The Scenario base Calculation of Ecohidrological Water Needs for Sustainable Development of Water Resources (Case Study: Kaji Salt Wetland of Nehbandan)

Document Type : Research Paper

Authors

1 Department of Environment, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran

2 Department of Environment, Faculty of Agriculture and Natural Resources, Ardakan University, Ardakan, Iran

Abstract

Introduction
Wetlands are actually the kidneys of the earth that lead to the environmental balance of the earth. Wetland is a unique environmental system with diverse performance and high biodiversity. Wetlands cover approximately 5 to 8 percent of the earth's surface (7-10 million square kilometers) and must be preserved in order to maintain their important functions as natural habitats and their role in the global carbon cycle. Wetlands have high primary productivity among all ecosystems and provide many ecological services, including environmental treatment, modification in the atmosphere and water cycle, wave intensity reduction and disasters resulting from them. However, a large proportion of wetlands in the transition zone from marine-river ecosystems lie in terrestrial ecosystems, making them a sensitive and fragile ecosystem. Due to changes in natural environments, over-exploitation of wetlands and irrational use of their resources, the structure of wetland ecosystems has been destroyed and the boundaries of wetlands are gradually shrinking, which leads to damage or their ecological performance is lost. Therefore, it is necessary to revive wetland systems through efficient engineering technologies and logical management approaches. In order to provide a scientific basis for protection and restoration, it is necessary to examine the ecological water requirement of the wetland. Researchers are trying to balance the ecological needs of the wetland with the rational allocation of water resources. Achieving this balance can ensure the natural flow of water in order to improve the overall ecological performance of the wetland system, with the aim of restoring its function and rebuilding its ecosystem.

Matherials & Methods
In studies of calculating the water requirement of wetlands, the functions of the study wetland should be identified first and the index should be determined for each function. The indicators should be determined in such a way that in addition to maintaining the main functions of the wetland, its functions are also maintained. Due to the characteristics of Nehbandan wetland, including water with salinity and high salts, lack of aquatic animals, lack of endangered species related to wetland water, as well as special socio-economic and cultural factors related to wetlands such as special traditional ceremonies , This wetland does not have a special production, socio-economic and cultural function and its most important functions are from the point of view of physicochemical, biological and ecosystem services. After identifying these functions, an indicator was selected for each of them to calculate the amount of water required of the wetland. Maintaining the area of the main spot of the wetland in minimum and maximum amount as a physicochemical index, maintaining the area of the main spot of the wetland in medium size as a ecosystem services index and preserving plant and animal species related to the wetland were selected as biological indicators. The MNDWI index was used to identify the water area of the wetland. After determining the boundaries of the wetland, in a process using the detection of the wetland underwater surface and depth measurement with satellite images, the volume of water at different levels was calculated according to the shape of the wetland bed and water depth. The water balance formula was used to calculate the hydrological needs of the wetland. The average amount of precipitation in the region was calculated using the monthly data of TRMM satellite, the amount of evapotranspiration was calculated using Modis satellite data and the amount of runoff was calculated using Terra climate data. After calculating the hydrological water requirement, three species of tamarix aphylla, haloxylon aphyllum and phragmetes australis were selected as plant indicators and anas platyrhynchos were selected as animal indicators and the ecological water needs of the wetland were calculated. After calculating the indicators, the amount of water demand of Nehbandan wetland is examined during 6 scenarios so that while identifying the condition of the wetland in different scenarios, it is planned to achieve the ideal situation.

