جستجوی مقالات مرتبط با کلیدواژه « دشت جیرفت » در نشریات گروه « آب و خاک »

The present study evaluates the water shortage indices in the agricultural sector of Jiroft Plain, taking into account the framework of water footprint during the 2008 to 2019. In this study, water stress, agricultural water stress, blue water scarcity, water self-sufficiency, water dependency and water poverty indices were evaluated. The results showed that the annual average of agricultural water resources is 1425 MCM, and the amounts of green and blue water resources are 11 and 1413 MCM, respectively. The annual average agricultural water footprint of Jiroft Plain is 354 MCM. The share of blue, green and gray water footprint is 40, 14 and 26%, respectively. The average water stress index is 37%, which shows that the moderate water stress in Jiroft plain. The average AWSI and BWS is 0.84 and 0.77, respectively, which are located in the class with high stress. The water self-sufficiency and dependency are 89% and 11%, respectively, which indicates high self-sufficiency and low dependency of the study area in terms of importing agricultural products. The high water self-sufficiency index despite the lack of rainfall in Jiroft Plain has caused high water poverty in the region. The most important reason for the high WSS is the high diversity of agricultural products in the food basket of this region. As an example, citrus fruits, dates, wheat, barley, potatoes and onions are cultivated in Jiroft plain.

Iran’s groundwater resources are considered as a vital water supply for a number of reasons, and inconsiderate usage and exhausting these vital resources would bring about a severe water crisis in the country. Underground waters are usually consumed for different purposes ranging from drinking and agriculture to industry, so that the quality measures of these resources depend on the main purpose that they are intended to be used. Consequently, different standards of quality restrict the water consumption in order to reduce harmful effects of them. Furthermore, Water quality is generally an extremely important subject in water studies, and identifying and analyzing the chemical compounds in groundwater resources could be beneficial in agricultural studies. In agriculture, both water quality and quantity play 2 part, and poor quality could certainly become a primary restricting factor in water usage. This can cause undeniable farming problems and could damage the soil as well. In this regard, the necessity of providing a proper, well-planned management system for monitoring and controlling water quality is of a great importance.Over the past years, in many parts of Iran, including Jiroft, in which this study is carried out, because of some important issues such as the growing population, frequent periods of drought and inconsiderate using of the dwindling supply of groundwater, the quality and quantity of these waters are rapidly diminishing. As the livelihood of a huge number of local people who lives in the region of Jiroft, depends on agriculture, the effective management of these water resources needs better and more up-to-date information about these resources. Having such data could definitely help us to be aware of recent changes and to be able to make better, informed decisions. The main purpose of this study would be analyzing the changes of chemical parameters in underground waters of Jiroft plain.

 Hydro-chemical analysis of Jiroft’s groundwater resources for agricultural consumption is our primary goal in this research. In order to achieve this goal, we gauged and analyzed different chemical parameters including electrical conductivity (EC), total soluble solids (TDS) and acidity (pH) in 30 samples of the wells with suitable dispersal in the region in the years of 2011 and 2018. To understand the spatial distribution of suitable areas, ArcGIS 10.5 software is used and the data layers were prepared.

 The results of the Wilcox diagram show that most of the samples are in class C2-S1, which is a sign of a low salinity line and therefore they are applicable in agriculture. Besides, a limited number of samples are in class C3-S1, C3-S2 and C4-S2, which have high salinity line and are consequently ideal for irrigating the plants that are not sensitive to salinity. It is noteworthy that none of the samples has a low salinity contamination (C1-S1). Considering the fact that most of the samples in the study area are in the range of C2-S1, they could be suitable for irrigation. According to the Wilcox diagram, the quality of agricultural water in the groundwater samples in Jiroft is in a good and mostly moderate category. Our research finding shows that TDS variations is between 320 and 2048 mgL-1, and pH variations is between 6.6 and 8.6, and therefore they are ideal for irrigation purposes.

