Watershed Data Report

This report was created with the free Global Watersheds web app on . Creative Commons License BY 4.0.

Contents

  1. Political Boundaries
  2. Population
  3. Land Cover
  4. Hydrology
  5. GRACE Terrestrial Water Storage
  6. Irrigation
  7. Dams
  8. Longest River
  9. Topography
  10. References

This report is for the watershed with an outlet near 25°23'13"N, 81°55'01"E, or (25.387, 81.917), with a drainage area of around 440,000 km².

Political Boundaries

The watershed is located in two countries, as shown below in Table 1 below.

Table 1. Countries in the watershed.

Country Area (km²) Percent of watershed
India 440,000 100%
China 274 0%

Data on political boundaries comes from Natural Earth, https://www.naturalearthdata.com.

Population

The watershed has an estimated population of 250,000,000 in the year 2020. Figure 1 shows how population has changed from 1990 to 2020. The population grew at an average rate of 1.8% per year over this time period.

Figure 1. Estimated watershed population from 1990 to 2020.

Population data comes from GlobPop, Global Gridded Population Estimates, created by researchers at Beijing Normal University (Liu 2024).

Human population growth can affect water quality via increased pollution from households, industry, and agriculture. Further, land use and land cover change associated with population growth can have a major impact on watersheds (see the next section of this report).

Land Cover

The most common land cover type in the watershed is cropland, covering 269,000 km² in 2020. More detailed information about land cover and how it has changed is shown in Table 3 and Figure 2 below. Pairs of bars represent the area for each land cover type in the years 2000 and 2020.

Figure 2. Land cover in the watershed.

Table 3. Land cover in the watershed.

Land Cover Type Area in 2000, km² Area in 2020, km²   Change
Cropland 253,000 269,000 6%
Dense short vegetation 102,000 80,800 -20%
Built-up 18,800 32,600 73%
Tree cover 29,200 28,800 -1%
Semi-arid 26,800 18,800 -29%
Open surface water 3,290 4,680 42%
Desert 2,370 2,800 18%
Snow and ice 2,960 2,460 -16%
Wetland + sparse vegetation 996 445 -55%

Land cover data comes from the GLAD: Global Land Cover and Land Use Change, 2000-2020 (Popatov et al. 2022). This dataset, created by researchers at the University of Maryland, is available online here. Classification is based on satellite imagery from Landsat and machine learning tools.

Land cover change can profoundly influence watershed hydrology and water quality. Urbanization and development can increase the impervious cover, causing more water to run off rather than infiltrate into the ground. This can decrease groundwater recharge and river baseflows, or the flows that occur during dry times. Deforestation and agricultural development are often accompanied by an increase in soil erosion and sediment loads. Other land use types are associated with water pollution. For example, agriculture can increase loads of pesticides and nutrients (nitrogen and phosphorus) from fertilizers. Urbanization and industrialization can cause contamination from a wide range of chemicals used in households and industry.

Hydrology

The average annual precipitation over the watershed is 937 mm/year. (Precipitation includes all forms of water, including snow and rain.) Some of this water leaves the watershed surface via evaporation and transpiration, or the loss of water from plants. Annual evapotranspiration is estimated at 483 mm/year. The basin climatology, or the monthly average precipitation and evapotranspiration, is shown in Figure 4.

Figure 4. Watershed climatology: monthly average precipitation and evapotranspiration over the watershed.

Precipitation data comes from WorldClim, a global gridded dataset by researchers at the University of East Anglia (Harris et al. 2020). This dataset is based on downscaling and bias-correcting the CRU-TS dataset (Fick and Hijmans 2017), which is based on a large collection of station observations that span 1901–2018.

Evapotranspiration is even more difficult to estimate than precipitation. Here, we use a dataset, GLEAM v3.6B, which combines modeling and remote sensing data (Martens et al. 2017; Miralles et al. 2011).

It is difficult to estimate water cycle variables over large areas. So you should keep in mind that these estimates are uncertain (not perfect).

Terrestrial Water Storage Anomaly

The GRACE satellites provide information about changes in the amount of water over different locations on the Earth. Figure 3 shows the average terrestrial water storage anomaly over the watershed.

🖱️Mouse wheel to zoom Click & drag to pan 📱Pinch to zoom on mobile

Figure 3. GRACE terrestrial water storage anomaly from 2002 to 2025.