Discussion of Results
In this study, in order to preserve and revive the Nehbandan wetland, its hydrochloric water requirement was calculated in 6 different scenarios. The wetland water balance was used to calculate the hydrological water needs of the wetland and the species of Haloxylon aphyllum, Phragmetes australis, Tamarix aphylla and Anas platyrhynchos were used to calculate the ecological water needs of the wetland. The results showed that currently the water balance of the wetland is negative and the outflows of the wetland are 0.452 million cubic meters more than its inputs. Using the MNDWI index, the highest area of the wetland was calculated in May 2016 and amounted to 20 square kilometers, the average limit of the wetland in May 2017 was 8.8 square kilometers and the minimum limit of the wetland was 6 square kilometers in November 2018. Therefore, due to the depth of the wetland in different years, which varied between 10 and 30 cm, the volume of water in these three areas was calculated. Therefore, in order to maintain the main spot of the wetland in the cold months of the year, 0.65 million cubic meters of water is needed for minimum extent, which is 1.32 million cubic meters in average extent and 6 million cubic meters in maximum extent. According to the calculations, the amount of wetland water required in different scenarios is as follows.

scenario Annual Water Needs (MCM)
Real scenario of plant water needs 0.1026
Ideal scenario of plant water needs 0.12345
The water needs of the wetland in order to preserve the important animal species 0.0003479
Hydrological wetland water requirement according to the low spot level (drought situation) 13.3
Hydrological wetland water requirement according to the average spot level (normal condition) 13.97
Hydrological wetland water requirement according to the high spot level (wet years condition) 18.65

Conclusions
According to the obtained results, in order to provide the average level of water stain in the cold months of the year (the time of the presence of the wetland), Nehbandan saltwater wetland, with a water volume of 13.97 million cubic meters per year, needs water, which 12.2 million cubic meters are supplied via surface runoff. Therefore, there is a shortage of 1.77 million cubic meters, which must be met by reducing the area's groundwater abstraction by about 20 percent. Also, in order to maintain and develop the vegetation of the region in an ideal condition, the annual need for water is equal to 0.12 million cubic meters. This is equivalent to 0.000348 million cubic meters per year for the protection of waterfowl in the region. Therefore, by providing the water needs of ecosystem services in order to preserve fine dust, the ecosystem related to the wetland, including plant and animal species of the region, is also preserved. The results in the scenario of ecosystem services show that in the current situation, water balance of wetland is negative and considering that the area of the wetland is one of the wind erosion centers of the province, so the most important ecosystem services of Kaji wetland is to deal with dust. Due to the hot and dry climate of the region as well as the recent droughts, there is a concern that with the drying up of the region's wetland, it will become a center of dust. Salt and mineral in the lagoon also exacerbate this concern. Therefore, it is necessary to maintain and rehabilitate it, and determining the water needs of wetlands can restore their ecological conditions and play an important role in improving their environmental performance.

