17 o'clock then increased rapidly. A model for rc which contains solar radiation as variable was adopted. On the basis of these results, a model for estimating the evapotranspiration was developed. Then sensible heat flux, latent heat flux, reflectivity, amount of dew and transpiration were estimated from air temperature, vapor pressure of air, wind speed, solar radiation, long wave radiation, net radiation and soil heat flux which were measured for 17 days at the alfalfa field. Computed diurnal change of reflectivity was about the same as measured one. There was a positive correlation between estimated daily amount of transpiration and measured daily soil water decrease.

On Ticks (Ixodidae) of Southern French Somaliland and the Rediscovery of Rhipicephalus Longicoxatus Neumann 19051

This brief tick survey of Southern French Somaliland was made in July 1950, during the height of the dry period. What remains of the human population at this season in the torrid, forbidding, sparsely inhabited land is concentrated in the capital, Djibouti, an important seaport and rail terminus and in small outlying oases. Many families have migrated to the Ethiopian highlands with their herds of sheep, goats and cattle in search of grazing and water. The area lies within the Somali Arid District of the Eastern Ethiopian fauna, and gradually rises from sea level desert or semidesert to sparsely vegetated, boulderstrewn foothills, outliers of the Abyssinian highlands, interspersed with salt flats.

An Early Neolithic Site at Hockham, Norfolk

In an arid district like Breckland, the vicinity of the meres, which provided a water-supply, fish, fowl and molluscs, remote from river-valleys, was eminently suitable for settlements of prehistoric man. Pile-dwellings have been found in two of the Wretham Park meres, and there are evidences of settlements on a small plateau on the east shore of Fowlmere, a similar plateau on the north-east bank of Langmere, and the north and south shores of Ringmere. The bed of Langmere confirms the evidence of an important settlement. The southern portion contains quantities of pot-boilers and a bank projecting into the mere from the south-west corner of the island seems to be chiefly made of pot-boilers. Many flakes, of types and patinas similar to those recorded hereafter, are also found in the bed of Langmere, and on its shores. Flakes and pot-boilers have also been found near most of the other meres, and Dr. Marr has described (Proc. Vol. I., p. 374) “A Late Palæolithic Site on Wretham Heath,” east of Langmere.

New and Noteworthy Plants from Southwestern Colorado

During the summer of I9I3 and the spring and summer of I9I4 it was the writer's privilege to make a collection of the plants of western Montrose County, from the Uncompahgre Plateau on the east to the La Sal Mountains of eastern Utah on the west. Of all parts of the state, the southwestern portion is the least known botanically and may therefore be expected to furnish novelties to the systematist for many years to come. This is especially true of the spring flora of the arid or so-called Upper Sonoran life-zone. The reason for this is obvious when one considers that most of the collections have been made upon the summer flora, and that by the middle of June most of the vegetation of the arid district has withered and even the seeds have scattered. Though the collections of I9I3 and I9I4 were made upon the montane as well as the desert flora, most of the interesting forms were discovered at the lower altitudes. The undescribed species, those that had not previously been reported from the state or had been omitted from recent manuals of the district, as well as some perplexing forms, are treated in this paper. A complete set of these plants, containing the types of the species and varieties characterized, is deposited in the Rocky Mountain Herbarium. CALOCHORTUS FLEXUOSUS Wats.-This lovely and interesting mariposa lily, which has heretofore been known only from farther south and west and has not generally been credited to Colorado, was collected in bloom near Naturita on May I2 and May 26, on a red clay hillside over which it was growing in great profusion. The stems were stiff and flexuous and showed no inclination to become prostrate or twining. The flowers have been described as purple or purplish, but as a matter of fact they are at first white and later become a very delicate pink; it is only in withering that they become purplish. Nos. 289 and 357.