The GRACE satellites make highly accurate measurements of the Earth's gravitational field, and provide measurements of changes in the mass of water on a monthly time scale. These measurements do not tell us how much water there is in a region, but rather, how it the amount of water has changed compared to a baseline. The measurement includes all forms of water, including water in rivers, lakes, and reservoirs, soil moisture, groundwater, glaciers, snow, and ice. For an introduction to GRACE, see the section of my PhD thesis on Remote Sensing of the Water Cycle.

The total amount of water in the watershed appears to be trending downwards at a rate of -20.2 cm per decade (P < 0.01). This P-value suggests that the observed trend is statistically significant; it is unlikely the trend is due to random chance.

GRACE Terrestrial Water Storage Anomaly data is from the Center for Space Research at the University of Texas, Austin (Save et al. 2016, 2022).

Irrigation

The watershed had about 157598.8 km² of land equipped for irrigation in 2005. This is about 35.8% of the watershed. Figure 5 shows the development of irrigated area from 1900 to 2005. These estimates are based on a global dataset published by an international team of researchers (Siebert et al. 2015).

Figure 5. Area equipped for irrigation in the watershed from 1900 to 2005

Irrigation brings many benefits for growing crops. In arid regions, it enables production where it would be otherwise impossible. In humid regions, irrigation can increase crop quality and yield, and provide more certainty against unpredictable climate. Yet, the expansion of irrigation can have impacts on watersheds that need to be carefully managed.

Increased irrigation usually requires more water to be withdrawn from rivers, lakes, or groundwater sources, which can reduce streamflow and alter natural flow patterns. This reduced flow can harm aquatic ecosystems and diminish the water available downstream for other uses. Irrigation often introduces fertilizers and pesticides into the watershed, and may increase soil erosion and sediment transport. When nutrients run off into rivers and streams, they can lead to nutrient pollution, algal blooms, and eutrophication. This plus chemical pesticides and herbicides negatively impacts aquatic life and water quality for human uses.

Dams

This watershed contains 518 dams identified in the Global Dam Watch database, with a total storage capacity of 34,000 million m³.

Information on these dams is listed in Table 4. The number and size of dams in a watershed is one measure of hydromodification, or how much the natural hydrologic cycle is influenced by human activities.

Table 4. Dams in the watershed. Unknown or missing data shown with a dash.