Keywords


تقوایی، م.، حسینی‌خواه، ح. 1396. برنامه‌ریزی توسعه صنعت گردشگری مبتنی بر روش آینده پژوهی و سناریونویسی (مطالعة موردی: شهر یاسوج)، برنامه‌ریزی و توسعة گردشگری، (23)6 : 8-32.
راد، م. 1397. نیاز آبی برخی از گونه‌های مورد استفاده در جنگل‌کاری مناطق خشک و نیمه‌خشک، طبیعت ایران، (4)3: 40-47.
سازمان حفاظت محیط‌زیست. 1397. آمار سرشماری پرندگان آبزی و کنار آبزی، چاپ اول، سازمان حفاظت محیط‌زیست خراسان‌جنوبی، بیرجند.
مجنونیان، ه.، کیابی، ب.، دانش، م. 1384. جغرافیای جانوری ایران (دوزیستان، خزندگان، پرندگان و پستانداران)، جلد دوم، انتشارات دایره سبز، تهران.
مدبری،ه.، شکوهی،ع. 1398. تعیین نیاز زیست‌محیطی تالاب انزلی با استفاده از روش‌های اکوهیدرولوژیکی، تحقیقات منابع آب ایران، (3) 15: 91-104.
وزارت نیرو. 1396. مطالعات بهنگام‌سازی بیلان منابع آب در محدوده‌های مطالعاتی حوزه آبریز درجه 2 کویر لوت، جلد پنجم، وزارت نیرو، تهران.
منصوری، ج. 1387. راهنمای صحرایی پرندگان ایران، چاپ اول، انتشارات نشر کتاب فرزانه، تهران.
Abatzoglou, J.T. Dobrowski, S.Z. Parks, S.A. and Hegewisch, K.C. 2018. Terra Climate, a high-resolution global dataset of monthly climate and climatic water balance from 1958–2015. Scientific data, 5: 170-191.
Abbaspour, M. and Nazaridoust, A. 2007. Determination of environmental water requirements of Lake Urmia, Iran: an ecological approach. International Journal of Environmental Studies, 64(2): 161-169.
Abdelaziz, R., El-Rahman, Y.A. and Wilhelm, S. 2018. Landsat-8 data for chromite prospecting in the Logar Massif, Afghanistan. Heliyon, 4(2): e00542.
Baird, A.J. and Wilby, R.L. 1999. Eco-hydrology: plants and water in terrestrial and aquatic environments. Psychology Press.
Catford, J. 2006. Ecohydrology: vegetation function, water and resource management. Austral Ecology, 31(8): 1028–1029.
Chen, H. 2012. Assessment of hydrological alterations from 1961 to 2000 in the Yarlung Zangbo River, Tibet. Ecohydrology & Hydrobiology, 12(2): 93-103.
Chen, H. and Zhao, Y.W. 2011. Evaluating the environmental flows of China's Wolonghu wetland and land use changes using a hydrological model, a water balance model, and remote sensing. Ecological Modelling, 222(2): 253-260.
Cheng, Q., Zhou, L.F. and Wang, T.L. 2018. Eco-environmental water requirements in Shuangtaizi Estuary Wetland based on multi-source remote sensing data. Journal of Water and Climate Change, 9(2): 338-346.
Cohen, M.J., Henges-Jeck, C. and Castillo-Moreno, G. 2001. A preliminary water balance for the Colorado River delta, 1992–1998. Arid Environments, 49(1): 35-48.
Covich, A.P. 1993. Water and ecosystems. In: Water in Crisis: A Guide to the World’s Fresh Water Resources. Oxford University Press, New York, 40–55.
Doorenbos, J. and Pruitt, W.O. 1977. Crop water requirements. (FAO irrigation and drainage paper 24).  FAO.
Falkenmark, M. 1995. Coping with water scarcity under rapid population growth. Conference of SADC Min-sters, Pretoria. 23: 24).
Ferrati, R. and Canziani, G.A. 2005. An analysis of water level dynamics in Esteros del Ibera wetland. Ecological Modelling, 186 (1): 17–27.
Gleick, P.H. 1998. Water in crisis: paths to sustainable water use. Ecological Applications, 8(3): 571–579.
Gottschalk, T.K., Huettmann, F. and Ehlers, M. 2005. Review article: Thirty years of analysing and modelling avian habitat relationships using satellite imagery data: A review. International Journal of Remote Sensing, 26(12): 2631-2656.
Haag, K.H., Lee, T.M., Herndon, D.C., County, P. and Water, T.B. 2005. Bathymetry and vegetation in isolated marsh and cypress wetlands in the northern Tampa Bay area, 2000-2004. US Department of the Interior, US Geological Survey.
Halliday, D., Resnick, R. and Walker, J. 2013. Fundamentals of physics. John Wiley & Sons.
Hayashi, M., van der Kamp, G. and Rosenberry, D.O. 2016. Hydrology of prairie wetlands: understanding the integrated surface-water and groundwater processes. Wetlands, 36(2): 237-254.
