Document Type : Research Paper
Management and decision-making issues related to water resources, especially groundwater, which is an important source of fresh water, is the main decisions of a country. According to population growth and increasing demand as well as lack of water, proper management for these resources will be needed. So integrated environmental assessment is one of the best and most effective tool in determining the economic, social and environmental problems.
By reviewing previous studies, most research is done on the effects of groundwater depletion or Environmental Impact Assessment (EIA) before and after construction of a project or plan and there is less comprehensive view in social and economic dimensions of the environment. In this study, Overview and integrated research on the causes and effects framework of groundwater depletion is used and Integrated Environmental assessment (IEA) as a main methods in water resource management, survey all present and future threats. So IEA can be used in environmental planning and management towards sustainable development.
The software used in this study called mDSS, has been used in the field of surface waters at the international level but this application isn`t used in IEA for GW depletion.
The study area is Ardabil plain, in Ardabil province in the northwest part of Iran. Ardabil plain area is about 853 square kilometers, and groundwater using has been raised during the past half century because of increasing population and agriculture development. Now, the plain decline is close to 10 meters.
Matherials & Methods
This study prepared by library documents, interviews and a questionnaire filling out by academics and experts. Integrated assessment should be provided in the form of a conceptual model called DPSIR to link between the data collected. The DPSIR framework aims at analyzing the cause-effect relationship between interacting components of complex social, economic and environmental systems and at organizing the information flow between its parts. Driving forces (D) represent major social and economic developments in societies and the corresponding changes in lifestyles, overall levels of consumption and production patterns. As an effect of driving forces, the pressures (P) are developed. The pressures represent processes affecting the resources (land, water) by producing for instance substances (emissions), physical and biological agents which consequently cause changes to the state of water resources (S). Depending on the changes of state, positive or negative consequences for society may occur. These consequences are identified and evaluated to describe impacts (I) by means of evaluation indices. In a generic decisional context, the perception of the existence of relevant impacts in the catchment area induces decision-makers to develop responses (R) which prevent, compensate, or mitigate the negative outcomes of state changes. Responses may be targeted to address the driving forces, the pressures or the state itself: either the driving forces may be re-organized (prevention, changing behavior, etc.), pressure mechanisms may be altered (e.g. the introduction of new production systems), or the state of the environment may be restored or adapted to reduce its sensitivity to pressures.
Software of mDSS (MULti-sectoral, INtegrated and Operational Decision Support System) is a useful application to support decision-making on issues related to water resources management and solving complex problems arising from it. The software mDSS also integrates environmental modeling techniques, social and economic in GIS with multi-criteria decision-making techniques (MCDMs).
Among the various indicators, according to expert`s opinion, population growth and agricultural development, are the most important factors (driving force) in groundwater declining. Land use and water consumption were considered as pressures. Depletion of groundwater that is the subject of this study is State and loss of water quality, the amount of surface water as well as increased vulnerability to drought (dry gardens and agricultural lands) are considered as the effects of this research respectively.
Climate Change: To evaluate the changes in climate, the temperature and precipitation data obtained from synoptic stations of Ardabil and evaporation data obtained from hydrological stations. The results of homogeneous data series, according to Mann-Kendall test, show the trend of rising temperature and evaporation, so could be one of the factors in groundwater declining.
Population growth: to assess the impact of population growth on groundwater resources, Ardabil population data were collected from 1355 to 1390 and the results show increasing demand for groundwater in agriculture, industry and drinking.
Agricultural development: more than 88% of water consumption in agriculture is supplied by numerous wells drilled in the plain area. By studying agriculture in three parts: the area under cultivation, production and type of products, we found that from 662,063 hectares of land, 434,541 ha is rain-fed land and 227,522 ha are irrigated, but much crop growth is in irrigation products. Product types were examined in this study too. Potato cultivation in the Ardebil plain that is the first place in Iran (about 14 percent), take place with irrigation method, which can cause overuse of groundwater.
Land use: In this study, Landsat images between June 1987 and 2014 were analyzed. Results classified by Maximum Likelihood method, reveals that made lands (29%) and pastures (21/5%) increased, while agricultural land and water have been reduced. One reason for the loss of agricultural land and surface water, is declining groundwater.
Groundwater consumption: according to the latest inventory of existing wells, 0.8 percent of wells are industrial, 8% for drinking and 91.2% for agricultural consumption.
State: Ardabil plain area is about 850 hectares that has 3667 deep and semi-deep wells, in this study, we selected wells data in 1987 compared with the same data in 2014. By Kriging interpolation, found that the depletion of GW in the South is much more increased, up to 83 meters.
Changing water quality: In this study, water conductivity indicator (EC) was used over a period of 12 years. The average annual EC's increasing from 834 µmho/cm (in 2000) to 1170 µmho/cm (in 2010).
Reducing the amount of surface water: In this study, data from Gilandeh, Kuzetapraghi and Gharehsou stations, over a period of 1978 – 2010, shows reducing these river`s discharging is clearly visible.
Responds: Based on the questionnaires, the best strategy is to improve the agriculture. Four important strategies defined by a hypothetical scenario. These scenarios include:
1. Part Participation (P.P) in watershed management under the supervision of co-operative plain and cooperation of non-governmental organization
2. Changing in G.W Cultivation Pattern (C.G.W)
3. Trying to create New Systems (N.S) and change traditional irrigation systems
4. Changing the Cost of Price (C.C.P) especially in the agricultural sector in order to reduce excessive consumption and increase savings