Dam Name Reservoir Name River Main Use Year Dam Height (m) Capacity (10⁶ m³) Latitude Longitude URL
23.789 79.336
Alaknanda -Badrinath Hydroelectricity 30.239 78.834
23.753 79.136
24.057 79.465
24.054 79.176
23.751 78.809
23.614 75.836
23.249 75.780
23.616 77.126
23.924 76.314
28.797 79.810
24.205 79.642
24.241 79.658
24.290 79.724
23.281 75.464
23.965 76.777
28.664 77.399
24.318 79.789
23.613 77.855
24.741 80.010
23.380 76.691
24.627 79.141
23.365 77.713
24.045 77.180
23.781 77.844
23.635 79.078
23.865 77.891
23.879 77.916
23.130 75.791
23.903 77.927
28.290 79.370
27.443 77.714
24.068 76.956
24.611 79.186
22.970 76.343
23.736 77.787
22.971 76.677
23.605 78.326
28.904 79.012
28.802 79.188
24.070 79.087
Gandhi Sagar Gandhi Local Nalla Irrigation Built 1960 62.0 7322.8 24.700 75.554
Tehri Bhagirathi Irrigation Built 2006 261.0 3540.0 30.375 78.476 link
Rana Pratap Sagar Rana Pratap Chambol Irrigation Built 1968 54.0 2898.7 24.917 75.580
Ramganga Ramganga Irrigation Built 1974 128.0 2450.0 29.521 78.760
Rajghat Rajghat Betwa Irrigation Built 1992 44.0 2172.0 24.760 78.231 link
Matatila Matatila Betwa Irrigation Built 1964 46.0 1132.7 25.097 78.372
Madikheda Sindh Hydroelectricity Built 2008 62.0 1105.2 25.556 77.845 link
Bisalpur Built 1993 40.0 1095.8 25.925 75.459
Built before 1990 308.4 26.224 76.118
256.4 25.823 74.805
Pagara 256.2 26.271 77.839
Halali Halali Irrigation Built 1976 30.0 252.8 23.501 77.551
Built 2016 210.3 24.140 75.899
Nanak Sagar Deoha Irrigation Built 1962 17.0 209.0 28.946 79.825
207.6 25.693 74.573
Harsi Parwati Irrigation Built 1935 29.0 207.0 25.751 77.921
Maudaha Birma Irrigation Built 1994 33.0 200.0 25.588 79.710
187.6 25.735 74.951
Built 2002 168.0 23.723 78.755
Rangawan Bannel Nalla Irrigation Built 1957 27.0 164.2 24.685 79.859
156.9 25.385 79.677
147.8 25.035 74.313
Built 2002 147.3 23.664 76.919
144.6 28.940 79.581
Tigra Sank Irrigation Built 1917 24.0 130.0 26.223 77.998
Shahjad Shahjad Irrigation Built 1992 29.0 130.0 24.948 78.521
Built before 1990 128.0 25.672 77.885
Gangau Ken Irrigation Built 1915 16.0 120.0 24.626 79.861
Urmil Urmil Irrigation Built 1994 26.0 116.6 25.131 79.701
114.2 25.439 79.897
Kotabarrage Chambal Irrigation Built 1960 52.0 108.1 25.175 75.826
107.3 25.452 74.567
Rajsamand Rajsamand Gomti Banas Irrigation Built 1671 39.0 107.1 25.061 73.894 link
Built 1998 102.6 25.217 81.133
Built 1991 98.3 24.826 74.523
Govind Sagar Shahjad Irrigation Built 1953 18.0 96.9 24.673 78.415
Built before 1985 96.5 25.933 74.555
Meja Kothari Irrigation Built 1956 14.0 96.2 25.395 74.542
Gudha Mechambal Irrigation Built 1958 25.0 95.7 25.498 75.459
Tumaria Dhela Irrigation Built 1961 23.0 94.3 29.308 78.939
Sagar Sagar Betwa Irrigation Built before 1990 27.0 93.7 24.341 77.838
Built before 1989 93.1 24.561 76.334
Jamni Jamni Irrigation Built before 1990 26.0 92.9 24.364 78.690
Kotwal Local Nalla Irrigation Built 1919 11.0 91.5 26.489 78.126
Built 2013 90.3 25.356 77.998
Koteshwar Bhagirathi Irrigation Built 2011 98.0 88.9 30.260 78.497 link
Built before 1989 85.9 29.364 78.785
Ruthiai Chopan Irrigation Built 1991 31.0 85.0 24.548 77.233
Sajnam Sajnam Irrigation Built 1990 22.0 83.5 24.522 78.594
Kaketo Parwati Irrigation Built 1934 34.0 80.5 25.899 77.694
Built before 1989 80.3 26.897 77.372
78.9 25.181 80.794
Paricha Betwa Irrigation Built 1886 17.0 78.8 25.514 78.781
Chhapi Irrigation Built 2000 34.0 78.5 24.342 76.472
Saprar Saprar Irrigation Built 1952 17.0 76.2 25.213 79.088
75.4 25.966 77.760
Built 2011 74.4 24.368 76.581
74.1 27.034 76.259
Built before 1990 74.0 25.077 78.758
Built 1993 71.7 22.834 76.597
Built before 1991 71.7 25.213 76.768
Built 1999 71.0 23.243 76.259
Baigul Baigul Irrigation Built 1968 14.0 70.7 28.887 79.621
Built 2002 69.1 24.655 75.171