Hirschi, M., Michel, D., Lehner, I. and Seneviratne, S.I. 2017. A site-level comparison of lysimeter and eddy covariance flux measurements of evapotranspiration. Hydrology and Earth System Sciences, 21(3): 1809-1825.
Laskowski, H. 2003. Dabbling ducks. Maryland Cooperative Extension, Fact sheet, 610, 1-12.
Liu, J., Wang, T. and Zhou, Q. 2018. Ecological water requirements of wetlands in the middle and lower reaches of the Naoli River.Water Policy,20(4): 777-793.
Lu, D., Mausel, P., Brondizio, E. and Moran, E. 2004. Change detection techniques. International Journal of Remote Sensing, 25(12): 2365-2401.
Mousazadeh, R., Ghaffarzadeh, H., Nouri, J., Gharagozlou, A. and Farahpour, M. 2015. Land use change detection and impact assessment in Anzali international coastal wetland using multi-temporal satellite images. Environmental Monitoring & Assessment, 187(12): 1–11.
Novák, V. and Hlaváčiková, H. 2019. Evaporation. In Applied Soil Hydrology. Springer.
Onamuti, O.Y., Okogbue, E.C. and Orimoloye, I.R. 2017. Remote sensing appraisal of Lake Chad shrinkage connotes severe impacts on green economics and socio-economics of the catchment area. Royal Society Open Science, 4(11): 171120.
Reddy, S.L.K., Rao, C.V., Kumar, P. R., Anjaneyulu, R.V.G. and Krishna, B.G. 2018. A Novel Method for water and water canal extraction from Landsat-8 OLI imagery. International Archives of the Photogrammetry. Remote Sensing and Spatial Information Sciences, 42(5): 323-328.
Roberts, J., Young, B. and Marston, F. 2000. Estimating the water requirements for plants of floodplain wetlands: a guide. Canberra, Australian Capital Territory: Land and Water Resources Research and Development Corporation.
Sekaranom, A. B., Nurjani, E., Hadi, M. P. and Marfai, M.A. 2018. Comparsion of TRMM Precipitation Satellite Data over Central Java Region–Indonesia. Quaestiones Geographicae, 37(3): 97-114.
Szabó, S., Gacsi, Z. and Balázs, B. 2016. Specific features of NDVI, NDWI and MNDWI as reflected in land cover categories. Acta Geographica Debrecina Landscape & Environment, 10(3-4): 194-202.
Thornthwaite, C.W. 1948. An approach toward a rational classification of climate. Geogr Rev, 38(1): 55–94.
Trajkovic, S., Gocic, M., Pongracz, R. and Bartholy, J. 2019. Adjustment of Thornthwaite equation for estimating evapotranspiration in Vojvodina. Theoretical and Applied Climatology, 138(3-4): 1231-1240.
Tuttolomondo, T., Leto, C., La Bella, S., Leone, R., Virga, G. and Licata, M. 2016. Water balance and pollutant removal efficiency when considering evapotranspiration in a pilot-scale horizontal subsurface flow constructed wetland in Western Sicily (Italy). Ecological Engineering, 87, 295-304.
Wang, H. and Xu, S.G. 2005. Calculation and analysis of evapotranspiration of reed marsh in Zhalong wetland. Water Resources and Hydropower Engineering, 36(2): 22-28.
Wang, L., & Yang, X. (2019). Estimation of Environmental Water Requirements via an Ecological Approach: A Case Study of Yongnian Wetland, Haihe Basin, China. In Sustainable Development of Water Resources and Hydraulic Engineering in China (pp. 377-386). Springer, Cham.
Xu, Y., Wang, Y., Li, S., Huang, G. and Dai, C. 2018. Stochastic optimization model for water allocation on a watershed scale considering wetland’s ecological water requirement. Ecological indicators, 92: 330-341.
Zhao, X.S., Cui, B.S. and Yang, Z.F. 2005. Study on the eco-environmental water requirement for wetland in Yellow River basin. Acta Scientiae Circumstantiae, 25(5): 567–572.
Zhou, L.F. and Xu, S.G. 2007. Study on safety threshold of eco-environmental water demand in Zhalong wetland. Acta Hydraulica Sinica, 7: 845–850.
Zotarelli, L., Dukes, M. D., Romero, C.C., Migliaccio, K.W. and Morgan, K.T. 2010. Step by step calculation of the Penman-Monteith Evapotranspiration (FAO-56 Method). Institute of Food and Agricultural Sciences. University of Florida