 During the statistical period, the level of water reduction is increasing; although, in some years, the number is lower. These considerable changes confirm frequent droughts and a vast amount of underground water consumption. In this situation, diminishing groundwater quality would be inevitable and if this trend continues, the quality level of these waters will be reduced gradually. In the years when water level reduction is lower than others, we can see higher level of rainfalls or even floods in which took place in the region frequently in recent years. This naturally fuels Jiroft’s aquifers and decreases the level of water reduction. According to the zoning map of the distribution of groundwater quality parameters, the Jiroft plain has a suitable quality for agricultural purposes. Only in the southwestern margin and some other parts of the plain, the groundwater quality is lower and could not be suitable for farming purposes. Overall, most areas of the plain are of good quality and suitable for agriculture.

In recent years, groundwater overexploitation has led groundwater depletion Jiroft plain and considering the strategic role of this plain in supplying water required for agricultural products, planning to improve the water resources of this plain is essential. Therefore, the purpose of this study was to investigate the effects of groundwater resources management in Jiroft plain in the past (2005-2019) and the near future (2019-2031) using GMS10.4 software based on hydrological, hydrogeological and Topographic data. Also, to investigate the impact of water resources changes on crops cultivation pattern, changes in cultivation pattern of major horticultural crops in terms of their water requirement in Jiroft plain were studied using information and statistics of major horticultural crops in Jiroft plain during the last three decades. The results showed that aquifer has yearly faced with a decline about 0.86 m during the baseline period (2005-2019), which indicates overexploitation of groundwater resources in this plain. The aquifer status was predicted in the future under different scenarios using the GMS 10.4 model. Also, studying the development trend of major horticultural products in Jiroft plain showed that despite the declining trend of groundwater resources over the past three decades, the share of horticultural products with high water requirement has been increased in the crop cultivation pattern of this plain and the behavior of farmers to develop the pattern of agricultural products cultivation has been influenced by factors except groundwater resources limitations. Therefore, it is suggested that scenarios of reducing groundwater resources exploitation in Jiroft plain and also paying attention to cultivation pattern appropriate to water resources in different parts of the plain should be a priority for agricultural planners.

Improving the drought quality indicators play an important role in water resources management. In this research, the Effective Reconnaissance Drought Index (eRDI) was used to detect agricultural droughts and present an early warning system in the Jiroft Plain. For this, the reliability of this index was evaluated using the NDVI and its relationship with storage changes of the aquifer was analyzed. According to the findings, the eRDI index shows the same effects in modeling of agricultural drought in different stages of plant growth but its severity is higher in the critical period of vegetation’s growth and therefore this period was considered for the spatial analysis of agricultural drought. The results showed that the occurrence of normal, dry and wet periods are associated with the accessibility or inaccessibility of effective precipitation. The results indicated a significant correlation between eRDI and NDVI in sparsely vegetation areas at the level of 5% (r = 0.87) due to the effective precipitation role in calculating the eRDI, although a weak correlation has been found between the NDVI and eRDI (r = 0.31) in the irrigated area that is probably due to the groundwater pumping and exploitation from the Jiroft dam. As a result, the eRDI-3 and eRDI-7 could be useful for early warning of the agricultural drought and groundwater storage depletion respectively.