68.9 26.605 77.589
Built before 1989 66.6 25.519 79.148
Built before 1990 61.7 23.027 77.488
59.6 29.411 78.609
Panchana Gambhira Irrigation Built 1977 33.0 59.5 26.560 77.005
58.3 25.168 75.053
Haripura Bhakra Irrigation Built 1975 11.0 58.2 29.116 79.325
58.2 23.654 75.694
Dhekwan Betwa Irrigation Built 1909 19.0 57.8 25.188 78.547
Built before 1991 56.0 26.539 76.682
Aoda Seep Irrigation Built 1934 17.0 55.7 25.517 76.790
Built before 1985 54.9 25.715 78.756
53.9 26.411 75.759
Built before 1988 53.1 25.260 79.578
Tillar Tillarchambal Irrigation Built before 1989 23.0 52.2 23.598 76.110
Built 2011 50.1 23.941 80.246
Built before 1990 50.0 24.644 78.845
Built 2015 48.7 24.270 77.723
48.2 24.028 77.760
Built 2015 45.2 23.398 78.789
44.3 24.353 74.913
Built 1992 43.7 23.672 77.513
43.6 24.797 79.871
43.6 25.134 81.032
43.0 25.395 74.394
Kalisil Kalisi Banas Irrigation Built 1956 25.0 41.7 26.271 76.769
Built before 1989 40.8 27.519 76.535
Built before 1989 40.7 26.710 76.777
40.6 25.030 74.824
Majhgawan Local Nalla Built 1914 20.0 40.5 25.192 79.548
Built before 1990 40.4 25.052 78.820
Built 1992 39.9 25.891 75.171
39.0 24.602 73.679
38.5 25.185 78.698
Built 1992 38.3 25.856 75.126
Built before 1990 37.2 24.374 77.241
36.9 25.011 79.044
36.4 25.001 75.880
Kaliasote Kaliasote Irrigation Built 1993 34.0 35.9 23.200 77.408
Dongari Built before 1990 35.8 25.381 78.460
35.0 25.463 78.325
Chhilar Chhilar Irrigation Built 1972 21.0 34.8 23.396 76.290
34.4 23.242 77.112
32.9 25.635 75.444
Built 1994 32.8 23.209 75.636
Built 2004 32.3 23.973 78.769
Built before 1985 32.3 22.826 75.694
31.9 23.795 75.172
Built before 1990 31.8 24.527 77.684
31.5 24.752 79.068
31.5 23.396 77.187
Built before 1990 31.5 26.719 77.098
Built before 1990 31.3 25.034 77.889
31.2 25.035 79.139
Built before 1990 30.8 22.950 77.700
30.7 24.840 79.639
30.5 24.724 77.273
30.2 25.432 77.710
Built 2003 29.9 24.067 77.312
Built before 1989 29.3 24.773 77.177
28.7 25.703 74.280
Built before 1990 28.6 26.981 76.230
28.3 24.821 76.096
28.0 24.259 79.031
Built before 1988 27.0 25.409 79.972
Kerwan Local Nalla Irrigation Built 1975 33.0 25.0 23.165 77.371
Built before 1985 23.9 26.598 76.669
23.9 27.171 76.292
23.6 23.723 76.102
Pillowa Local Nalla Irrigation Built 1914 10.0 23.2 26.450 78.146
22.9 25.891 74.949
Built before 1990 22.7 25.130 78.661
22.3 22.592 75.671
Built before 1985 22.3 26.125 77.141
22.2 27.482 76.131
22.0 24.969 79.453
Built before 1989 21.8 23.248 75.827
Built before 1990 21.7 24.701 74.731
Built before 1990 21.1 24.127 74.831
21.0 23.827 78.745
Built before 1991 20.9 26.318 77.190
20.6 25.118 80.581
20.6 22.989 76.803
Built 2003 20.5 23.773 76.126
20.5 25.048 76.829
20.2 23.420 78.972
Built 1995 20.1 25.853 76.138
Mala Son Built 1929 16.0 20.0 23.695 79.737
Pahuj Pahuj Irrigation Built 1909 11.0 19.8 25.501 78.531
Built before 1991 19.2 25.673 78.398
Built before 1989 18.9 26.138 78.059
Built before 1990 18.9 25.073 77.960
Built before 1989 18.9 25.317 74.996
Built before 1985 18.8 29.958 78.181
18.1 24.927 73.780
18.1 27.220 76.420
Built 1995 18.0 26.685 76.739
18.0 25.148 76.044
Built before 1989 17.9 26.953 75.855
Built before 1990 17.5 25.365 79.043
Built before 1988 17.0 24.581 74.623
17.0 25.201 79.838
16.8 25.209 78.719
Built 1999 16.8 25.084 77.817
Built before 1990 16.7 25.246 75.209
16.6 25.318 78.829
16.6 25.614 75.286
Built before 1989 16.5 26.448 76.331
Hathaikheda Ghorapachad Irrigation Built 1962 17.0 16.3 23.271 77.501
16.0 23.116 77.683
16.0 22.489 75.706
15.6 24.840 80.090
Built 1998 15.5 23.902 79.849
15.2 25.416 75.111
15.0 26.909 76.476
14.7 25.020 76.283
Built before 1990 14.7 25.069 75.285
Built before 1989 14.7 27.490 76.584
14.5 27.119 76.410
14.3 24.907 74.498
Built before 1990 14.2 23.277 77.532
