جستجوی مقالات مرتبط با کلیدواژه "آب های زیرزمینی" در نشریات گروه "اقتصاد کشاورزی"

In Bushehr province finishing and becoming salty of groundwaters in some fields like Dayer, Kangan, Jam, Assaluyeh make alarm as an active for water lack in other fields of Bushehr province. This study considers the objectives of achieving the maximum economic gross margin, the minimum underground water draft as well as the reduced greenhouse gas emissions, then, attempts to determine optimal cropping pattern for farmers in Jam County. The data for the study were obtained following the completion of questionnaires 60 farmers in Jam County in the years 2017 and 2018. In this regard, a Fuzzy Multi-Objective Linear Programming Model was applied. The results illustrated that in the homogeneous group of farmers with more than 3 hectares, growing of such crops as wheat, tomato, cucumber, onion was decreased, the production of barely, aubergine was increased, water intake from ground fields 35%, emission of greenhouse gases 25% was decreased. However, government may consider some facilities for other cost making farmer’s activities providing stability, sustainability for coinciding this type of patterns for farming of mentioned region.

Extraction from underground waters more than natural discharge of watershed has led to balance deficit and lowering level of water tables and water shortage in many regions. The current research mainly aims to estimate economic and environmental consequences of extraction from underground waters in Ardakan County. In order to determine final personal cost of consumers, sum of annual pumping costs and sum of well drilling costs were calculated 63 billion and 290 billion Rials respectively. In section of additional costs due to extraction, the sum of protective value of underground waters was estimated 22 billion Rials in Ardakan County, using conditional valuation and a two-dimensional technique. The cost for reducing production of farming crops as a part of additional costs caused by extraction was estimated 1’211 billion Rials with respect to statistics of years i.e. 1987-2016. Much difference between additional cost of extraction and personal cost of consumers may be useful in changing attitude of the officials and sectors of industry and agriculture as the greatest consumers of water supplies for optimal consumption of subterranean water supplies. Also, sum of cost for extraction from underground waters (1’586 billion Rials) contribute to the government and policymakers to justify alternative for water transfer in this zone.

Orzooiyeh plain is the most important and the largest crop production in Kerman province in Iran. The main sources of water supply in the plain are groundwater resources and unfortunately their excessive extraction has declined water table and created economical and environmental externalities. The aim of present study is estimation of the effect of ground water tables decline on welfare of farmers. For this purpose, first, production and cost functions of corn and then welfare function was estimated and Welfare changes were calculated in respect to changes in groundwater table. The required data and information were obtained through interviews with 151 farmers in the area in cropping year 2014-15 and Agriculture Organization of Kerman and Kerman Regional Water Authority. Results of this study showed that per one meter drop in water ground water table due to excessive withdrawals, welfare of farmers reduce to the amount of 72.3 million rials and total of welfare reduction of Orzouiyeh plain due to aquifer deficit is 58.3 billion rials.

Over pumping of ground water, especially in arid and semiarid areas, has had negative effects on environment. Recognition of productivity of water and soil resources is the first step toward planning and managing for increasing optimum operation of these resources. In this study, using a sample of 110 farmers, the condition of efficiency and farmer's desperation and migration due to over using of groundwater in Rafsanjan plain was investigated in 2012. Analysis and regression methods were used in this regard. Marginal product of water was estimated 0.04 kg per cubic meter that 33 present has decreased with compare to past tense (15 year ago). Also negative counteraction between decreasing efficiency of water resources and not hope to the condition of future of water resources was specified. This case was effective on farmer's migration. For elimination or reduction of ground water degradation and its effects, this paper recommended that in economic evaluation is attended to the social costs and benefits. Finally, for preventing the negative effect of farmer's desperation for future, it is better to give information to pistachio producers with introducing efficient methods for solving the problem.

Recognition and Economic evaluation of ground water resources is the first step toward optimum operation of these resources. Over pumping of ground water، especially in arid and semiarid areas، has had negative effects on environment. This is because of low price of water in relation to its real value. In this study، using a sample of 110 farmers، the number of displacement of Irrigation wells and its costs due to over using of groundwater in Rafsanjan plain was investigated. Analysis and regression methods were used in this regard. Average of number of times is 2/18 times in Lifetime for each well and Transportation costs 750000000 rials، was estimated in each time of displacement of well. Between these cases with over drafting of ground water، and decreasing quality and quantity of water has had significant relationship in the one percent. For elimination or reduction of ground water degradation and its effects، this paper recommended to Economic evaluation in addition to the social costs and benefits.

Over-pumping of groundwater resources has caused some problems in recent decades leading to reduction of farmers, welfare. To determine its magnitude, factors affecting groundwater salinity were estimated first. Then production function of wheat was estimated and by calculating marginal productivity of each factor, it was found that marginal productivity of all factors except salinity was positive. Finally, the welfare function due to reduction of water level was estimated. The results indicated that farmers, welfare decreased significantly due to reduction of water level. In order to improve the situation some measures such as restricting production of water-intensive crops and exploitation of groundwater are suggested.

Diversity in natural aspects for relaxation, entertainment as well as recreational opportunities associated with walking, sightseeing, camping near wells, qanats, and springs to spend leisure time and to enjoy landscapes, represents the recreational values which can be perceived due to surface water limitations. Recreational value of water includes the benefits derived from those who leave water resources and their attributes intact for others. Areas with groundwater resources (Chack-Chack, Gharbalbiz, Tamehre and Darehghahan) in Yazd- Ardakan plain attract many tourists annually. This study endeavors to determine the recreational value of groundwater resources of Yazd- Ardakan plain and to elicit visitors’ willingness to pay using contingent valuation method. To collect data, a questionnaire with a single-bounded dichotomous choice format was developed in 2009. Results reveal that the total recreational value and the household’s recreational value are 1.38 billion Rials and 11280 Rials, respectively. Considering the weighted mean of WTP, the entrance fee for water-based recreation areas would be 4700 Rials. These estimates provide rational justification for policy makers and managers to support the conservation of water-based recreational areas.

In this study, irrigation water pricing was investigated as a tool for under ground water demand management in Dashtestan district. The data were collected by interviewing pioneer farmers. Applying present worth procedure, the factor cost of each cubic meter of water was obtained to be 84.96 Rials. On the other hand, shadow price of water (i.e. marginal productivity of each cubic meter of water) was obtained in interval [178, 2328] in sparing, [364, 549] in summer and [210, 1802] Rials in fall and winter by Interval Mathematical Programming (IMP). Moreover, water normative demand function for various seasons and years were estimated in order to study water pricing effectiveness. Results indicated that farmers pay much lower than the real value of water in framework of water extraction costs. The results of normative demand function estimation indicated that demand for irrigation water in various seasons is inelastic with respect to water price changing in these seasons and is more inelastic for the years. In fact, farmers react against increasing water price not only as decreasing in consumption at same season, but also with reallocating a part of water in the year. Based on the findings, water pricing policy is not very effectiveness on diminishing consumption of irrigation water.