The Jiroft Plain Basin is part of the Jazmurian Waters Basin, located in the south of Iran, Kerman province. The uncontrolled extraction of groundwater from the aquifer of the forbidden Jiroft plain has caused the aquifer's water level to fall, which could seriously threaten the agricultural economy of the region. If this action is not considered seriously, this plain will not only exacerbate environmental impacts in the future, but will also face economic and social problems. The purpose of this paper is to identify the status of Jiroft Plain Aquifer in recent decade and compared the cost of water extracting from wells in two types of water extraction technology: diesel and electric pumps. Initially, based on available statistics and information, which collected from Iran Water Resources Management Company, Kerman Regional Water Company and Jiroft District Water Company, the status of the groundwater Aquifer in Jiroft plain has been investigated. Then the cost of water pumping from wells with electric and diesel water removal technology was compared. To achieving the study purposes, questionnaires was collected from beneficiaries of Jiroft plain agricultural water wells in the crop year 2014-2015.The sample size was determined by the simple random sampling method. In the meanwhile, the data of the questionnaire include: crops production cost in 2015-2016, how to use water wells, energy consumption, and cost of energy and pump maintenance costs. To sum, 227 questionnaires were collected that 202 cases of them used electro pump technology, and 25 cases used diesel pumps for withdrawing water from wells. The results showed that average depth of electric and diesel wells were 101 and 55 meters, and their average discharge was 25 and 15 liters per second, respectively. It can be seen that the electric pump, in comparison with the diesel pump, results in more drainage and further increase in annual drop of groundwater level. Whereas, its energy cost is less than diesel pump. Also, the results showed that the cost of water extraction per cubic meter of water with electro pumps and diesel pumps are 169 and 365 IRR, respectively. It means that extraction cost with electro pump is about half of diesel pump cost. So, if we change the technology of water extraction from diesel to electro pumps, we can save 1.525.670 and 3815920 IRR on cultivating cost for one hectare of wheat and orange, respectively. The wells with electro pump technology, in comparison with wells with diesel engine motors, have more average depth and average discharge rates. From working hours' side, electric pump is more than diesel pumps. Therefore, by using electric pumps, more water will extracted from groundwater resource and eventually decrease the level of water aquifer. Although the converting pump type policy from a diesel to electric pump has been supported by the government in recent years and has been included subsidized facilities, it has caused negative effects. This policy could save up to 50 percent of pumping and pump maintenance costs for agricultural operators and consequently reduced the cost of production but the lack of some policies by the government such as pricing, tariff and incentive policies to control the volume of groundwater extraction has led to increase a pressure on groundwater resources. Farmers who have economic logic accepts the fixed costs of changing diesel pump to electric pump to reduce production costs in the long run and exploit the benefits of more water extraction, but the policy makers have not taken any action for maintaing the groundwater resources of the plain. Therefore, the fallowing approaches are suggested: implementing policies to control the volume of water extraction to prevent the continuation of the process of discharging strategic reserves, contributing to the equilibrium of the aquifer's plain water level, reducing the discharge rate of the exploitation at the request for change of diesel pump to electric pump

Land-use change is one of the most important factors influencing soil microbial communities, which play a pivotal role in most biogeochemical and ecological processes. In order to determine the effect of land use on the relative abundance and composition of soil bacterial communities by using Real-time PCR, a study was carried out in three different land uses (orchard land, farmland and shrubland) in Jiroft plain, Iran. 12 surface soil samples were collected from each land use and some soil physicochemical properties were measured. The NucleoSpin® Soil kit was used for extraction and purification of DNA from soil samples. Quantitative comparison of the concentration and melting temperature of 16S rDNA amplicons, respectively, for assessment of the relative abundance and composition of soil bacterial communities in different land uses were performed by using Real-time PCR system and based on the relative standard curve method. The results related to the concentration and quality of soil DNA indicated that extraction of DNA from soil samples by using NucleoSpin® Soil kit was favorable. As the results of Kruskal-Wallis nonparametric ANOVA showed, land use had significant effect on the relative abundance and composition of soil bacterial communities at the level of 5%. Means comparison showed that the relative abundance of soil bacterial communities in orchard land use was higher than that of two other land uses. Furthermore, the composition of soil bacterial communities in orchard and farm land uses was significantly different from shrub one. It can be concluded that land-use changes in Jiroft plain from shrubland to orchard land, and from shrubland to orchard land and farmland have caused an increase in the relative abundance as well as a significant change in the composition of soil bacterial communities, respectively.