Built 1997 14.1 25.952 75.888
14.0 23.306 76.799
Built before 1990 13.8 23.541 78.112
13.7 24.609 79.336
Built before 1990 13.6 25.422 77.067
13.5 25.565 75.398
13.3 25.552 73.930
13.2 25.288 78.912
13.2 25.325 74.347
12.9 30.075 78.290
Built before 1990 12.9 25.485 78.919
Built before 1989 12.5 23.155 77.128
Built before 1990 12.4 24.762 77.861
12.4 25.091 74.211
Rohini Rohini Irrigation Built 1983 18.0 12.1 24.358 78.792
Built 1991 12.0 24.685 73.848
12.0 25.446 76.704
Built 1997 12.0 25.723 77.467
Built before 1988 11.9 25.243 75.123
Built before 1990 11.7 26.180 78.122
Built before 1991 11.7 24.831 78.423
11.6 22.889 76.809
Built before 1989 11.6 22.935 76.940
11.5 24.972 79.136
11.5 23.413 76.142
11.5 25.832 77.719
11.5 25.802 77.718
Built before 1989 11.4 26.651 77.753
Built before 1985 11.4 25.260 78.960
Pagara Local Nalla Irrigation Built 1948 12.0 11.3 26.400 78.141
Built before 1990 11.2 23.915 78.153
Built before 1990 11.2 25.897 77.547
11.1 23.751 79.410
Built before 1990 11.1 25.630 78.340
Built before 1989 11.0 23.213 75.832
10.9 25.994 77.369
Built before 1990 10.9 25.314 79.092
10.9 23.843 79.828
Built before 1989 10.7 24.543 76.168
Built before 1990 10.6 25.615 78.324
10.6 26.434 76.958
10.6 24.844 74.784
10.5 25.719 75.106
10.5 22.663 75.869
10.4 25.834 76.787
10.2 25.794 77.501
10.1 25.767 76.150
Built before 1989 10.1 25.371 77.099
Built 2000 10.0 25.520 75.342
Built before 1990 10.0 26.007 78.293
Built before 1985 10.0 23.559 79.719
9.9 23.685 79.608
9.9 25.056 77.135
Built before 1990 9.9 25.436 78.452
9.9 25.181 74.631
Built before 1989 9.8 23.419 75.938
Built 2000 9.7 23.611 79.406
Built before 1989 9.7 25.447 74.913
Built 1993 9.6 24.935 74.960
9.5 25.410 74.076
Built before 1990 9.4 25.302 79.042
9.4 24.726 79.049
9.3 24.577 73.823
9.3 22.970 76.408
9.3 23.277 77.791
Built before 1990 9.2 25.086 76.110
9.2 24.710 77.156
9.1 25.924 76.442
Built before 1990 9.0 24.306 74.886
Built before 1988 8.9 25.327 80.106
Built before 1990 8.9 25.459 78.085
8.7 23.094 77.041
Built before 1990 8.7 23.217 77.763
8.6 24.903 79.250
8.6 25.481 79.123
8.5 23.778 79.435
Built before 1989 8.3 26.127 78.026
Built before 1989 8.3 23.150 77.075
Built before 1990 8.2 26.614 77.251
8.2 24.860 79.027
8.2 27.869 75.952
8.2 22.618 76.323
8.1 24.307 79.152
Built before 1990 8.1 25.058 76.109
8.1 23.227 76.548
8.0 24.822 79.135
8.0 23.327 79.318
Railway 7.9 25.427 78.505
7.6 22.958 76.822
7.6 24.655 77.165
7.5 25.713 76.180
Built before 1990 7.4 25.744 77.478
Built before 1989 7.4 23.810 76.131
7.3 26.138 76.266
7.1 27.045 76.059
Built before 1991 7.1 26.667 76.721
Built before 1990 7.1 25.543 78.080
Built before 1989 7.1 25.294 77.057
7.0 25.288 79.693
Built before 1985 7.0 23.801 79.491
7.0 25.290 74.230
6.9 22.671 75.649
6.9 23.575 79.606
Built before 1989 6.9 23.410 75.947
Built before 1989 6.8 23.085 76.314
Built 1999 6.8 23.976 76.473
6.8 22.487 75.644
Built before 1990 6.8 25.695 75.652
6.8 25.319 74.314
6.7 25.048 74.356
6.7 25.514 74.043
6.6 23.886 76.118
Built 1999 6.5 25.461 75.284
Built before 1990 6.5 24.693 78.544
6.5 23.806 79.823
Built before 1990 6.4 24.589 77.802
6.4 26.596 77.779
Built before 1985 6.4 23.636 78.809
6.3 23.710 79.920
Built before 1990 6.3 24.289 75.528
Built 1995 6.3 23.157 76.302
6.3 25.322 74.385
6.2 23.633 79.649
6.1 26.675 77.208
6.0 26.713 77.012
6.0 25.184 81.218
Built before 1989 5.9 23.656 76.131
Built 2007 5.8 23.923 76.820
5.8 24.374 77.877
Built before 1985 5.7 26.726 77.038
Built before 1985 5.7 26.787 75.455
5.7 24.869 74.917
5.7 26.635 77.678
Built 1999 5.7 23.232 76.520
Sijar Sijar Irrigation 14.0 5.6 25.203 79.195
5.6 25.192 76.400
5.6 30.436 77.666
5.6 24.939 79.370
5.6 23.203 77.420
5.6 25.310 79.366
Built before 1991 5.5 24.135 75.706
5.4 24.518 74.651
Built before 1989 5.4 30.503 77.798
Built 2004 5.3 25.381 76.253
Built before 1989 5.2 22.935 76.395
5.2 23.843 76.130
5.2 25.081 76.799
Built before 1985 5.1 29.344 79.560
Built before 1990 5.0 24.914 76.858
Built 1994 5.0 25.351 75.177
5.0 25.183 81.268
4.9 27.759 75.967
Built before 1988 4.9 23.638 79.689
4.8 24.838 79.082
4.8 23.771 79.546
4.8 25.883 76.278
Built before 1990 4.8 25.438 78.269
Built before 1989 4.8 23.802 77.077
Built before 1985 4.6 23.846 79.783
4.6 24.480 74.664
Built before 1985 4.6 25.644 79.206
4.6 23.353 79.411
4.5 23.616 78.784
4.5 26.608 77.206
4.5 25.117 78.861
4.5 23.406 78.967
4.4 25.138 78.920
Built before 1990 4.3 23.305 77.887
4.3 25.164 76.734
4.3 23.193 76.495
4.2 25.803 76.343
4.2 25.809 74.905
Built 1990 4.2 23.898 80.145
4.2 25.203 77.033
Built before 1990 4.1 26.428 78.430
Built 1996 4.1 25.649 75.580
Built before 1989 4.1 26.631 77.794
Built before 1990 4.0 26.876 77.034
Built before 1989 4.0 25.231 79.135
3.9 26.026 78.310
3.9 23.831 79.526
3.9 25.155 78.939
3.8 28.142 76.940
Built 2010 3.8 24.246 76.644
3.8 26.699 77.263
Built before 1990 3.8 26.882 77.014
Built 1993 3.8 27.503 75.851
Built before 1989 3.7 26.256 77.772
3.6 25.205 79.131
3.6 24.224 74.861
Built before 1985 3.6 26.599 77.556
Built before 1989 3.6 24.114 75.798
Built before 1987 3.6 25.213 81.372
Built 1992 3.6 25.415 79.037
3.5 25.002 76.810
3.5 26.359 78.240
Built before 1989 3.5 25.994 75.022
Built before 1989 3.4 23.659 77.092
3.4 25.138 77.062
Built before 1989 3.4 23.445 75.919
Built before 1991 3.3 26.330 76.790
Built before 1988 3.3 23.855 80.036
3.3 25.775 76.861
Built before 1989 3.3 25.386 75.328
Built 1994 3.3 24.352 75.896
3.3 26.667 77.800
3.3 25.862 76.192
Built before 1990 3.2 23.250 77.821
3.2 25.186 81.327
3.2 23.815 79.552
3.2 24.961 79.276
Built before 1989 3.1 25.005 76.296
3.0 24.644 79.463
2.9 26.842 76.650
2.8 25.293 79.808
2.8 25.726 74.134
Built 1994 2.8 23.167 76.313
2.7 25.304 75.447
Built before 1988 2.7 23.657 79.715
2.7 25.222 81.424
Built 1998 2.6 25.764 74.193
2.6 26.593 77.037
2.6 24.755 79.032
Built before 1987 2.6 25.020 80.882
Built 1997 2.5 22.950 77.593
2.4 25.134 76.672
2.4 30.588 77.467
Built before 1990 2.4 25.286 78.861
2.4 27.103 76.130
2.3 26.340 76.897
2.2 25.323 75.157
2.2 23.805 79.784
Built before 1990 2.2 25.154 75.139
Built before 1989 2.1 23.712 77.091
2.1 26.205 76.812
2.1 27.244 76.393
2.0 26.623 77.447
2.0 27.581 75.826
2.0 24.743 73.719
Built 1994 2.0 27.598 75.856
2.0 27.124 76.155
Built 1991 1.9 26.035 76.579
Built before 1989 1.9 23.415 76.535
1.9 26.648 77.198
Built before 1989 1.9 25.563 74.917
Built 1992 1.8 25.477 78.187
Built 1990 1.8 26.898 76.559
1.8 25.427 77.717
Built 1997 1.7 26.572 77.166
Built 1992 1.6 26.597 77.490
Built before 1989 1.6 27.809 76.466
Built before 1989 1.6 26.689 77.823
1.6 25.823 74.988
1.6 25.117 80.134
Built before 1990 1.4 24.400 76.262
Built before 1990 1.4 26.164 77.208
1.4 25.213 81.446
Built 1992 1.3 24.534 76.415
1.2 25.059 74.525
Built before 1985 1.1 26.510 77.186
1.1 25.082 78.941
1.0 26.613 77.789
Built 1997 0.9 26.584 77.186
Built before 1989 0.9 27.740 75.976
0.9 25.062 74.503
0.9 26.688 77.863
Built 1996 0.9 26.382 76.934
0.8 27.619 75.853
0.7 26.479 77.104
0.7 27.090 76.261
0.7 26.576 77.203
0.6 26.595 77.200
Built 2000 0.5 27.788 75.942
0.4 26.510 77.091
0.4 26.682 77.819
Built 1999 0.4 25.697 74.142
0.3 25.008 74.678
0.3 25.006 80.861
Built 2003 0.3 26.313 76.887
Built before 1985 0.3 26.503 77.157
Built before 1985 0.3 26.510 77.220
0.3 26.547 77.138
Built 2004 0.3 27.561 75.848
0.3 27.538 76.506
Built before 1985 0.3 26.810 75.793
Built 1996 0.3 26.711 77.189
Built before 1989 0.2 26.674 77.813
Built before 1985 0.2 25.740 74.158
0.1 26.684 77.835
0.1 25.061 74.155
0.1 26.686 77.846
Built 1997 0.1 26.508 77.073

Dams serve many useful purposes including electric generation, water supply, irrigation, flood control, and recreation. However, if not carefully planned and managed, dams can have a heavy environmental impact. Today, many governments are removing dams to bring rivers back to life.

For a detailed look at the impact of dams on people and the environment, I encourage you to read the book Silenced Rivers by Patrick McCully. To help conserve free-flowing rivers, consider supporting the nonprofit International Rivers.

Data on dams comes from the Global Dam Watch database, published in July 2024. For more details, see the journal article by lead researchers at McGill University (Lehner et al. 2024).

Longest River

The longest river is the watershed is 1,690 km long. It is shown highlighted in the map in Figure 5 below.

This is the longest continuous flowline in the source dataset, MERIT-Basins. It is not necessarily the mainstem of the river, or the one with the same name. When it comes to naming rivers, historical, legal, and cultural influences are also important.

Figure 5. The longest river that flows to the watershed outlet (highlighted).

Figure 6 shows the elevation profile of the longest river reach. Elevations on the plot are in meters above mean sea level. The river begins at 4,610 m, and the outlet is at 70 m.

🖱️Mouse wheel to zoom Click & drag to pan 📱Pinch to zoom on mobile

Figure 6. Elevation profile of the longest river reach.

Elevation data for the profile plot is from MERIT-DEM (Yamazaki et al. 2017). Actual distances on the plot may be underestimated somewhat. This is because river paths are based on a grid or raster data, which simplifies the meandering path of real-world rivers.

Topography

Terrain elevations in the watershed range from 81.0 m to 6485.0 m above sea level. The average, or mean, elevation is 510.1 m. Figure 7 shows a distribution of terrain elevations in the watershed.

Figure 7. Distribution of terrain elevations in the watershed.
Scale for x-axis: Linear   Log

Elevation data is provided by EarthEnv (Amatulli et al. 2021), and is based on the Global Multi-resolution Terrain Elevation Data 2010 dataset (GMTED2010). Statistics are based on gridded elevation data with pixels that are about 5 km on a side. Because of the size of the pixels, some smoothing takes place, and so the statistics reported above may not capture the true minimum and maximum elevation.

References

Amatulli, G., Domisch, S., Tuanmu, M.-N., Parmentier, B., Ranipeta, A., Malczyk, J., & Jetz, W. (2018). A suite of global, cross-scale topographic variables for environmental and biodiversity modeling. Scientific Data, 5(1), 180040. https://doi.org/10.1038/sdata.2018.40

Fick, S.E., and R.J. Hijmans. 2017. “WorldClim 2: New 1‐km Spatial Resolution Climate Surfaces for Global Land Areas.” International Journal of Climatology 37 (12): 4302–15. https://doi.org/10.1002/joc.5086

Harris, I., Osborn, T.J., Jones, P. et al. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Scientific Data 7, 109 (2020). https://doi.org/10.1038/s41597-020-0453-3

Lehner, B., Beames, P., Mulligan, M. et al. The Global Dam Watch database of river barrier and reservoir information for large-scale applications. Scientific Data 11, 1069 (2024). https://doi.org/10.1038/s41597-024-03752-9

Liu, L., X. Cao, S. Li, and N. Jie. “A 31-Year (1990–2020) Global Gridded Population Dataset Generated by Cluster Analysis and Statistical Learning.” Scientific Data 11, no. 1 (January 24, 2024): 124. https://doi.org/10.1038/s41597-024-02913-0

Martens, B., Miralles, D.G., Lievens, H., van der Schalie, R., de Jeu, R.A.M., Fernández-Prieto, D., Beck, H.E., Dorigo, W.A., and Verhoest, N.E.C. 2017. GLEAM v3: satellite-based land evaporation and root-zone soil moisture, Geoscientific Model Development, 10, 1903–1925. https://doi.org/10.5194/gmd-10-1903-2017

Miralles, D.G., Holmes, T.R.H., de Jeu, R.A.M., Gash, J.H., Meesters, A.G.C.A., Dolman, A.J. 2011. Global land-surface evaporation estimated from satellite-based observations, Hydrology and Earth System Sciences, 15, 453–469. https://doi.org/10.5194/hess-15-453-2011

Potapov P., Hansen M.C., Pickens A., Hernandez-Serna A., Tyukavina A., Turubanova S., Zalles V., Li X., Khan A., Stolle F., Harris N., Song X.-P., Baggett A., Kommareddy I., Kommareddy A. (2022) The global 2000-2020 land cover and land use change dataset derived from the Landsat archive: first results. Frontiers in Remote Sensing. https://doi.org/10.3389/frsen.2022.856903

Save, H., S. Bettadpur, and B.D. Tapley (2016), High resolution CSR GRACE RL05 mascons, Journal of Geophysical Research Solid Earth, 121. https://doi.org/10.1002/2016JB013007

Save, H., 2020, "CSR GRACE and GRACE-FO RL06 Mascon Solutions v02." https://doi.org/10.15781/cgq9-nh24

Siebert, S., M. Kummu, M. Porkka, P. Döll, N. Ramankutty, and B. R. Scanlon. “A Global Data Set of the Extent of Irrigated Land from 1900 to 2005.” Hydrology and Earth System Sciences 19, no. 3 (March 25, 2015): 1521–45. https://doi.org/10.5194/hess-19-1521-2015.

Yamazaki, D., D. Ikeshima, R. Tawatari, T. Yamaguchi, F. O’Loughlin, J.C. Neal, C.C. Sampson, S. Kanae, & P.D. Bates. (2017). A high‐accuracy map of global terrain elevations. Geophysical Research Letters, 44, 5844–5853. https://doi.org/10.1002/2017GL072874.